This record was kindly provided by the generous assistance of Tony Cooper

 
 
 
 
INTERROGATION OF SURVIVORS FROM "U 175," A 740-TON U-BOAT
 
SUNK BY U.S.C.G. "SPENCER" ON 17th APRIL, 1943
 
     
 
I.  INTRODUCTORY REMARKS
 
     
          "U 175 " a 740-ton U-Boat was sunk by U.S.C.G. "Spencer" assisted by gunfire from U.S.C.G. "Duane," in position 47° 58' N., 021° 12' W. at 1427 on 17th April, 1943.  Nineteen survivors were picked up by "Spencer" and 22 by "Duane," out of a total complement of 54.  Kapitänleutnant Heinrich Bruns, "U 175's" Commanding Officer, did not survive.  
          As it was more expedient to bring survivors to England, and agreement was made with the U.S.N. authorities to interrogate prisoners in the United Kingdom.  
          It was ascertained that "U 175" was on her third patrol and had sunk a total of 41,152 tons of Allied shipping, of which nine ships, totalling 33,975 tons, were sunk on her first patrol in September/October, 1942, between Trinidad and the mouth of the Orinoco.  As is not unusual, survivors actually claimed a higher tonnage of ships sunk and average estimates were in the neighbourhood of 48 to 50,000 tons.  Every ship sunk was unescorted and in all but one case was independently routed.  
          As has been the case with other U-Boats sunk recently, there was a marked falling off in security-consciousness among rating prisoners.  At the same time there was no indication that there had been any decrease in the morale and fighting efficiency of the ship's company prior to capture.  Survivors are in fact agreed that the loss of "U 175" was due to the audacity of her Captain in attempting a midday attack on a strongly-escorted convoy, when, had he wished, he might have delayed his attack until nightfall.  
          Features of this report are:  
                  (1)  Further details on G.S.R. and a description of an improved G.S.R. aerial carried by the U-Boat.  
                  (2)  Details of instruction given to U-Boat A/A personnel in accordance with the recent policy of remaining above water to engage aircraft which have taken U-Boats by surprise. (See Section VI (i) ).  
          German and British naval rank equivalents used in this report are:  
 
Kapitän zur See Captain.
Fregattenkapitän Commander (Senior Grade).
Korvettenkapitän Commander (Junior Grade).
Kapitänleutnant Lieutenant-Commander.
Oberleutnant zur See Lieutenant.
Leutnant zur See Sub-Lieutenant.
Oberfähnrich sur See Midshipman (Senior Grade).
Fähnrich zur See Midshipman (Junior Grade).
 
          "Zur See" after an officer's rank denotes an Executive Officer.  (Ing.) after an officer's rank denotes Engineer Officer.  
     
 
II.  DETAILS OF "U 175 "
 
     
  (i)  Builders  
         Deschimag, Bremen.  Type IXC.  
     
  (ii)  Armament  
          Guns.  One 105 mm. (4.1 in.) forward (maximum elevation given as 50°.;  
                      One 37 mm. (1.45 in.) aft;  
                      One 20 mm. (0.79 in.) on bridge;  
                      Two or three light portable machine-guns.  
          Prisoners said that, had "U 175" returned from the patrol on which she was sunk, she was to have an additional gun platform, with possibly a quadruple 20 mm. mounting, abaft the conning-tower.   A protective shield for look-outs was also to be fitted.  
          (N.I.D. Note.  It is known that some boats have this arrangement of armament.)  
          105 mm. Ammunition.  About 100 rounds of mixed H.E., S.A.P. and incendiary shells.  Of these shells, 25 were stowed on each side in the engine room ratings' quarters.  
          Torpedoes.  22-23 carried.  On 2nd patrol; 15 electric, 8 air.  On 3rd patrol:  14 electric, 8 air.  Stowage on 2nd patrol:  
                  6 electric torpedoes in tubes;  
                  4 electric torpedoes in bilges forward;  
                  2 electric torpedoes on bow compartment floor plates;  
                  3 electric torpedoes stowed aft;  
                  8 air torpedoes in upper deck containers.  
          It was alleged by one rating that on her last patrol "U 175" carried four "Curly" torpedoes.  
     
  (C49300)                                                                                                                    B*  
     
     

 

 
 
 
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          Torpedo Tubes.  Four bow, two stern.  
          Torpedo Pistols.  G.7H, four whiskered Pi. 1's and a few new "long" Pi. 2 pistols (see Section V (iv) ).  
          Electric Torpedoes.  The motor was run every two or three days off an auxiliary 24-volt battery.  The torpedoes themselves had two batteries each of 56 lead acid cells, believed to be connected in parallel.  Batteries were recharged every six to seven days.  Electric torpedoes have to be ventilated every day and charged every five days.  The charging current is 23 amps.  
          Speed was confirmed as 30 knots.  
          Depth settings were from 0 to 12 metres.  
     
  (iii)  Propulsion  
          Diesel Engines.  Two 9-cylinder, four-stroke, Type M.9V.40/46, 2,200 h.p. engines.  Fitted with Büchi superchargers.  
          Fuel consumption.  An average of three to four tons per day at normal cruising speed.  
 
Speeds. 160 r.p.m. (one Diesel) 6 knots (dead slow).
  240-250 r.p.m. 8 knots (slow).
  300 r.p.m. 10-12 knots (half speed).
  400 r.p.m. 15 knots (three-quarter speed).
  480 r.p.m. 16 knots (full speed).
 
          During trials it was said that a speed of 20 knots was attained, but never used in operations.  
          Fuel Carrying Capacity.  Total capacity:  About 230 tons, including 32 in the trimming tank.  
          A Leading Stoker said that fuel tanks were numbered 1-3 inside the pressure hull, and 4-8 outside.  It appeared that Nos. 1 and 5 were not fuel tanks, but were free flooding tanks.  
          A C.P.O. Stoker said, that "U 175" had 16 fuel tanks and corroborated the use of the trimming tank for 32 extra tons.  He said that on her last patrol "U 175" first used 50 litres from each of Nos, 3, 4, 6 and 7 tanks, these being too full, and then the 32 extra tons.  
          Capacity of individual tanks:  
 
Diving tank 2. (Port and Starboard.) 13 cu.m., together 26 cu.m.
Diving tank 3. (Port and Starboard.) 11 cu.m., together 22 cu.m.
Diving tank 4. (Port and Starboard.) 15 cu.m., together 30 cu.m.
Fuel tanks (outside the pressure hull);
  (Port and Starboard.) 20 cu.m., together 40 cu.m.
Fuel tank 6. (Port and Starboard.) 12 cu.m., together 24 cu.m.
Diving tank 7. (Port and Starboard.) 13 cu.m., together 26 cu.m.
Trimming tank. (Port and Starboard.) 16 cu.m., together 32 cu.m.
Fuel tanks. (inside pressure hull.) 17 cu.m. |
  (Port and Starboard.) 13 cu.m. | together 30 cu.m.
                                 230 cu.m.
                      (about 195 tons.)
 
          It was said that corresponding starboard and port fuel tanks are not connected, nor is, for example, Tank 2 port connected to Tank 3 port.  
          Piston Rings.  These had never been changed in "U 175" since commissioning.  
          Electric motors.  Two 500 h.p., Siemens.  
 
Maximum speed submerged 8 knots.
Cruising speed submerged 4-5 knots.
Revolutions: 90 r.p.m. (dead slow).
  110 r.p.m. (slow).
  145 r.p.m. (half speed).
  210 r.p.m. (full speed).
 
          Diesel-electric speed.  About 6 knots.  
          Noise.  "U 175" was regarded as a very noisy U-Boat.  Extreme difficulty was found in ascertaining a silent submerged speed.  It was finally decided that 90 r.p.m. gave the best results.  
     
  (iv)  Pressure Hull  
          "U 175" did not have a double pressure hull, but the hull was described as "double-skinned."  The pressure hull, was 2 cm. (0.79 in.) thick, the outside skin being 5 mm. (0.2 in.).  
     
  (v)  Electrical Equipment  
          Switchboards.  Two main switchboards and auxiliary switchboards No. 1, 2, 2A, and 3.  Lighting is taken from No. 1, power for motor generators for wireless transmitters, etc., from Nos. 2 and 2A; charging of electric torpedoes is from 2A and light and power are taken from 3, the latter in the control room.  The other switchboards are all in the motor room above the motors.  
     
     

 

 
 
 
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          Main Batteries.  Two A.F.A. (Akkumulator Fabrik Aachen) units, each of 62 cells.  Total capacity 24,000 amp. hours.  
          It was said that the batteries were topped up with distilled water when the water was only 5 mm. above the glass plates.  As the loading temperature was high when batteries were being charged at Lorient, the batteries had to be refuelled after eight days.  
          Life of the batteries was given as at least two years.  
          Auxiliary Accumulators.  Eight small cells.  
          Accumulators for Running Motors of Electric Torpedoes.  Twelve cells.  
     
  (vi)  Compressors  
          One Germania electric compressor, said to be very reliable.  This compressor had a 110-volt motor taking approximately 400 amps.  
          One Junkers free piston compressor, which broke down easily if not properly handled.  There was constant trouble with valves and with water getting into the cylinder.  
     
  (vii)  Pipes  
          It was said that in order to prevent corrosion in water circulating pipes, special anti-corrosion oil was pumped through them.  The pipes were no longer made of brass or copper, owing to shortage of these metals in germany.  
     
  (viii)  Bilge Pumps  
          Rated for 100 metres (328 ft.), but failed to pump at 80 metres (263 ft.).  
     
  (ix)  Drinking Water  
          Capacity of the drinking water tanks was given as follows.  
 
No. 1 185 gallons
No. 2 141 gallons.
No. 3 380 gallons.
No. 4 135 gallons.
 
          An electric distilling plant was also fitted.  
     
  (x)  Welding  
          With port main motor run as generator and driven by a Diesel engine.  Two sorts of covered welding rods were carried.  The outside diameter of the rods was about 6 mm. and the core diameter about 3 mm.  Oxy-acetylene welding equipment was also carried, the U-Boat being piped for it.  One bottle of acetylene was carried inside the conning tower casing.  Oxygen was obtained from the normal ship's supply.  All types of welding rods, both ferrous and non-ferrous and suitable fluxes were available on board.  
     
  (xi)  W/T Equipment:  
          Transmitters.  One 200-watt short wave  |  
                                  One 150-watt long wave   |   Telefunken  
                                  One 40/50-watt reserve    |  
          Receivers.  One short wave  |  
                             One All-wave    |  Telefunken  
          U/T.  Carried but never used.  
          V.H/F.  Removed in Stettin during final adjustments to the U-Boat.  
          Wireless Entertainment.  One Radione set in officer's cabin
     
  (xii)  Hydrophones  
          G.H.G. (Multi-unit Type).  Fitted.  
          K.D.B.  Removed in Stettin.  
     
  (xiii)  R.D.F.  
          It was said that "U 175" was shortly to have been fitted with an R.D.F. set and that a P.O. operator would then have joined the ship's company.  (See G.S.R. below.)  
     
  (xiv)  G.S.R. (See also Section V (v-ix) )  
          On her second patrol "U 175" carried old type Metox R.600 G.S.R. with a wooden "Southern Cross" type aerial.  This set was replaced for her third patrol by the improved Metox R.600A set and a new type aerial, familiarly known as the "wire-basket" type; the latter carried in addition to the Southern Cross, which was, however, not used.  The features of the new aerial are:  
                  (a)  It can remain in position when the U-Boat submerges;  
                  (b)  It can apparently be used for R.D.F. transmissions when the aerial leads are disconnected from the G.S.R. receiver and plugged in to the R.D.F. set.  In such a case this would give only approximate direction and range, but this would be useful to U-Boats surfaced at night.  
          (N.I.D. Note.  This development is possible; but it is noted that survivors did not state that the aerial had been used for this purpose.  
     
  (C49300)                                                                                                                    B*2  
     
     

 

 
 
 
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          It was said that the new aerial cannot be rotated but received transmissions over 360°.  
          The aerial is described as consisting of two horizontal rings of about 5 mm. thickness, 20 cm. diameter and 10 cm. apart.  On the after portion of the upper ring were fixed two rods (described as "dipoles") about 15 cm. high.  The space between the upper and lower ring is covered by a band of wire mesh.  One prisoner only said that mesh also covered the lower ring, thus forming a bottom to the "basket."  
          Only one cable leads through the pressure hull, and this passes through the stand which supports the aerial.  
          The height of the aerial system, including the support, was only about 35 cm. and it was fitted to the port side of the bridge.  
          The cable was permanently sealed through the U-Boat hull.  
          There was only one plug to the receiving set.  Earlier G.S.R.sets had two.  The cable did not have to be changed periodically.  
          The new aerial arrangement was thus unable to distinguish horizontally or vertically polarised transmissions.  A telegraphist said this was quite unnecessary, as the frequencies of all land, sea and air-based R.D.F. were known to Germany.  
          When the U-Boat surfaced, the set was manned permanently.  On contact being reported, the commanding officer crash-dived at once and remained submerged usually from quarter to half an hour, but sometimes as long as one hour.  
          (N.I.D. Note.  Officers of U.S.C.G. "Spencer" reported seeing a drum-shaped object on top of a vertical shaft attached to the port side of the conning-tower and extending about 14 in. above the latter.  The drum was about 10 to 12 in. in diameter; from its upper surface extended three wires about 12 in. in length.  These wires extended radially from the drum in the form of a prong or fork.  Location was near the gyro repeater.)  
          Prisoners disagreed there were three rods.  
          According to a P.O. Telegraphist the Metox R.600A set carried by "U 175" on her last patrol was designed to enable the reception of frequencies not normally audible.  It included a second oscillator, which, when not switched in as an oscillator, functioned as a rectifier.  The oscillator switch is an additional one on the right side of the receiver.  
          It was expected that the British would transmit what was referred to as "inaudible frequencies."  To counteract this, the second oscillator would set up another inaudible frequency and the Metox receiver would pick up an intermediate frequency, consisting of the difference between the two.  
          It was also said that the sets have a "magic eye" (see Section V(v).)  the presence of aircraft being betrayed by a green light, no sound being heard.  
          Range was given as between 80 and 220 cm.  The set could receive down to 20 cm. on harmonics.  
          Telegraphists said that at night they connected one of their earphones to the G.S.R. set and the other to their all-wave receiver.  
          (N.I.D. Note.  This practice would make their G.S.R. watch useless.  
     
  (xv)  S.B.T.  
          Fitted in the officers' "heads."  It was never used, although it was alleged that the captain was about to order some charges to be ejected when the sinking of "U 175" occurred.  The cylinder was stated to be about 50 cm. long and 10 cm. in diameter.  
     
  (xvi)  Extensible Lookout Mast  
          Not fitted.  
     
  (xvii)  German Asdic  
          Not fitted.  
     
  (xviii)  D/F  
          Fitted.  
     
  (xix)  Sounding Devices  
          Echo Sound.  Fitted.  
          "Elektrolote."  Not carried.  
   
  (xx)  W/T Codes  
          It was said that these were kept in a strong box fitted in the bilges, possibly below the captain's cabin.  It was necessary to open three locks before they could be reached.  
     
  (xxi)  Camouflage  
          Officers and men from U.S.C.G. "Spencer" stated that the U-Boat appeared to be freshly painted with conning tower and bridge painted a light grey, and the hull a darker grey with black boot topping.  
     
  (xxii)  Conning-Tower Badge  
          Two juxtaposed paragraph signs.  This was a play on the U-Boat's number and referred to paragraph 175 of the German Code of Criminal Law which deals with homosexual offences.  
     
  (xxiii)  Field Post Number  
          M.41704.  
     
     

 

 
 
 
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III.  THIRD AND LAST PATROL OF "U 175"
 
     
  (i)  Officers  
 
Kapitänleutnant Heinrich Bruns Captain.
Leutnant zur See Wolfgang Verlohr 1st Lieutenant.
Leutnant zur See Paul Möller 2nd Lieutenant.
Oberleutnant (Ing.) Nowroth Engineer Officer.
 
     
  (ii)  Torpedoes Carried  
          14 electric, 8 air.  The space in which a fifteenth electric torpedo had been housed on the second patrol had been filled with cases of lemons.  
     
  (iii)  Passage of Bay of Biscay  
          "U 175" left Lorient at 1800 on 10th April, 1943.  She was accompanied by one 500-ton U-Boat of which neither the number nor the name of the Commanding Officer have been ascertained.  Escort for two and a half hours and until the 100 fathom line was reached, consisted of one "Sperrbrecher" and three A/S vessels.  Ile de Groix was passed close to port and Iles de Glenan some distance to starboard.  At 2030 escort parted company and the two U-Boats proceeded away on different courses.  Although they said they were not actually informed, prisoners believed that their operational area for this patrol was to be off the U.S.A. or Canadian coast.  
          After proceeding surfaced throughout the night on a course of 270° at between 12-14 knots, "U 175" dived at 0700 on 11th April.  She remained submerged throughout the day, making about 3 knots, on the same course, but surfaced at 2200 and continued at 10-12 knots.  The same procedure was followed on 12th April.  On both days, however, surface speed was occasionally reduced to allow cooling of the batteries, which tended to overheat if charged too rapidly.  One prisoner said that on 12th April, at about 0220, "U 175" submerged for one hour as a result of A/C location by G.S.R.  Two nights later they again submerged for the same reason at 0400.  
          "U 175" continued her routine of submerging by day and surfacing by night until 15th April, when it was considered that she was well out of the range of shore based aircraft.  
     
  (iv)  Instructions from Admiral U-Boats  
          On 16th April a signal was received from Admiral U-Boats giving the position of an approaching convoy and ordering "U 175" to the attack.  At 0400 G.M.T. on 17th April, the convoy was reported by another U-Boat.  The report included the position of the convoy and the number of ships, but no details of the escort.  Nothing more was heard from this boat and "U 175" concluded that she had been forced to submerge by aircraft.  
     
  (v)  A Convoy Sighted  
          Somewhat later a report giving the position of the convoy was received from another U-Boat, and at 1100 G.M.T. "U 175" herself sighted the ships.  She approached from the north and saw the convoy on her starboard bow.  
          Standing off at some distance, she proceeded parallel with the ships and then took up position ahead, at extreme visual range.  
          The Chief Quartermaster said that Bruns' reason for taking up this position was that it was daylight and a surface attack was impossible.  Had "U 175" approached the convoy from astern, submerged, she could never have kept up with it, do, according to proscribed policy, she took up position ahead.  
          Towards midday one of the escort vessels was observed zigzagging astern of them, but as she was heading away from "U 175," the U-Boat merely submerged to periscope depth.  
     
 
IV.  SINKING OF "U 175"
 
     
  (i)  "U 175" Attacks  
          As the minutes passed, it became apparent to Bruns that "U 175" would shortly become enveloped by the convoy.  This apparently excited him and imprudently he attempted to stalk as large merchantman, then about 4,000 yards distant, which was shaping course to pass down his starboard beam.  He did this against the advice of his First Lieutenant, who argued that it would be far safer to wait till nightfall.  Very shortly afterwards the Petty Officer on the hydrophones reported that the screws of an approaching "destroyer" had become audible.  This warning and others that followed it with increasing urgency were ignored.  Not until the "destroyer" could be heard within the U-Boat without the assistance of hydrophones and, as prisoners alleged, the "Ping" of Asdics had become insistent, did Bruns realise his danger.  
     
  (ii)  First Depth-Charge Attack on "U 175"  
          With only a few seconds to go before he gave the order to fire torpedoes, Bruns suddenly changed his mind, decided to evade, and ordered full speed ahead and slight starboard rudder.  Prisoners believed that at this moment the "destroyer" also altered course to starboard.  A heavy and accurate D/C attack instantly followed.  
          (N.I.D. Note.  The "destroyer" was in fact U.S.C.G. "Spencer" forming a part of the escort of Convoy H.X.233, which was composed of 57 ships bound from the Western Atlantic to the British  
     
  (C49300)                                                                                                                    B*3  
     
     

 

 
 
 
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  Isles between 12th and 20th April, 1943.  Prior to the action involving the sinking of "U-175" two attacks on U-Boats had been made:  
          At 0340Z/16 in position 45° 03' N., 26° 48' W. and at 0412Z/17 in position 47° 04' N., 22° 26' W.  Following the latter attack S.S. "Fort Rampart" was torpedoed at 0605Z/17 in position 47° 20' N., 22° 11' W.  
          At 1250Z on 17th April, "Spencer," while patrolling Station (A), and with Convoy Commander bearing 245° T., range 5,000 yards, made firm sound contact on a U-Boat bearing 039° T., range 1,500 yards.  
          At 1252Z, "Spencer" made an urgent attack on the U-Boat, firing a pattern of 11 depth-charges set at 50 ft. and 100 ft.  This was considered a hurried and inaccurate attack which was not believed to have caused any damage to the U-Boat, except possible shaking up.)  In point of fact, damage was very considerable.  
          "U 175," submerging to a safer depth, was caught at about 65 ft., and it appeared to prisoners that the depth-charges exploded beneath them.  The following damage was sustained:  
                  Fracture of the air trunking.  
                  Fracture to pressure hull between forward torpedo tubes causing water entry.  
                  Bilge pumps put out of action.  
                  Hydroplanes defective.  
                  Heads of Diesel engine holding down bolts snapped off.  
                  The entire pressure hull strained so that watertight doors could not be properly closed.  
                  Partial failure of lighting.  
                  Breaking of pressure, depth and other gauges.  
                  The majority of the W/T equipment torn from its fastenings and hanging loosely from its wiring.
          "U 175" now began to plunge downward out of control, and some prisoners claimed that she had reached a depth of below 900 ft. before trim was restored.  Frantic efforts were being made to repair the damage, and in the case of the air trunking this was successful.  The leak forward was also found to be less serious than was at first thought, and it was said that it was partially plugged.  
     
  (iii)  Second Depth-charge Attack on "U 175"  
          A soon as "U 175's" downward course had been checked, she began to rise at a rate that gradually gave cause for anxiety.  Accordingly, all hands who could be spared from the controls were sent forward.  Trim had hardly been restored when as second attack was experienced.  
          (N.I.D. Note.  After her first attack "Spencer" reported that she held contact and at 1258Z, she made a deliberate attack, firing a second pattern of 11 depth-charges set at 200 ft. and 250 ft., very close to the convoy.)  
          This second attack caused further severe damage.  A second fracture of the pressure hull occurred, and battery containers were smashed, resulting in the generating of chlorine gas.  One electric motor was put out of action.  In addition the driving wheel on the propeller shaft for the revolution indicator slipped and made much noise.  Two of the bow torpedoes had begun to run in the tubes, but could not be ejected owing to the depth at which the U-Boat still lay.  
          Without waiting for "Brun's" decision, the Engineer Officer then gave the order to surface.  Without protesting, "Bruns" ordered all men to put on life-jackets and assemble in the Control Room.  
     
  (iv)  Third Depth-charge Attack on "U 175"  
          As "U 175" was rising, a third depth-charge attack was made, but prisoners thought that this attack did not materially increase the damage already done.  
          (N.I.D. Note.  Following her second attack, "Spencer" had maintained sound contact and stood down through the convoy between Columns 7 and 8, although unable to attack due to the proximity of merchant ships.  U.S.C.G. "Duane" then on the port flank of the convoy, was instructed to close "Spencer" in attack.  "Duane" proceeded through the convoy toward the area of contact.  
          At 1317Z, while passing through the convoy, "Spencer" obtained a third firm sound contact bearing 042°, range 1,700 yards, and at 1321 fired a pattern of eight mousetrap charges from which no results were noted.  Contact was lost immediately.  No periscope was seen at any time.  "Duane" was coached on in expectation of immediate resumption of contact, when at 1338Z, a conning tower breaking water was observed, bearing 270°, 2,500 yards from "Spencer," who was then about 2,500 yards astern of the last ship of Column 8.  "Spencer" immediately opened fire on the U-Boat with all guns of the port battery, rang up full speed and headed toward the enemy.  "Duane" opened fire about one minute later, waiting for "Spencer" to clear the firing bearing, and began to close the enemy also.  Several convoy ships began firing at the U-Boat shortly thereafter.)  
     
  (v)  "U 175" Surfaces  
          On breaking surface "U 175's" ship's company abandoned ship precipitately, many forgetting to take their life-jackets with them.  Shortly before, the two "hot-running" torpedoes had been ejected.  Complaints were made by prisoners that they were fired on while leaving the U-Boat, but no one attempted to hoist a white flag.  The Engineer Officer, who was wounded was the last to leave, after opening the vents.  It was denied that scuttling charges were fired.  Kapitänleutnant Bruns was standing on the bridge when a direct hit was obtained.  One of his legs was blown off, and he sustained other injuries which instantly killed him.  
     
     

 

 
 
 
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          It has not been definitely ascertained whether or not a signal reporting the sinking to Admiral U-Boats, was made.  It is known that the Captain ordered such a signal, and one P.O. Telegraphist, later found to be unreliable, alleged that he made it.  Other more reliable prisoners said that no signal could be made, and the W/T equipment had been rendered completely unserviceable.  
          (N.I.D. Note.  When surfaced, the U-Boat was seen to have way on her, moving forward at a speed of about 1-1/2 to 2 knots, turning slowly to starboard, with the bow well surfaced, the stern slightly under, as though damaged aft.  "Spencer" was now close aboard the U-Boat preparing to ram, but as no life was seen aboard her, and as she was so badly damaged, cease firing was ordered by the Escort Commodore at 1345 Z, and "Spencer" was instructed to avoid ramming if possible.  
          At 1427, in approximate position 47° 58' N., 021° 12' W., the U-Boat was seen to sink stern first.  
          Nineteen survivors were picked up by "Spencer" and 22 by "Duane."  
          "Spencer" reported that survivors, while in the water, acted in a very hysterical manner.  Sea was calm, water temperature 54° F., air temperature 57° F., there were three escorts immediately at hand, and the survivor work was begun about 20 minutes after the U-Boat surfaced.  Considerable survivor work previously witnesses by "Spencer" in heavier and colder seas "brought forth no such cries of hysteria and fear as were made by practically all of the prisoners rescued from this U-Boat.")  
     
 
V.  GENERAL REMARKS
 
     
  (i)  U-Boat Anti-Aircraft Measures  
          (N.I.D. Note.  The following information has been compiled in collaboration with the R.A.F.  This report is based in the main on the interrogation of three members of the bridge watch of "U 175," who completed a special A.A. course on March 12th, 1943.  It also contains confirmatory evidence obtained from the prisoners of other U-Boats sunk this year.)  
          (a)  Tactical Instructions.   According to prisoners, new instructions were circulated among U-Boat officers about four months ago recommending greater use of U-Boats H/A armament in preference to the standard evasive action of crash-diving on sighting an aircraft.  
          The responsibility for deciding between diving and engaging lies with the Officer of the Watch.  It is recommended that the U-Boat should still dive if she sights the aircraft in good time to avoid a "surprise attack,"  Prisoners all agreed on defining a "surprise" attack as one in which the aircraft gets within 2,000 yards to 3,000 yards before being sighted, and in this case U-Boats are now encouraged to fight it out on the surface.  
          (b)  Anti-Aircraft Gunnery Training.  One man from each watch has now to be a trained A/A gunner, able efficiently to operate the 20 mm. (0.79 in.) guns, Types C.30 and C.38, and to this end the Naval Flak School at Mimizan, Southern France, has been conducting five-day short A/A course for U-Boats each week since January, 1943.  
          Three seamen of "U 175" had attended the 12th Short A/A Course for U-Boats" at Mimizan from 8th March to 12th March, 1943, inclusive.  They stated that the complement of "U 175" included three more ratings who had done a special A/A course during normal U-Boat training.  
          A reliable prisoner from "U 444" corroborated this statement that an attempt is being made to see that a crew includes three others, not necessarily members of the bridge watch, able to handle the 20 mm. gun efficiently.  
          The following is a resume of the curriculum of the 12th short A/A Course which illustrates the nature and quality of training.  The trainees from "U 175" left Lorient on 6th March and arrived at the school after 2300 on 7th March.  
 
8th March.  
0800-1200 F.F.I. and registration.  Personnel of the Short U-Boat Course detailed into three classes of eight to ten men each.
1200-1330 Dinner.
1330-1500 2 cm. gun, sub-types C.30 and C.38.  Description of parts and theory of operation.  Half an hour's instruction in the use of the front V-sight in conjunction with the rear double ring sight.
1500-1700 Practice in stripping and assembling 2-cm. gun.
9th March.  
0830-0900 Drill.
0900-1130 Ground to air firing against a drogue towed by a W.34 at heights varying from 200-400 yards, and range between 1,000-1,500 yards.  Each man fired three magazines of 20 rounds against the drogue as it was towed in three semicircular flights.
1130-1200 Guns cleaned.
1200-1400 Dinner.
1400-1700 Each man fired 20 rounds each of four "fly-pasts" in a semicircle flown alternatively from port to starboard and back.
1700-1730 Cleaning of weapons used.
 
     
  (C49300)                                                                                                                    B*4  
     
     

 

 
 
 
8
 
     
 
10th March.  
0800-0930 Drill.
0930-1130 Revision of first day's theoretical training with the addition of stoppages, four only being taught.
1130-1330 Dinner.
1330-1630 Fifty rounds fired against a drogue flown to simulate a curve of pursuit concluding in an attack from dead astern.
1630-1700 Cleaning of weapons used.
11th March.  
0830-0900 Drill.
0900-1130 Sixty rounds against a drogue flown to simulate a quarter attack, a beam attack, and an attack from dead astern.
1130-1200 Weapons cleaned.
1200-1400 Dinner.
1400-1630 Forty rounds against a drogue simulating two dead astern attacks, 20 rounds against a quarter attack and 20 rounds against a beam attack.
1630-1700 Weapons cleaning.
12th March.  
0830-1130 M.G.15 (German Air Force type).  Description of parts and theory of operation.  Cleaning.
1130-1330 Dinner.
1330-1600 One hundred and fifty rounds fired from M.G.15 at a  drogue towed at a range of 1,500 metres.  Guns cleaned.
 
          On the last night each man fired 20 rounds against a drogue fitted with a small light so as to ensure that fire was not directed against the towing aircraft.  In addition they were to have fired 20 rounds against a drogue with a searchlight on the ground trying to dazzle the firing number.  Glasses were not allowed.  They were told that an aircraft was distinguishable as a white blob even in the glare of a searchlight.  The course was dismissed that night.  
          The three men from "U 175" left Mimizan in the morning of 13th March, arriving back at base at 0800 on 14th March.  
          (c)  Theory of Sighting, Range Estimation, Use of Tracer.  It will be seen from the above that only the most rudimentary theory of sighting can have been taught on this course, although interrogation revealed that the longer 8-week courses for minesweeping and surface ship personnel at the same school included the zone theory of sighting, a chart for which hung in trainees' classrooms.  
          Gunners on the short course were merely told that the outer ring of the 2 cm. gunsight allowed for an aircraft speed of 360/720 k.p.h. (194-388 knots), the inner ring for a speed of 180/360 k.p.h. (97-194 knots), and that they could use this to make their sighting allowance.  They were told the difference between real and apparent line of motion.  They were also told to aim slightly above the target, but were given no instruction on gravity drop.  
          They were instructed to fire a short opening burst at 2,000 yards and to watch the position of the trace in relation to the target, but they were given no instruction in the use of tracer; nor did they know the range at which it disappeared.  Range estimation was not taught, but was left to the judgment of the gunner.  
          In the opinion of prisoners interrogated, the instructors assumed that their classes had already received sufficient instruction during their normal U-Boat training and that although a keen man on this course would probably grasp the principles involved, too much was asked of the average man in too short a time.  
          (d)  Stoppages.  They were told that if they had a stoppage it was most probably due to a defective round, to be cleared by pulling the cocking handle.  The next most frequent stoppage to be expected was due to an insecurely mounted magazine, in which case the round would not go in straight.  
          The only other stoppages taught were those due to an inefficient firing pin and worn or twisted breech block guides, both of which were infrequent occurrences.  
          (e)  Theory versus Practice.  During training the instructor announced the estimated speed and range of the target and the firing number called out when he thought he had the target lined up in his sights with an adequate sighting allowance.  The instructor gave permission to fire.  A second trainee spotted and ordered the necessary corrections.  No. 3 elevated the gun, and No. 4 was the loading member.  
          In practice, the firing number makes his own corrections, a second man elevated or depresses the gun as required, while a third man is responsible for ammunition supply.  
          It will be noted that the last day of the course wa devoted to the use of the M.G.15.  Prisoners believed that it was intended to distribute this weapon to U-Boats in place of the standard C.34, but this had not been done at the time of "U 175's" departure from Lorient on 10th April.  
          None of the instructors had had any sea-going experience, a fact which was duly noted by their classes in spite of "pep" talks telling them how easy it all was.  
     
     

 

 
 
 
9
 
     
          (f)  Engaging an Attacking Aircraft.  Prisoners were taught to fire a sighting burst of three or four rounds when the target was 2,000 yards range.  Having then corrected aim, they were to open fire again within a few seconds.  
          The easiest shot was against an aircraft attacking up to 10° to dead astern.  The most difficult possible shot was against an aircraft flying on the beam, giving maximum deflection.  
          It was agreed that it was impossible to fire effectively with the 2 cm. gun at an aircraft attacking from dead ahead to 10 on the bow owing to the bridge superstructure and the remainder of the watch.  The tactics to be expected against such an attack were increased speed by the U-Boat with violent alterations of course to increase air gunners' aiming difficulties and enable the U-Boat gunners to bring guns to bear.  Estimated as to the safety height for the run-up during this type of attack varied between 160 ft. and as much as 3,280 ft.  
          The position of the gun platform near the centre of the U-Boat minimises the effect of its own evasive action.  Prisoners claim that the platform movement is not very serious, provided that the boat is kept head on to or running with the sea in a sea of not more than force 4, but that the condition deteriorates rapidly in heavier seas.  It is considered hopeless for the U-Boats' gunners if the boat is beam on to the seas.  
          There is no evidence of anti-dazzle glasses being carried for use when fighting searchlight aircraft, but it is suggested by prisoners that the anti-flash glasses used for protection when manning the 105 mm. gun would also answer the purpose.  
          (g)  Increased A.A. Armament.  The introduction of two twin 12.7 mm. (0.5 in.) guns in addition to the 20 mm. gun has already been reported as a result of interrogation of prisoners from Mediterranean U-Boats.  The introduction of an additional gun platform abaft the "bandstand" has also been reported.  
          Prisoners have stated that these additional platforms may be fitted in both 740-ton and 1,200-ton U-Boats and that the guns to be expected will be quadruple 20 mm. guns.  They claim to doubt their efficacy on the grounds that they are magazine-fed and will require too many to load them, as one man already finds his time cut out in an endeavour to load one.  They also feel that larger gun crews mean more casualties with a consequent shattering effect on crew morale in a confined space.  
          No prisoners had any knowledge of any belt-fed 2 cm. guns.  
          (h)  Nuisance Value.  In prisoners' opinion the new policy may not lead to the shooting down of many more aircraft, but it would have great nuisance value in putting the aircrew off their aim during the run-up to bomb.  It is admitted, however, that the air gunners will probably do quite as much to upset the U-Boat gunners.  
          (N.I.D. Note.  It will be noted that the standard of training so far set is not very high, and that there is not even a passing-out test, but nevertheless aircraft are liable to meet individual boats with gunners trained on a longer course and kept up to the mark by the energy of their captains.  
          Though the emphasis is at present all on the 20 mm. gun, the four M.G.s, type C.34 with ordinary carbine type rear and foresight have also to be considered as a subsidiary A.A. weapon.  
          Two can be mounted in slots at each corner of the conning tower.  "U 175" used to set them up whenever surfacing in the Bay of Biscay and they can be considered to have a good nuisance value at 1,000 yards.  
          The possible introduction of improved gunsights or subsidiary A.A. weapons must also be borne in mind.)  
     
  (ii)  20 mm. (0.79 in.) Guns  
          A prisoner said that the two types of 2 cm. gun now in use are 2 cm. sub-types C.30 and C.38.  Most U-Boats are now equipped with the latter.  The C.38 has the advantage that stoppages are easier to clear, and the breech block is more rapidly accessible, and usually it is sufficient merely to pull the cocking handle to clear the most usual stoppages.  
          The nominal rate of fire is 220 rounds per minute, but in practice, allowing for magazine changes, it is more nearly 120 rounds per minute.  
     
  (iii)  Minesweeping Methods  
          A Chief Petty Officer prisoner and the Midshipman (E) had had some experience of minesweeping in the English Channel and off the West coast of France and they gave the following information.  
          The Chief Petty Officer had served in a sweeper attached to the 38th M/S Flotilla, which is based on Ostend and Dunkirk.  The prisoner's sweeper belonged to "B" group, which operated from Ostend.  In eighteen months two of his group were badly damaged by mines, one sinking.  He had heard a claim on the British wireless that one boat in his group had been sunk by gunfire; the boat had in fact caught fire but had limped home.  The boats were all converted Dutch trawlers called auxiliary minesweepers ("Hilfminensuchboote").  They had Diesel propulsion.  Their usual armament was one 40 mm. (1.6 in.) two 2 cm., one 13 mm. and six M.G.s.  
          Degaussing ("M.E.S.").  One coil round the whole ship lying on deck along the bulwarks.  Ten turns, 53 amperes.  This was much higher than the average number of amp/turns, required for similar vessels.  
     
  (C49300)                                                                                                                    B**  
     
     

 

 
 
 
10
 
     
          Sweep.  A loop of two turns of buoyant cable is towed nominally 90 yards astern, but in their case, due to frequent splicing, it was only 55 yards astern.  The loop is towed by means of a steel cable attached to a towing buoy ("Trugboje").  The loop is kept spread by means of two Oropesa type floats ("Scheefboje") and three other small buoys.  The current is initially 200, falling to 150 amperes, being reversed on a regular cycle; reversal is practically instantaneous.  The length of cycle depends on the type of mine laid by the British, and ships sweep together working on different cycles.  
          This prisoner professes to know nothing of acoustic mines, and said that no hammer was fitted to the sweepers in which he served.  He left minesweepers in July, 1942.  He described the British mines as "highly ingenious."  
          He claimed that, while minesweeping, his flotilla had shot down 14 British planes.  
          The Midshipman (E) claimed to have swept mines in the Bay of Biscay in sweepers fitted with the latest type of magnetic minesweeping gear.  He said that this gear was only being used in the Bay of Biscay up till Christmas 1942, and not in the Channel.  
          The gear was designed to produce a horizontal field.  The boat in which the prisoner served was apparently the size of a trawler; they towed a buoy about 130 to 160 yards astern over the top of which passed an electric cable from the trawler; the end of the cable reached down until it was just off sea bottom.  On the end of the cable was an electrode, a "Membrane" ("Stromtopf"), which appeared to have been roughly spherical and generally had to be replaced if a mine exploded near it.  It was not clear where the other electrode was, but it seemed possible that it was the buoy on the end of the towing cable.  It appeared possible that the electric cable was buoyant as far as the buoy.  Polarity is reversed periodically, but few particulars could be obtained as to the exact cycles, nor have particulars been obtained of the currents used, nor how the timing gear operated in two ships when working together.  All that the prisoner would say was that the magnetic sweeping gear worked on a very long cycle of several minutes positive and several minutes negative.  The currents used were not standardized and he did not know why different currents were used.  
          The sweeping formation consisted of four boats, the two leading boats having hammers ("Krschmacher"), and the two following boats, magnetic sweeps.  
          Acoustic mines are exploded anything up to 160 yards ahead of the hammer and magnetic mines are exploded quite close to the end of the "Stromtopf."  
          Minesweepers could sweep simultaneously for acoustic and magnetic mines, the hammer being over the bow.  
          Generators are driven by small Diesels.  
          The Midshipman (E) described the hammer mechanism used for exploding acoustic mines as attached to a spar about 10 ft. long and rigged over the bow.  It was enclosed in a box, 12 in. by 12 in. by 12 in., and consisted of a wheel which, rotated electrically, swung hammers against the sides of the box.  
          Moored mines are swept by the usual Otter sweep.  The swept channel is immediately marked with buoys.  
          The Channel Boulogne-Brest-Lorient-St. Nazaire was swept continuously.  
          It was said that the minesweeper crews, when not at sea, underwent training in shock troop tactics and assaults on machine-gun nests.  Their officer instructors were men with experience of the Russian front.  
          It was usual for minesweepers to sweep for two or three days at a time and then to be in harbour for two days.  
          Losses of minesweepers in the Bay of Biscay were given as one or two per month.  
     
  (iv)  Torpedoes  
          The following statements regarding torpedoes were made by prisoners:  
                  (a)  The angling gear of all torpedoes can be set to 90° and the radius of turn when used is 95 metres.  
                  (b)  Air torpedoes are now being fitted with propellers of some new alloy, differing somewhat in colour from the old ones.  
                  (c)  Prisoners have made obscure references to a new type of pistol.  
          One prisoner said that, in addition to the standard Pi. 1, or Short Pistol, a new Long Pistol, Pi 2, has been produced.  He claimed that four torpedoes in "U 175" were fitted with the new long pistol, which was primarily intended to be used with "Curly" torpedoes.  
          (N.I.D. Note.  This is thought to be unlikely.)  
          The shaft of the pistol was approximately 18 in. long.  
          The prisoner also said that the new long pistol had magnetic actuation, which would cause it to explode under a ship even if no hit was registered.  Pistols were connected to the torpedo battery by an internal cable and plug-in contact.  He stated that torpedoes fitted with the long pistol were set to run at five metres (16.5 ft.) depth, whereas normal torpedoes ran at three to four metres (10-13 ft.) depth.  
          One prisoner said that all torpedoes fitted with Pi. 2 pistols, which were carried by "U 175," were electric; another that three were electric and one air.  Three were forward in the bow compartment two being actually in the tubes.  One was carried in the stern compartment.  
          These pistols were carried on her second patrol.  One torpedo so fitted was fired, but missed, and the three others were brought home.  
     
     

 

 
 
 
11
 
     
          Another prisoner referred to the pistols having magnetic actuation, and said that the arming propeller had to make 170 revolutions before the pistols were armed.  Prisoners said that only officers received instruction in these pistols.  
          (N.I.D. Note.  The arming distance for German contact pistols is 150 metres.)  
     
  (v)  G.S.R. "Magic Eye"  
          Referring to the Metox R.600A G.S.R., a P.O. Telegraphist prisoner, with operating experience, described what he termed a "Magic Eye" which, when elucidated, appeared to be either a Cathode Ray Tube or something similar to C.R.T.  He said that this could give visual indication of any R.D.F. reception by the set.  He hinted that this fitting was already in operation in later G.S.R. types.  When asked to illustrate his remark by a sketch, he drew an apparatus which, in size and function, appeared remarkably similar to the Bendix visual tuning indicator.  
          (N.I.D. Note.  The fitting is probably a standard broadcast receiver "magic eye" visual tuning indicator.)  
     
  (vi)  Combined R.D.F. and G.S.R.  
          The same prisoner also referred to a combined R.D.F./G.S.R. set, which he claimed was in course of production.  He first said that this set would have been fitted to "U 175" on her return to base, but then corrected himself and stated that he thought the set would only be fitter to new U-Boats, leaving the boats already in service to carry on with an interim equipment.  
     
  (vii)  Quality of Metox Receiver  
          When it was suggested to the P.O. Telegraphist that the Metox receiver was not up to standard that one might have expected of first-rate German technicians, and that, although serving its purpose, the circuit appeared to be the work of inferior men, he agreed.  He pointed out that it did serve its purpose, however, and that the established German factories were so over-burdened with producing G.A.F. R.D.F. apparatus, that an experimental invention of this type was inevitably left to second-raters.  He suggested that the new equipment previously hinted at would be the work of first-rate men.  
     
  (viii)  Use of G.S.R. near Convoys  
          A prisoner claimed that, for the last three of four months, the use of G.S.R. had been forbidden in the immediate vicinity of a convoy.  It had been ascertained that convoy escorts and even the merchant ships themselves now had so many R.D.F. sets in operation, that use of the G.S.R. in such circumstances only ended to lower morale in the U-Boat.  
     
  (ix)  R/T Interception  
          It was said that, either independently, or on direct orders, U-Boat W/T personnel quite frequently attempted to intercept British R/T.  In "U 175" the Captain was said to understand English, and on one or two occasions, when what was recognised as a British message was intercepted, the Captain endeavoured to translate and make use of it.  Such messages, whether deliberately or accidentally intercepted, were immediately passed back to Admiral U-Boats via a shore station.  One prisoner claimed to have worked in one of these shore stations which was operating at Kiel.  He said that the station was purely a "Post Office" for relaying information obtained, making no attempt to utilize it.  He alleged that on one occasion in February, 1943, he picked up a message addressed to "Commander U.S. Forces, Dakar, West Africa" and duly passed it on to Admiral U-Boats.  
          This prisoner added that he usually intercepted such messages on a wavelength of about 40 metres.  
          (N.I.D. Note.  R/T intercepted at sea would almost certainly be on 2,419 kc/s = 124 metres.)  
     
  (x)  U-Boat to Aircraft Communication  
          A P.O. Telegraphist prisoner said quite positively that on occasion U-Boats did communicate direct with aircraft, but this was only done in certain specified areas in the North Atlantic and only on direct orders from Admiral U-Boats.  This communication might be by either W/T or R/T, but in the latter case permission had again to be obtained from the Admiral.  
          Another prisoner stated that when a returning blockade runner is sighted by reconnaissance aircraft, U-Boats in the vicinity are sometimes informed direct by the aircraft in order that the ship may be suitable protected.  
          The method of reporting the presence of a convoy by aircraft to U-Boats is, as previously reported that of transmitting "A," repeated, for outgoing and "R," repeated for incoming convoys on a long wavelength.  These signals are D/F'd by U-Boats.  Longer signals may be occasionally transmitted.  For this purpose both U-Boats and aircraft carry special code tables known as "Reconnaissance and Battle Tables" ("Aufklarungs und Kampf Tafeln").  These consist of one page for every day of the month, generally for three months.  On each page is given the code groups, two or three letters or numbers and their meaning in plane language, in German and Italian.  Code groups are contained, such as "large convoy," number of air and or surface escort.  
     
  (xi)  Attacks on Convoys  
          It was said that it rested entirely with a U-Boat captain whether he waited ahead of the convoy or on its beam.  It was denied that attack sectors were laid down.  U-Boat captains used their own initiative and selected the best target they could find in relation to the position in which they had managed to maneuvre.  A prisoner said that he had never heard of two U-Boats making a concerted attack on one target, but it frequently happened that one U-Boat sank a target which a second U-Boat had been shadowing and stalking for hours.  
     
     

 

 
 
 
12
 
     
  (xii)  Pre-Patrol Tests  
          A prisoner said that U-Boats overhauled at operational bases undergo the following tests in the following order before proceeding on their next patrol:  
                  (a)  Tests of torpedo tubes;  
                  (b)  Checking of W/T equipment;  
                  (c)  Trimming test;  
                  (d)  De-magnetisation.  
     
  (xiii)  Bridge Watch Routine  
          A prisoner gave the positions of the bridge watch when proceeding on the surface as the following:  
                  (a)  One seaman as port quarter look-out, responsible for the sector red 90° to 180°.  
                  (b)  Officer of the Watch, red 90° to right ahead.  
                  (c)  One petty officer, right ahead to green 90°.  
                  (d)  One seaman as starboard quarter look-out, green 90° to 180°.  
          The crash-diving alarm was given in the first place by an electric bell, followed immediately by being passed from mouth to mouth.  The petty officer first went below to his station at the forward hydroplanes.  The port quarter look-out followed and remained in the conning-tower with the captain.  The starboard quarter look-out went next to the after hydroplanes.  The Officer of the Watch was last below, being responsible for closing the conning-tower hatch.  When this was done, he took up his station in the control room.  
     
  (xiv)  Anti-Dazzle Glasses  
          One prisoner said that so far bridge look-outs had not been equipped with anti-dazzle glasses as a precaution against attack by searchlight aircraft.  
     
  (xv)  Passage of Bay of Biscay  
          A number of prisoners agreed that it was the routine for "U 175" to submerge for five days in succession on both entering and leaving the Bay of Biscay and to surface during the nights.  
          (N.I.D. Note.   A recent increase in sightings of U-Boats by day and a decrease in sightings at night suggests that the practice of submerging by day has been greatly modified.)  
          One prisoner said, however, that "U 175's" commander was particularly cautions and that "U 175" submerged a day longer than was usual procedure, both on entering and leaving the Bay.  Average surface speed at night through the Bay was 12 knots and submerged speed by day was 4-5 knots.  On leaving the Bay, U-Boats did not submerge until reaching the 100 fathom line, owing to the danger of exploding magnetic mines.  Within the 100 fathom line it was compulsory for all men to wear life-jackets.  Average cruising depth by day was said to be about 130 ft.  
     
  (xvi)  Two-Man U-Boats  
          The coxswain said that Hanomags were in reality two-man U-Boats.  These are intended to be launched by a parent ship.  A speed of 28 knots was claimed for them.  He added that they are building in the covered dock at Hel and trials are still in progress.  
          (N.I.D. Note.  A Hanomag is thought to be an experimental type of E-Boat.  The prisoner is describing a human torpedo, which is probably in the experimental stage.)  
     
  (xvii)  Faster U-Boats  
          The coxswain also said that German Admiralty technical experts had been asked to construct a U-Boat capable of 15 knots submerged and 25 knots on the surface.  So far they had not succeeded.  
     
  (xviii)  Triple Purpose Minelaying, Supply and Operational U-Boats  
          Prisoners said that "U 117" and "U 118" (Korvettenkapitän Czygan) were used for supply and minelaying, but they also had torpedo tubes and carried torpedoes.  
          The mineshafts were fitted on either side amidships.  From prisoners' descriptions they appeared to be fitted in the free-flooding tanks.  The opening into each shaft is covered with a grating and is circular in shape.  It was said that "U 118," which refuelled "U 175" in February, 1943, had already sunk one ship on her patrol before making the rendezvous.
          (N.I.D. Note.  It is very probable that this class of U-Boat is used both for minelaying and for supplying other U-Boats, but there is no confirmation that they are also used as ordinary operational boats.)  
     
 
VI.  SURFACE SHIPS
 
     
  (i)  "Prinz Eugen," "Schleswig-Holstein" and "Schlesien"  
          A prisoner said that these three ships were now being used purely for instructional purposes.  The regular complements had been largely drafted to U-Boats.  
          (N.I.D. Note.  The "Prinz Eugen" may carry a certain proportion of men under training, but is considered to be available for operations.)  
     
     

 

 
 
 
13
 
     
  (ii)  "Nürnberg"  
          Said to be now used as a training ship at Kiel.  
     
  (iii)  "T.3"  
          An officer prisoner said that this torpedo boat had been sunk at Le Harve in late 1940 during an air attack.  Kapitänleutnant Bruns was Commanding officer at the time.  
     
  (iv)  "Brahe," "Nogat" and "Prügel" (A/S Vessels)  
          A P.O. Telegraphist said that in February, 1941, he joined the A/S training ship "Brahe" at Kiel.  This was a ship or 1,000 tons, and, although primarily for training, she was also used operationally.  Sister ships were named "Nogat" and "Prügel."  They were armed with a French 50 mm. (2 in.) gun and two 20 mm. (0.79 in.).  They carried K.D.B. and depth-charges.  The prisoner said that his A/S vessel operated in the North Sea from Wesermünde, Cuxhaven and Kristiansand S.    
  (v)  Unknown Raider  
          A midshipman prisoner stated that, among many ships sunk by mine between Lorient and Bordeaux, was a raider which was camouflaged as a merchantman and was preceded by a Sperrbrecher.  
     
  (vi)  "Frieda Horn"  
          This 3,200-ton ship, formerly belonging to the H.C. Horn Line, Hamburg, was said to be among depôt ships based at Gdynia.  
     
 
VII.  BASES AND TRAINING ESTABLISHMENTS
 
     
  Lorient  
          (N.I.D. Note.  A separate report on this base has been completed and contains full details of shelters, harbour facilities for U-Boats, etc.)  
          Prisoners said that the Personnel Reserve at Lorient was quartered in the Salzwedel Barracks.  It consisted of 100 seamen and about 15 stokers under the command of Oberleutnant zur See Fahrenkamp.  
          The officer prisoner said that during the R.A.F.'s heaviest raid on Lorient in February, 1943, 150 torpedo warheads detonated at a dump just outside the town.  He thought that it was also during this raid that a large store of T-mines ("Tellerminen"), stowed at the Salzwedel Barracks, was exploded.  
          He alleged that naval casualties during air raids had been very light.  
          Prisoners said that out of 50 U-Boats of the 10th Flotilla at Lorient, only 32 remained.  
     
VIII.  TRANSPORT OF 250-TON U-BOATS AND SMALL NAVAL CRAFT TO THE BLACK SEA
     
          A prisoner from "U 432" stated that in 1942 he had accompanied a 250-ton U-Boat during her transport from the Baltic to the Black Sea.  He gave the following details of the methods of transport:  
          First preparations were made on 1st April, 1942.  "U 24," the first U-Boat to be so transported, left Kiel on 28th June, 1942.  
          U-Boats are prepared for transport by Deutsche Werke, Kiel, the ship's companies being accommodated at Plön during this time.  
          In the yard the pressure hull of the U-Boat is first stripped and the U-Boat is laid on her side.  Eight floats are then welded to the outside of the hull.  Strictly speaking, there are only four floats, each with a port and starboard compartment and connected beneath the pressure hull in the form of an inverted saddle-tank.  The two outside compartments are said to be 3 metres long and the two inside compartments 2 metres long.  
          The floats and pressure hull are then charges with air at 28 lbs. per sq. in. in case the floats should become damaged.  Floats then have a draught of 6 ft. with 2 ft. freeboard.  
          When preparations are complete, the U-Boat is camouflaged as an ordinary canal barge and towed to Hamburg.  The prisoner thought that each "barge" was towed separately.  
          From Hamburg the "barge" is towed up the Elbe to a point at, or near, Dresden.  Here, on the left bank, is a hydraulic lifting system, which places the U-Boat and floats on to a 36-axle trailer wagon.  The whole is then drawn down the Reichsautobahn to Obersell, on the Danube below Passau.  
          Still welded to the floats, the U-Boat is then launched on the Danube by means of a special slipway.  It was said that launching was only practicable with normal Danube water-level.  The spring and winter levels made launching impossible, and the prisoner thought that the only possible season in which the transport could be carried out was between mid-June and September.
          Having been launched, the U-Boat is floated down the Danube to Linz.  
          At Linz, the U-Boat is delivered to the Deutsche Werke,who have taken over a part of the Linzerwerft, employing their own workmen, who live in adjacent, newly-built barracks.  The Deutsche Werke Yard is open and is barely camouflaged.  In autumn, 1942, the yard had only a temporary guard system and the dock area was merely barricaded off.  
     
     

 

 
 
 
14
 
     
          The first procedure in reconditioning the U-Boat is to remove the floats.  As there is no dry dock, this work is done under water.  All floats are flooded to lower the boat further into the water.  The floats are then removed and the pressure hull righted.  It was said that the passage from Kiel to Linz took 16 days, and from Linz to Constanza, where the U-Boats were finally delivered, 14 days.  They are towed from Linz to Constanza.  
          The prisoner said that nearly all Germany's 250-ton U-Boats were destined for the Black Sea, having first been school boats at Gdynia and Pillau.  
          In Autumn, 1942, he had heard that two flotillas were to be formed, one in Odessa and one in Constanza.  He believed that eight or nine U-Boats were already there and he gave the following particulars of them:  
 
"U 9" (Definitely there).  This U-Boat belonged to the 1st U-Boat Flotilla at the outbreak of war.  She became a school boat in January, 1940, with all other 250-tonners.  On 1st May, 1940, she joined the 21st School Flotilla at Pillau.  In 1942 her captain was Schmidt-Weichert.  She was recommissioned at Linz on 28th September, 1942, and left about that date for the Black Sea.
"U 24" (Definitely there).  Oberleutnant zur See Petersen (ex "U 14") commands her.  The Engineer Officer is Oberleutnant (Ing.) der Reserve Arlt.
 
          The prisoner also stated that Schmidt-Weichert, formerly in command of "U 9," had taken over a flotilla in the Black Sea.  Previous prisoners have stated that Rosenbaum, ex "U 73," commanded a Flotilla in the Black Sea.  
          (N.I.D. Note.  The total number of U-Boats in the Black Sea at present probably does not exceed six, though possibly more than this number will eventually be based there.)  
     
  Transfer of Small Craft to the Black Sea  
          The same prisoner said that other craft, including R-Boats, E-Boats and L.C.T.s are also being transferred to the Black Sea by exactly the same route.  
          He had seen six R-Boats (all school boats from Pillau and Gdynia, including "R 33") at Linz, and also two E-Boats and ten to 15 L.C.Ts.  
          He said that the L.C.T.s were built in Stettin.  They take the sea route to Hamburg, where the engines are taken out.  Thence they follow the same route as the U-Boats.  
          Crews of U-Boats and other craft are accommodated in Linz at the Donau Flotilla Barracks, near the Steinbrücke.  
          The Donau Flotilla had already left for the Black Sea, where it had suffered severe losses.  
     
     
     
     
     
     
     
 
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15
 
     
 
APPENDIX A
 
 
 
 
EARLY HISTORY AND TRIALS OF "U 175"
 
     
  (i)  Building  
          "U 175" was built by Deschimag, Bremen.  It was not ascertained when she was laid down or launched, but prisoners said that they were drafted to the U-Boat to stand by the final stages of construction in October and November, 1941.  At this time they were housed, two to a room, in a building formerly the property of the North German Lloyd Shipping Company.  Kapitänleutnant Heinrich Bruns had already been appointed Captain of "U 175," and he remained with her until her sinking.  
          It was said that "U 175" took nine months to complete.  While building she lay between "U 174" and "U 176."  
     
  (ii)  Commissioning  
          "U 175" was commissioned on, or about, 10th December, 1941.  A celebration was held in the Lloyd building.  
     
  (iii)  U.A.K. (U-Boat Acceptance Command) Trials  
          After remaining a few days at Bremen, "U 175" proceeded to Kiel.  U.A.K. trials began on  23rd December and lasted until 6th January, 1942.  It was said that three 500-ton U-Boats and one other of 740-tons were undergoing these trials during the same period.  
     
  (iv)  Agru-Front.  "U 175" is Frozen in  
          On 6th January "U 175" left Kiel for Gdynia.  After her arrival she put to sea for two days for torpedo exercises and was then icebound in harbour until the end of April.  Prisoners said that at that time the only other U-Boat frozen in with "U 175" was a 500-tonner, stated to be commanded by Kapitänleutnant Dierksen (or Dicksen).  "U 175's" ship's company were quartered in the depot ship "Frieda Horn."  
          Agru-Front exercises, which lasted fourteen days, were finally held off Hel, in May.  Kapitänleutnant (Ing.) Müller frequently boarded "U 175" for these exercises.  
     
  (v)  Tactical Exercises.  "U 175" Damages her Periscope  
          "U 175" completed her tactical exercises off Gdynia at the beginning of June.  She was in company with three 500-ton U-Boats and one 740-ton minelaying U-Boat, of which neither the numbers nor the Captain's names were known.  These exercises lasted ten days.  During this time the periscope, when being raised as "U 175" was surfacing, fouled the bottom of a cutter and the U-Boat had to return to Danzig, where a new periscope was fitted.  
     
  (vi)  Silent Running Tests  
          Silent running tests were carried out off Bornholm Island in mid-June.  
          On subsequent patrols it was found, to general disgust, that "U 175" was an exceptionally noisy U-Boat.  
     
  (vii)  Final Adjustments at Stettin  
          Towards the end of June "U 175" proceeded to the Oderwerke Yards at Stettin for final adjustments.  These lasted for approximately six weeks.  In this period Oberleutnant (Ing.) Nowroth was taken ill with appendicitis and was removed to hospital, but returned ten days later.  
          The ship's company were housed in the Breedower Barracks and they were given long leave by watches.  Compulsory rifle exercises ashore filled the mornings for the majority, all of whom were amused to find that their Chief Petty Officers had forgotten the drill.  
          Among other U-Boats undergoing final adjustments at Stettin during this time were said to be "U 512" (Kapitänleutnant Wolfgang Schultze), which was sunk on 2nd October, 1942, and a U-Boat commanded by Kapitänleutnant Lüth.  
          Prisoners said that final adjustments were completed about 25th July, and they then fuelled and embarked torpedoes.  They left for Kiel on 27th July, where they remained until 10th August.  
     
     
     
   
     
     
 
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16
 
     
 
APPENDIX "B"
 
 
 
 
PREVIOUS PATROLS OF "U 175"
 
     
 
A.  First Patrol
 
     
  (i)  Officers  
 
Kapitänleutnant Heinrich Bruns Commanding Officer.
Oberleutnant zur See Ehrich First Lieutenant.
Leutnant zur See Verlohr Second Lieutenant.
Oberleutnant (Ing.) Nowroth Engineer Officer.
 
     
  (ii)  Torpedoes Carried  
          23;  15 electric, 8 air.  
     
  (iii)  "U 175" Sails  
          "U 175" left Kiel in the forenoon of 10th August, 1942, in company with "U 179," a 1,200-ton U-Boat commanded by Korvettenkapitän Sobe.  The two U-Boats were escorted by a "Sperrbrecher" ahead and a minesweeper acting as an A/A vessel astern.  
          After making the passage of the Kattegat and Skagerrak, the U-Boats out into Kristiansand S. where they arrived in the afternoon of 17th August.  Overnight "U 175" topped up with drinking water and 3 to 4 tons of fuel.  
          On the afternoon of 13th August, the two U-Boats left Kristiansand S. together, though each was now to act independently.  "U 175" followed the Norwegian coast up to the approximate latitude of Bergen, being 7 to 8 miles off shore at the beginning of this stage of her patrol, but later standing away further to sea.  From position 60° N., 003° E., she altered course to 325° to position 64° 30' N., 003° 60' W., leaving the Faeroes 30 to 40 miles on the port beam.  
          The first dive, apart from daily practice, occurred off the Faeroes when an aircraft was sighted.  It was not thought in the U-Boat that they had been seen, but they remained submerged for some hours for safety.  Speed up to this position had averaged 7 to 8 knots.  
     
  (iv)  Passage of Rosengarten  
          From position 64° 30' N., 003° 30' W., "U 175" passed into the North Atlantic between the Faeroes and Iceland, making a surface crossing of the Rosengarten, where a number of floating mines were sighted.  Course was approximately 245° to position 62° N., 15° W.  
     
  (v)  Rosengarten to West Indes  
          Shortly after leaving the Rosengarten another aircraft had been sighted and "U 175" again submerged.  She came to periscope depth at intervals only to find the aircraft still circling overhead, and it was some time before she was finally able to surface and proceed.  
          Course from 62° N 15° W., was altered to 225° to approximate position 45° 12' N., 045° W., when a further alteration was made to 202°, which finally brought "U 175" to Barbados.  Orders had originally been received from Admiral U-Boats that "U 175's" operational area to the Windward Passage.  
          (N.I.D. Note.  Possibly to relieve "U 94" (Oberleutnant zur See Ites) sunk in the Windward Passage by U.S.N. P.B.Y. Plane and H.M.C.S. "Oakville" on 27th August, 1942.)  
          These orders were subsequently changed and "U 175" was instructed to patrol along the hundred fathom line between Trinidad and the mouth of the Orinoco.  
     
  (vi)  "U 175" off Barbados  
          Arriving off Barbados, "U 175" half circled the island.  Prisoners said that, one day before their arrival off the island, about 9th September, they intercepted a signal from another U-Boat claiming to have sunk two tankers off Bridgetown (Barbados) harbour.  The next day they sighted the stern of one of the tankers still above water off the harbour mouth.  The patrol round the island was made at periscope depth and they claimed that through the periscope, they often saw bathing parties on the beaches.  
          For some hours they lay off Bridgetown.  Only a fishing vessel of some 500 tons left the harbour and this they did not consider worth attacking.  
     
  (vii)  "U 175" Reaches her Patrol Area.  
          Deciding that little could be gained by remaining where they were, they proceeded north from the harbour to the northernmost point of the island.  They then put about and proceeded south, leaving Tobago 10 to 12 miles on the port beam.  Leaving Trinidad to the west, they reached their operational area.
     
  (viii)  "U 175's" first Success  
          "U 175's first success came in the early morning of 18th September, when what was claimed to be a 4,000-ton freighter was sighted off the South American coast.  The U-Boat was surfaced and fired a torpedo which passed astern of the ship.  It was thought that, owing to the intense phosphorescent disturbance created by the torpedo it wa seen in time and, by altering course, the ship managed to evade it.  "U 175" then fired two rounds from her 105 mm. gun in the direction in which it was thought that the ship lay, she still being obscured by early morning mist.  As far as prisoners knew, both rounds missed.  It was then noticed that "U 175" had a bare fathom below her keel and it was taken for granted that their intended victim had run aground.  Because of their extreme vulnerability to air attack in such shallow water, "U 175" proceeded out to sea.     
          (N.I.D. Note.  Sorvangen," a 2,400-ton Norwegian freighter ran aground on 18th September, in position 08° 25' N., 50° 35' W., after being attacked by torpedo and gunfire.  She was subsequently refloated.)  
          After proceeding seawards until 25 fathoms of water was reported "U 175" altered course south.  
     
  (ix)  "U 175" Torpedoes her First Ship  
          At about 1000 G.M.T. what appeared to be a small tanker was sighted when the U-Boat was at periscope depth.  One torpedo was fired, the ship was seen to break her back and sink within two minutes.  It was thought that there were few, if any, survivors.  
          (N.I.D. Note.  "Norfolk," a British freighter of 1,901 tons with funnel and engines aft, was sunk in position 08° 36' N., 59° 20' W. on 18th September.)  
     
     

 

 
 
 
17
 
     
  (x)  "U 175 Sinks Two More Ships  
          No prisoners have given any definite or unanimous evidence regarding the next ships sunk, but sufficient data has been collected in some cases to merit identification with ships known to have been sunk in this area at that time.  
          The majority of prisoners claimed to have sunk a ship on the 19th September,  
          (N.I.D. Note.  If this is so, the only shipping casualty reported on that day which could be admitted as a possibility is the United States freighter "Mae," 5,607 tons, sunk in position 08° 03' N., 58° 13' W.)  
          Prisoners were unanimous that the next sinking occurred on 21st September.  
          (N.I.D. Note.  The only ship sunk on this day in the area was "Predsednik Kopajtic," 1,798 tons in position 08° 30' N., 59° 30' W.; some survivors were picked up.  
          It was now again considered in "U 175" that they were operating too near shore in water too shallow for safety and she again stood out to sea.  
     
  (xi)  "U 175" Attacked by Aircraft  
          Towards midday "U 175" was attacked by a fast bomber which dropped an accurate pattern of depth charges just as she was submerging.  The lookouts were surprised by the attack and prisoners said that they only sighted the aircraft when it was 600 yards distant.  Considerable damage was caused within the U-Boat.  Two battery cells were smashed, there were several short circuits and fuzes blew.  Several hours passed before repairs were completed.  
     
  (xii)  "U 175's" Further Successes  
          This experience had made Bruns warier than ever of operating close inshore, and it appeared that he decided to chance an encounter with a merchant ship in the waters where he was, rather than make again for the coast.  It was not until 24th September that such a chance occurred.  What was claimed as a 5,000-ton freighter was sighted sailing in company with a second ship of an estimated 10,000 tons.  The 5,000-ton ship was sunk from periscope depth by torpedo.  An unsuccessful attack was also made upon the larger ship.  It was thought that both ships were bound for Cape Town.  
          (N.I.D. Note.  The only ship sunk on this date was "West Chetac," United States, of 5,627 tons, in position 08° 45' N., 57° W.  Nineteen survivors were rescued.)  
          Another ship was claimed sunk on 26th September, after "U 175" had moved further into the Orinoco Estuary.  
          (N.I.D. Note.  The ship may have been S.S. "Tambour," 1,827 tons, Panamanian freighter owned by U.S. Maritime Commission, torpedoes without warning at 1006 G.C.T. 26th September, 1942, in position 08° 50' N., 50° 50' W., while on passage from Paramaribo to Trinidad.  The vessel sank by the stern in one minute.  Twenty-four survivors were picked up out of a crew of thirty-two.)  
          On or about 28th September, it was claimed that a 6,000-ton munition ship was sunk in approximately the same area.  Between 0800 and 0900 two hits were scored and the ship sank in a cloud of smoke at 1000.  
          (N.I.D. Note.  The only ship of about this tonnage sunk in this area on this day was "Alcoa Mariner," United States 5,590 tons, in position 08° 57' N., 60° 08'W., on 28th September, 1942.  One torpedo was fired without warning at 0550 E.W.T., and again at 0705 E.W.T.  "Alcoa Mariner" was empty, carrying no cargo or ballast, and was bound from Trinidad to Georgetown.)  
     
  (viii)  Torpedoes Transferred from Upper Deck Containers  
          At about this time the eight torpedoes in upper deck containers were transferred inside the U-Boat.  This operation took six to seven hours and was performed at night.  "U 175" did not move out of her operational area and completed the task without being disturbed.  
     
  (xiv)  "U 175's" Final Successes  
          In the early hours of the morning of 1st October she attacked "Empire Tennyson," British 2,880 tons, and scored a hit with one torpedo.  After the attack "U 175" surfaced and interrogated men in one of the lifeboats.  
          (N.I.D. Note.  "Empire Tennyson" was torpedoed at 0340 on 1st October in position 09° 27 N., 60° 05' W., and subsequently blew up and sank.  After the crew of the port lifeboat had been questioned, the U-Boat which was recognised as of the 740-ton type, proceeded.)  
          The last two ships claimed were sunk on the 4th and 5th October.  
          (N.I.D. Note.  The only two ships sunk on these days were "Carib Star," United States, 2,592 tons, sunk on 4th October in position 08° 30' N., 50° 37' W., and "William A. McKenny," United States, 6,153 tons, sunk in position 08° 35' N., 59° 37' W.  Two boats from the latter ship got away with 34 survivors, who were later picked up.  Nothing is known of survivors from "Carib Star.")  
          Prisoners said that the first of these two ships sank by the stern in shallow water, so that her bows still showed above the surface.  
          Only one torpedo remained for the last ship, and she was finished off by gunfire.  
          For these ships prisoners claimed a total of 42,000 tons excluding "Sorvangen."  It will be seen that the actual tonnage sunk did not exceed 33,975.  
          One other ship, protected by aircraft, which had come within firing range and "acted in a peculiar manner," had not been attacked, as it was suspected that she might be a Q-ship.  Prisoners heard later that she had been sunk by another U-Boat.  
     
  (xv)  "U 175" Returns to Lorient
          Having expended all her torpedoes, "U 175" was ordered to Lorient.  Her course was approximately 050° to Santa Maria Island (Azores), where an alteration was made to 040° until she reached the latitude of Lorient (45° 40' N.), when she turned due East.  Passage through the Bay of Biscay was made submerged by day and on the surface at night.  
          According to prisoners they had been forbidden to dive after crossing the 100-fathom line (about 80 miles off the Scorff Estuary) because of the danger of magnetic mines.  
          Forty miles from Lorient "U 175" was met by one Sperrbrecher and three A/S vessels, which escorted her north of the Ile de Grebs into Lorient.  She arrived on 27th October, having been at sea a total of 78 days.  
          She was first moored alongside a hulk near the Salzwedel Barracks, but the same evening she was moved to No. 1 Pen in the Scorff Shelter.  After four or five days she was docked in Pen 17 of the Keroman Shelter.  While in the shelter "U 175's" periscope was removed and later replaced; her electric motors were overhauled and the Junkers and Electric compressors taken out, checked, and built in again.  
          Metox R.600A G.S.R. was fitted.  
     
     

 

 
 
 
18
 
     
          This work was completed by 16th November, whereupon "U 175" left the shelter and for two days remained moored in the open near the arsenal.  It is thought that she was then again moved into a shelter while various minor repairs were executed.  
          "U 175" had now joined the 10th Flotilla and her ship's company, including Petty Officers, were housed in the Hundius Barracks.  Long leave was granted by watches.  
     
 
B.  SECOND PATROL
 
     
  (i)  Officers  
 
Kapitänleutnant Heinrich Bruns, Commanding Officer.
Oberleutnant zur See Ehrich, First Lieutenant.
Leutnant zur See Verlohr, Second Lieutenant.
Oberleutnant (Ing.) Nowroth, Engineer Officer.
 
     
  (ii)  Torpedoes Carried  
          Twenty-three in all 15 electric, 8 air.  
     
  (iii)  Passage through Bay of Biscay  
          "U 175" embarked torpedoes, ammunition and provisions in the Scorff Shelter.  Between 1700 and 1900 on 1st December she left Lorient, being seen off from the pier by Kapitänleutnant Kuhnke, S.O. of the 10th Flotilla.  She left accompanied by one 500-ton U-Boat, a "guest" U-Boat from Brest, and was escorted by a Sperrbrecher to a point about five miles beyond the Ile de Groix, which was left on the starboard beam.  Course was approximately 250°.  About one hour after parting company with the escort what was first taken to be a salvo of four torpedoes was seen approaching from the port side.  A rapid turn to port was made, and one "torpedo" narrowly missed "U 175's" bows.  It was then seen that the alleged torpedoes were in fact porpoises.  In the middle of the night a G.S.R. contact was reported and a hurried dive was made for a short interval.  "U 175" later surfaced once more, and did not dive again until dawn.  At about 0100 the sound of depth-charges was heard, and it was presumed that the 500-ton U-Boat was being attacked.     
          The routine of surfacing by night, when as speed of about 13 knots was achieved, and submerging by day, was continued until the fifth day (6th December), when "U 175" remained surfaced throughout the day for the first time.  
     
  (iv)  Passage to Operational Area  
          After reaching position 45° N., 15° W., "U 175" had altered course to 195°.  It was calculated that the course she had thus far followed would place her as speedily as possible outside the range of landbased aircraft.  After reaching the approximate latitude of the Azores "U 175" set a south-easterly course towards the coast of Africa.  She passed through the Canary Islands between Gran Canaria and Fuerteventura.  Skirting the African coast being so close at times that prisoners said they occasionally saw natives on the beach, "U 175" finally arrived off Freetown in what was to be her operational area.  On passage she had sighted six Portuguese and three Spanish ships, which she had chased in the hope that they might be enemy shipping.  Considerable time and fuel was thus expended in fruitless effort.  
          "U 175" remained off Freetown during Christmas and the New Year.  She was surfaced the entire time, approaching nearer land at nightfall.  It was said that on one occasion she picked up landbased R.D.F. on her G.S.R. and at once dived.  On 1st January, 1943, "U 175" experienced an attack by aircraft in approximate position 11° 30' N., 21° W.  Six bombs were dropped which did no harm, although "U 175" had not had time to submerge to any great depth.  
     
  (v)  "U 175" Sinks a 7,000-ton Freighter  
          "U 175" continued her patrol without success until 23rd January, when she arrived off Cape Palmas.  Here she sighted a U.S. freighter which appeared to be anchored about 15 miles off shore.  "U 175" approached at periscope depth and coming within range, fired one torpedo.  At that moment the ship, which apparently had been weighing anchor, moved on, and the torpedo missed.  The ship shaped course for the south-east, but "U 175," following, fired a salvo of four torpedoes, all of which found their mark.  The vessel sank about 10 miles from shore and it was growing dark.  Prisoners said that they spoke to a boat and learnt that the ship was "Benjamin Smith," and that she was carrying a cargo of asphalt and cement from U.S.A. to an African port.  
          (N.I.D. Note.  "Benjamin Smith," United States, 7,177 tons, was sunk on 23.1.43 in position 04° 05' N., 07° 50' W.)  
          Following this attack, "U 175" received orders to proceed north, but Bruns considered it more prudent first to head west away from the coast.  
     
  (vi)  "U 175" Sustains a Heavy Aircraft Attack  
          On 30th January, when about 240 miles west of Bathhurst, "U 175" sustained a heavy aircraft attack.  The sky was overcast at the time and prisoners freely admitted that the aircraft which approached from the starboard bow took them completely by surprise.  Reliance had been placed on the look-outs alone, and the G.S.R. was not in use.  "U 175" attempted to crash dive, but barely had she got below surface when a number of depth charges fell uncomfortably close, one actually bouncing off the deck aft.  "U 175" rapidly reached a depth of at least 300 ft.  Damage had been considerable.  Water entered through the stuffing box and exhaust cut-out.  Lighting temporarily failed, the hydrophones were rendered useless and the steering was seriously affected.  Number 4 fuel tank was fractured causing a leak which might have proved serious in view of the long distance "U 175" was from her base.  Owing to the water entry aft causing her to be dangerously down by the stern, batteries spilled and a certain amount of chlorine gas developed.  A large variety of dials and gauges were smashed.  In view of the serious nature of the damage Bruns decided to risk surfacing in the hope that the aircraft had made off.  Fifteen minutes after her initial dive, "U 175" broke surface.  It was at once seen that the aircraft was still circling the vicinity, and Bruns again dived.  Some three hours later a second pattern of depth-charges was heard to explode, but these were well away from the U-Boat and caused no damage whatsoever.  Following this second attack, "U 175" surfaced at once and, according to prisoners, they were then machine-gunned, but did not reply to the fire.  The aircraft then flew off.  
          (N.I.D. Note.  A Catalina attack on a U-Boat in position 12° 08' N., 20° 30' W., on 30th January was reported.)  
          All hands were set to repairing the damage.  After 16 hours everything possible had been done, including the plugging of the water entry aft.  It was found, however, that the propeller guard between the propellers and the ship's side had been loosened and the port propeller, when revolving, struck against the guard, causing considerable noise.  It was therefore decided to use the starboard shaft only, which, it was realised, would seriously handicap the U-Boat should she have to crash dive.  
     
  (vii)  "U 175" is Refuelled  
          Before this attack "U 175" still had about 72 tons of fuel left, more than sufficient to see her safely back to Lorient.  Owing to the burst tank, however, the fuel situation had become critical and Bruns signalled Admiral U-Boats that he wished a rendezvous with a supply U-Boat.  
     
     

 

 
 
 
19
 
     
          This rendezvous was arranged and took place on, or about, 15th February in approximate position 29° N., 019° 30' W., "U 175" having passed through the Cape Verde Islands between Porta Praya and Mayo.  Prisoner said the supply U-Boat was commanded by a tall gaunt man, whom they were told was Korvettenkapitän Czygan ("U 118").  The two U-Boats met in the early morning hours, and the transfer of between 25 and 30 tons of oil was completed by 1130, hoses of 4-in. diameter being used.  Few of "U 175's ship's company were allowed on deck at the time owing to the danger of air attack, and for the same reason there was no exchange of visits between the two U-Boats.  "U 175" was also given some new valves for her G.S.R. and some fresh provisions.  During the transfer of oil the sea was Force 1 or 2.  Prisoners said it was not possible to refuel in a sea of more than Force 4.  
     
  (vii)  "U 175" returns to Lorient  
          Having refuelled, "U 175" set course for base.  She held a general course of 010° to the latitude of Lorient when she headed due east, reaching the Scorff estuary having passed north of Ile de Groix.  
          The G.S.R. was operating throughout the return through the Bay of Biscay, but prisoners said that the ship's company preferred to be without it, for while it was manned they were constantly waiting to reports of enemy aircraft, and this unnerved them.  
          For five days before reaching port she had submerged by day and surfaced at night.  "U 175" reached Lorient on 24th February.  
          The ship's company found that the town had been razed by R.A.F. raids.  Streets were impassable and not a home was left whole.  The Salzwedel Barracks were in ruins and the Hundius Barracks heavily hit.  Because no other accommodation was available the men joined the complements of other U-Boats and were quartered in the air raid shelters of the Hundius Barracks, 48 men to a shelter.  
          "U 175" was first docked in the Scorff Shelter for two or three days, while her periscope was unshipped, then moved to Shelter III for about 24 hours, and finally dry-docked in Shelter II, dock 8.  Her the base of the electric compressor was strengthened, having been damage in the aircraft attack; a number of battery cells were also replaced, and the Junkers compressor was again taken out and overhauled.  Repairs were also made to the electric motors.  
          After work in dry-dock was completed, "U 175" re-entered Shelter III for 24 hours and was then returned to the Scorff Shelter.  It had been scheduled that work upon her in dock should be completed by 4th April, but the time was slightly exceeded.  
          At the end of March or beginning of April the ship's company of "U 175" joined all available personnel of the 2nd and 10th Flotillas in an excursion to "Camp Lemp," near Pont Scorff, where they were received and addressed by Admiral Doenitz.  
          At this time Oberleutnant zur See Ehrich left the U-Boat to do his U-Boat commanding officer's course.  Leutnant zur See Verlohr became First Lieutenant and Leutnant zur See Paul Moeller joined as Second Lieutenant.  
          On 9th April, a day before "U 175" sailed on her third and final patrol, a muster was held at which it was found that the two midshipmen were absent.  As punishment they were ordered to keep extra watches at sea.  
     
     
     
     
     
     
     
     
     
 
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20
 
     
 
APPENDIX C
 
 
 
 
SHIP'S COMPANY OF "U 175"
 
     
  (i)  Complement  
          The complement of "U 175" totalled 54 including three Executive Officers, two Executive Midshipmen, one Engineer Officer and a Midshipman (E).  Forty-one men survived in all; among them were the First and Second Lieutenants, the Engineer Officer and two Midshipmen.  
     
  (ii)  Captain  
          Kapitänleutnant Heinrich Bruns, the Commanding Officer, was killed on the bridge of his boat by a shell during the final action.  He was about 30 years of age and belonged to the 1931 term.  He had qualified as a Gunnery Officer.  In 1940 he was Captain of Torpedo Boat T3, until this ship was sunk in the harbour of Le Harve during an air-raid in that year.  In 1941 he had been appointed to a U-Boat Commanding Officers' course and had made one U-Boat patrol as a prospective captain.  He commissioned "U 175" in December, 1941, and remained in command until her sinking.  
          Bruns does not seem to have been a popular officer.  His men regarded him as too ambitious and accordingly incautious because of this.  His First Lieutenant criticised him severely for making his final attack in daylight when he had every reason to wait for nightfall and the added cover that darkness would bring.  The general gossip among the ratings was that "U 175" was not a healthy U-Boat to be in, and a number of prisoners spoke of the fact that there was a general air of foreboding on board when the U-Boat sailed on her last patrol.  
          Bruns had frequently read his men lectures on what to say when captured, and cautioned them that if they gave any more information than their name, rank or rating, number, and home address they would subsequently be tried in Germany for high treason.  
     
  (iii)  First Lieutenant  
          Leutnant zur See Wolfgang Verlohe, the First Lieutenant, aged 22, joined the German Navy in 1939.  His first experience of U-Boats was in the winter of 1940/41 when, as Midshipman, he made a patrol with Kapitänleutnant Helmut Rosenbaum in "U 73."  This patrol was to an area off Iceland.  Verlohr then attended a U-Boat school and then joined "U 175" at Bremen during the final stages of her construction in November, 1941.  He had made all three patrols, the first two as Second Lieutenant and the last as First Lieutenant when he took the place of Oberleutnant zur See Ehrich, who left "U 175" in March at Lorient to train for his own command.  
          Verlohr was quite a pleasant young man with no undue quams about security.  Rather effeminate in appearance, he was conceited and considered the fact that he had spent a total of 195 days at sea in U-Boats entitled him to criticise his Captain and others.  
     
  (iv)  Second Lieutenant  
          Leutnant zur See der Reserve Paul Möller, aged 34, was the oldest man on board.  He joined "U 175" in Lorient in April for her last patrol.  Previously he had been a Merchant Navy captain with the Hansa Line.  Little was thought of Möller's capabilities on board "U 175" and he, himself, does not seem to have worked up much enthusiasm for U-Boat life.  A typical remark of his was, "At one time I thought that all good things came from above, but after depth-charges had been exploding round my head for five minutes I soon changed my mind."  He was a very keen Nazi and extremely security-conscious.  
     
  (v)  Engineer Officer  
          Oberleutnant (Ing.) Nowroth, the Engineer Officer, was still in hospital and could not be interrogated before this report was compiled.  He had been promoted from the Lower Deck and had taken part in all three of "U 175's" patrols.  He was considered an efficient though unpopular officer.  While no alcohol was allowed in "U 175" during her patrols, prisoners related that Bruns and Nowroth were given to excessive drinking bouts together in harbour.  
     
  (vi)  Midshipmen  
          Fähnrich zur See Walter Weppelmann was an insignificant youth with little to say for himself.  Fähnrich zur See (Ing.) Karl Voelker, on the other hand, was a young Nazi firebrand, who boasted that he had joyfully taken part in the destruction of Jewish synagogues in Germany, presumably during the anti-Jewish rioting in November, 1938.  He claimed that he had actually killed Jews with his own hand.  He was popular on board.  
     
  (vii)  General  
          The remainder of "U 175's" complement showed a good average of U-Boat experience,. although frequent replacements had been made following her return from each patrol.  Those who had been with the U-Boat on her first and second patrols complained bitterly of the hardships they had undergone in tropical waters.  The heat was said to be intolerable and in addition the U-Boat was filled with the stench of rotting food, stale sweat and imperfectly flushed toilets.  
     
     
     
     
     
 
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21
 
     
 
APPENDIX D
 
 
 
 
NOMINAL ROLL OF "U 175"
 
     
 
(i)  Survivors:
 
 
 
Name.
Rank.
English Equivalent.
Born.
Nowroth, Leopold Oberleutnant (Ing.) Lieutenant (E)
28.  9.10
Möller, Paul Leutnant zur See Sub-Lieutenant
29.11.10
Verlohr, Wolfgang Leutnant zur See Sub-Lieutenant
21.  4.21
Weppelmann, Walter Fähnrich zur See Midshipman
12.17.23
Völker, Karl Fähnrich zur See Midshipman
22.  9.23
Klotzsch, Helmut Obersteuermann Chief Q.M., 1st Class
12.  2.14
Keutken, Karl Obermaschinist Chief E.R.A.
7.  1.14
Schlosser, Hellmuth Maschinist E.R.A.
6.  2.07
Saurbach, Alois Bootsmannsmaat Boatswain's Mate, 2nd Class
13.  7.14
Kahmann, Werner Maschinenmaat Stoker P.O., 2nd Class
27.  8.19
Niemann, Werner Maschinenmaat Stoker P.O., 2nd Class
22.  6.21
Küffner, Hermann Maschinenmaat Stoker P.O., 2nd Class
24.  3.18
Geimeier, Erwin Maschinenmaat Stoker P.O., 2nd Class
22.  8.19
Böhnisch, Alfred Maschinenmaat Stoker P.O., 2nd Class
19.  9.19
Butscheidt, Josef Maschinenmaat Stoker P.O., 2nd Class
3.  2.16
Köhler, Hermann Funkmaat P.O. Telegraphist, 2nd Class
29.  8.21
Brunken. Herbert Mechanikersmaat P.O. Artificer, 2nd Class
13.12.19
Schwarze, Herbert Matrosenobergefreiter Able Seaman
6.  3.23
Sichler, Albert Matrosenobergefreiter Able Seaman
19.  7.22
Urbaneck, Ewald Matrosenobergefreiter Able Seaman
29.  4.22
Wolf, Dieter Matrosenobergefreiter Able Seaman
7.  4.22
Winkler, Gerhard Matrosenobergefreiter Able Seaman
22.  2.23
Klinger, Max Matrosenobergefreiter Able Seaman
20.  3.22
Woehlmann, Heinz Matrosenobergefreiter Able Seaman
10.11.23
Herklotz, Werner Maschinenobergefreiter Stoker 1st Class
20.  8.22
Bickel, Werner Maschinenobergefreiter Stoker 1st Class
13.  3.23
Labs, Phillip Maschinenobergefreiter Stoker 1st Class
5.10.21
Grund, Werner Maschinenobergefreiter Stoker 1st Class
6.12.21
Schröder, Walter Maschinenobergefreiter Stoker 1st Class
19.  1.20
March, Rudolf Funkobergefreiter Telegraphist
11.  6.22
Rosenkranz, Josef Mechanikerobergefreiter Artificer, 1st Class
15.  8.23
Banberg, Jean Matrosengefreiter Ordinary Seaman, 1st Class
8.  4.24
Kistler, Wilhelm Matrosengefreiter Ordinary Seaman, 1st Class
16.  4.23
Tepke, Alfred Matrosengefreiter Ordinary Seaman, 1st Class
6.  3.22
Herzke, Otto Maschinengefreiter Stoker, 2nd Class
12.  1.22
Brückmann, Gustav Maschinengefreiter Stoker, 2nd Class
29.  4.23
Petrik, Josef Maschinengefreiter Stoker, 2nd Class
2.  1.23
Bluemling, Peter Maschinengefreiter Stoker, 2nd Class
31.  1.22
Noak, Gerhard Maschinengefreiter Stoker, 2nd Class
27.  2.22
Wannemacher, Peter Mechanikergefreiter Artificer, 2nd Class
17.  4.24
Stachel, Ludwig Matrose II Stoker, 3rd Class
3.  5.24
     
 
Officers . .
3
Chief and Petty Officers . .
12
Men . .
24
   
41
 
     
  (ii)  Casualties:  
     
Name.
Rank.
English Equivalent.
Bruns, Heinrich Kapitänleutnant Lieutenant-Commander
Lohmeyer Fähnrich zur See Midshipman
Schlie Obermaschinist Chief E.R.A.
Schlüter Bootsmannsmaat Boatswain's Mate, 2nd Class
Krause Bootsmannsmaat Boatswain's Mate, 2nd Class
Falter Maschinenmaat Stoker P.O., 2nd Class
Zacharias Funkmaat P.O. Telegraphist, 2nd Class
Flickinger Maschinenobergefreiter Stoker. 1st Class
Kordt Maschinengefreiter Stoker, 2nd Class
Steinle Maschinengefreiter Stoker, 2nd Class
Wönnemann Funkgefreiter Ordinary Telegraphist, 1st Class
Wienand Mechanikergefreiter Artificer, 2nd Class
Fritze Matrose II Stoker, 3rd Class
     
 
Officers . .
2
Chief and Petty Officers . .
5
Men . .
6
   
13
 
     
  (iii)  Total Crew:  
     
 
Officers . .
7
Chief and Petty Officers . .
17
Men . .
30
   
54
 
     
     
     
     
     
     
  (C49300)   500   7/43  
     
     

 


 

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