CONFIDENTIAL REPORT 2G-9C
S88
     
 
FORMER GERMAN SUBMARINE TYPE IX-C
 
 
 
 
DAMAGE CONTROL
 
     
 
SUMMARY
 
     
          The German arrangements call for the establishment of repair parties, and establish the equipment to be carried on board for repair kits.  
          A number of means exist, of varying the effectiveness for altering trim or correcting a list.  The German discussion of damage control for this type of vessel omits, however, any reference to counterflooding.  
     
     
     
     
     
     
     
     
     
     
     
 
July, 1946
 
 
 
 
PORTSMOUTH NAVAL SHIPYARD, PORTSMOUTH, N. H.
 
     
 
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9C-S88
     
 
C  O  N  F  I  D  E  N  T  I  A  L
 
 
 
 
DAMAGE CONTROL
 
     
  GENERAL  
          Damage control has been in part discussed under the appropriate section of the S29 report.  
          No information is locally available with regard to damage control books, or practice instruction.  Repair party equipment is discussed in the S29 report.  This section will, therefore, be confined to a discussion of compartment check-off lists, repair parties, and of list and trim control.  
     
  CHECK-OFF LIST  
          The compartment check-off list was known to the Germans as Tauchtafeln (Diving Tables).  It consists of a book which lists, for condition A (fuel ballast tanks as main ballast tanks) and condition B (fuel ballast tanks carrying fuel), and for each compartment, conning tower, bridge and superstructure, the operations necessary to rig for diving.  
          Under the head "shut", with a red indicator, are listed the valves to be closed.  Under the head "open", with a green indicator, are listed the valves to be opened.  Under the head "miscellaneous" are listed other operations, checks and adjustments ending with operation of the compartment clear indicator lamp switch.  
          Copies of the appropriate pages are posted in each compartment for ready reference.  
          The general information book, in the section devoted to counter-measures for leaks (lecksicherung) gives detailed description of measures to be adopted in case of damage while surfaced or submerged.  
     
  PARTIES  
          It provides for the establishment of damage control parties composed and stationed as follows:  
          a)  Hull party No. 1 - after torpedo room  
 
1 motor machinist's mate
1 auxiliary striker (Mech Gast)
1 seaman (Matr. II)
 
     
 
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9C-S88
     
          b)  Electrical party No. 1 - maneuvering room  
 
1 seaman (Matr. II)
 
          c)  Machinery party - engine room  
 
2 seaman (Matr. II)
 
          d)  Hull party No. 2 - wardroom  
 
1 boatswain's mate
1 seaman
 
          e)  Electrical party No. 2 - automatic battery switch  
 
1 electrician's mate
1 seaman (Matr. II)
 
          f)  Hull party No. 3 - forward torpedo room  
 
1 auxiliaryman (Mech Maat)
1 auxiliary striker (Mech Gast)
1 seaman (Matr. II)
1 seaman
(if available, 1 machinist's mate (Masch Maat))
 
     
  MEASURES  
          It provides a table of tanks with lever arms and moments for use in determining means for lightening ship.  
          It describes the different measures:  
          a)  Blowing of MBT and FBT as an immediate measure in order to surface the vessel, with the further requirement that this be done on an even keel to avoid dangerous trimming moment resulting from free masses of water.  
          b)  Segregating each compartment by closing the bulkhead doors and voice tube openings, and controlling bulkhead valves in ventilating lines and drain piping.  
          c)  Stopping the leak with the means on board.  This section lists the timbers to be carried, and the contents of the seven damage control kits which include cutting pliers, hammer, adjustable wrench, crowbar, chisels, saw, axe, iron pins (dorne), nails, wedges, plugs and oakum  
          d)  Pumping.  This section gives the maximum rating of the main drain pump as 527 gal. per minute at a depth of 49.2 feet, and provides a table showing for depths up to 328 feet the size of the leak in square centimeters which can be controlled by the main drain pump.  Suggestions are made on the use of series connections of the main drain pump beyond 164 feet, and the use of the auxiliary drain and trim pump with the main drain pump to increase the discharge at depths beyond 164 feet.  
          It is to be noted that counterflooding, water ballast compensation are not included in the measures for control of damage, and that the only inferences which can be drawn  
     
 
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9C-S88
     
  from the text material available relate to the possibility of blowing to compensate for flooding.  Not until the X-B type is reached is there any discussion of counterflooding.  
     
  LIST AND TRIM CONTROL  
          The division of so much of the tankage into separate port and starboard halves brought with it a number of alternative methods for controlling list and trim.  
          The normal methods for controlling list were to blow or pump from one side to the other of the regulating tank (regelzelle) or from the regulating bunker (regelbunker).  It was also possible to flood the starboard half of MBT 5 via the main drain pump or, if desired, to blow this half-tank to sea via the auxiliary trim piping, using the normal separate H.P. blow connection to the tank.  In an emergency it was physically possible to segregate any desired half of any half-tank on the high pressure blow system.  A further possibility of controlling list exists in the WRT tank air and water connections in each torpedo room, which are such as to permit water from one WRT tank to be blown into the other, or to permit flooding of either WRT tank, there being a port and starboard WRT tank in each torpedo room.  
          Trim control is normally provided by moving water forward or aft, as desired, between the trim tanks.  On this type of vessel this is commonly done by pumping, using the auxiliary drain and trim pump, but some vessels of the type appear to have been fitted with trim tank blow lines on the low pressure air system to permit use of compressed air in lieu of the pump.  The line connecting the forward and after trim tanks is normally fitted with a meter to permit determination of the amount of water transferred.  Additional means to obtain altered trim, on simultaneous altered trim and transverse shift of weights, exist in the regulating system piping, which permits transfer of water forward or aft between the regulating half-tank and regulating bunker half-tank on the same side, or diagonally across the vessel to the opposite half-tank.  
          It is also physically possible, although attended by some danger because of the resulting exposure of low-pressure piping to sea pressure, to transfer fuel oil from any tank to the regulating bunker.  
          An additional possibility for changing trim exists in the means provided for transfer of water between the WRT tanks and the related torpedo tubes.  
     
 
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