This document was generously provided by Ken Dunn

Translated by:  Maciej Florek

   
Copy No.  ____
                                                                                                    
     
     
     
 
SECRET
 
     
     
     
     
 
Preliminary U-boat Information
 
     
 
for
 
     
 
U-boat Type XB
 
     
     
     
     
     
     
     
     
     
     
     
     
 
Navy Official Instruction No.  371/184
 
     
     
     
   

 

   
     
     
     
     
     
     
 
This is a Secret item for the purpose of Reich Penal Code § 88 [24 April 1934 version].  Violation is punishable in accordance with this code, if any other criminal law rules do not apply.
 
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     

 

   
     
     
     
     
     
     
 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
  In accordance with H.K.U.B. No. 219 of 10 April 1943 the following designations are changed:
  1.) "Emergency control station" to "Emergency rudder".   This means the designation of  emergency rudder for the rudder operated by hand in the after ship, while the designation emergency control station remains for the whole installation, i.e. associated with the emergency rudder command systems.
  2.) "Design to Type".
  3.) "Kitchen" to "Galley".
  4.) "Test Negative buoyancy tank" to "Residual water test".
  5.) "Main rudder" to "Lateral rudder".
     
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
     
     
     
     
     
     
     
     
     
     

 

   
U-Boat Type XB
U-boat Information
Page  I
Title
     
     
 
SECRET!
 
     
     
     
     
 
Preliminary U-boat Information
 
     
 
for
 
     
 
U-boat Type XB
 
     
     
 
 
     
     
     
     
     
     
 
Shipyard:
 
 
Fried. Krupp Germaniawerft A.G., Kiel-Gaarden
 
 
 
 
 
 
Year of construction:  1940 - 1943
 
     
     
                                                                                               Navy Official Instruction No.  371,184  
     
     

 

   
Page  II
U-boat Information
U-Boat Type XB
Amendments
     
 
Note the section, page and paragraph No., to which changes or additions are registered:
Certified to be Correct
Page Contents Paragraph No.   Place Date Signed
             
             
             
             
             
             
             
 
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     

 

   
U-Boat Type XB
U-boat Information
Page  III
Table of Contents
     
 
Table of Contents
 
 
Chapter A:  Ship's Information
 
     
 
I. General
Page:
  1) Shipyard information
1
  2) Principal measurements
1
    a) Dimensions
1
    b) Measured displacement
2
    c) Volume and distance from center of mass
3
      1. Interior rooms
3
      2. Exterior spaces
4
      3. Ballast tanks, main ballast and reserve fuel oil tanks, supply and collecting tanks.
6
      4. Total volume
7
    d) Test and operating pressures
7
    e) Materials
10
    f) Weights
11
    g) Stability
11
  3) Weapons overview
14
  4) Safety and rescue equipment overview
14
    a) Structural safety installations
14
    b) Safety equipment
15
    c) Rescue equipment
15
  5) Test data
16
    a) Speed   [surfaced] and [submerged]
16
    b) Diving time
16
    c) Pressure dock trials
17
    d) Depth differences for bow and stern
17
  6) Practical values
19
    a) Speeds for various operating conditions
19
    b) Behavior of the boat under different rudder angle and wind conditions
19
    c) Turning circles
20
    d) Behavior in a seaway
22
    e) Diving characteristics
22
    f) Depth control
23
 
     
     

 

   
Page  IV
U-boat Information
U-Boat Type XB
Table of Contents
     
     
 
   
Page:
    g) Vibrations
25
    h) Sound levels
26
         
II. Boat and pressure hull - including through-hull openings.
29
  1) General construction of the boat
29
  2) Construction of the pressure hull
30
  3) Partitioning of the pressure hull
30
  4) Conning tower structure
33
  5) Openings in the pressure hull
34
  6) Construction of the outer shell
35
  7) Partitioning of the outer shell
37
         
III. Diving installations.
38
  1) Tanks and fuel oil tanks
38
    a) Main ballast tanks
38
    b) Main ballast and reserve fuel oil tanks
38
    c) Bow and stern buoyancy tanks
38
    d) Regulating tanks and regulating and reserve fuel oil tanks
39
    e) Trim tanks
40
    f) Negative buoyancy tanks
41
    g) Torpedo compensating tanks
41
    h) Mine compensating tanks
41
  2) Blowing and exhaust gas blowing installation
42
    a) Compressed air blowing
42
    b) Exhaust gas blowing
42
  3) Venting and vent valves
43
  4) Compressed air systems
45
    a) Air compressors
45
    b) High pressure compressed air flasks
45
    c) Compressed air equipment
46
  5) Pumps
47
  6) Dive planes
47
         
IV. Armament.
48
  1) Mine installations
48
  2) Torpedo installations
49
    a) Torpedo tubes
49
 
     
     

 

   
U-Boat Type XB
U-boat Information
Page  V
Table of Contents
     
 
   
Page:
    b) Stowage
49
    c) Torpedo loading equipment
49
    d) Torpedo fire control system
50
    e) Weight compensation
51
    f) Charging and heating the electric torpedoes
52
  3) Gunnery
53
    a) Weapons
53
    b) Ammunition
53
  4) Demolition equipment
54
  5) Small arms
54
         
V. Communications.
55
  1) Visual and acoustic equipment
55
  2) Electronic communication equipment
56
    a) Radio installation
56
    b) UT [Underwater Telegraphy] installation (sound)
56
    c) Reporting and broadcast system
57
    d) Ultra short wave gear
58
  3) Direction finding and listening equipment
58
    a) Radio direction finder
58
    b) K.D.B. installation
59
    c) G.H.G. installation
59
    d) Nah S installation [active sonar to detect mines]
59
  4) Power supply for electronic communications equipment
59
  5) Aerials
60
         
VI. Steering system and anchor installations.
62
  1) Steering system
62
    a) Main rudder installation
62
    b) Dive planes installation
64
  2) Anchor installation
65
         
VII. Equipment and installations for navigation.
66
  1) Ship control
66
  2) Periscopes
66
    a) Attack periscope (aft conning tower periscope)
67
    b) Night attack periscope (forward conning tower periscope)
67
    c) Control room periscope
67
 
     
     

 

   
Page  VI
U-boat Information
U-Boat Type XB
Table of Contents
     
 
   
Page:
    d) Periscope drive
67
  3) Compass installation
68
    a) Gyro-compass
68
    b) Projector compass (magnetic compass)
69
  4) Signal equipment
69
  5) Depth sounding equipment
69
    a) Echolot
69
    b) Elektrolot
70
    c) Hand lead
70
  6) Log installation
70
  7) Alarm installation
70
  8) Ordering and reporting installations
71
         
VIII. Safety and rescue installations.
76
  1) Installations for submerged and surfaced boat
76
    a) Emergency lighting
76
    b) Hand lamps
76
    c) Fire extinguishers
76
    d) Flooding installation
77
    e) Drainage installation
77
    f) UT installation
77
    g) Emergency steering gear
77
    h) Emergency escape gear and diving suit
77
    i) Life rafts and mats
77
    k) Damage control materials
77
  2) Installations for surfaced boat
78
    a) Battery ventilation
78
    b) Emergency vent valves
78
    c) Coaming
78
    d) Life buoy, night signal buoy and dinghy
79
    e) Life jackets
79
    f) Railing and tethers
79
    g) Inflatable boat
79
  3) Installations for submerged boat
79
    a) Compartmentation
79
    b) Air purification system
80
    c) Compressed air and emergency blowing manifold
81
    d) Emergency air supply system
81
 
     
     

 

   
U-Boat Type XB
U-boat Information
Page  VII
Table of Contents
     
 
   
Page:
    e) Air trap
82
    f) Net deflector
82
    g) Net cutter
82
    h) Compartment ready indicating system
82
    i) Hull closure indicating system
82
    k) Vent valve indicating system
83
         
IX. Damage control.
84
  1) General
84
    a) Damage control parties
84
    b) Balancing the boat
84
    c) Reserve buoyancy
85
  2) Weights and trim adjustment with water flooding
85
    a) Leakage into external tanks with the boat surfaced
85
    b) Leakage into pressure hull with the boat surfaced
87
    c) Leakage into external tanks and into pressure hull with the boat surfaced
89
    d) Leakage with the boat submerged and with the boat lying on the bottom
95
  3) Leakage counter measures
95
    a) Blowing
95
    b) Sealing the compartments
96
    c) Sealing leaks
96
    d) Pumping
98
    e) Weight relief
98
  4) Escape from a sunken boat
98
    a) Escape procedures
98
    b) The flooding of the boat and effects on the crew
99
    c) Escaping from the boat
101
    d) Flooding options
102
  5) Gas hazard
106
  6) Fire hazard
106
  7) Fire extinguishing equipment and flooding installation
106
  8) Drainage and compressed air systems
106
 
     
     

 

   
Page  VIII
U-boat Information
U-Boat Type XB
Table of Contents
     
 
Chapter B:  Machinery Installations
 
     
 
   
Page:
I. Propulsion plant
107
  1) G.W. diesel engine installation
107
    a) General and performance figures
107
    b) Construction of the propulsion plant
107
    c) Auxiliary machinery
107
      1) Supercharger
107
      2) Pumps
108
      3) Governor
108
  2) Battery
108
    a) Technical and performance data
108
    b) Construction and maintenance
109
    c) Capacity, discharging, final voltage
110
    d) Charging
110
  3) The main switchboards and battery connections
111
  4) E motor installation
111
    a) General and performance data
111
    b) Motor construction and connections
112
    c) Auxiliary machinery
112
  5) Shaft lines
113
    a) Propellers
113
    b) Drive shafts, bearings and shaft brakes
113
    c) Main thrust bearing
114
    d) Clutches
114
  6) Interaction of the engines and motors
115
    a) General
115
    b) Diesel engine only drive
115
    c) E motors only
115
    d) Support and buffer mode
115
    e) Charging operation
116
    f) Diesel-electric drive
116
         
II. Auxiliary machinery for propulsion
117
  1) Ship's auxiliary machinery
117
    a) Main rudder and diving planes
117
    b) Anchor and warping capstan installation
117
 
     
     

 

   
U-Boat Type XB
U-boat Information
Page  IX
Table of Contents
     
 
   
Page:
    c) Air compressor
118
    d) Auxiliary drain and trim pump
119
    e) Main drain pump
119
    f) Auxiliary drain pump 1 and 2
120
    g) Intake and exhaust air fan
120
    h) Battery ventilation fan
120
    i) Pressure oil pump
121
    j) Periscope drive
121
    k) Refrigeration plant
121
    l) Compartment ventilation installation
123
    m) Distilling unit
123
    n) Hand pumps
123
    o) W.C. installation
124
    p) Gyro compass installation
124
    q) Circulating fan for air purification system
124
  2) Auxiliary machinery for the diesel engine installation
124
    a) Auxiliary lubricating oil pump port and starboard
124
    b) Hand lubricating oil pump
124
    c) Fuel oil feed pump
125
    d) Hand dirty lubricating oil pump
125
    e) Auxiliary cooling water pump
125
    f) Hand cooling water pump
125
    g) Lubricating oil purifier
125
  3) Auxiliary machinery for the E installation
125
    a) E motor fan blower
125
    b) E motor room cooling pump
126
    c) Bearing lubricating oil cooling installation for the E motors
126
         
III. Draining and flooding
127
  1) Main drainage installation
127
  2) Auxiliary drainage installation
127
  3) Hand drainage installation
128
  4) Artificial flooding installation
128
  5) Natural flooding installation
128
 
     

 

   
Page  X
U-boat Information
U-Boat Type XB
Table of Contents
     
 
   
Page:
IV. Sea, wash, and fresh water installations
129
  1) Sea water installation
129
  2) Wash water installation
129
  3) Fresh water installation
131
  4) Waste water installation
131
         
V. Ventilating systems
132
  1) Boat ventilation
132
  2) Battery ventilation
133
  3) Additional ventilation for air purification while running at silent speed
134
         
VI. Heating installation
135
  1) Steam heating
135
  2) Electric heating
136
  3) Steam generating installation
136
         
VII. Lubricating oil installation
137
         
VIII. Fuel oil installation
139
         
IX. Electrical installation
141
  1) E motors
141
  2) Batteries
141
  3) Main switchboards
141
  4) Auxiliary switchboards and power distribution
141
  5) Electric equipment (table)
142
    a) E drive motors and their current draw
142
    b) Rotary converters and associated equipment
142
      1. Gyro compass converter (2 unit)
142
      2. Communications equipment converter
143
      3. UT converter
144
      4. Depth sounding converter
144
      5. Rotary amplifier for the gyro angle setting gear
145
    c) Ordering and reporting installations
146
      1. General information and power supply
146
      2. Engine order telegraph system
146
      3. Shaft revolution indicator system
147
      4. Rudder order telegraph and rudder angle indicator system
147
      5. Diving planes angle indicator system
148
 
     

 

   
Page  XI
U-boat Information
U-Boat Type XB
Table of Contents
     
 
   
Page:
      6. Alarm bell and flashing light system
148
      7. Compartment ready indicating system
149
      8. Hull closure indicating system
149
      9. Vent valve indicating system
150
      10. Torpedo fire control and orders indicator system
151
      11. Shaft mine launching reporting installation
151
    d) Signal equipment
152
      1. General
152
      2. Running lights
152
      3. Searchlight equipment
153
    e) Electric welding equipment
154
 
     
 
Chapter C.
 
     
 
Appendix.
Enclosure
1) Boat's silhouette
1
2) Installations plan (Horizontal section)
1
3) Installations plan (Length section with height scale)
1
4) Tanks arrangement
1
5) Trim table
1
6) Ballast tank flooding and venting installation, exhaust gas blowing and diver emergency blowing equipment
1
7) Blowing and emergency blowing equipment, piping for pressurizing regulating tanks
1
8) Compartment and battery ventilating systems
__1__
   
8
 
     
 
-.-.-.-.-.-.-.-.-.-
 
     
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  1
U-boat Information
I.  General
            1
     
 
A.  Ship's Information.
   
I.  General.
     
1) Shipyard information.
     
  Construction yard:
  Fried. Krupp Germaniawerft A.G., Kiel - Gaarden
     
 
U-boat No.
Construction yard
Keel laying
Launching
1st Commissioning
Decom-missioning
2nd Commissioning
U-116
GW
27.11.39
3.5.41
26.7.41
   
U-117
GW
27.11.39
26.7.41
25.10.41
   
U-118
GW
1.3.40
23.9.41
6.12.41
   
U-119
GW
15.11.40
6.1.42
18.4.42
   
U-219
GW
31.5.41
6.10.42
12.42
   
U-220
GW
16.6.41
23.2.43
5.43
   
U-233
GW
15.8.41
29.6.43
9.43
   
U-234
GW
1.10.41
28.9.43
12.43
   
     
2) Principal measurements. (ship's construction)
  a) Dimens'ions. (See Secret Military document)
   
Length:
Length overall
m
Length at the waterline
m
Length of the pressure hull with end caps
m
Length of pressure hull without end caps
m
 
Width:
Maximum width
mm
Maximum width at the waterline
mm
Maximum width of the pressure hull
mm
Diameter of the forward end of the pressure hull
mm
Diameter of the aft end of the pressure hull
mm
 
     
     

 

   
Page 2
A. Ship Information
U-Boat Type XB
           2
I.  General
U-boat Information
     
 
   
Draft:
Draft aft
m
Draft amidships
m
Draft forward
m
Length of pressure hull without end caps
m
Note:  For length, width, and draft see Secret Military document.
 
Height:
Upper deck above keel
6535
mm
Top of conning tower above keel
10100
mm
Top of attack periscope and air search periscope above conning tower fairing
5036
mm
Top of control room periscope and air search periscope above conning tower fairing
2145
mm
Extended air search periscope above keel
15136
mm
Extended control room periscope above keel
12245
mm
 
Conning tower and keel:
Height of conning tower above pressure hull
2427
mm
Length of the conning tower
3460
mm
Width of the conning tower
2080
mm
Height of the keel
900
mm
Width of the keel
2200
mm
Length of straight keel
50800
mm
     
  b) Measured displacement.
   
Surfaced displacement
Submerged displacement
Official displacement
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  3
U-boat Information
I.  General
            3
     
 
  c) Volume and distance from center of mass.
    1)  Interior rooms:
     
Designation
Location
Volume
Total volume m³
Distance / meters
Aft torpedo room Room 1, Comp. 1
75.00
- 28.80
E motor room Room 2)
  95.00
- 20.75
Diesel engine room Room 3) Comp. II
153.00
347.00
- 12.00
Galley and petty officers room Room 4)
99.00
of this:    
 
Petty officers room + galley  
70.00
Battery room 1  
29.00
Control room Room 5, Comp. III
100.00
+ 4.95
of this:    
 
Munitions magazine  
27.00
+ 6.10
Nah sonar room  
  4.00
+ 8.55
Living room Room 6, Comp. IV
175.00
+ 14.50
of this:   
Provision room  
  18.00
Battery room 2  
  27.00

Crew room

 
  17.00
Remainder of room  
113.00
Forward mine room Room 7, Comp. V
115.00
+26.40
    Total:
812.00
 
     
     
 
     
     

 

   
Page 4
A. Ship Information
U-Boat Type XB
           4
I.  General
U-boat Information
     
 
    2)  Exterior spaces:
         [translators note:  A frame = outer hull frame  D frame = pressure hull frame]
From
Location
Volume
Distance
Designation
Frame - Frame
Stb.     Port
meters³
meters
Main ballast tank 1
A -9 - +8
44.30
- 34.75
Main ballast and RFO 2 port
A 8 - 24
port)
43.25
- 26.92
Main ballast and RFO 2 stb.
A 8 - 24
stb.
      )
- 26.92
Main ballast and RFO 3 port
port)
58.20)
- 20.27
Main ballast and RFO 3 stb.
A 24 - 34
stb.
      )
Fuel oil tank 1a port
A 34 - 43
port)
83.2
- 15.40
Fuel oil tank 1a stb.
A 34 - 43
stb.
      )
83.3
Main ballast tank 4 port)
A 43 - 53
port)
78.40)
- 10.43
Main ballast tank 4 stb.)
A 43 - 53
stb.
      )
Main ballast tank 5 port)
A 53 - 63
port)
88.95)
- 29.87
Main ballast tank 5 stb.)
stb.
      )
Regulating and RFO tank 1 port)
D 41-1/2 - 43-1/2
port
16.85)
- 0.60
Regulating and RFO tank 1 stb.)
stb.
16.85)
Regulating tank 2 port)
D 45 - 48
port
13.30)
+ 2.11
Regulating tank 2 stb.)
stb.
13.30)
Mine compensating tank 1)
D 41-1/2 - 43-1/2
stb.
7.55)
- 1.24
Mine compensating tank 2)
port
7.55)
Mine compensating tank 3)+
D 43-1/2 - 45-1/2
stb.
7.55)
 + 0.54
Mine compensating tank 4)+
port
7.55)
Negative buoyancy tank port)
D 45-1/2 - 48
port
7.85)
+ 2.36
Negative buoyancy tank stb.)
stb.
7.85)
Main ballast tank 6 port)
A 73 - 83
port)
88.20)
+ 6.04
Main ballast tank 6 stb.)
stb.
      )
Main ballast tank 7 port)
A 93 - 99
port)
75.75)
+ 11.52
Main ballast tank 7 stb.)
stb.
      )
Fuel oil tank 2a port)
A 93 - 99
port)
54.9
+ 15.86
Fuel oil tank 2a stb.)
stb.
      )
55.2
+ Mine compensating tanks 3 and 4 can be used as spare wash water tanks.
 
     
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  5
U-boat Information
I.  General
            5
     
 
    Exterior spaces (continued)
     
From
Location
Volume
Distance
Designation
Frame - Frame
Stb.     Port
meters³
meters
Main ballast and RFO tank 8 port
A 99 - 109
port)
69.05
+ 19.72
Main ballast and RFO tank 8 stb
A 99 - 109
stb.
      )
Main ballast and RFO tank 9 port
A 109 - 128
port)
33.77
+ 26.76
Main ballast and RFO tank 9 stb.
A 109 - 128
stb.
      )
33.77
Main ballast tank 10
A 128 - 147
39.00
+ 36.36
Stern buoyancy tank
A -16 - -9
8.40
- 40.42
Bow buoyancy tank
A 128 - 152
28.00
+ 37.63
     
     
     
     
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
Page 6
A. Ship Information
U-Boat Type XB
           6
I.  General
U-boat Information
     
 
    3.  Ballast tanks, fuel oil tanks, tanks and storage: (Ordered from aft to forward)
     
Designation
Location
From
Volume in
Distance in
Frame - Frame
meters³
meters
Trim tank 1
stb.
D 7 - 11
3.940)
- 27.52
Trim tank 2
port
D 7 - 11
3.940)
Torpedo compensating tank 1
stb
D 11 - 13-1/2
3.240
- 25.04
Torpedo compensating tank 2
port
D 11 - 13-1/2
3.920
- 24.90
Waste water tank 1
stb.
D 12-1/2 - 13-1/2
0.760
- 24.33
Alkali tank
port
D 14 - 15
0.063
- 23.49
Water distillate tank 1
center
D 18-1/2 - 21
0.195
- 20.06
Water distillate tank 2
center
D 18-1/2 - 21
0.580
- 19.49
Water distillate tank 3
port
D 86 - 87
0.200
+ 33.15
Fuel oil gravity feed tank
center
D 26 - 28
2 x 600
- 13.33
Dirty lubricating oil tank
center
D 24 - 26
1.360
- 15.09
Lubricating oil collecting tank stb.
center
D 28 - 30
1.360
- 11.89
Lubricating oil collecting tank port
center
D 26 - 28
1.360
- 13.49
Fuel oil collecting tank
center
D 30 - 31
0.680
- 10.69
Waste water tank 2
center
D 34 - 35-1/2
0.625
- 7.30
Fresh water tank 1
center
D 35-1/2 - 36-1/2
0.780
- 6.47
Wash water daily supply tank
port
D 36-1/2 - 37-1/2
0.060
- 5.69
Lubricating oil supply tank 1
stb.
D 35-1/2 - 41
3.900
- 4.43
Lubricating oil supply tank 2
port
D 35-1/2 - 41
3.900
- 4.43
Lubricating oil supply tank 3
stb.
D 41 - 45-1/2
4.200
- 0.39
Lubricating oil supply tank 4
port
D 41 - 45-1/2
4.200
- 0.39
Fresh water tank 2
port
D 49 - 49-1/2
0.230
+ 4.23
Hydraulic oil supply tank
stb.
D 47-1/2 - 49-1/2
1.250
+ 3.24
Fresh water tank 3
stb.
D 58 - 61
2.000
+ 11.71
Fresh water tank 4
port
D 58 - 58-1/2
0.830
+ 10.79
Wash water tank 1
port
D 61 - 62
0.850
+ 13.31
Waste water tank 4
port
D 70-1/2 - 72
0.780
+ 21.18
Wash water tank 2
port
D 72 - 73
0.610
+ 22.11
Mine compensating tank 5
stb.
D 74 - 77
3.650)
+ 24.38
Mine compensating tank 6
port
D 74 - 77
3.650)
Mine compensating tank 7
stb.
D 77 - 80
2.250)
+ 26.75
Mine compensating tank 8
port
D 77 - 80
2.250)
Trim compensating tank 3
stb.
D 87 - 89
3.780)
+ 34.45
Trim compensating tank 4
port
D 87 - 89
3.780)
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  7
U-boat Information
I.  General
            7
     
 
    4.  Total volume.
   
Main ballast tanks
414.60
Main ballast and reserve fuel oil tanks
238.05
Main ballast and main ballast and reserve fuel oil tanks
652.65
Fuel oil tanks 1a port and stb., 2a port and stb.
138.1
Fuel oil tanks, main ballast and reserve fuel oil tanks, and regulating and reserve fuel oil tanks
409.75
Lubricating oil supply tanks 1, 2, 3 and 4
16.00
Lubricating oil collecting tanks port and stb.
2.72
Lubricating oil, total
18.72
Fresh water tanks, total
3.010
Wash water tanks, total
16.320
Waste water tanks
2.985
High pressure compressed air flasks at 205 kg/cm²
12.47
Oxygen flasks at 160 kg/cm²
0.800
Main ballast tanks, main ballast and reserve fuel oil tanks, fuel oil tanks, bow and stern buoyancy tanks
826.15
(All spaces that can be blown, without regulating, mine compensating and negative buoyancy tanks)    
     
  d) Test and operating pressures.
   
Pressure hull and conning tower including periscope shafts with internal pressure equivalent to water pressure at the bottom of the pressure hull to
30 meters pressure head
Pressure-proof curved watertight bulkheads from the cupped side with internal pressure equivalent to water pressure at the bottom of the pressure hull to
30 meters pressure head
Watertight flat bulkheads with internal pressure equivalent to water pressure at the top of the pressure hull to
2 meters pressure head
Pressure-proof coning tower and hatch covers for assembly to
7.5 and 18 kg/cm²  respectively
All hull shut off valves to construction specification
18 kg/cm²
The test for gas leaks (testing bulkhead tightness) has taken place per construction regulation SA 5 to 25 mm vacuum
Flood valves and emergency vent valves with internal pressure equivalent to water pressure at the top of main ballast tanks and main ballast and reserve fuel oil tanks to
8 meters pressure head
The body of the vent valves actuators are pressurized with water for strength to
25 kg/cm²
 
     
     

 

   
Page 8
A. Ship Information
U-Boat Type XB
           8
I.  General
U-boat Information
     
 
   
The body of the vent valves are pressurized with air for tightness to
12 kg/cm²
The valve for the vent ducts (main ballast and reserve fuel oil tanks) for strength and tightness to
18 kg/cm²
Vent valves with pressure equivalent to water pressure at the top of main ballast tanks or main ballast and reserve fuel oil tanks to
8 meters pressure head
Deck of the battery compartment by filling the battery compartment with air under pressure
100 mm Pressure head
    High pressure air, oxygen and pressure oil flasks
   
28 high pressure compressed air flasks: Operating pressure
205 kg/cm²
  Test pressure
280 kg/cm²
2 starting air flasks: Operating pressure
75 kg/cm²
  Test pressure
120 kg/cm²
16 oxygen flasks: Operating pressure
150 kg/cm²
  Test pressure
200 kg/cm²
4 pressure oil flasks: Operating pressure
40-80 kg/cm²
  Test pressure
120 kg/cm²
     
Test and operating pressure (inner pressure)
Designation

From

frame - frame

Tested with
Test pressure equivalent to water pressure at top of tank
Operating pressure kg/cm²
Stern buoyancy tank
A -16 - -9
 
air
2 meters
Main ballast tank 1
A - 9 - +8
 
water
8 meters
Main ballast and reserve fuel oil tank 2
A 8 - 24)
 
water
Main ballast and reserve fuel oil tank 3) port
A 24 - 34)
Main ballast and reserve fuel oil tank 8) stb.
A 99 - 109)
Main ballast and reserve fuel oil tank 9
A 109 - 128)
Fuel oil tank 1a port and stb.
A 34 - 43)
 
fuel oil
8 meters
Fuel oil tank 2a port and stb.
A 93 - 99)
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  9
U-boat Information
I.  General
            9
     
 
     
Designation

From

frame - frame

Tested with
Test pressure equivalent to water pressure at top of tank
Operating pressure kg/cm²
Main ballast tank 4
A 43 - 53)
 
water
8 meters
Main ballast tank 5) port
A 53 - 63)
 
Main ballast tank 6) stb.
A 73 - 83)
 
Main ballast tank 7
A 83 - 93)
 
Main ballast tank 10
A 128 - 147
 
water
8 meters
Bow buoyancy tank
A 128 - 152
 
air
2 meters
Regulating and reserve fuel oil tank 1 port
D 41-1/2 - 45)
 
water
140 meters
16.5
Regulating and reserve fuel oil tank 1 stb.
D 41-1/2 - 45)
 
Regulating tank 2 port
D 45 - 48)
 
Regulating tank 2 stb.
D 45 - 48)
 
Negative buoyancy tank port
D 45-1/2 - 48)
 
Negative buoyancy tank stb.
D 45-1/2 - 48)
 
Mine compensating tank 1
A 63 - 66-1/3)
 
water
140 meters
Mine compensating tank 2
A 63 - 66-1/3)
 
Mine compensating tank 3
A 66-1/3 - 69-1/2)
 
Mine compensating tank 4
A 66-1/3 - 69-1/2)
 
Trim tank 1
D 7 - 11)
 
water
30 meters
Trim tank 2  
Trim tank 3
D 87 - 99)
 
Trim tank 4  
Torpedo compensating tank 1
D 11 - 13-1/2)
 
water
30 meters
Torpedo compensating tank 2  
Water distillate tank 1)
D 18-1/2 - 21
 
water
0.5 meters
Water distillate tank 2)
D 18-1/2 - 21
 
Water distillate tank 3)
D 86 - 87
 
Fresh water tank 1
D 35-1/2 - 36-1/2)
 
water
4 meters
Fresh water tank 2
D 49 - 49-1/2)
 
Fresh water tank 3
D 58 - 61)
 
Fresh water tank 4
D 58 - 61)
 
Wash water tank 1
D 61 - 62)
 
Wash water tank 2
D 72 - 73)
 
 
     

 

   
Page 10
A. Ship Information
U-Boat Type XB
           10
I.  General
U-boat Information
     
 
     
Designation

From

frame - frame

Tested with
Test pressure at top of tank
Operating pressure kg/cm²
Waste water tank 1
D 12-1/2 - 13-1/2)
 
water
1 meter
Waste water tank 2
D 33-1/2 - 35-1/2)
 
Waste water tank 3
D 58 - 58-1/2)
 
Waste water tank 4
D 70-1/2 - 72)
 
Fuel oil gravity feed tank
D 26 - 28
 
oil
6 meters
Pressure oil reservoir
D 47-1/2 - 49-1/2
 
oil
6 meters
Munitions magazine
D 49-1/2 - 55
 
water
filled to upper edge
Dirty lubricating oil tank
D 24 - 26
 
oil
6 meters
Lubricating oil collecting tank port
D 26 - 28
 
oil
6 meters
Lubricating oil collecting tank stb.
D 28 - 30
 
oil
6 meters
Lubricating oil supply tank 1
D 35-1/2 - 41
 
oil
6 meters
Lubricating oil supply tank 2  
Lubricating oil supply tank 3
D 41 - 45-1/2
 
oil
6 meters
Lubricating oil supply tank 4  
Mine compensating tank 5
D 74 - 77
 
water
8 meters
Mine compensating tank 6  
Mine compensating tank 7
D 77 - 80
 
water
8 meters
Mine compensating tank 8  
Fuel oil collecting tank
D 30 - 31
 
fuel oil
6 meters
Brine tank
D 14 - 15
 
water
 0.5 meters
     
  e) Materials.
   
Pressure hull, regulating and reserve fuel oil tanks, regulating tanks, external mine compensating tanks, negative buoyancy tanks S M ship construction steel St 52
Conning tower casing Special material Wh - n/A
Conning tower deck Chromium Nickel-Molybdenum-Steel
Flood valves Steel casting
Flood valve frame Steel casting
Vent valves, casing Welded mild steel, with bronze
Vent valves, seat Steel casting
Emergency vent valves Steel casting
Intermediate valves (main ballast and reserve fuel oil tanks Steel casting
Draining installation, piping Steel 3529
Draining installation, equipment parts Steel casting, seats bronze or red brass
 
     
     
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  11
U-boat Information
I.  General
            11
     
 
   
Piping (in ballast tanks, fuel oil tanks, battery rooms, fresh water tanks ) Galvanized mild steel
HP compressed air flasks Chromium Nickel-Molybdenum steel
HP compressed air piping Copper
Oxygen flasks Chromium Nickel-Molybdenum steel
Oxygen piping Copper
Pressure oil flasks Chromium Nickel-Molybdenum steel
Pressure oil piping Steel tubing, copper plated interior
Equipment parts oxygen installation Bronze
Ventilation ducts Iron or aluminum
Pressure-proof equipment parts of the ventilation ducts Bronze
Steam heat piping and heaters Copper
Steam heat equipment parts Bronze
    All gear rods and linkages with their bearings installed outside the pressure hull are galvanized or made from sea water-proof material.
     
  f) Weights. (see Secret document)
   
I.
  Ship's hull including ballast =                %
II.
  Auxiliary machinery for propulsion =                %
III.
  Armor =                %
IV.
  Propulsion plant including associated auxiliary machinery =                %
V.
  Gunnery =                %
VI.
  Torpedo weaponry =                %
VII.
  Equipment =                %
VIII.
  Fuel and lubricating oil =                %
IX.
  Weight reserve =                %
  Sum of I - IX = Construction displacement                          =           100%
Note: Above data is not filled because it is secret.
     
  g) Stability.
    The type XB U-Boat during -cruise has form stability and during -cruise it has weight stability.  To achieve a sufficiently large arm
     
 
     
     
     
     
     

 

   
Page 12
A. Ship Information
U-Boat Type XB
           12
I.  General
U-boat Information
     
 
    during -cruise and FG during -cruise, to increase stability, 50 kg weights are located in the ballast keel.
    General:
    The stability of the boat can be expressed as the large lever arm , called also "meta centric height", i.e. the distance between the center of gravity G and transverse meta center M (intersection of the upward force of buoyancy and ship vertical center-line).
    Heeling of the boat by the force P by angle creates the righting arm (stabilizing arm):
   
    The position of M over the buoyancy center F during -cruise depends on the position of the floating line (transverse water line gives the height of M).
    When heeling angles are small (0-2) the position of M can be considered as constant, so stabilizing arm * sin is also constant (starting stability).
    At large heeling angles the position of M is changing.  In U-boats however, the stability at large declinations is not calculated - as you know, U-boats with sufficient starting stability are stable at large heeling angles.  The "starting stability" will be called "stability".
    During -cruise M overlaps with buoyancy center F:
   
    The stabilizing arm * sin is equal for longitudinal and lateral declinations. Longitudinal stability during -cruise is also as large as transverse stability, whereof it reacts to trim changes.
    During -cruise the longitudinal stability is very large (MG approximately = ship length).
     
     
     
     
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  13
U-boat Information
I.  General
            13
     
 
     
     
Location of transverse meta center (F), buoyancy center (M) and center of gravity (G)

 
     
 
    Note: Free surfaces are not accounted for in stability considerations.
     
    For the following trim conditions the corresponding approximate stability values ratio apply:
    a    :     b    :     c    :     d   :     e     :     f    :     g    :    h
    10  :  9.35  :  9.80  : 9.05  :  3.37  :  3.52  :  3.04  : 3.12
 
     
     
     

 

   
Page 14
A. Ship Information
U-Boat Type XB
           14
I.  General
U-boat Information
     
 
  a) Condition A with mines 
  b) Condition A without mines
  c) Condition B with mines
  d) Condition B without mines
  e) Condition A with mines 
  f) Condition A without mines
  g) Condition B with mines
  h) Condition B without mines
     
    For the absolute values of the meta centric height see secret documents.
    The difference between the stability values for the boat with and without mines is not important and in practical operations in each case may be not taken into account.
     
3) Weapons overview (armament)
  Boat armament:
  6 bow mineshafts (each with 3 SMA-mines)
  24 side mineshafts (each with 2 SMA-mines)
  2 stern torpedo tubes
  1 10.5 cm cannon (forward of the coning tower)
  1 3.7 cm cannon (aft of the conning tower)
  1 2 cm anti-aircraft gun  ) on the conning tower
  1 MG C/34                   )
  2 Machine guns
  6 Mauser pistols
  3 Side arms
     
4) Safety and rescue equipment overview.
  a) Structural safety installations:
   
Spherical bulkheads for pressure-tight partition
4
Units
Watertight bulkheads
2
"
Half height watertight bulkheads
3
"
Hatch coamings
5
"
Air traps
5
"
Net cutter (removed)
Net deflector
3
"
Railing and tethers    
     
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  15
U-boat Information
I.  General
            15
     
 
  b) Safety equipment:
   
High pressure air system, air volume at 205 kg/cm²
12,470
liters
Emergency blowing manifolds for all main ballast, main ballast and reserve fuel oil , and fuel oil tanks
2
units
Emergency air supply connection in the control room and in end rooms
5
units
Emergency vent valves for the main ballast tanks
10
units
Emergency vent valves for main ballast and reserve fuel oil tanks
8
units
Air purification system, sodium hydrate cartridges: 
590
units
Oxygen renewal system, oxygen volume at 150 kg/cm²
800
liters
Battery ventilation with special battery ventilation fan
Compartment ready indicating system
Hull closure indicating system
Vent valve indicating system
Automatically switched on emergency lamps: 
10
units
GHG installation
KDB installation
Nah S sonar installation
UT installation
Dry fire extinguishers ( CO2 )
7
units
Flooding installation
Drainage installation
Damage control materials
     
  c) Rescue equipment:
   
Rescue buoys with night signal light
2
Battery powered hand lamps
10
Life buoys
3
Emergency escape gear
72
Life jackets
55
Diving suit
1
Diving suit without weighting systems
1
Watertight suit for the emergency escape set
1
Life raft
2
Dinghy
1
 
    For further information about safety and rescue equipment see section VIII.
     
 
     
     

 

   
Page 16
A. Ship Information
U-Boat Type XB
           16
I.  General
U-boat Information
     
 
5) Test data.
  a) Speed   and :
   
Diesel engines
E motors
Turns
Condition A
Condition B
Turns
Speed
R.P.M.
knots
knots
R.P.M.
knots
knots
Ahead
KF
170
7    
6.0
70
2.1
1.8
LF
220
8.65
8.2
130
3.6
3.3
HF
270
10.5  
10.0
180
4.8
4.6
2 x HF
320
12.25
11.7
220
6.0
5.7
GF
375
14.4 
13.7
260
6.8
6.7
2 x GF
430
15.95
15.4
AK
470
17.2  
16.4
300
7.6
7.5
3 x AK
485
17.65
16.8
   
Astern
KFz
170
70
LFz
220
130
HFz
270
180
2 x HFz
340
240
AKz
400
290
     
  b) Diving times.
    1)  While staying still                                  seconds
    2)  At HF forward                                     seconds
    3)  Fast diving                                            seconds
    4)  Deepest allowable depth                       meters
     
     
     
     
     
     
     
     
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  17
U-boat Information
I.  General
            17
     
 
  c) Pressure dock trials.
     
     
     
     
     
     
     
     
     
     
     
     
     
     
  d) Depth differences for bow and stern.
    See the chart on page 18.
     
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
Page 18
A. Ship Information
U-Boat Type XB
           18
I.  General
U-boat Information
     
 
 
     

Click the text to view an enlarged version of the chart turned 90 clockwise

Tauchungeunterschiede von Bug und Heck gegenüber der Druckmessertiefe
Diving differences for bow and stern as opposed to the depth meter
Achterlastig Down by the stern
Bock für Netzabweiser Support for net deflector
Bug Bow
Bug (untere) Netzsäge Bow (bottom of) Net saw/cutter
Bug höher Bow higher
Bug tiefer Bow deeper
Grad Degrees
Heck Stern
Höhertauchung Shallower immersion
Kiel Keel
Netzsäge (oben) Net saw/cutter (top of)
Rudderhacke Rudder heel (bottom of the rudder)
Tiefertauchung Deeper immersion
Turm Conning tower
Vorlastig Down by the bow

   
U-Boat Type XB
A. Ship Information
Page  19
U-boat Information
I.  General
            19
     
 
6) Practical values.
  a) Speeds for various operating conditions.
     
     
     
     
     
     
     
     
     
     
     
     
     
  b) Behavior of the boat under different rudder angle and wind conditions.
     
     
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
Page 20
A. Ship Information
U-Boat Type XB
           20
I.  General
U-boat Information
     
 
  c) Turning circle.
   
Turning circle diameter.
    Depending on main rudder angle and speed.
     
    Surfaced:
   
Trim Condition
Rudder angle
Turning circle diameter in meters
AK RPM=
GF RPM=
HF RPM=
LF RPM=
KF RPM=
           
           
A
           
           
           
           
           
B
           
           
           
     
    Submerged:
   
Circle to
Rudder angle
Turning circle diameter in meters
AK RPM=
GF RPM=
HF RPM=
LF RPM=
KF RPM=
           
           
Stb.
           
           
           
           
           
Port
           
           
           
     
    Note:  RPM are valid at the moment of running into the turning circle and during the steady turning condition of the boat are accordingly lower.
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  21
U-boat Information
I.  General
            21
     
 
   
Time to Reciprocal heading
   
Rudder Hard Over and
   
Speed
setting
Time to reciprocal heading
Trim Condition A
Trim Condition B
Submerged
AK
     
GF
     
HF
     
LF
     
KF
     
   
   
Time to put in and to take effect
   
with main rudders in astern cruise
   
Rudder angle
Time to put in
Time to result
RPM=100
RPM=360
RPM=100
RPM=360
32°
       
30°
       
25°
       
20°
       
15°
       
10°
       
     
   
Main Rudder Limits
   
astern cruise
   
AKz
GFz
HFz
LFz
KFz
       
     
     
 
     
     

 

   
Page 22
A. Ship Information
U-Boat Type XB
           22
I.  General
U-boat Information
     
 
  d) Behavior in a seaway.
     
     
     
     
     
     
     
     
     
     
     
     
  e) Diving characteristics, crash dives.
     
     
     
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  23
U-boat Information
I.  General
            23
     
 
  f) Depth control characteristics normal.
   
     
     
     
     
     
     
     
     
     
     
     
     
   
In a seaway
     
     
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
Page 24
A. Ship Information
U-Boat Type XB
           24
I.  General
U-boat Information
     
 
   
During torpedo firing
     
     
     
     
     
     
     
     
     
     
     
   
During mine deployment
     
     
     
     
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  25
U-boat Information
I.  General
            25
     
 
  g) Vibration:
   
By engines at different RPM
     
     
     
     
    By torpedo firing
     
     
     
     
    By periscope with drag at speed
    Fixed eye-level periscope
     
     
    Attack periscope
     
     
    Control room periscope
     
     
    Rod antenna (extended)
     
     
    By mine deployment
     
     
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
Page 26
A. Ship Information
U-Boat Type XB
           26
I.  General
U-boat Information
     
 
    On this page (26 and the temporarily missing pages 27 and 28) sound levels will be added later, as soon as these are established for type XB submarines.
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
 
     
     

Note:  Pages 27 and 28 are missing

   
U-Boat Type XB
A. Ship Information
Page  29
U-boat Information
II.  Boat and Pressure hull
            1
     
 
II. Boat and pressure hull - including through-hull openings.
  1) General construction of the boats.
    The Type XB U-boat is large, double-hull vessel.  Between the pressure hull and the outer shell are located main ballast tanks, main ballast and reserve fuel oil tanks, fuel oil tanks, pressure-proof regulating tanks, mine compensating tanks and negative buoyancy tanks.  During submerged cruise, the main ballast tanks, main ballast and reserve fuel oil tanks and fuel oil tanks are connected with surrounding sea-water, so the outer shell need not be pressure-proof.  In the free-flooding spaces over the pressure hull are located installations and equipment that do not need to be placed inside the pressure hull, such as the dinghy, inflatable boat, high pressure compressed air flasks, the mufflers and storage place for nautical equipment.  The upper deck is designed to provide footing for handling and seamanship.  It is also serves as the gun shooting platform.  Above the upper deck is a pressure-proof conning tower, covered with a free-flooding casing.  The bridge is located on the conning tower ceiling and is used as command station with armored casing during cruise.  The command station during cruise is located inside the pressure-proof conning tower.
    The main engine installation consists of two 9-cylinder - 4 cycle diesel engines each of 2100 HP with charging manufactured by Fried. Krupp Germaniawerft for   cruise and two E motors each of 550 HP manufactured by Fa. AEG for cruise.
    The boat's weaponry consists of 66 mines in 6 shafts of 3 each and 24 shafts of 2 each, also, a 10.5 cm gun, a 3.7 cm gun, a 2 cm anti-aircraft gun and a MG C 34.
    The torpedo armament consists of 2 aft tubes.
    The crew consists of:
    5 Officers
    5 Chief Petty Officers
    13 Petty Officers
    27 men
    Total crew:  50 men
     
     
 
     
     

 

   
Page 30
A. Ship Information
U-Boat Type XB
           2
II.  Boat and Pressure hull
U-boat Information
     
 
  2) Construction of the pressure hull.
    The pressure hull is formed as cylindrical tube, which tapers towards both ends and is capped by two outside cambered dished plates.  The hull encloses all installations which are not pressure-proof or water-tight.  The pressure-proof conning tower is located at half of the pressure hull length.  It is accessible from outside by the conning tower hatch and from the pressure hull by the control room hatch.  The pressure hull is divided into 5 compartments by 4 pressure-proof spherical bulkheads and subdivided into 7 rooms by two watertight bulkheads.
    The pressure hull is constructed from 17 mm and 20.5 mm thick rolled steel plates and is stiffened by means of 88 inner frames which are made from bulb tee girders.
    The distance from one frame to another is almost 800 mm.  The distance of individual frames varies slightly.  Particularly stressed areas (i.e. under the conning tower and around the torpedo hatch, exhaust valves and diesel engine room patch) are further strengthened with thicker plates and transverse frames.  The forward end of pressure hull is capped by an outside cambered dished plate of cast steel, with no openings for torpedo tubes.  The aft end is capped by an outside cambered dished plate with openings for torpedo tubes 1 and 2.  The thickness of plating in the cylindrical part of the hull is 20.5 mm, in the end parts is 17 mm, the thickness of plating at aft hull ending is 30 mm, and at the forward hull ending is 22 mm.
     
  3) Partitioning of the pressure hull.
   
Compartment I Room  1:  Aft torpedo room  (Frame D 0 - 13-1/2).
    The access to this room is through torpedo loading hatch, aft torpedo room hatch (over the aft WC to starboard) and through the hatch in the curved bulkhead (frame 13-1/2).
     
     
     
     
     
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  31
U-boat Information
II.  Boat and Pressure hull
            3
     
 
    The room is used as quarters for 8 men.  Located there are:  torpedo tubes 1 and 2 with the associated auxiliary equipment, driving motors for the main rudder and diving planes, main rudder emergency steering station, auxiliary drain pump 1, 5 oxygen flasks.
    Trim tank 1 and 2, torpedo compensating tank 1 and 2, waste water tank 1, aft WC, high and low pressure air distributors, emergency blowing manifold, compressed air pistons for operating vent valves, vent valves for main ballast tank 1 and main ballast and reserve fuel oil tanks 2 and 3, charging switchboard for electric torpedoes, auxiliary switchboard 1 (110 V).
     
   
Compartment II  E motor, diesel engine, galley and petty officers room (battery room 1)                                                       (Frame D 13-1/2 - 45-1/2).
    Room 2:  E motor room                      (Frame D 13-1/2 - 22).
    Access to this room is through the hatch in the curved bulkhead 13-1/2 and through the hatch in the watertight bulkhead (aft) of the diesel engine room.
   

 In this room are located:  E motors starboard and port with two fan blowers, main switchboards starboard and port, auxiliary switchboard 2 and 2a (220 V), compressed air operated main clutches starboard and port, main thrust bearings starboard and port, electric air compressors 1 and 2, distilling units 1 and 2, 1 brine tank, 2 water distillate tanks and cooling water pump.  Also the gyro-compass, radio receivers and transmitters rotary converters, as well as 1.4 kVA and 6 kVA converters.  Also the converters for gyro angle setting gear, fire control and UT installation.

    Room 3:  Diesel engine room               (Frame D 22 - 35-1/2).
    Access to this room from aft is through the hatch in the watertight bulkhead (Frame D 22) from the E motor room and from forward through the hatch in the galley watertight bulkhead (Frame D 35-1/2).  In this room are located:  diesel engines starboard and port with associated auxiliary machinery, compressed air operated diesel engine clutches starboard and port, 2 auxiliary lubricating oil pumps, 1 auxiliary cooling water pump, starboard and port lubricating oil cooler, 1 intake and 1 exhaust air fan, air conditioning unit, diesel air compressor 3 and 4, 1 hand lubricating oil pump, 1 hand cooling water pump, 1 fuel oil supply pump, 1 hand dirty oil pump, 1 dirty oil tank, lubricating oil purifying system, lubricating oil collecting tanks starboard and port, fuel oil collecting tank, 1 lubricating oil and 1 fuel oil-
 
     

 

   
Page 32
A. Ship Information
U-Boat Type XB
           4
II.  Boat and Pressure hull
U-boat Information
     
 
    gravity tanks, waste water tank 2, compressed air pistons for operating vent valves vent valves for main ballast tanks 4 and 5, the inboard exhaust valves with operating gear, 2 diesel engine air induction trunk foot valves starboard and port, 1 ventilation intake foot valve, 1 ventilation exhaust foot valve, 8 mine release arrangements for mine shafts 51/53 - 64/66.
    Room 4:  Galley (Frame D 35-1/2 - 38).
    Access to this room from the upper deck is through the galley hatch, from the diesel engine room through the hatch in the forward watertight diesel engine room bulkhead, from forward from the Petty Officers room.  In this room are located:  battery automatic circuit breaker 1 to starboard, refrigerator plant with small provision locker, wash and dryer room, 1 stove, 2 mine release arrangements for mine shafts 50/48 - 49/47.
    Room 4:  Petty Officers room (Frame D 38 - 45-1/2).
    The access is through the galley and the hatch in the curved bulkhead 55-1/2.  In this room are located:  battery room 1 with battery 1, fresh water tank 1, lubricating oil supply tanks 1, 2, 3 and 4.  It is used as quarters for 12 petty officers.  2 mine release arrangements for mine shafts 46/44 and 45/43.
     
    Compartment III
    Room 5:  Control room (Frame D 45-1/2 - 55-1/2).
    The access is through the hatches in curved bulkheads at frame 45-1/2 and 55-1/2 and through the control room hatch.  In the control room are located:  main drain pump, auxiliary drain and trim pump, drive for control room periscope, auxiliary switchboard 3, 4 pressurized hydraulic oil flasks, blowing distributor for main ballast tanks and main ballast and reserve fuel oil tanks, regulating tanks, fuel oil tanks and so on, 2 hydraulic oil pumps, 1 battery ventilation fan, 5 oxygen flasks, diving planes control station, gyro-compass, 1 main rudder control station, 1 emergency main rudder control station, radio direction finder, rod antenna, TDC, depth sounding equipment, compressed air pistons for operating vent valves, vent valves for main ballast tanks 6 and 7, munitions magazine, log installation, 2 engine order telegraphs, 6 mine release arrangements for mine shafts 42/40 - 33/31, and trim controller.
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  33
U-boat Information
II.  Boat and Pressure hull
            5
     
 
    Compartment IV Room 6:  Officers room, Chief Petty Officers room and 2 rooms for crew one above the other (Frame D 55-1/2 - 70-1/2).
    The access is through the hatches in the curve bulkheads at frame 50-1/2 and 70-1/2 and through the officers' room hatch.  The officers' room, chief petty officers room and 2 rooms for crew are separated by 3 wooden bulkheads.  In this room are located:  battery automatic circuit breaker 2, captain, officers, chief petty officers quarters, rooms for men one above the other, listening room, radio room, provision locker, fresh water tanks 3 and 4, waste water tank 3, wash water tank 1, 6 mine release arrangements for mine shafts 30/28 - 21/19, compressed air pistons for operating vent valves, vent valves for main ballast and reserve fuel oil tanks 8 and 9.
     
    Compartment V Room 7:  Forward mine room (Frame D 70-1/2 - 89).
    Access is through the hatch in the curved bulkhead at frame 70-1/2 and through forward mine room hatch.  In this room are located:  auxiliary drain pump 2, 6 forward mine shafts (16/18 - 1/3) with mine release arrangements and release controller, mine compensating tanks 5, 6, 7, 8, trim tanks 3 and 4, waste water tank 4, wash water tank 2, forward WC, lathe and drill stand, 5 bunks for men, forward capstan driving motor, compressed air pistons for operating vent valves, vent valves for main ballast tank 10, a second refrigerator plant (until the installation of deep-freezer equipment), potato storage and driving motor for Voith-Schneider-Propeller (only on U-118).
    Conning tower (Frame D 48 - 53)
    Access through the control room and conning tower hatches.  In this room are located:  forward and aft conning tower periscopes with their driving motors, 1 main rudder control station, 1 torpedo fire control station, 2 engine order telegraphs, main rudder angle indicator, diving planes angle indicators, log repeater, gyro-compass repeater.
     
  4) Conning tower structure.
    The conning tower is used as command station during cruise.
    The conning tower in horizontal cross-section is an ellipse in the aft section and the arc of a circle in the lateral and forward sections.  The radius of the forward arc is 700 mm, and that of the side arcs 2500 mm.  The conning tower is topped with a cast steel plate with openings for the conning tower hatch and conning tower periscopes.  Clear width of the conning tower is 2080 mm, clear
     
     
     
     
     
     
     
     
     
 
     
     

 

   
Page 34
A. Ship Information
U-Boat Type XB
           6
II.  Boat and Pressure hull
U-boat Information
     
 
    length is 3460 mm.  The conning tower is also enclosed by the casing, which reduces drag during cruise.
    In the conning tower casing are located:  cooling water head tank, 2 pressure-proof containers for 3.7 cm ready-use ammunition, 2 diesel engine air induction trunks, 1 ventilation intake and 1 ventilation exhaust air ducts and 1 upper deck WC.
     
  5) Openings in the pressure hull.
    The most important openings are:
     
    Aft torpedo room (Frame D 0 - 13-1/2)
    Aft torpedo room hatch, torpedo loading hatch, torpedo tubes 1 and 2, 1 hull valve from the sea for flooding torpedo compensating tanks 1 and 2, 1 hull valve for auxiliary drain pump 1 discharge, 2 openings for the aft WC, 1 opening for main rudder, 1 opening for aft diving planes.
     
    E motor room (Frame D 13-1/2 - 22)
    2 openings for propeller shafts starboard and port, 1 hull valve for cooling water pump intake and air compressor cooling line, 1 hull valve for cooling water, air cooler and air compressor cooling line discharge, E motor assembly patch.
     
    Diesel engine room (Frame D 22 - 35-1/2)
    Diesel engine assembly patch, 2 openings for exhaust gas valves, 2 hull valves for cooling water lines for cooling internal exhaust gas valves, 2 diesel engine air induction trunk foot valves, 1 ventilation intake foot valve, 1 ventilation exhaust foot valve, 2 hull valves for cooling water intake
     
    Galley (Frame D 35-1/2 - 38)
    Galley hatch
     
    Petty officers room (Frame D 38 - 45-1/2)
    Assembly patch for battery 1
     
     
     
     
     
     
     
     
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  35
U-boat Information
II.  Boat and Pressure hull
            7
     
 
    Control room (Frame D 45-1/2 - 55-1/2)
    Control room hatch, radio direction finder, control room periscope, rod antenna, connection of the battery exhaust trunk to the ventilation exhaust duct, 1 hull valve main drain pump intake and for flooding the regulating tanks.
     
    Conning tower (Frame D 48 - 53)
    Conning tower forward and aft periscopes, conning tower hatch and voice tube.
     
    Officers room (Frame D 50-1/2 - 70-1/2)
    2 openings for the antenna trunks, officers room hatch, assembly patch for the battery 2.
     
    Forward mine room (Frame D 70-1/2 - 89)
    Forward mine room hatch, 1 hull valve for auxiliary drain pump 2 discharge and for flooding the mine compensating tanks 5-8, 1 opening for forward diving planes and 1 opening for the rotating passive hydrophone (KDB)
     
  6) Construction of the outer shell.
    The outer shell consists of an outer hull, which encloses the pressure hull and the upper deck, located above the pressure and the outer hull.  The outer hull determines the form of the boat in the water and hence the drag during cruise.  The outer hull in the type XB boats is divided into main ballast tanks, main ballast and reserve fuel oil tanks, fuel oil tanks, regulating and reserve fuel oil tanks, regulating tanks, mine compensating tanks, negative buoyancy tanks, bow and stern buoyancy tanks and exhaust gas spark arrestors.  The space between the outer hull and upper deck is used to locate various ship and machinery installations as well as for storage of nautical equipment and ready-use ammunition.
    The distance between the outer shell frames is typically 500 mm, but there is some variation resulting from the boat's construction.
    The upper deck stretches over the entire boat and is fitted to the vessel's form.
    Between frames A 20 - A 90 the upper deck is horizontal, in the forward part it rises and in the aft part it falls.
    Between frames A 2 - A 128 the upper deck is covered with wood, while at the forward and aft end parts it is constructed of steel plates.
    The distance between the upper deck frames is equal to the distance between the outer shell frames located below.
     
     
     
     
     
 
     
     

 

   
Page 36
A. Ship Information
U-Boat Type XB
           8
II.  Boat and Pressure hull
U-boat Information
     
 
    The conning tower is covered with steel plate casing.  It encloses four air ducts, antenna trunk, radio direction finder, the rod antenna, control room periscope, 3.7 cm ready-use ammunition in pressure-proof containers, upper deck WC and the cooling water head tank.  Over the conning tower there is a bridge, which is used as command station during cruise and as the battle station for the 2 cm anti-aircraft gun.  Two extended diesel engine air induction trunks are installed in the bridge steel plate fairing on both sides.
    Special stiffeners:
    The parts of the torpedo tubes extending beyond the pressure hull are supported by torpedo tube bulkheads located in stern part of the outer shell.
    Places especially exposed to loads (area of dive planes, the widest part of the hull, lateral mine shafts, propeller shaft supports, anchor capstan etc.) are braced with stringers, girders and beams.
     
  7). Partitioning of the outer shell.
   
The outer shell is divided by means of watertight, oil tight and pressure-proof bulkheads into following tanks:
Stern buoyancy tank
Frame
-16 - -9
Main ballast tank 1
"
-9 - +8
Main ballast and reserve fuel oil tank 2 stb. and 2 port
"
8 - 24
Main ballast and reserve fuel oil tank 3 stb. and 3 port
"
24 - 34
Fuel oil tank 1a stb. and 1a port
"
34 - 43
Main ballast tank 4 stb. and 4 port.
"
43 - 53
Main ballast tank 5 stb. and 5 port
"
53 - 63
Regulating and reserve fuel oil tank 1 stb. and 1 port
"
63 - 68-1/2
Regulating tank 2 stb. and 2 port
"
68-1/2 - 73
Mine compensating tank 1 and 2  )
"
63 - 66-1/3
Mine compensating tank 3 and 4  ) lying underneath the regulating tanks
"
66-1/3 - 69-1/2
Negative buoyancy tank)
"
69-1/3 - 73
Main ballast tank 6 stb. and 6 port
"
73 - 83
Main ballast tank 7 stb. and 7 port
"
83 - 93
Fuel oil tank 2a stb. and 2a port
"
93 - 99
Main ballast and reserve fuel oil tank 8 stb. and 8 port   99 - 109
 
     

 

   
U-Boat Type XB
A. Ship Information
Page  37
U-boat Information
II.  Boat and Pressure hull
            9
     
 
   
Main ballast and reserve fuel oil tank 8 stb. and 8 port
"
109 - 128
Main ballast tank 10
"
128 - 147
Bow buoyancy tank (over main ballast tank 10)
"
128 - 152
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
Page 38
A. Ship Information
U-Boat Type XB
           1
III.  Diving Installations
U-boat Information
     
 
III. Diving Installations.
1) Tanks and fuel oil tanks.
  a) Main ballast tanks.
    During surfaced cruise the boat floats by means of 6 main ballast tanks.  Main ballast tanks 1 and 10 are located in the bow and stern parts of the outer shell and have flooding slits.  The pairs of starboard and port main ballast tanks 4 and 5 are located in the outer shell behind the regulating tanks, the pairs of starboard and port main ballast tanks 6 and 7 are located forward of the regulating tanks.  Each main ballast tank is flooded by means of 4 flooding valves, each pair is operated by means of linkage rods from the inside of the boat.  The lateral mine shafts are located within main ballast tanks 4, 5, 6, 7 starboard and port.
     
  b) Main ballast and reserve fuel oil tanks.
    Four pairs of main ballast and reserve fuel oil tanks 2, 3, 8 and 9 (starboard and port) are provided located in the outer shell, of those each individual tank can be flooded by means of 4 flood valves just as for the main ballast tanks.  Each pair of adjacent flood valves is operated by means of a linkage rod from inside the boat.  Main ballast and reserve fuel oil tanks 2 and 3 are located in the outer shell between main ballast tank 1 and fuel oil tank 1a, main ballast and reserve fuel oil tanks 8 and 9 are located between the fuel oil tank 2a and main ballast tank 10.
     
  c) Bow and stern buoyancy tanks.
    The aft and forward parts of the outer shell are constructed as stern and bow buoyancy tanks and are used to dampen longitudinal pitching of the boat.  Both tanks have flood slits and are vented by means of one vent valve each operated from the inside of the boat.  Stern and bow buoyancy tanks can be blown with compressed air.
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  39
U-boat Information
III.  Diving Installations
            2
     
 
   
Location and capacity of main ballast tanks, main ballast and reserve fuel oil tanks, stern buoyancy tank and bow buoyancy tank.
     
   
Main Ballast tanks (and reserve fuel oil tanks)
Location
Net capacity
Stern buoyancy tank Frame
-16 - -9
8.40 m³
Main ballast tank 1 Frame
-9 - +8
44.30 m³
Main ballast and reserve fuel oil tank 2 Frame
+8 - 24
43.25 m³
Main ballast and reserve fuel oil tank 3 x) Frame
24 - 34
58.20 m³
Main ballast tank 4 Frame
43 - 53
78.30 m³
Main ballast tank 5 Frame
53 - 63
88.95 m³
Main ballast tank 6 Frame
73 - 83
88.20 m³
Main ballast tank 7 Frame
83 - 93
75.75 m³
Main ballast and reserve fuel oil tank 8 x) Frame
99 - 109
69.05 m³
Main ballast and reserve fuel oil tank 9 Frame
109 - 128
67.55 m³
Main ballast tank 10 Frame
128 - 147
39.00 m³
Bow buoyancy tank Frame
128 - 152
28.00 m³
    x) Applies only with opened flood valves
     
  d) Regulating tanks and regulating and reserve fuel oil tanks.
    To compensate for changes of weight caused by different load conditions and differences in water density, 2 regulating and reserve fuel oil tanks and 2 regulating tanks are provided. They are located in the outer shell and are constructed as pressure-proof.
     
    Location and capacity of regulating tanks:
     
   
Designation
Location
Net capacity
Regulating and reserve fuel oil tank 1 port
D 41-1/2 - 45
16.85 m³
Regulating and reserve fuel oil tank 1 starboard
D 41-1/2 - 45
16.85 m³
Regulating tank 2 port
D 45 - 48
13.30 m³
Regulating tank 2 stb.
D 45 - 48
13.30 m³
     
 
     
     

 

   
Page 40
A. Ship Information
U-Boat Type XB
           4
III.  Diving Installations
U-boat Information
     
 
    The 2 regulating and reserve fuel oil tanks and regulating tanks can be flooded from the sea and emptied by means of compressed air or by means of main drain or auxiliary drain and trim pump.  The tanks are tested under a pressure of 14 kg/cm², and should be blown with a maximum pressure difference between the external pressure and blowing air equal to 16 kg/cm² (see paragraph I 2 d).
    As a protection against too rapid increase in the pressure in the regulating and reserve fuel oil tanks and in regulating tanks while blowing (when the tanks are filled with water), the vent lines are lengthened, so when the tanks are flooded, an air cushion of 6% of tank capacity is created.
     
  e) Trim tanks.
    To keep the boat balance during submerged cruise two trim tanks in aft torpedo room and two trim tanks in forward mine room are installed.  They are connected with two trim lines by means of two trim controllers.  In each of the two trim lines a trim valve and a water meter is installed.  Trimming takes place by means of compressed air or the auxiliary drain and trim pump.
    All 4 trim tanks are tested at a pressure of 3 kg/cm² and are located 6.97 meters apart.
    Position and capacity of trim tanks:
    Aft - 27.25
    Forward + 34.45
     
   
Designation
Location
Net capacity
Trim tank 1
D 7 - 11
3.940 m³
Trim tank 2
D 7 - 11
3.940 m³
Trim tank 3
D 87 - 89
3.778 m³
Trim tank 4
D 87 - 89
3.778 m³
     
     
     
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  41
U-boat Information
III.  Diving Installations
            5
     
 
  f) Negative buoyancy tanks.
    The pressure proof negative buoyancy tanks starboard and port located in the outer shell under regulating tank 2 and are used to gain negative buoyancy during crash diving.  The capacity of each tank is 7.85 meters³.  The tanks are flooded through the flooding valves and are also blown through the same valves by means of compressed air.  The tanks are vented to the inside of the boat.  The flooding valves are operated form the control room. The negative buoyancy tanks are located between frames 45 ½ - 48.
     
  g) Torpedo compensating tanks.
    Torpedo compensating tanks 1 and 2 are located in the aft torpedo room and are flooded through the water flow meter.  Each tank has a sounding line and is connected to the drain line.
     
   
Designation
Location
Net capacity
Test pressure
Torpedo compensating tank 1
D 11 - 13-1/2
3.24 meters³
3 kg/cm²
Torpedo compensating tank 2
D 11 - 13-1/2
3.92 meters³
3 kg/cm²
     
  h) Mine compensating tanks.
    8 mine compensating tanks are used to equalize the weight during mine launching.  Tanks 1 - 4 are located outside the pressure hull, under the regulating and reserve fuel oil tanks and are pressure proof.  Tanks 4 - 8 are located inside the pressure hull, in the forward mine room, at its sides and are pressure proof up to a pressure of 4 kg/cm².  All tanks are connected to the drain and flooding line and can be drained by means of drain pumps.  Pressure proof tanks 1 - 4 can be also drained by means of compressed air.
     
     
     
     
 
     
     

 

   
Page 42
A. Ship Information
U-Boat Type XB
           4
III.  Diving Installations
U-boat Information
     
 
     
   
Designation
Location
Net capacity
Test pressure
Mine compensating tank 1
D)
41-1/2 - 43-1/2
7.55³)
14 kg/cm²
Mine compensating tank 2
D)
7.55³)
Mine compensating tank 3
D)
43-1/2 - 45-1/2
7.55³)
Mine compensating tank 4
D)
7.55³)
Mine compensating tank 5
D)
74 - 77
3.65³)
4 kg/cm²
Mine compensating tank 6
D)
3.65³)
Mine compensating tank 7
D)
77 - 80
2.25³)
Mine compensating tank 8
D)
2.25³)
     
2) Blowing and exhaust gas blowing installation.
  a) Compressed air blowing.
    The main ballast tanks and main ballast and reserve fuel oil tanks are blown with compressed air up to 30 kg/cm², fed from the blowing distributor, which is located on the starboard side of the control room.  The ballast tanks are gathered and grouped into 3 groups, which are fed through the common main blowing valve from the high pressure air distributor or through the auxiliary blowing valve from high pressure compressed air bank 7.
    Group 1 = Main ballast tank 1, Main ballast and reserve fuel oil tank 2 and Main ballast and reserve fuel oil tank 3
    Group 2 = Main ballast tank 4 starboard., Main ballast tank 4 port, Main ballast tank 5 starboard, Main ballast tank 5 port, Main ballast tank 6 starboard, Main ballast tank 6 port, Main ballast tank 7 starboard, Main ballast tank 7 port.
    Group 3 = Main ballast and reserve fuel oil tank 8, Main ballast and reserve fuel oil tank 9 and Main ballast tank 10
    The dedicated blowing distributor is used to blow the bow and stern buoyancy tanks and both fuel oil tanks 1a and 2a (starboard and port).
    (for the compressed air and emergency blowing manifold see Safety and Rescue Installations).
     
  b) Exhaust gas blowing.
    Exhaust gas from the diesel engines is used to blow residual water from the ballast tanks.  Exhaust gases are fed through the main blowing valves port and starboard to the exhaust gas blowing manifold.  The manifold is located outside the pressure hull, over the control room, on the starboard side.  From the manifold the gases go through 10 valves - operated from the control room by means of linkage rods passing through the hull - to the main ballast tanks and main ballast and reserve fuel oil tanks.  Exhaust gas pressure should be 0.7 at.
     
 
     
     

 

   
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A. Ship Information
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III.  Diving Installations
            6
     
 
3) Venting and vent valves.
  Vent valves of the main ballast tanks and main ballast and reserve fuel oil tanks are operated by means of compressed air (or by hand) and are gathered into 6 groups:
 
Compressed air control valve 1 (aft) Group 1 - Main ballast tank 1
Group 2 - Main ballast and reserve fuel oil tank 2, Main ballast and reserve fuel oil tank 3
Compressed air control valve 2 (amidships) Group 3 - Main ballast tank 4, Main ballast tank 5
Group 4 - Main ballast tank 6, Main ballast tank 7
Compressed air control valve 3 (forward) Group 5 - Main ballast and reserve fuel oil tank 8, Main ballast and reserve fuel oil tank 9
Group 6 - Main ballast tank 10
  Each main ballast tank and main ballast and reserve fuel oil tank (except main ballast tank 1) is provided with a vent trunk on the starboard and port side.  Each trunk can be shut off by means of its own emergency vent valve.  The emergency vent valves are operated from inside the pressure hull.   Gate valves are installed in the vent trunks of the main ballast and reserve fuel oil tanks (starboard and port), which should be closed when tanks are used as reserve fuel oil tanks.  These trunks are pressure proof between the gate valves and emergency vent valves.  The vent valve of main ballast tank 1 is located in the top cover of the tank, at the height of the upper deck.  No emergency vent valve is provided for this tank.  Two separate vent trunks are combined at the vent valve chamber for main ballast tank 10, which begin at the aft part, at the starboard and port side of the tank, and which are provided with emergency vent valves at the tank top cover.  The pairs of main ballast tanks (starboard and port) 4 and 5, 6 and 7 and the pairs of main ballast and reserve fuel oil tanks (starboard and port) 2 and 3, 8 and 9 combine their 4 vent trunks in 2 vent valve chambers, with 2 coupled vent valves located side by side.   And so, for example main ballast and reserve fuel oil tanks 2 and 3 starboard are vented through main ballast and reserve fuel oil tanks 2 and 3 starboard vent valve, while the main ballast and reserve fuel oil tanks 2 and 3 port are vented through the main ballast and reserve fuel oil tanks 2 and 3 port vent valve.  Both vent valves are connected by means of a transverse beam, which in turn is operated from the inside of the boat by means of a vertical linkage rod.
  (see the drawing)
 
     
     

 

   
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A. Ship Information
U-Boat Type XB
           7
III.  Diving Installations
U-boat Information
     
 
 
     
     

Anordung der Entlüftungsleitungen - Layout of the Vent trunks
druckfest ausgefürt Pressure-proof construction
Entlüftungsanschluß Gate valve
Entlüftungsventil Vent valve
hinten Aft
Notverschlußklappe Emergency vent (flap) valve
Tauchz. Main ballast tank
Traverse Cross-connection
Treibölb. Fuel oil tank
vorn Forward

   
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A. Ship Information
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III.  Diving Installations
            8
     
 
4) Compressed air systems.
  a) Air compressor.
    Compressed air, which is used for blowing the main ballast tanks, main ballast and reserve fuel oil tanks, regulating and reserve fuel oil tanks, regulating tanks, starting diesel engines, for the torpedo launching installation, anchor installation and other systems, is produced by 2 electric air compressors located in E motor room and by 2 diesel air compressors located in diesel engine room.
    Compressed air is under maximum pressure of 205 kg/cm².
    (for details see section B II 1 c)
     
  b) High pressure compressed air flasks.
    Compressed air is stored in 28 compressed air flasks with total capacity of 12.47 meters³. The flasks - tested with pressure 255 kg/cm² - are gathered into 8 groups:
   
Group and number of flasks
Location
Capacity of the Group
Capacity of each flask
1  (2)
In Aft torpedo room
900 liters
445 liters
2  (4)
Upper deck above the E-motor room
1780 liters
445 liters
3  (4)
Upper deck above the Diesel engine room
1780 liters
445 liters
4  (2)
In Wardroom over the forward battery
890 liters
445 liters
5  (4)
Upper deck over the Wardroom
1780 liters
445 liters
6  (4)
Upper deck over the Forward mine room
1780 liters
445 liters
7  (4)
In Forward mine room
1780 liters
445 liters
8  (4)
Upper deck over the Forward mine room
1780 liters
445 liters
    Therefore there are 3570 meters³ of compressed air in the pressure hull (groups 1, 4, 7) and 8900 meters³ of compressed air outside the pressure hull, under the upper deck (groups 2, 3, 5, 6, 8).
     
     
     
     
 
     

 

   
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U-Boat Type XB
           9
III.  Diving Installations
U-boat Information
     
 
  c) Compressed air equipment.
    The 8 compressed air flask groups are connected by lines to the group distributor, located on the port side of the control room.  From this distributor the air is led to the high pressure air distributors in the control room and in the aft torpedo room, to the blowing distributor and to the other distributors.  In the aft torpedo room and in the forward mine room there are also emergency blowing manifolds.
    From the high pressure air distributor in the control room lines go to separate medium and low pressure air distributors.
    Available medium-pressure air distributors:
   
1) 3 Main ballast tanks and or main ballast and reserve fuel oil blowing distributors with a common main blow valve
2) 1 blowing air distributor for regulating tanks
3) 1 blowing air distributor for mine compensating tanks 1-4
4) 1 regulating valve for negative buoyancy tanks
5) 1 blowing air distributor for watertight bow and stern, fuel oil tank 1a and 2a
6) 1 emergency blowing manifold in the aft torpedo room and 1 in the forward mine room
    Available low pressure distributors:
   
1) Low-pressure distributor in the control room to starboard (air entry via 2 regulating valves)
2) Pressure reducing valve and air pressure regulating valve for stern capstan motor (205 at > 4 at)
3) Pressure reducing valve and air pressure regulating valve for anchor capstan motor (205 at > 4 at)
    The following use compressed air:
   
1) High-pressure equipment
  a) Torpedo test installation in the aft torpedo room
  b) Hydraulic oil system in the control room
2) Medium-pressure equipment
  a) Blowing all main ballast tanks, main ballast and reserve fuel oil tanks, watertight bow and stern, fuel oil tanks
  b) Blowing regulating and reserve fuel oil tanks and regulating tanks (safety valve 10 at)
  c) Blowing negative buoyancy tanks
  d) Starting air flasks in the diesel engine room
  e) Blowing mine compensating tanks 1-4
    In case of damage the control room, the main ballast tanks and main ballast and reserve fuel oil tanks can be blown by means of separate emergency blowing manifolds.
     
     
 
     
     

 

   
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III.  Diving Installations
            10
     
 
   
3) Low-pressure equipment  (branched direct from the low-pressure air distributor)
  a) Torpedo launching installation in aft torpedo room, blowing torpedo compensating tank 1 and 2
    Aft head, forward head, air driven tool connection in aft torpedo room
  b) Blowing out the cooling water hull valve in the E-motor room
    Main clutch air pressure valve
    Blowing out the 3 cooling water hull valves in the diesel engine room
    Tool connection in the diesel engine room
    Grinding mechanism for the exhaust valves
    Blowing out the heater lines of the steam generator system starboard and port
  c) Forward diving plane clutch
    Aft diving plane clutch
  d) Main ballast tanks and main ballast and reserve fuel oil vent valve operating gears
  e) Marcks raft/buoy above the petty officers room
    Marcks raft/buoy above the ward room
  f) Rod antenna raising gear
    Direction finding loop raising gear
    2 tyfone air whistles on the conning tower
    Antenna shaft
    Tool connection in the control room
    Trim system
    Blowing out the hull valve to the sea
     
5) Pumps.
  Regulating and reserve fuel oil tanks, regulating tanks and pressure-proof mine compensating tanks 1 - 4 can be blown by means of compressed air, but the regulating tanks and all mine compensating tanks (1 - 8) can also be drained by means of the main drain pump, both auxiliary drain pumps as well as by the auxiliary drain and trim pump.
     
6) Diving planes.
  The boat is provided with a forward and aft pair of diving planes.  The planes are driven by means of a hydraulic oil motor, powered from the hydraulic oil system in the control room. In case of failure of the hydraulic drive, the planes can switched from the control room by means of low pressure compressed air driven clutches to manual operating mode.  Switching back to the hydraulic drive is done manually in the forward mine room or aft torpedo room respectively.
  (For performance data see section B II 1 a)
 
     
     

 

   
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U-Boat Type XB
           1
IV.  Armament
U-boat Information
     
 
IV. Armament.
1) Mine installations.
  The boat can carry 66 SMA mines in 30 vertical, rounded shafts.  6 pressure-proof shafts are located one after another in the forward mine room, welded to the pressure hull, each holding 3 mines.  The 6 shafts extend from the bottom edge of the keel up to about 50 cm over the upper deck.  The upper parts of the shafts rising above the deck are covered by a common, streamlined casing.
  6 mine shafts are installed on each side of the boat, in the main ballast tanks (4, 5, 6, 7) starboard and port.  Each shaft can carry two mines.  The shafts extend from the bottom up to the top edge of the outer shell, which at this location is almost rectangular in the transverse section.  All mine shafts are open at the bottom, while at the top end they are closed by a hinged, perforated cover.  Laterally, on the outer side of the mine shafts, at the height of the anchor of each loaded mine, there are openings for the mine releasing and mine holding gear.  The gear consists of horizontal locking plates, rotated by vertical shafts.  The shafts are rotated hydraulically by means of a bevel wheeled gear from the inside of the boat.  The parts of the locking plates which protrude inside the mine shaft lock the mines with their locking cleats. When the locking plate is rotated in such way, that it no longer protrudes inside the mine shaft, the mine falls out of the shaft or the mines can be loaded to the shaft from above.  The locking plates in each mine shaft are so located, that the loading and launching of the mines is to be done in fixed sequence.  In case of damage to the hydraulic oil drive for the releasing gear, it can be driven manually by means of a handle and auxiliary gear.
  The SMA mines weigh 1575 kg, displace 1100 liters of water, so have 475 kg of negative buoyancy.
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  49
U-boat Information
IV.  Armament
             2
     
 
2) Torpedo installations.
  a) Torpedo tubes.
    The boat is provided with 2 underwater, standard caliber torpedo tubes.  These are located side by side in the aft torpedo room and are supported by the aft end cap of the pressure hull and the torpedo bulkhead.  Streamlined shutters are connected to the outer doors.  When the horizontally pivoting torpedo tube outer doors are opened, the shutters are pushed up, into the outer shell.  The tube end located inside the pressure hull is closed by the breech door with a locking ring.  The interlock mechanism between the breech and outer door operating gears prevents simultaneous opening.
     
  b) Stowage.
    Apart from torpedoes loaded into torpedo tubes I and II, there can be also 5 reserve torpedoes stored inside the pressure hull.  Three of them are stored under the floor plates of the aft torpedo room, on the torpedo compensating tanks and trim tanks.
    2 more torpedoes can be stored on the floor plates in the same room.
    8 pressure-proof, upper deck containers installed outside the pressure hull, on both sides at the top covers of saddle tanks.  These containers are made of aluminum and can store one torpedo each.
    These torpedoes are designated for transfer to other boats.
     
  c) Torpedo loading equipment.
    The torpedo loading equipment is the same for the G7a or G7e torpedo.  A portable crane, which is stored under the upper deck, can be mounted on the starboard or port side of the upper deck, just in front of the torpedo loading hatch and is used for loading from the sea or other vessels.
     
     
     
     
     
 
     
     

 

   
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U-Boat Type XB
           3
IV.  Armament
U-boat Information
     
 
    The portable crane is mounted in pivot bearings installed at the upper deck.  The torpedoes are slid down into the inside of the boat by means of a chute and boom with winch and corresponding support beams which assure proper motion of the torpedo.
    Transport splints with gear racks are installed in the boat.  Each splint is hung by means of two hoists and 3 holding lugs.  The splint is equipped with 2 trolleys.  The torpedo is attached to these trolleys by means of steel bands.  The torpedo is moved longitudinally by means of the aft trolley, which is equipped with gear rack and crank arm.  Two transverse splints are provided for lateral movements.
    The torpedoes stored in the upper deck containers can be pulled out with twisted steel wire rope and taken from the deck by means of the portable crane.  Pivot bearings installed for mounting the crane, at both sides of the deck, corresponding to each container.
     
  d) Torpedo fire control system.
    The torpedo direction computing installation is intended to calculate the gyro angle based on estimated and measured values and to transmit it to torpedo tube electrically.
    The following equipment makes up the torpedo fire control installation:
    On the bridge:
            Surface sight with target bearing transmitter
    In the conning tower:
            1 Torpedo data computer
               Target bearing transmitter I
               Target bearing transmitter II
            1 Blue switch
            1 Switch box
            1 Fuse box
    In the control room:
            1 Main switch box
            1 Torpedo spread shot timer
            1 Fuse box
     
     
 
     
     

 

   
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A. Ship Information
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IV.  Armament
             4
     
 
    In the aft torpedo room:
            1 torpedo gyro angle receiver
            1 rotary amplifier for the gyro angle setting gear
            1 resistor box
    In the E-motor room:
            1 rotary converter with starter and regulator
            1 fuse box
    The torpedo firing installation enables mechanical launching at the torpedo tubes, and also electrical firing from the bridge and from the conning tower.
    The following equipment makes up the torpedo firing installation:
    On the bridge:
            1 pressure resistant firing switch
    In the conning tower:
            1 firing switch
            1 lamp board (Tube I and II)
    In control room:
            1 fuse box
    In aft torpedo room:
            1 tube distributor box
            1 lamp board
            1 resistor box
     
  e) Weight compensation.
    To drain water from tubes and to compensate for the weight of launched torpedoes 2 torpedo compensating tanks are provided in the aft torpedo room.
    Torpedo compensating tank 1    Frame D 11 - 13-1/2     3.24 meters³
    Torpedo compensating tank 2    Frame D 11 - 13-1/2     3.92 meters³
    The tanks can be flooded from the sea through the common hull valve on the port side and then through flood valves associated with each tank.
    The tanks are drained by the main drain pump, the auxiliary drain and trim pump, auxiliary drain pump 1 and auxiliary drain pump 2.
    Because the torpedo is heavier than the water it displaces, after the shot, a corresponding amount of water must be taken into the torpedo compensating tanks. For accurate measuring of this amount of water, a water meter is installed in each flooding line.
 
     
     

 

   
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U-Boat Type XB
           5
IV.  Armament
U-boat Information
     
 
    Torpedo weight table.
     
   
 
Deadweight (kg)
Volume to flood tube (liters)
Torpedo displacement (liters)
Negative or positive buoyancy (kg)
G 7a model empty
1245
370
1310.5
65
G 7a model combat weight
1540.5
370
1310.5
230
G 7e model combat weight
1573
370
1310.5
263
G 7a drill 60 at
1400
476
1254
150
G 7a drill 100 at
1438
426
1254
184
G 7a drill 200 at
1518
426
1254
264
G 7a combat 200 at
1528
426
1254
274
G 7e drill
1279
374
1306
27
G 7e combat
1603
374
1306
297
     
  f) Charging and heating the electric torpedoes.
    1 charging switch board and 2 main switch boards are installed in aft torpedo room for maintenance and charging electric torpedo batteries.  For removing the oxyhydrogen gases and for cooling the batteries during charging a connection to the compartment ventilating system with cut off valves and vacuum gauges is installed.
    (for further details see secret publication list under E Torpedoes)
     
     
     
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  53
U-boat Information
IV.  Armament
             6
     
 
3) Gunnery.
  a) Weapons.
    The armament of the boat consists of:
   
1 10.5 cm cannon on the upper deck in front of the conning tower, bolted to a pyramid shaped case mount with stiffeners and welded to the pressure hull.
1 3.7 cm anti-aircraft gun on the upper deck behind the conning tower, bolted to a reinforced cylinder welded to the pressure hull.
1 2 cm anti-aircraft gun on the bridge.
1 MG C 34 (air cooled)
     
  b) Ammunition.
    In the non-floodable magazine (D frame - 55-1/2) below the deck in the control room the following ammunition is stored in cases:
   
227
rounds
10.5 cm ammunition in cans M/32
944
"
3.7 cm ammunition
1300
"
2.0 cm ammunition in cartridge boxes M 30/a
120
"
2.0 cm ammunition in a magazines
3000
"
0.8 cm ammunition for MG C 34
3000
"
0.8 cm ammunition with tracer
In the conning tower:
80
rounds
2.0 cm ammunition in 4 magazines
10
"
Signal munitions
In the upper deck (frame 82-1/2-86):
30
rounds
10.5 cm ammunition in pressure-proof cans M 32
In the conning tower casing:  laterally between the cannon and conning tower under the upper deck:
2 x 32
rounds
3.7 cm in 2 pressure-proof containers in the conning tower casing in pouches of 16 rounds each
In the control room:
80
rounds
NES munitions and 180 rounds of signal munitions
 
     
     

 

   
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IV.  Armament
U-boat Information
     
 
4) Demolition equipment.
  In the forward mine room 2 cases each with 12 time fuses A [detonators]
  In the aft torpedo room 3 cases each with 4 scuttling charges [cartridge type] and 2 cases each with 12 demolition blocks [in containers]
     
     
5) Small arms.
  1 MG C 34 in the petty officers room
  2 Sub machine guns in petty officers room
  3 Side arms in the munitions magazine in the control room
  6 Mauser pistols in lockers
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  55
U-boat Information
V.  Communications
             1
     
 
V. Communications.
1) Visual and acoustic equipment.
  a) Visual equipment:
    Searchlight (250 watt)
    Hand signal searchlight (each 100 watts)
    Aldis lamp
    Signal lanterns
    Signal and semaphore flags
    Star signal pistols
    Flares
    The searchlight (250 Watt) is powered by 24 V AC through the transformer from the TDC converter and is attached to a dedicated mounting in the bridge casing.
    Both hand signal searchlights (each 100 W) can be powered either by 24 V DC through the resistor from the boat light circuit or by 24 V AC through the transformer from the 1.5 kVA or 6 kVA radio rotary converter.
    These searchlights are stored in the conning tower.
    The following running lights are installed: 
    Head lights
    Steaming lights
    Side lights    starboard and port
    Stern lights    1 and 2
    All these lamps can be turned on by means of one common switch.
    Stern light 1 is on the bridge casing aft
    Stern light 2 is on the upper deck on the stern above main ballast tank 1.
    Either stern light 1 or stern light 2 can be turned on, they can not be turned on simultaneously.
    For firing star signals a double and a single barreled star pistol are provided in the conning tower.
 
     
     

 

   
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V.  Communications
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  b) Acoustic equipment.
    Two tyfone air whistles are installed in the conning tower and they can be operated manually from the conning tower or from the bridge by means of a foot switch.  The ship's bell can be mounted on the bridge.
     
2) Electronic communication equipment.
  a) Radio installation:
    The radio installation consists of long and short wave equipment.
    1)  Long wave:
    For the longwave range a long wave transmitter with output power 150 Watt (500 - 1000 meters) is installed in the radio room.  As receiver the direction finding receiver (300 - 4000 meters) is used, which is located in the radio room.
    2)  Short wave:
    For the short wave range a short wave transmitter with output power 800 Watt (13 - 100 meters) and a short wave receiver (12 - 200 meters) are installed in the radio room.  In the listening room a 40 W transmitter (18 - 60 meters) with all-wave receiver (15 - 20000 meters) is installed.
    3)  Longest wave:
    For receiving the longest wave range, there is a direction finding receiver (12000 - 20000 meters) which uses the loop antenna.  No transmitter is provided for this range.
    It is possible to receive the longest waves when submerged.
     
  b) UT [Underwater Telegraphy] installation.
    The installation is used to send and receive waterborne sonic signals.  The signal frequency is beyond the frequency of sound generated by the engines and propellers.
    The UT installation consists of:
   
1.) 4 sound transmitters in 2 groups
  (2 each  on the starboard and port side of the bow)
2.) 4 sound receivers in 2 groups
  (2 each on the starboard and port side of the bow)
3.) Control unit, radio room
4.) 1 rotary converter, E-motor room
 
     
     

 

   
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V.  Communications
             3
     
 
    The transmitters and receiver groups on the starboard and port side of the bow are built in the aft part of the GHG receivers group.  The connecting lines are gathered together and led through the cable socket into the pressure hull.  By means of the selector switch in the control unit the transmitters or receivers on both sides of the vessel or from the one side only can be used.  The control unit of the UT installation is located in the radio room. (see the classified document - Description and operation manual of the underwater sonic transmitting-receiving installation -).
     
  c) The combined announcement and broadcast system.
    The combined announcement and broadcast system is used to pass orders and radio broadcast transmissions.
    It consists of:
    Amplifier and broadcast radio receiver in radio room, 10 fixed mounted speakers, one each in:
   
1. Aft torpedo room
2. E-motor room
3. Diesel engine room
4. Petty officers room
5. Control room
6. Conning tower
7. Radio room
8. Officers room, Chief petty officers room
9. Upper crew room
10. Forward mine room
    6 microphones located in
    Conning tower 2 x
    Aft torpedo room
    E-motor room
    Control room
    Forward mine room
    Each microphone can be connected with headphones.
     
 
     
     

 

   
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           4
V.  Communications
U-boat Information
     
 
  d) Ultra short wave gear
    The ultra short wave gear is a device with transmitting (with output power 10 W) and receiving capability, manufactured by Lorenz and installed in the radio room.
    It enables:
            toneless telegraphy
            sounding telegraphy
            telephony
            broadcast receiving
   

By means of a connected telescoping antenna, it provides communication with other vessels cruising in formation.  The additional ultra short wave portable transmitter and receiver, which can be found in land applications, there, with the rod aerial installed. (see the document - Ultra short wave portable transmitter and receiver -)

     
3) Direction finding and listening equipment.
  a) Radio direction finder.
    The radio direction finder is used to get own location by means of wireless signals.  The direction finder is a rotatable loop antenna fitted in the front of the conning tower.  The shaft of the antenna goes through the pressure hull into the control room and can be raised from there by means of compressed air.  The direction finder has the property, that the wireless signal transmitter is heard the quietest (the minimum-method) when the plane of the antenna loop is aligned with its direction.  To find own location, the 2 or more transmitters have to be located in such way, that the transmitted signals are quietest.  The direction must be taken as a true bearing.  The point of intersection of the bearings gives own location.
    The radio direction finder installation consists of:
            Loop antenna
            Direction finder receiver
            Dedicated power supply
            Gyro compass repeater
    The direction finder is also used as:
    1)  navigation device for determining the line of position
    2)  receiver for long and longest waves
    3)  device for observation of the enemy vessels movements based on their radio transmissions
 
     
     

 

   
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V.  Communications
             5
     
 
    4)  device for determining direction when directing to the other vessel or given position
    The control unit is located in the radio room.
     
  b) K.D.B. equipment.
    The crystal rotating base gear is used to listening the noises generated by enemy vessels.  It makes possible to determine the direction (range) and type of propulsion and consists of:
            1 emitter, located on the upper deck, above the forward mine room
            1 amplifier with dedicated power supply
    The control unit is located in the forward mine room.
    (see the classified document - K.D.B. Equipment- )
     
  c) G.H.G. installation.
    The group listening apparatus have the same purpose as the K.D.B equipment.  The installation consists of 48 receivers, 24 of which are installed on the port side and the other 24 on the starboard side of the bow.  The receiver control unit is located in the listening room. (see classified document - G.H.G. Installation -)
     
  d) Nah S installation. [active sonar to detect mines]
    This installation is used to detect and locate, that is, to determine the distance and direction of naval mines.  It consists of a crystal oscillator fixed mounted on the bow of the boat and the case, in which all necessary auxiliary equipment is installed, and which operates the oscillator, amplifies the received signals which can be read on the scale.
    The case is located in the listening room when the boat is equipped with a radio location device [radar].  In case the boat without such device, the case is located in the control room, on the port side, near frame 60.
    For details see the description of the Nah S installation. (classified)
     
4) Power supply for electronic communications equipment.
    The radio equipment is powered through the DC and AC switchboards located in the radio room.  They are powered with 220 V from the auxiliary switchboard 2 installed in the E motor room.
    From the DC switchboard the following rotary converters and
 
     
     

 

   
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    devices are powered:
            6 kVA - converter in the E-motor room
            1.5 kVA - converter in the E-motor room
            0.3 kVA - converter in the E-motor room
            UT converter in the E-motor room
            Echo sounding converter in the E-motor room
            Echo sounding device display in the control room and the conning tower.
            Transmitter switchboard in the radio room
    The 6 kVA, 1.5 kVA and 0.3 kVA (listening equipment converter) converters power the 220 V AC switchboard.  To this board the following equipment is connected:
            Power supply for receivers
            Radio direction installation
            Combined announcement and broadcast system
            Coding machine (Schlüssel M) via a 6 volt transformer
            Vacuum tubes testing equipment
            40 watt transmitter
            K.D.B. equipment
            UT installation
            Depth sounding equipment
            G.H.G. installation
            Nah S installation
            Ultra short wave installation
     
5) Aerials.
  The boat has the following aerials:
    Forward net deflector
    Starboard aft net deflector
    Port aft net deflector
    Extendable rod antenna
    Radio direction finding loop antenna
    Ultra short wave telescoping antenna
 
     
     

 

   
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    All three jumping wires as well as the rod antenna can be used as transmitter and receiver aerials for short and long wave and broadcast radio equipment.
    The rod antenna is used for transmitting and receiving when the boat is at periscope depth.  The direction finder loop antenna is used for direction finding and for receiving long wave transmissions.
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
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VI. Steering system and anchor installations.
1) Steering system.
  The steering system consists of:
    the forward diving planes
    the aft diving planes
    the two main rudder planes parallel to each other
    the plane drive
    the plane steering lines
    the steering stations.
    All steering planes are built as balanced rudders.  They are made from watertight plating on both sides (displacement rudders), with stiffeners provided between the plates. The spaces between plates are filled with well preserved wood.
     
  a) Main rudder installation.
    The main rudder is twin type and can be either electrically or manually driven.
    The area of each main rudder is 3.85 meters², the maximum deflection is 30° on each side. They are driven by means of a vertical intermediate shaft, which is located outside the pressure hull, between the axes of the main rudders. This shaft is driven by a rudder spindle, by means of a connecting rod.  The connecting rod passes through the pressure hull aft ending cap above the torpedo tubes in the longitudinal direction.  At the intermediate shaft are mounted two arms at 90°, from which one is connected with rudder spindle through the connecting rod.  The other arm (which is in the longitudinal plane of the boat) transfers its movements to both rudder planes by means of two short connecting rods.
    The electric motor drives the rudder spindle by means of a worm gear, when manual drive is engaged - from the emergency steering station in the aft torpedo room by means of bevel gear wheels.  Electric drive is limited by limit switches to 28°, plane deflection is limited to 30° by means of mechanical stops.
    For electric drive there are
     
 
     
     

 

   
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    2 steering stations in the control room near the projector compass and near the gyro compass.  One portable steering station can be moved to the bridge or the conning tower (the portable station for both locations is provided with portable cable).  The emergency steering station for manual drive is located in the aft torpedo room.
    Protection of the main rudder.
    Two arms lead from the skeg located under the stern-post to both rudders and are attached to the rudder pins.  These arms protect the main rudder from hitting the bottom.  All faces of the planes are rounded and all linkages are made smooth to avoid entanglement with antisubmarine nets and naval mine wires.  The outer edges of dive planes are protected against naval mine wires.
    All planes are protected against corrosion (galvanic current between bronze and steel in sea water) with zinc protection plates - also boats with steel propellers.
    Main rudder angle indicator system and rudder order telegraph.
    The steering system is also equipped with an electric rudder angle indicator system.  It consists of the rudder position transmitter driven by the rudder spindle and of the rudder angle receivers.
    The receivers are located:
            on the emergency steering station in the aft torpedo room
            in the E-motor room
            in the diesel engine room
            in the control room
            in the conning tower
            on the bridge (pressure proof)
            in the listening room.
    Steering commands can be transmitted by means of the rudder order telegraph from the transmitter in the control room to the receiver at the emergency steering position in the aft torpedo room.
    In addition, a mechanical rudder angle indicator is also provided.
     
 
     
     

 

   
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  b) Diving plane installation.
    The forward and aft diving planes are adapted for power and manual drive and can only be operated from the control room.  The forward diving planes pair has an area of the 2 x 4.50 meters² and a maximum deflection of 25° up and 35° down.
    The aft diving plane pair is mounted aft of the propellers and has an area of 2 x  4.00 meters² and a maximum deflection 35° up and down.  One hydraulic motor is installed for each plane pair, in the aft torpedo room and forward mine room respectively.  The planes are driven either by the hydraulic motor by means of the worm gear, or manually from the starboard side of the control room by means of bevel gear wheels and connecting shafts.
    The required operating mode is selected by a switching lever.  Switching from power to manual drive is done by compressed air piston controlled from the control room.  Switching back to power drive is only possible manually at the coupling gear.  The end positions of both pairs of the planes are limited by means of mechanical stops.  The electric limit switches limit the hydraulic power drive at 2° before achieving the maximum deflection.
    Diving plane angle indicator system.
    Both diving planes are provided with an electric angle indicator system.  The transmitter of each divining planes pair is installed at the diving planes gear.
    The following receivers are available:
            1)  one for each rudder pair at the diving plane control station to starboard in the control room.
            2)  in a double needled receiver for both diving planes in the conning tower
    In addition, each diving plane pair has a mechanical angle indicator installed at the diving gear in forward mine room and aft torpedo room respectively.
    In the control room, when the manual drive is engaged, the plane position is shown by means of mechanical indicators located at the control station, which are driven from the connecting shafts.  These indicators can also be used when power drive is used as an emergency indicators in case of damage to the electric angle indicator system.
     
     
 
     
     

 

   
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    In this case, hand wheels in the control room are disengaged from the connecting shafts by means of the special coupling, and both connecting shafts in the bow and aft rooms are coupled with diving planes gear by means of a special lever.  Then the power drive rotates both shafts and drives the mechanical indicators in the control room.
     
2) Anchor installation.
  The boat is equipped with a 700 kg weight Hall stockless type anchor with a shortened shank, which is located in the hawsehole on the starboard side.  The anchor chain is 150 meters long and consists of 6 parts each 25 meters long.  It is made from 28 mm chain steel as studded-chain.  In the anchor chain locker the chain is attached by means of slip hooks and can be released from the inside of the pressure hull.  The chain locker is located in main ballast tank 10.  To keep the anchor chain in any position and for releasing anchor windlass, a chain stopper is provided between the chain sprocket and the guide drum, located beneath the upper deck.
  The anchor windlass and capstan installation are installed in the forecastle.  They are driven by a driving shaft rotated by the compressed-air engine of 33 hp at 500 rpm, installed in the forward mine room.
  The time needed for the winding the totally released chain is:  time = 15 minutes.
  The aft capstan installation is installed on the stern and is driven by a compressed air engine of 7 hp at 1000 rpm.  Both engines are reversible.  Starting, stopping as well as reversing takes place by linkage, which can be operated from the inside of the pressure hull and from the upper deck.  Both capstans have spoke wreaths at theirs heads and after disengaging the power drive, can be rotated manually by means of the spokes.
     
     
     
     
     
     
 
     
     

 

   
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VII. Equipment and installations for navigation.
1) Ship control.
  During -cruise the bridge is used as ship control station.  For this purpose the pressure-proof gyro-compass repeater, pressure-proof telescope bearing, and pressure-proof main rudder angle indicator are installed there.  The portable main rudder steering station can be taken on the bridge from the conning tower.
  During -cruise the conning tower is used as ship control station.  The portable main rudder steering station, main rudder angle indicator, fixed-mounted gyro-compass repeater, engine order telegraph starboard and port, alarm bell activating switch and fixed-eye periscope (aft) and night periscope (forward) are located there.
  The auxiliary ship control station is located in the control room.  For this purpose the control room periscope, engine order telegraph starboard and port, 2 control stations for the main rudder with movable steering console (one at the gyro-compass at port side and the other near the fix-mounted gyro-compass repeater and projector compass at the forward curved bulkhead) are located there.  The control station for both diving planes is also located in the control room.
     
2) Periscopes.
  The boat is equipped with three periscopes:
  1. The aft conning tower periscope (attack fixed-eye-level periscope)
  2. The forward conning tower periscope (night attack periscope)
  3. The control room periscope (air search periscope)
  The periscopes are used to:
  1. Control the boat as the targeting instrument during attack
  2. Observe the water surface during submerged cruise
  3. Navigate as a bearing instrument.
  All these periscopes are equipped with a tilt mechanism for the objective, which allow for the following tilt angles:
 
Name
Tilt angle
upward
downward
Aft conning tower periscope
20°
10°
Forward conning tower periscope
90°
10°
Control room periscope
90°
10°
 
     
     

 

   
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  All periscopes are identical in length, have the same diameter at the cylindrical part and connections for a desiccator.
     
  a) Attack periscope.  (aft conning tower periscope)
    The aft conning tower periscope is used as the main attack periscope during day attack approaches, the upper part of the scope is thin to make spotting difficult.  It is a fixed-eye-level type, is located in the aft part of the conning tower and can be rotated together with the observer seat by means of the driving motor (hydraulic motor).  The observation depth is about 14.5 meters.
     
  b) Night attack periscope. (forward conning tower periscope)
    The forward conning tower periscope is the night attack scope.  It is located in the conning tower, in front of the aft conning tower periscope and used as a general purpose scope.  Because it is used mainly for a submerged night attacks, its objective is relatively big (to allow greater light transmission) and the diameter of the upper part is large.   It can be also used as an air search periscope.
    The observation depth is about 14.5 meters.
     
  c) Control room periscope.
    The control room periscope is operated from the control room.  It is the air search periscope, and can be also used as the auxiliary periscope for the control the boot during submerged cruise in case of damage the conning tower periscopes or damage to the whole conning tower.  Its guide bushes are located in the pressure hull plating, in the top most point of the pressure hull, forward of the conning tower.  A second guide bearing installed over these bushes.  The control room periscope is covered by the conning tower casing.
    The observation depth is about 14.5 meters.
     
  d) Periscope drive.
    All periscopes are raised and lowered by means of a periscope winch, driven by a hydraulic motor.  Two electrically driven screw pumps, installed horizontally, in the aft part of the control room, on the starboard side,
     
     
 
     
     

 

   
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    (one of them used as a reserve pump) pressurize the hydraulic oil from the collecting tank into 4 steel flasks of capacity 300 liters each, connected in parallel.
    Each periscope is provided with a hoisting drum driven by the hydraulic motor for raising and lowering.  The fixed-eye-level periscope is also provided with additional motor for rotating the scope with the observer.  These motors operate under pressures between 48-80 kg/cm².
    In each flask, there is precisely measured air cushion over the surface of the oil.  Each flask is connected to the high pressure air installation to create and manage these cushions.  The hydraulic motor of each periscope is powered by hydraulic oil through the main control valve, which in turn is set in corresponding position by oil running from the raising and lowering control valve.  The hydraulic motor drives the gear hoisting drum, which by wrapping or unwrapping the cable raises or lowers the periscope.  Each periscope is provided with a limit switch, which shorts before achieving the end position cutting off the hydraulic oil flow and stopping movement of the periscope.
    Both electrically driven hydraulic oil pumps are automatically (or manually) switched on and off by means of an automatic float switch and remote starter at the limiting pressures (48-80 kg/cm²) respectively.
     
3) Compass installation.
  The compass installation consists of:
  1. The gyro compass (by Anschütz)
  2. The magnetic projector compass (by Askania)
  a) Gyro compass.
    The gyro compass is installed in the middle of the control room, on the port side.  It can be powered by one of two rotary converters installed beneath the ceiling of the E-motor room.
    To the master compass are connected:
            1)  a bridge steering repeater (pressure proof)
            2)  a bridge bearing repeater (pressure proof)
            3)  a conning tower steering repeater (removable)
            4)  a control room steering repeater (removable)
     
 
     
     

 

   
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            5)  a control room port wall repeater for the navigator table and sonar system (fixed)
            6)  a repeater in the sound room (fixed)
            7)  a bearing repeater in the radio room (fixed)
            8)  a steering repeater in the stern room (removable)
     
  b) Projector compass.
    The projector compass is the magnetic compass.  It is installed in a pressure proof casing in the front of the conning tower and through a system of mirrors and ground glasses can be viewed from the control room.  Non-magnetic materials are used in a radius of 900 mm from the middle of the compass in order to eliminate the influence of magnetic fields and the influence of electric current.
    The projector compass should be used as the auxiliary direction device in case of damage to the gyro compass.
     
4) Signal equipment.   (See also V. 1 a )
  The signal equipment consists of:
  a) Running lights:
    Stern light 1 (conning tower)
    Stern light 2 (stern)
    Side lights starboard and port
    Steaming lights
    Head lights
  b) Search light equipment.
    Searchlight 24 Volt AC (250 watts)
    2 hand signal searchlights 24 Volt DC or AC (each 100 watts)
     
5) Depth sounding equipment.
  a) Echolot.
    The boat is equipped with an all-purpose depth sounding device, which has 2 main measuring ranges:
            1.  0-125 meters and 0-1000 meters
            2.  for all depths.
 
     
     

 

   
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    Range 1:  One transmitter and one receiver are provided for each of these measuring ranges, which are installed above the keel, between pressure hull frames 54/55 and 55/56.
    Range 2:  3 transmitters and 3 receivers are provided for this measuring range. The 3 transmitters are installed between frames 47/48 and the 3 receivers are installed between frames 59/60 at the keel.
    The depth sounding device is powered from the switchboard in the listening room.
    For reading the measured depth there are 2 switchable depth indicators located as follows:
            1)  Control room port side
            2)  Conning tower starboard side.
    Both indicators are selectable from the control room.
     
  b) Elektrolot. (explosive charge)
    In this method, an explosive charge is thrown into the sea and a stopwatch is started when it breaks the water surface.  When the device reaches the sea bottom (the sound of explosion returns) the timer is stopped (rate of sinking is 2 meters/second).
     
  c) Handlot.
    The hand lead consists of sounding line and plummet.  The line is 50 meters long and is provided with marks spaced at 2 meters for reading the depth.
     
6) Log installation.
  Speed is obtained by measuring the pressure difference between dynamic pressure created by boat's movement and static pressure (respective to the depth).  Dynamic pressure is obtained by two nozzles located on the port and starboard side of the bow, while the static pressure is obtained by two nozzles (single bores) located on the port and starboard side of the outer shell.  Each nozzle is connected by means of pipes with the master unit installed in the control room.  Speed can be read there or at the electrically operated repeater in the conning tower.  Separate from this repeater, a distance counter is installed in the conning tower.
 
     

 

   
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    The installation consists of:
            tubing with control manifold
            master unit (transmitter)
            repeater (receiver)
            the distance counter
    The control manifold and master unit are installed in the control room.  The height of the quicksilver column is transmitted by means of a magnetic clutch.  The indicator axis is coupled by variable resistance to transmit the indicator position to the log repeater and to the integrator of the distance counter.
    The repeater is installed in conning tower.  The coil of the indicator is powered by 24 V current, taken from the light circuit through the voltage divider.
    The rotating indicator shows the speed on a linear 270° arc scale.
    The distance counter is installed in the conning tower.  The device has two mechanical counters, the upper one showing the traveled distance.  The counter is resetable. The second counter can be set to a desired distance.  The optical indicator signals when that distance is traveled.  The device is powered with 220 V, which by means of a voltage divider is lowered to 24 V.
     
7) Alarm installation.
  (See B IX 5, c) 6)
     
8) Ordering and reporting installations.
    The ordering installations make it possible to quickly pass orders and reports to the corresponding stations.  They are divided into:
    Ordering and reporting installation
    Ordering installation
    Reporting installation
     
     
 
     
     

 

   
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  a) Ordering and reporting installation.
    1)  Voice tube connections (see Sketchbook)
    2)  Engine order telegraph system
    The transmitters with answering indicator are installed in the conning tower and control room, the receivers with answering transmitters are installed in diesel engine room and in the E-motor room, one each for the starboard and port side.
    3)  Sound powered phone installation
    Sound powered telephones, as they are not connected to any power line, are used for passing orders when all other ordering systems are damaged.
    Terminals are located as follows:
    1.  in aft torpedo room
    2.  in E-motor room
    3.  in diesel engine room
    4.  in the control room
    5.  in the conning tower
    6.  in the forward mine room
     
  b) Ordering installation.
    1)  Ship's announcement system
    The system is used to pass orders from the control room, conning tower, E-motor room, forward mine room and aft torpedo room to all rooms of the boat.  It is also used as a radio broadcast system and is provided with dedicated amplifier.  Speakers are installed in all rooms.
    2)  Rudder order telegraph installation (See B IX c 4)
    3)  Alarm bell and flashing light system
    Alarm activation switches: in the conning tower and control room
    Alarm bells: one in each room.
     
  c) Reporting installation.
    1) Compartment ready indicating system
    The system is used to report readiness for diving of the:
            Aft torpedo room,
            E-motor room,
            Diesel engine room,
            Petty officer room, (aft battery)
            Living space forward, ((forward battery)
            Forward mine room.
 
     

 

   
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    Readiness reports are passed to the control room.  The readiness indicator box in the control room has 6 lamps labeled with "Aft torpedo room ready" and so on.   Reporting takes place by turning the switch located in the reporting room, which in turn lights up the corresponding lamp in the readiness indicator box in the control room.
     
    2).  Hull closure indicating system
    The system is built on simple switch on and off principle, which indicates diving readiness by lighting lamps.
    This system has also indicator box in the control room with the following lamps:
            Exhaust gas (flap) valve starboard inner
            Exhaust gas (flap) valve port inner
            Exhaust gas (flap) valve starboard outer
            Exhaust gas (flap) valve port outer
            Diesel engine air induction trunk head valve starboard
            Diesel engine air induction trunk head valve port
            Ventilation exhaust, head valve
            Ventilation supply, head valve
    Switches for the lamps are mechanically linked to the drive of the relevant hull closure and is turned on, when the closure is CLOSED.  The system is implemented as bright and dim lighting system - the lamps are lighting bright when the hull closures are closed, and dim when the closures are opened.
     
    3)  Vent valve indicating system
    The system indicates if the vent valves are closed or opened in the control room.  Each state of the vent valves is shown, when the valves are operated from the control room by means of the compressed air.
    The indicating box of the vent valves indicating system in the control room has 6 lamps, 3 push buttons for 3 main vent valves groups "aft", "amidships", "forward" and the power switch.
 
     
     

 

   
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    The lamps also work on the bright-dim principle, so when the vent valves are opened, the lamps light bright, when the valves are closed, they light dim.  The indicator system monitors vent valves chambers for:
    1.  Main ballast tank 1
    2.  Main ballast and reserve fuel oil tanks 2 and 3
    3.  Main ballast tanks 4 and 5
    4.  Main ballast tanks 6 and 7
    5.  Main ballast and reserve fuel oil tanks 8 and 9
    6.  Main ballast tank 10.
    When operating the low pressure air control valve for the vent valves (i.e. for the amidships main ballast tanks), the applicable mechanically coupled vent valve indicator switch is turned on, enabling current flow for the red lamps.  These lamps (i.e. for main ballast tanks 4, 5 and 6, 7) illuminate simultaneously at the vent valves indicating box in the control room and on the vent valves ordering box.  This box is used when the compressed air vent valves operating pistons are damaged to order manual opening. When the compressed air driving system is not operable, the associated low pressure control valve indicator switch can be bridged with the push button at the indicating box.
    The opening of the vent valve (i.e. for main ballast tanks 4, 5 and 6, 7) causes the applicable vent valve one-pole switch to close the circuit for the white, bright lighting lamps. These lamps illuminate at the indicating box in the control room as well as at vent valves ordering box, which are connected serially.  In case of damage to the associated one-pole switch, the circuit can be closed by means of a push button.
     
  d) Bow and stern buoyancy tanks indicating system.
    The system is implemented with the bright-dim lamp principle, and the indicating lamps are grouped at the vent valve indicating box.  The lamps illuminate brightly when the vent valves are opened.
     
     
     
 
     
     

 

   
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  e) Rudder angle and shaft revolution indicator system.
    These systems allow for the continuous viewing of the position of the main rudder and diving planes as well as shaft revolutions in the conning tower, control room and a few more stations (listening room, diesel engine room).  The main rudder angle indicator is located on the bridge (in a pressure-proof casing).
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
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VIII. Safety and rescue installations.
1) Installations for submerged and surfaced boat.
  a) Emergency lighting.
    There are 11 lamps in pressure-proof cases, automatically switched on when the light circuit is not operating, powered by 2-cell, small batteries.
    Distribution:
            1 lamp in aft torpedo room
            1 lamp in E-motor room
            2 lamps in diesel engine room
            1 lamp in the galley
            1 lamp in the officers room
            1 lamp in the control room
            2 lamps in the forward living space
            1 lamp in the forward mine room
     
  b) Hand lamps.
    10 portable, battery powered hand lamps (4 V) are also provided as emergency lightning.
     
  c) Fire extinguishers.
    7 extinguishers are provided on board for fire fighting (CO2 extinguishers).
            Aft torpedo room
            E-motor room
            Diesel engine room
            Petty officers room
            Control room
            Forward living space
            Forward mine room.
    In the case of a fire on the upper deck, the upper deck wash line can be used.
    In the case of a large fire, air access must be cut off by closing the compartment.
     
 
     
     

 

   
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A. Ship Information
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VIII.  Safety and rescue installations
             2
     
 
  d) Flooding installation. (see B III 5)
     
  e) Drainage installation.
    The drainage installation includes:
            1.  Main drain pump in the control room
            2.  Auxiliary drain and trim pump in the control room
            3.  Auxiliary drain pump 1 in the aft torpedo room
            4.  Auxiliary drain pump 2 in the forward mine room
            5.  Emergency drain pump
            6.  The electrically driven auxiliary cooling water pump in the diesel engine room (only to drain the diesel engine room).
    (for more drain installation B III 1, 2 and 3)
     
  f) UT installation.
    This is used for underwater communication during submerged cruise.
    (for more see Communications A V 2b)
     
  g) Emergency steering gear.
    The emergency steering station with the mechanical transmission to the main rudder is located in the aft torpedo room.
     
  h) Emergency escape gear and diving suit.
    72 sets of emergency escape gear are provided on board.  The escape gear is so located, that during submerged cruise, in case of emergency, there is a sufficient number of sets in each compartment for each crew member at their diving stations.
    Also, two full diving suits (one with and one without weights) are provided on board. Moreover there is 1 simple diving suit for usage with emergency escape gear.  74 breathing masks with carrying bags for the sodium hydroxide cartridges are provided.
     
  i) Life rafts and mats.
    2 Life rafts with buoys are stored at the upper deck and can be released from the inside of the boat.
     
  k) Damage control materials.
    (see IX 3c)
 
     
     

 

   
Page 78
A. Ship Information
U-Boat Type XB
            3
VIII.  Safety and rescue installations
U-boat Information
     
 
2) Installations for surfaced boat.
  a) Battery ventilation.
    The batteries are ventilated while charging by means of the battery blower, located in control room, on the starboard side.  The intake and exhaust air fans installed in the diesel engine room can also be used for that purpose.
     
  b) Emergency vent valves.
    Each main ballast tank (except main ballast tank 1) and each main ballast and reserve fuel oil tank starboard and port, there is an emergency vent valve located at joint of the tank cover with vent trunk, which is operated from the inside of the boat.
    These valves are located as follows :
   
Aft torpedo room 2 Emergency vent valves for main ballast and reserve fuel oil tank 2 starboard and port - at D frame 5
E-motor room 2 Emergency vent valves for main ballast and reserve fuel oil tank 3 starboard and port - at D frame 16
Diesel engine room 2 Emergency vent valves for main ballast tank 4 starboard and port - at D frame 28
  2 Emergency vent valves for main ballast tank 5 starboard and port - at D frame 35
Control room 2 Emergency vent valves for main ballast tank 6 starboard and port - at D frame 49
Forward living space 4 Emergency vent valves for main ballast tank 7 starboard and port and main ballast and reserve fuel oil tank 8 starboard and port - at D frame 56-1/2 and at D frame 67
Forward mine room 4 Emergency vent valves for main ballast tank and reserve fuel oil tank 9 starboard and port and main ballast tank 10 starboard and port - at D frame 73-1/2 and at D frame 86-1/2
     
  c) Coaming.
    The torpedo hatch in the aft torpedo room, access hatches in the aft torpedo room (on the starboard side), galley, forward living room and forward mine room are provided with protective coamings against entry of water.  These are made from steel plates and extend from the pressure hull up to the bottom of the wood finish of the upper deck or upper edge of the mine shafts casing respectively.  The coaming is provided with a drain gate valve.  The coaming of the torpedo hatch is located in such way, that it does not prevent torpedo loading.
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  79
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VIII.  Safety and rescue installations
             4
     
 
  d) Life buoy and dinghy.
    Available aboard:
    1 Dingy with an outboard motor stowed in a pressure-proof container
    2 Marcks life rafts/buoys
    2 Life rings on the outside of the bridge.
     
  e) Life jackets.
    35 standard life jackets and 20 pilot life jackets (inflated with the compressed air from the attached flask) are provided at all diving stations.
     
  f) Railing and tethers.
    The railing is installed on the upper deck on both sides and leads from the bow to the stern.  The railing pennants are mounted in railing supports by means of clamping bolts.  Demounted railing can be stowed in the upper deck casing.  At the 10.5 cm deck cannon, at both sides of the conning tower and at the 3.7 cm cannon the railing is fixed mounted.
    Tethers and safety belts provided for use by the bridge watch and the crew operating the deck gun while cruising in stormy seas.
     
  g) Inflatable boat.
    The inflatable boat is 9.5 meters long and 2.4 meters wide.
     
3) Installations for submerged boat.
  a) Compartmentation.
    Four spherical, pressure and water proof bulkheads located at frames 13-1/2, 45-1/2, 55-1/2 and 70-1/2 divide the pressure hull into 5 pressure-proof compartments (I, II, III, IV, V).  Compartment II is further divided by two water-tight bulkheads at frames 22 and 35-1/2 into 3 water-tight rooms, so the entire pressure hull has 7 water-tight rooms (Rooms 1, 2, 3, 4, 5, 6 and 7).
 
     
     

 

   
Page 80
A. Ship Information
U-Boat Type XB
           5
VIII.  Safety and rescue installations
U-boat Information
     
 
  b) Air purification system.
    1. Oxygen system
    The oxygen system is used to enrich the air with the oxygen.  16 oxygen flasks with capacity 50 liters each and total capacity of 800 liters of oxygen under a pressure of 150 kg/cm² are located as follows:
            5 oxygen flasks in aft torpedo room
            5 oxygen flasks in the control room
            6 oxygen flasks in forward mine room
    The distribution installation consists of:
    Aft torpedo room:
    1 oxygen distributor
    1 oxygen supplementing regulating valve
    1 oxygen replenishment station for emergency escape gear
    Control room and forward mine room:
    As in the aft torpedo room.
    Conning tower:
    1 oxygen supplementing regulating valve
    The oxygen intake connection is located on the upper deck, at the starboard side of the conning tower.
     
    2.  Air purification system
    The air intake and exhaust fans circulate air inside the boat.  Doing so, the air is forced through the air purifiers, where the CO2 is absorbed.  The purified air is then released into the rooms.  During silent running, these two fans can be replaced by two noiseless, small blowers.  These are located in the control room and in the E-motor room, installed on the rubber mountings.
     
    3.  Sodium hydroxide cartridges
    590 sodium hydroxide cartridges are at hand.  They chemically bind CO2 in exhaled air.  These cartridges can be used for air purification by connecting them to the air exhaust ducts as follows:
            8 units in retaining racks in aft torpedo room
            8 units in retaining racks in control room
            8 units in retaining racks in forward mine room
 
     

 

   
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A. Ship Information
Page  81
U-boat Information
VIII.  Safety and rescue installations
             6
     
 
    The remaining cartridges are stored in dedicated holders and are evenly distributed over all rooms of the boat.
     
  c) Compressed air and emergency blowing manifold.
    1.  Compressed air distribution:
   
  High pressure manifold Control room amidships,
    Aft torpedo room
  Medium pressure manifold Control room starboard
  Low pressure manifold Control room starboard
    2.  Emergency blowing manifold
    The regulating valves of the blowing distributors for the forward, midship and aft group are built as check-valves, so even when these valves are opened, blowing is possible from the end rooms.  The cones of cone valves are closed by the air flowing from the emergency blowing manifolds located in the end rooms.
            1 Emergency blowing manifold in aft torpedo room
            1 Emergency blowing manifold in forward mine room
            1 Diver emergency blowing manifold
    In the front of the conning tower, at the upper deck, just forward of the magnetic compass casing there is a diver emergency blowing manifold with cut-off valves for main ballast tanks 1, 4, 5, 6, 7, 10 and main ballast and reserve fuel oil tanks 2, 3, 8, 9. Separate valves are provided for main ballast tank 10 and fuel oil tanks 1a port and 2a port and fuel oil tanks 1a starboard and 2a starboard.  Named tanks can be blown from the outside by means of this installation, if necessary, with the help of a diver.
     
  d) Emergency air supply system.
            2 Hull valves for emergency air supply and emergency air exhaust in the aft torpedo room
            2 Hull valves for emergency air supply and emergency air exhaust in the control room
            2 Emergency air exhaust selector valves in the control room and conning tower
            2 Hull valves for emergency air supply and emergency air exhaust in the forward mine room
 
     
     

 

   
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U-Boat Type XB
            7
VIII.  Safety and rescue installations
U-boat Information
     
 
  e) Air trap.
    Hatches in the aft torpedo room - access hatch (not the torpedo loading hatch), in the control room, in the forward living space and in the forward mine room are provided with coamings which extend downward, which in the case of escaping from the flooded compartment trap some of the air.
    The distances between the bottom edge of the coaming and the deck plating:
   
Aft torpedo room 1570 mm
Galley (air trap extended) 1850 mm (otherwise 1970)
Control room 1650 mm
Forward living space 1780 mm
Forward mine room 1650 mm
    All of these coamings (except the one in the galley) are not extendable downward.
     
  f) Net deflector.
    The forward net deflector is made of stranded wire, which is extended from the bow to the conning tower, while the aft deflector consists of two stranded wires extended from the stern to the conning tower.
     
  g) Net cutter.
    At the upper part of the bow and at the bottom part of the stem post two net cutters are installed.  The cutters are not protected by any cover.
     
  h) Compartment ready indicating system.
    The lamp box indicating the readiness for dive of each compartment is located in the forward part of the control room, at the starboard side.  When the compartment reports readiness, the corresponding lamp lights up.
     
  i) Hull closure indicating system.
    The lamp box of the large hull closure indicating system is located in the forward part of the control room, at the starboard side.  When the closure is closed, the corresponding lamp lights "bright".
     
 
     
     

 

   
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A. Ship Information
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VIII.  Safety and rescue installations
             8
     
 
    They are associated with:
            2 diesel air intake head valves
            2 inboard exhaust gas valves starboard and port
            2 outboard exhaust gas valves starboard and port
            1 ventilation air supply valve
            1 ventilation air exhaust valve.
     
  k) Vent valve indicating system.
    The lamp box of this system is also located in the forward part of the control room, at the starboard side, at the curved bulkhead.  When the vent valves of the main ballast and main ballast and reserve fuel oil tanks are "open", the lamps light "bright".  When the vents are closed, they glow powered with lower voltage.  When the vents are opening, the lamps are off.
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
Page 84
A. Ship Information
U-Boat Type XB
            1
IX.  Damage Control
U-boat Information
     
 
IX. Damage Control.
1) General.
  a) Damage control parties.
    To increase the safety of the boat, hull, electrical and machinery parties are formed. These parties have following tasks:
    Removing leaks due to enemy action; removing damage to machinery and electrical installations due to enemy action;
    Passing orders through the boat;
    Reducing noise during approach and evasion and thereby improving depth keeping, which is especially demanding in the presence of the enemy;
    Damage control parties are formed from off duty crew members.
     
  b) Balancing the boat.
    The boat is so designed, that when in trim condition A with standard load (main ballast and reserve fuel oil tanks filled with water) and empty regulating and reserve fuel oil tanks, regulating tanks and negative buoyancy tanks (mine compensating tanks 1-4 are filled with ~30 m³ of water),
   
at sea water of density = 1.003 it has 0 tons of buoyancy.
    The excess buoyancy which - when with trim condition B - is 29.98 tons. It is compensated by loading on board additional supplies:
   
7.28 tons Lubricating oil (0.91)
2.00 tons Fresh and wash water
5.30 tons Provisions
15.40 tons Water in regulating tanks
     
     
     
     
 
     
     

Note: The average density of seawater at the ocean surface is 1.025 grams/ml. Seawater is denser than both fresh water and pure water (density 1.0 grams/ml at 4 °C (39 °F)) because dissolved salts add mass without contributing significantly to volume. Sea water density varies with salinity and temperature from about 1.020 - 1.030 grams/ml.
The water density 1.003 cited above (at which the boat would have 0 buoyancy) is very low and would never be encountered by the boat while it was operating in sea water.
The density of sea water in the Baltic is significantly lower (as low as 1.005 at salinity 7.5%) due to fresh water from rivers than in the North sea (1.025 at salinity 35%).

   
U-Boat Type XB
A. Ship Information
Page  85
U-boat Information
IX.  Damage Control
             2
     
 
    The following loading proportions are established:
   
Supply
Trim Condition A
Trim Condition B
Fuel oil (density = 0.87) (including fuel oil in the gravity tank)
121.200 tons    
356.483 tons   
Lubricating oil
9.130 tons
16.410 tons
Provisions
6.200 tons
11.500 tons
Fresh and wash water
4.530 tons
19.330 tons
    When combat ready, the larger load (trim condition B) is used.
     
  c) Reserve buoyancy.
    Reserve buoyancy is created by removing water from the boat structure.  When submerged, it is destroyed by flooding the main ballast tanks and main ballast and reserve fuel oil tanks.
    The reserve buoyancy in:
    Trim Condition A (main ballast and reserve fuel oil tanks empty)  is 652.6 meters³
    Trim Condition B (main ballast and reserve fuel oil tanks filled with fuel oil)  is 414.6 meters³
     
2) Weights and trim adjustment with water flooding.
  a) Leakage into external tanks with the boat surfaced.
    Leaks into external tanks are not dangerous for the boat.  The reserve buoyancy in each case gives enough displacement, which also is not affected by trim change except when accidentally all main ballast and reserve fuel oil tanks and main ballast tanks are so damaged that they are completely flooded.  In such case, the boat is floatable only with empty regulating and reserve fuel oil tanks, regulating tanks and negative buoyancy tanks.
     
 
     
     

 

   
Page 86
A. Ship Information
U-Boat Type XB
            3
IX.  Damage Control
U-boat Information
     
 
    Buoyancy amounts with flooded individual external tanks:
   
Leak
Capacity meters³
Remaining buoyancy in meters³
Trim Condition A
Trim Condition B
Main ballast tank 1
44.30
608.30
370.30
Main ballast and reserve fuel oil tank 2
43.25
609.35
371.35
Main ballast and reserve fuel oil tank 3
58.20
594.40
356.40
Main ballast tank 4
78.40
574.20
336.20
Main ballast tank 5
88.95
563.65
325.65
Main ballast tank 6
88.20
564.40
326.40
Main ballast tank 7
75.75
576.85
338.85
Main ballast and reserve fuel oil tank 8
69.05
583.55
345.55
Main ballast and reserve fuel oil tank 9
67.55
585.05
347.05
Main ballast tank 10
39.00
613.60
375.60
    To avoid a large decrease in seaworthiness when leakage into external tanks occurs, to remove the inconvenient trim and heel of the boat, counter ballasting which does not threaten the buoyancy of the boat is to be used.
    In cases where to relieve the boat fuel oil is blown from the fuel oil tanks, the values given in the following table are applicable.
     
     
     
     
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  87
U-boat Information
IX.  Damage Control
             4
     
 
    Weight and trim changes with leaks in external tanks.
 
Water
Fuel oil density = 0.87
Tank
Arm + meters
Weight tons
Moment + meter tons
TU cm
Weight tons
Moment + meter tons
TU cm
Main ballast tank 1
-34.75
44.3
-1540
67
Main ballast and reserve fuel oil tank 2
-26.92
43.25
-1160
50
37.5
-1010
44
Main ballast and reserve fuel oil tank 3
-20.27
58.2
-1180
51
50.5
-1030
45
Fuel oil tank 1a
-15.40
83.2
-1280
56
72.3
-1110
48
Main ballast tank 4
-10.43
78.4
-818
35
Main ballast tank 5
  -4.87
99.95
-433
19
Regulating and reserve fuel oil tank 1
  -0.60
29.32
-17
Mine tank 1+2
  -1.24
15.0
-19
Regulating tank 2
  +2.11
26.6
+56
2
Mine tank 3+4
  +0.54
15.0
+8
Main ballast tank 6
  +6.04
88.2
+532
23
Main ballast tank 7
+11.52
75.75
+875
38
Fuel oil tank 2a
+15.86
54.9
+870
38
47.7
+760
33
Main ballast and reserve fuel oil tank 8
+19.72
69.05
+1360
59
60.0
+1180
51
Main ballast and reserve fuel oil tank 9
+26.76
67.55
+1810
79
58.6
+1570
68
Main ballast tank 10
+30.36
39.00
+1180
51
    TU = depth difference [tauchunterschied]
     
  b) Leakage into pressure hull with the boat surfaced.
    Small leaks (see paragraph 3 d) can be removed by means of the hand drain pump. Large leaks which lead to flooding the room are restricted by the watertight bulkheads. With one fully flooded room (not compartment) the trim is held within tolerable limits (the largest depth difference between stem post and stern post is 1.48 meters with fully flooded forward mine room).
    When the leakage occurs, counter ballasting must be taken immediately.  This step is necessary to avoid the appearance of large trim changes.  Thereto in case of leak, counter ballasting must be adjusted adequately to the situation.  When large trim changes appear, main ballast tanks 1 and 10 can not be flooded, because the flood slits are above the water surface.  The flooding of main ballast tanks 1 and 10 is appropriate as counter ballasting only when the boat has greater immersion (see the table).
 
     
     

 

   
Page 88
A. Ship Information
U-Boat Type XB
            5
IX.  Damage Control
U-boat Information
     
 
    Weight and trim changes with leaks in internal rooms.
   
Room
Weight tons
Arm + meters
Moment + meter tons
TU cm
Aft torpedo room
75
-28.80
-2160
94
E-motor room
95
-20.75
-1970
86
Diesel engine room
153
12.00
-1840
80
Galley and petty officer room
99
-2.70
-267
11.5
Control room
100
+4.95
+495
22
Forward living space
175
+14.50
+2540
111
Forward mine room
115
+26.40
+3040
148
 
     
 
Measures for leaks in internal rooms.
 
     
 
 
MBT
MB/RFOT
FOT
MBT
FOT
MB/RFOT
Leak
Trim Cond.
1
2
3
1a
4
5
6
7
2a
8
9
10
RB + tons
TM + tons
TU cm
Aft torpedo room
A
 
649
-1050
-44
 
B
427
-120
-5
E motor room
A
 
629
-860
-37
 
B
414
+70
+3
Diesel engine room
A
 
571
-730
-32
 
B
349
+200
+9
Galley, PO room,
A
No immediate measures necessary
553
-267
-11
Battery
B
   
315
-267
-12
Control room
A
No immediate measures necessary
552
+495
+21
 
B
 
314
+495
+22
Forward living room
A
 
 
B
Forward mine room
A
 
 
B
 
     
 
Flood
Blow
Fuel tank filled with oil
 
     

 

   
U-Boat Type XB
A. Ship Information
Page  89
U-boat Information
IX.  Damage Control
             6
     
 
    It should be noted, that as the pressure inside the boat increases, the depth meter no longer shows the true diving depth.  It shows less depth, according to the pressure difference between the water pressure and the pressure inside the hull.  Depth must also be controlled by the Bourdon pressure gauge, periscope or the conning tower air supply valve.
     
  c) Leakage into external tanks and into pressure hull with the boat surfaced.
    The narrow compartmentation of the boat provides great safety in case of leakage.  In the following tables is given, that always both sides are equally flooded.  In case of one-side damage, the other side has to be flooded to remove the list.
    In case of small list counter ballasting is not necessary - the boat keeps the better trim and buoyancy relationships.
    The depth difference between the stem post and stern post has similar values as occurs during immersion and trim changes under normal conditions.  When the upper edge of the tanks due to large trim angle and immersion come under the water surface, new, reduced stability values related with the large trim angles must be computed.  In the tables values are computed assuming all tanks are fully filled.  When the tanks are filled partially, the weight and moments must be estimated.
     
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
Page 90
A. Ship Information
U-Boat Type XB
            7
IX.  Damage Control
U-boat Information
     
 
    Weight and trim changes with leaks in internal and external spaces.
 
  Aft.  
 
Space
Trim Condition
Weight tons
Arm + meters
Moment + meter tons
Trim condition without countermeasures
Aft torpedo room
A
75
-28.8
-2160
Condition B:  not floatable
MBT 1
B
44
-34.8
-1540
 
   
119 
-3700
 
Aft torpedo room
A
75
-28.8
-2160
not floatable
MBT 1
44
-34.8
-1540
MBT/RFOT 2
43
-26.9
-1160
MBT/RFOT 3
58
-20.3
-1180
   
220 
-6040
 
 
B
133
-6040
E-motor room
A
95
-20.75
-1970
MB/RFOT 3
58
-20.3
-1180
 
153
-3150
 
B
103
2120
 
E-motor room
A
95
-20.75
-1970
not floatable
MB/RFOT 2
43
-26.9
-1160
MB/RFOT 3
58
-20.3
-1180
 
196
-4310
 
B
109
2270
 
Diesel engine room
A
153
-12.0
-1840
Condition B:  not floatable
FOT 1a
B
11
-15.40
-170
 
 
164
-2010
 
Diesel engine room
A
153
-12.0
-1840
Condition B:  not floatable
FOT 1a
11
-15.4
-170
 
MBT 4
B
78
-10.4
-811
 
 
242 
-2821 
 
Diesel engine room
A
153
-12.0
-1840
not floatable
MBT 4
B
78
-10.4
-818
MBT 5
89
-4.9
-436
 
320 
-3094 
Petty Officers room
A
99
-2.70
-267
not floatable
MBT 5
B
89
-4.9
-436
 
188 
-703
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  91
U-boat Information
IX.  Damage Control
             8
     
 
    Weight and trim changes with leaks in internal and external spaces.
 
  Forward.  
 
Space
Trim Condition
Weight tons
Arm + meters
Moment + meter tons
Trim condition without countermeasures
Control room
A
100
+4.95
+495
MBT 6
B
88
+6.04
+532
188 
+1027 
Forward living space
A
175  
+14.50
+2540
Condition B:  not floatable
MBT 7
B
76 
+11.52
+875
 
FOT 2a
7
+15.86
+111
 
 
258  
+3526 
 
Forward living space
A
175 
+14.50
+2540
 
MBT 7
76 
+11.52
+875
 
FOT 2a
7
+15.86
+111
 
MB/RFOT 8
69
+19.72
+1360
 
 
327 
+4886
 
 
B
267
+3700
 
Forward mine room
A
115 
+26.40
+3036
 
MB/RFOT 9
68
+26.76
+1820
 
 
183 
+4856
 
 
B
124

+3280

 
Forward mine room
A
115 
+26.40
+3036
 
MB/RFOT 9
68
+26.76
+1820
 
MB/RFOT 8
69
+19.72
+1360
 
 
252 
+6216
 
 
B
133
+3460
 
Forward mine room A 115 +26.40 +3036  
MBT 10   39 +36.36 +1418  
MB/RFOT 9   68 +26.76 +1820  
    222   +6274  
  B 163   +4460  
 
     
     

 

   
Page 92
A. Ship Information
U-Boat Type XB
            9
IX.  Damage Control
U-boat Information
     
 
Measures for leaks in internal rooms with adjoining external tanks.
 
 
MBT
MB/RFOT
FOT
MBT
FOT
MB/FOT
Leak/ Room
Trim Cond.
1
2
3
1a
4
5
6
7
2a
8
9
10
RB + tons
TM + tons
TU cm
Rmks.
Aft torp.
A
538
-765
-32
able to
 
B
455
-550
-24
float
Aft torp.
A
426
-580
-25
"
 
B
Aft torp.
A
328
-327
-15
"
 
B
238
-615
-28
E-motor
A
503
-230
-10
"
 
B
421
0
0
E-motor
A
391
-30
-1
"
 
B
338
+240
+11
Diesel
A
420
-200
-9
"
engine
B
338
+30
+1
Diesel
A
303
+417
+18
"
engine
B
184
+80
+4
Diesel
A
336
-170
-7
"
engine
B
254
+60
+3
Petty Off.
A
464
-700
-30
"
 
B
264
+410
+18
Control
A
421
-130
-5
"
 
B
286
-150
-7
F. Living
A
248
-335
-16
"
 
B
217
-40
-2
F. Living
A
104
+185
+8
"
 
B
83
-230
-10
F. mine
A
371
+210
+9
"
 
B
353
-200
-9
F. mine
A
224
+750
+33
"
 
B
207
+340
+15
F. mine
A
254
+825
+38
blow WT bow
 
B
237
+400
+18
blow WT bow
 
     
 
Leaking external space
Fuel tank filled with oil
Flood
Blow
 
     

 

   
U-Boat Type XB
A. Ship Information
Page  93
U-boat Information
IX.  Damage Control
           10
     
 
Additional measures for weight reduction and trim adjustment.
 
     
 
Name
Location
Volume meters³
Arm + meters
Moment water + meter tons
Moment oil meter tons
Trim change in cm TU
Trim tank 1
starboard
3.94
-27.52
-108.5
5
Trim tank 2
port
3.94
-27.52
-108.5
5
Torpedo compensating tank 1
starboard
3.240
-25.04
-81.1
3.5
Torpedo compensating tank 1
port
3.920
-24.90
-97.6
4
Waste water tank 1
starboard
0.760
-24.33
-18.5
1
Water distillate tank 1
centerline
0.195
-20.06
-3.9
Water distillate tank 2
centerline
0.580
-19.49
-11.3
Water distillate tank 3
port
0.215
+33.15
+7.13
Fuel oil gravity feed tank
centerline
2 x 0.600
-13.33
13.9
Dirty lubricating oil tank
centerline
1.360
-15.09
18.7
Lubricating oil collecting tank
starboard
1.360
-11.89
14.7
Lubricating oil collecting tank
port
1.360
-13.49
16.7
Fuel oil collecting tank
centerline
0.680
-10.69
6.6
Waste water tank 2
centerline
0.625
-7.30
0.5
Fresh water tank 1
centerline
0.780
-6.47
Wash water daily supply tank
0.060
-5.69
Lubricating oil supply tank 1
starboard
4.000
-4.34
15.1
Lubricating oil supply tank 2
port
4.000
-4.34
15.1
Lubricating oil supply tank 3
starboard
4.000
-0.43
1.6
Lubricating oil supply tank 4
port
4.000
-0.43
1.6
Stern buoyancy tank
8.4
-40.42
 
          TU = depth difference [tauchunterschied]  
     
     
     
     
     

 

   
Page 96
A. Ship Information
U-Boat Type XB
           13
IX.  Damage Control
U-boat Information
     
 
    on an even keel so that no dangerous trim moments are caused by the free water surfaces.  In addition to the main ballast tanks and main ballast and reserve fuel oil tanks, the fuel oil tanks, regulating and reserve fuel oil tanks, regulating tanks, negative buoyancy tanks, bow and stern buoyancy tanks can be also be blown.
     
  b) Sealing the compartments.
    All pressure and watertight bulkheads are to be shut.
    Shut isolating valves on voice tube connections:
   
In aft torpedo room: Voice tube to control and conning tower plus their whistling tubes;
In E motor room: Voice tube to the control room
In diesel engine room: Voice tube to the control room
In control room: Voice tube to the diesel engine room
  Voice tube to the E-motor room
  Voice tube to the aft torpedo room
  Whistling tube to the aft torpedo room
  Whistling tube to the forward mine room
  Voice tube to the forward mine room
  Voice tube to the radio and listening rooms
  Voice tube to the forward living room
In conning tower: Voice tube to the radio and sound rooms
  Voice tube to the Commander's room
  Voice tube to the bridge
  Whistling tubes 2
In forward living room: In the Commander's room to the conning tower
  In the radio room and listening room to the conning tower
  In the radio room and listening room to the control room
In forward mine room: Voice tube to the control room, conning tower
  Whistling tube to the control room, conning tower
     
  c) Sealing leaks.
    7 leak sealing kits are available, 1 in each watertight compartment.
    Their contents are:
   
  1 Hammer
  1 Pincher pliers
 
     

 

   
U-Boat Type XB
A. Ship Information
Page  97
U-boat Information
IX.  Damage Control
           14
     
 
   
  1 Chisel
  1 Pry bar
  1 Flat chisel
  1 Cross-cut chisel
  2 Clamps
  1 Adjustable wrench
  2 Tapered punches
  1 Hatchet
  1 Crosscut saw with guard
  30 Nails (3" to 5")
  20 Leak plugs (spruce, various sizes)
  20 Wedges (beech, flat, various sizes)
    Also at hand in the following rooms are:
    In the aft torpedo room:
            2 timbers 10 x 10 x 400 cm
            2 boards  75 x 30 x 4 cm
    In the diesel engine room:
            4 timbers 10 x 10 x 400 cm
            2 boards  75 x 30 x 4 cm
    In the forward mine room:
            4 timbers 10 x 10 x 300 cm
            2 boards  75 x 30 x 4 cm
     
    Leakage with the boat lying on the bottom.
    The same measures as in paragraph IX 2 d are to be conducted.  The tables can be used as a basis for estimation of the boat's buoyancy - as long as the pressure-proof compartmentation is stated (aft torpedo room, control room, forward living space, forward mine room).  Additionally it must be noted, that if the boat is lying on a sand-type sea bottom in such way that the keel is not washed out by the water.  The boat is sucked down and with the corresponding force the keel of area 90 meters² presses on the bottom.  Weight relief (blowing) is effective only when the boat is trimmed or heeled or the additional weight (water from the leaks) is removed.
 
     
     

 

   
Page 98
A. Ship Information
U-Boat Type XB
          15
IX.  Damage Control
U-boat Information
     
 
  d) Pumping.
    The performance of main drain pump is 160 meters³/hour at a pressure head of 10 meters H2O in the operation mode II (one stage) and 58 meters³/hour at a pressure head of 105 meters H2O in the operation mode I (three stage) without pipelines flow resistance influence.  Due to flow resistance the highest performance is only 75 meters³/hour at a pressure head of 10 meters H2O in the control room, 60 meters³/hour in forward mine room and 55 meters³/hour in the aft torpedo room.
    Its performance allows for pumping the leaks through the holes of the following cross sections:
     
   
Water depth
in meters
Pump
operating mode
Leak cross section in cm²
in aft torpedo room
in the control room
in the forward mine room
5
II
24.0
32.0
26.7
10
II
12.2
17.5
14.0
15
II
4.8
7.7
4.8
25
I
8.9
8.9
8.9
50
I
6.0
6.3
6.0
100
I
4.0
4.5
4.1
     
  e) Weight relief.
    (See paragraph IX 2 c) (Additional measures for weight reduction and trim adjustment)
     
4) Escape from a sunken boat.
  a) Escape procedures.
    As soon as it becomes clear, that the boat is not able to surface, immediately, without waiting for any help, the crew prepares for escape.  Pressure equalization takes place by intentional flooding of the pressurized compartment or the entire boat.  For closures which should be opened see paragraph 4 d.  Escape from the control room takes place via the conning tower, from the after ship through the torpedo loading hatch, and from the fore ship through officers' room hatch and forward mine room hatch.  All hatches except the torpedo loading hatch are provided with air traps.  After beginning flooding, the cover of the escape hatch is unscrewed and the hand bar with the catch is
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  99
U-boat Information
IX.  Damage Control
           16
     
 
    fixed, so that when the pressure is equalized, the cover can be raised and flooding process up to the air trap will be accelerated.  The crew is to gather near the hatch, because after flooding orientation becomes difficult.  The crew should stay high.
    During preparations to escape and final awaiting all available measures should be taken to prevent the increasing of the carbon dioxide level in the remaining air, as the air purification system is not operable  Each crew member must breathe through the sodium hydroxide cartridges, must not make unnecessary movements, the unemployed must lie down.
     
  b) The flooding of the boat and effects on the crew.
    All available means must be used to flood the boat as quickly as possible.  Staying in a flooded boat at sea pressure is limited by influence of chlorine gas and hazard of the bends, so it should be as short as possible.  For flooding options see paragraph 4 d.
    During flooding up to the actual escape the crew stay in the air bubble - ready with the emergency escape gears - and breathe the compressed air.  To save the oxygen and minimize the harmful influence of pressurized oxygen, the emergency escape gear must be used for the first time just before actual escape, or in case of increasing carbon dioxide level or in presence of the chlorine gas.
    The pure water pressure or increased air pressure is meaningless for the men staying under over-pressure.  Slow accustoming is not required.  At fast pressure increase, ear ache can appear.  However this condition does not lead to ear damage and hearing ability will soon come back.  So these symptoms may not be taken into account while flooding.
     
     
     
     
     
     
     
     
     
     
 
     
     

 

   
Page 100
A. Ship Information
U-Boat Type XB
            17
IX.  Damage Control
U-boat Information
     
 
    Chlorine gas is created when the batteries are flooded with sea water.  It can reach poisonous levels in the air remaining in the room.  This gas is immediately noticeable because of its strong, piercing smell and irritating effect on the airways (cough) and forces the use of the emergency escape gear as well as putting on goggles.
    While flooding, together with the pressure inside the boat, the partial pressure of the carbonic acid in the air remaining in the room, also increases (the partial pressure of the gas it is the % content in the air times absolute pressure).  The influence on the organs is caused by the partial pressure of the gas - not its concentration.  When increased partial pressure of the carbonic acid due to flooding is noticeable by difficulty breathing, the emergency escape gear must be used.   2% CO2 under the pressure of 5 at (corresponding pressure at the 40 m) corresponds i.e. 10% CO2 under atmospheric pressure.
    Under the over-pressure, an increased amount of nitrogen is entering to the body from the breathing air.  When it is in sufficient amounts in the blood and in the tissues of the body, then, when the pressure rapidly drops, as during the surfacing with the emergency escape gear, it is released in the organs and causes the bends.  The appearance of the bends depends on: 1) depth, from which escaping, 2) time of staying under the pressure corresponding to the depth, 3) the speed of surfacing.  The following staying times under the pressure corresponding to water depth and breathing the air remaining in the room
   
Water depth
Staying Time
30 meters
37 minutes
45 meters
18 minutes
51 meters
17 minutes
56 meters
14 minutes
62 meters
13 minutes
    do not cause the symptoms of the bends, when emergency surfacing speed is not greater than 15 meters/minute, i.e. normal, medium surfacing speed.
     
     
     
     
 
     
     

 

   
U-Boat Type XB
A. Ship Information
Page  101
U-boat Information
IX.  Damage Control
             18
     
 
    The hazard of the bends necessitates flooding the boat as fast as possible and leaving the boat immediately after pressure equalization.
    When escaping from a sunken boat from a depth greater than 20 meters, oxygen can be used only when diluted with air. The following rules apply:
   
  1.