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

U 473 SUNK BY SHIPS OF ESCORT GROUP 2 on 6th MAY, 1944, and
ESCORT GROUP 5 on 6th MAY, 1944.
(i)     U-473
        U 473, a 500-ton Type VII C U-boat, under the command of Kapitänleutnant Heinz STERNBERG was sunk in position 49° 29' N., 21° 32' W. by H.M. Ships "STARLING", "BENTLEY", "WREN", "GORE" and "WILD GOOSE" on 6th May, 1944.
          U 473 was carrying experimental G.S.R. equipment similar to that carried in U 406 and described in CB 04051(99) pages 8-9.  (For description of U 473's equipment see Section V.)  She was, however, on an operational patrol and was not being used as a purely experimental boat.  
          She carried a complement of 50, including four officers and seven W/T ratings.  There were 30 survivors.  The Engineer Officer, who was very unpopular with the ship's company, was the only officer picked up.  The Commanding Officer, Kapitänleutnant STERNBERG, had a very bad name among the men.  He had formerly served in the "GNEISENAU" and U 473 was often referred to as "U-GNEISENAU".  His men accused him of trying to introduce battleship routine into the U-boat and of punishing them for the slightest offence.  
          During her only patrol U 473 sank U.S.S. "DONNELL".  
          U 473 was attached to the 9th Flotilla at Brest, but she never reached this port.  The only French port she visited was Lorient, where she spent about seven days between her passage from Germany and the start of her last patrol.  
  (ii)    U-765  
          U 765, a 500-ton Type VII C U-boat, commanded by Oberleutnant zur See Werner WENDT was sunk in position 52° 30' N., 28° 28' W., by a Swordfish from H.M.S. "VINDEX" and ships of Escort Group 5.  She had been operating as a weather reporting boat in the North Atlantic, but had been relieved of these duties shortly before her sinking.  
          From her complement of 48, only 11 survived, including the Commanding Officer and First Lieutenant.  The Commanding Officer was accused of acting with great cowardice at the time of the sinking.  Many of the prisoners said that he was the first to leave the boat.  
          Two executive officers only were carried, the C.O. and First Lieutenant, two C.P.Os. (Navigation) carrying out the duties of second and third watchkeeping officers.  
          On returning from her only patrol, U 765 was to have joined the 1st Flotilla at Brest.  
(iii)   Equivalent Ranks
          The following are the Royal Navy equivalents to German Navy ranks used in this report:  
Kapitan zur See   Captain
Fregattenkapitän   Commander
Korvettenkapitän   Lieutenant Commander
Kapitänleutnant   Lieutenant
Oberleutnant zur See   Sub-Lieutenant
Leutnant zur See   Junior Sub-Lieutenant
Oberfähnrich zur See   Senior Midshipman
Fähnrich zur See   Junior Midshipman
          The suffix "(Ing)" after a German rank in place of "zur See" denotes an Engineer Officer.  The suffix "der Reserve" denotes a Reserve Officer.  
- 1 -


U 473
U 765
(i)  Type: VII C   VII C.
(ii)  Tonnage: 500 tons   500 tons
(iii)  Building Yard: Deutsche Werke, Kiel   Deutsche Werke, Wilhelmshaven
(iv)  Commissioned: Beginning June, 1943   19th July, 1943
(v)  Armament:      
        (a)  Guns: One 37 mm. fully automatic on lower bandstand   One quadruple 20 mm. on lower bandstand.
  Two twin 20 mm. on upper bandstand   Two twin 20 mm. on upper bandstand
        (b)  Ammunition: On her first patrol U 473 carried ordinary A.P. for the 20 mm.  This was changed in Lorient for "Minenspreng" ammunition.  The 37 mm. ammunition was "Minenmunition."    
        (c)  Torpedoes: Ten carried.  Six of these were Eto Fat, some of which were T 3A, and four were T 5.   Ten carried.  Eight of these were T 3 and two were T 5.  The T 5 were loaded in Tubes III and V
  Two T 5 torpedoes were loaded in Tubes II and V.  One was stowed forward and one aft.    
  On her first patrol (March 1944) U 473 carried 10 torpedoes stowed as follows:    
Tube I T 3A
Tube II T 5
Tube III T 3
Tube IV T 3
Tube V T 3
Port upper T 3
Port lower Fat I
Starboard lower Fat I
Starboard upper Fat 1
After bilge T 3A
- 2 -


U 473
U 765
        (c)  Torpedo Tubes: U 473 had bronze torpedo tubes   U 765 had steel torpedo tubes with four bronze rails inside them.  The tubes were continually rusty.
(vi)  Radar: None carried   None carried
(vii)  G.S.R.: U 473 carried experimental G.S.R. equipment similar in most respects to that installed in U 406 (See C.B. 04051(99)).  For description of this equipment see Section V (i).  U 473 carried Wanz II, Borkum, and Naxos G.S.R.  She had one drum-shaped aerial and one standard Naxos aerial which was installed before the last patrol.  An order was received not to use Radione in connection with the Naxos set but to attach the headphones direct to the amplifier stage.   U 765 carried Naxos, Wanz II and Borkum.  She carried two aerials for the Naxos.  One was a Fleige type aerial (See Section V (i) a     ).  The other was a normal Southern Cross aerial.  The Wanz was operated with a drum shaped aerial.
(viii) Infra-Red Apparatus: U 473 carried "seehund" and "Flamingo" apparatus.  For description of this apparatus see C.B. 04051(99), page 9.    
(ix)  Hydrophones: One prisoner stated that G.H.G. and K.D.B. were fitted.  A special log of all noises heard on the K.D.B. in the Bay of Biscay had to be kept.    
(x)  Flotilla: Attached to the 9th Flotilla, Brest, but never reached the port.   Was to join 1st Flotilla at Brest on completion of her sole patrol.
- 3 -


(i)  Departure from Lorient
        U 473 left Lorient on 27th April, 1944, with orders to proceed direct to her operational area.  She was escorted out of harbor by three minesweepers.
(ii)  First attack by Aircraft
        Shortly after leaving Lorient U 473 was attacked at night by an aircraft which approached the boat from astern and switched on its searchlight partially illuminating the U-boat.  The guns' crews immediately opened fire and the aircraft turned and made off.  In turning it presented a very good target to the U-boat's fire, and prisoners thought that if their aim had been more accurate they could easily have brought this aircraft down.  (N.I.D. Note:  At 0327 on 28th April, 1944, an attack on a U-boat was carried out by a Halifax M/58 in position 46° 58' N. 10° 30' W.  The aircraft on anti U-boat patrol had a radar contact at eight miles and on homing dropped flares and sighted a U-boat fully surfaced, course 225 speed 15 knots.  Aircraft attacked with seven 250 lb. Torpex D/Cs from 100 ft., spacing 80 ft. which are believed to have straddled the U-boat.  During this attack the aircraft was hit by flak, but the captain regained control.)
(iii)  Second attack by Aircraft
        Shortly afterwards U 473 was again attacked by a four-engined bomber which dropped four bombs in the immediate neighborhood.  No damage was done.  (N.I.D. Note:  At 0215 on 29th April an attack was made by a Wellington W/304 in position 45° 30' N., 11° 00' W.  The aircraft on anti-U-boat patrol obtained radar contact at five miles, homed and sighted in the moonlight a fully surfaced U-boat at half a mile.  Aircraft attacked with six 250 lb. Torpex D/Cs from 50 ft.  Saw last explosion about 20 yards ahead of U-boat, the remaining explosions being obscured.  Aircraft shadowed U-boat for one hour, U-boat remaining on surface during this time.)
  (iv)  Attack on U.S.S. "DONNELL"  
          On 3rd May, 1944, U 473 came to periscope depth to receive wireless routines.  While proceeding at this depth, STERNBERG sighted a convoy and two destroyers, one of which was proceeding ahead and one abeam of the convoy.  U 473 reported to Control that she was in contact with a convoy.  She then attacked one of the destroyers, firing a T 5 from her stern tube.  Immediately after the attack she crash dived to 180 metres (590 ft.).  A depth charge attack followed immediately and thirty-four depth charges were counted by the ship's company.  (N.I.D. Note:  U.S.S. "DONNELL" was torpedoed on 3rd May, 1944.)  
          This attack took place about mid-day and when U 473 surfaced at about 2300 she followed the convoy at top speed in an attempt to overhaul.  At about 0500 on 4th May she had sighted nothing and dived.  She had been only slightly damaged during the depth charge attack, but found that she was leaving an oil track and discharged two tons of oil to empty the leaking tank.  
  (v)  Sinking of U-473  
          On the night of 4th May U 473 surfaced to charge batteries.  She dived again at dawn and nothing occurred until a few hours later when a depth charge attack commenced.  (N.I.D. Note:  At 0859 on 5th May the Second Support Group was in the middle of and "E.I." turn from 270 to 180 when "WILD GOOSE" obtained an asdic contact in position 49° 20' N. 21° 02' W. and dropped a ten charge pattern.  "WREN" and "STARLING" closed her while "BENTLY" and "GORE" carried out operation "Observant".  Following the initial attack, a large number of further attacks were carried out by "WILD GOOSE", "WREN" and "STARLING" until 1843.  In all 345 D/Cs were fired at settings from 50-700 feet but the U-boat was very deep and the charges exploded above.  S.O. E.G.2 reported that during the D/C attacks the enemy at times used continuous circling tactics.  Prisoners stated that for a period the compass was out of order but that part of the circling was due to the Commanding Officer ordering large amounts of rudder.)  
- 4 -


        Throughout these attacks prisoners counted 334 D/C explosions.  The U-boat was submerged for about 20 hours but as none of the D/Cs exploded beneath the boat very little damage was done.
        After an initial dive to 180 m.  (590 ft.), U 473 was steadied on 200 m.  (656 ft.) and remained at that depth for most of the attacks.  She never went deeper.  The CO2 content gradually rose 3.5% and both batteries and high pressure air were very low.  (N.I.D. Note:  After having harassed and attacked the U-boat all day the S.O. of the Support Group decided to wait until she came up for air.  After dark "STARLING", "WILD GOOSE" and "WREN" followed about one mile astern of their victim on a north westerly course while "BENTLEY and "GORE" took station six miles to the North Westward to cut off the U-boat if she tried to escape at high speed.)
        U 473 finally surfaced at 0014, 6th May, when owing to the condition of the air in the boat, it was impossible to remain submerged any longer.  She was immediately engaged by the attacking destroyers.  (N.I.D. Note:  The U-boat surfaced at 0014 on 6th May and was immediately illuminated and engaged by "STARLING", "WILD GOOSE" and "WREN".  All ships scored numerous hits on the high speed zig-zagging U-boat.)  As soon as she surfaced a T 5 was fired from the stern tube which missed the stern of a destroyer by 3 metres.  The order was given to prepare tubes I, III, and IV, but before STERNBERG could give the order to fire, he was killed on the bridge and these tubes were never fired.  (N.I.D. Note:  At least one torpedo was fired which passed down "WREN'S" port side.)
        One prisoner stated that a shell penetrated the conning tower and damaged the electric steering gear.  (N.I.D. Note:  Early on in "STARLING" it was difficult to see the target in the surf and spray, but later a red glow in the conning tower provided a perfect aiming mark.  "STARLING" herself fired 133 rounds of 4-inch H.E. from "A" mounting.  "WILD GOOSE" refers to five H.E. shells which were fired at this particular U-boat.  Shell No. 1 was observed to hit on the water-line forward of the conning tower, it penetrated and burst; no damage was observed.  Shell No. 3 hit on after gun platform, threw gun overboard and opened up the hull.  Shell No. 4 burst well forward, no damage observed.  Shell No. 5 hit on water line about 12 ft. abaft the conning tower, penetrated and burst internally.)  No sinking report was made to Control as all W/T gear had failed during the depth charge attack.  (N.I.D. Note:  The ship's company soon took to the water and the U-boat was left circling at high speed.  She finally sank in position 49° 29' N., 21° 22' W.  at 0033.  Two small underwater explosions were heard at 0035, probably scuttling charges and at 0042 a very heavy explosion marked the end of U 473.  Thirty prisoners were picked up.)
- 5 -


(i)    Commencement of Patrol
        U 765 left Kiel on 18th March, 1944.  She proceeded without escort to Kristiansand S., where she remained about seven hours topping up with fuel.  She was then escorted to Bergen and spent about ten days there, undergoing repairs to a joint in the pressure hull.  On 3rd April she left Bergen, accompanied by an A/S vessel and two VII C type U-boats.
(ii)    U 765 as Weather Reporter
        After parting company with the other U-boats and the escort, U 765 proceeded through the Rosengarten to take over weather reporting duties from a U-boat commanded by REFF.  She remained in an area south of Iceland (C) about fourteen days, subsequently moving southward to operate off the coast of Ireland (R) and changing her area of operation every eight days.
        (N.I.D. Note:  During the forenoon of 30th April orders were received for H.M.S. "VINDEX" and the 5th Escort Group, consisting of H.M. Ships "BICKERTON", "AYLMER", "KEMPTHORNE", "GOODSON", "KEATS" and "BLIGH" to proceed to the vicinity of 52° N., 30° W., to hunt a U-boat apparently patrolling there on weather reporting duties.
        At 0840 2nd May, when position 53° 42' N., 28° 00' W. had been reached, a U-boat making a WW message was heard bearing 035° fairly close, but not within 30 miles.  The force was turned in that direction to sweep, but at 1104, a message from Admiralty placed the U-boat to southward which seemed to indicate that bearing was reciprocal and as this was confirmed by a signal intercepted from H.M.S. "HOSTE", course was reversed and sweep carried out to the southwestward.
          During the next 48 hours, although information from Admiralty was received that the U-boat was making regular WW reported twice a day, nothing was heard by H/F D/F operators in the group.  The U-boat never used the same frequency twice, so that it was not possible to have reliable H/F D/F ships ready on the right frequency.  At 0922, 5th May, when in position 52° 10' N., 16° W., a bearing was obtained by "BICKERTON", which greatly reduced the field of search.)  
  (iii)   Attack on Destroyer  
          At 1900 on 5th May U 765 came to periscope depth and sighted a convoy.  She fired a T-5 torpedo from one of her bow tubes and immediately dived to 100 meters (328 ft).  Two explosions were heard and WENDT believed that he had sunk a destroyer.  
          (N.I.D. Note:  It was learnt afterwards that "BICKERTON" and "BLIGH" passed close to the U-boat and were presumably the objects of this attack.)  
  (iv)   U 765 sighted by Aircraft  
          Four hours later U 765 surfaced to charge batteries but after about three quarters of an hour an aircraft was sighted flying towards her.  The U-boat opened fire on the aircraft, which did not attack, but trained a searchlight on her and a destroyer two miles to port was said to have opened fire.  U 765 crash-dived to 60 metres (197 ft.) and proceeded for three hours on a southwesterly course at slow speed.  
          (N.I.D. Note:  At 0024, 6th May, a confirmed sighting of a U-boat by an aircraft was reported from "VINDEX".  As this was only twelve miles from the carrier, "KEATS" was detached from close escort and commenced operation "Observant" round the aircraft's marker.)  
  (v)  Depth Charge attack on and sinking of U 765  
          At dawn on 6th May U 765 made another attempt to charge her batteries.  On coming to periscope depth, however, she sighted three destroyers, one only about 100 yards away.  She therefore dived again to a depth of 200 metres (658 ft.).  
- 6 -


        A depth charge attack developed.  At this time diving tank Ii (Internal Tank 1) was leaking and was having to be blown practically continuously.  After the first series of depth charges it also became necessary to blow the outer tank I continuously due to the boat being stern heavy.  Diving tank III developed a leak into the control room and U 765 was driven down to a depth of about 260 metres (853 ft.) by the depth charges.  Another series of depth charges then blew the boat up towards the surface again.  By this time there was a water entry aft near the Diesels, the drinking water distiller was lying on the floorplates, smashed, and the bow hydroplanes were destroyed.  Just before surfacing there was a dispute between the Commanding Officer and the Engineer Officer.  WENDT ordered the Engineer Officer to take the boat down to 100 metres (328 ft.).  U 765, however, was now about 60 metres (196 ft.) and was steadily rising out of control.  WENDT then entered the conning tower and as soon as the boat surfaced he abandoned ship without giving any further orders.  The boat sank after being on the surface for about half a minute.
        (N.I.D. Note:  Shortly after 0410, "KEATS", having obtained A/S contact, carried out a series of depth-charge attacks.  These attacks, however, were made on a non-submarine target.
        At 0518 in position 52° 21' N., 28° 30' W., while still about 2-1/2 miles from "KEATS", "BICKERTON" obtained a contact classified as submarine.  "BLIGH" began a creeping attack at 0540 and delivered it at 0603.
        The last charge had scarcely exploded when the U-boat conning tower was seen to break surface in the centre of the pattern.  Fire was opened by "BICKERTON", "BLIGH" and "AYLMER", a number of hits being obtained.
        While the gun action was proceeding a Swordfish from "VINDEX" dropped two depth charges which straddled the boat and hastened her end.  Eleven survivors were picked up.)
- 7 -


(i)     Experimental G.S.R. Equipment carried by U 473
        Permission had been sought from Grossadmiral DOENITZ to use U 473 as a G.S.R. experimental boat.  This was, however, refused and she was ordered to sail operationally, but to continue with her trials.
        The experimental gear carried resembled in many ways that carried in U 406 (See C.B. 04051(99)).  The wave bands covered were 5 cm. to 320 cm.  A prisoner thought that this probably excluded the "Fliege" combination.
        U 473 carried seven W/T ratings, which included one P.O. Telegraphist, one Leading Telegraphist, three W/T operators for routine W/T work and two additional ratings who had taken a special six months course in G.S.R.
          (a)  Aerials
Bali I and Bali II. The large and small drum-shaped aerials used with "PUDEL" and "BULLDODGE".
Cuba 1.a and Cuba 1.b. The large and small "parapol Spiegel" (dipoles with parabolic reflectors) used with "DACKEL" and "SPITZ".  One of these is extensible by air pressure to half periscope height, the other by hand to periscope height.
Fliege This aerial consisted of a ring about 35 cm. in diameter, the centre of which was covered with a fine wire mesh.  In the centre of this, with its axis vertical, was propeller-like object, about 15 cm. long, mounted on top of a brass rod connected to the bottom of the ring.  A cable led from the bottom of the ring through the conning tower hatch to the set.  The aerial was fixed to the top of the D/F aerial and when it was used two men were required, one to stand by the aerial and one in the conning tower to unship it if required.  During the patrol six or seven contacts, giving a clear singing tone in the headphones were obtained with this aerial.
Biskayu Kreuz This was fixed to the after periscope block.  It was identical with the old Southern Cross aerial.
Alderney Similar to Fliege and used as a reserve for it; held in the hand and said to give cover up to 12 cm.
Dempferlaterne An experimental aerial looking like a ship's light, which was tried out at Stolpmünde.  It is fitted into the D/F loop and gives contacts from Rotterdam transmissions at a distance of 60 km.  As it was not pressure tight it had to be removed.  A german a/c fitted with a copy of the British "Rotterdam" set was detected at a height of 800 m.  and at a distance of 80 km.  This was said to have been used instead of the Fliege aerial.
            (b)  Sets and Combinations  
  1. "SAMOS" A G.S.R. set covering a higher wave-band than "FANÖ".  The set radiated badly and was consequently used only occasionally with "BULLDODGE".
- 8 -


  2. "FANÖ" This set is identical in appearance with "SAMOS" but covers the wave-band immediately below.  It should have been used with "PUDEL" but, since it radiated badly, was not so used.
  3. "WANZ G. II" Radiated slightly but not seriously.  Was kept switched on circuit with "BULLDODGE" and "PUDEL".  This set was never used in U 473.
4. "BULLDODGE" This combination consists of the large drum-shaped aerial + Borkum + Hela + oscillograph + headphones.  "SAMOS" can also be used with it.  One prisoner said that this set covered from 80-320 cm.  (Hela amplifiers are described in (d) below.)
5. "PUDEL" This combination consists of the smaller drum-shaped aerial + Borkum + Hela + oscillograph + headphones.  "FANO" could also be used with it but never was in U 473.
    No contacts were received with "BULLDODGE" and "PUDEL" during the patrol.
    One man kept a joint watch on the "BULLDODGE" and "PUDEL" combinations.
"SPITZ" This combination covers 12-36 cm. and consists of Cuba aerial, Hela II, Borkum and polarisatic switch.  The range is 20 - 30 Km.  The combination was given by another prisoner as Cuba aerial + Borkum + Hela + headphones and  oscillograph.  The frequency meter could also be used, but was not during U 473's patrol.  Hela I was also said to have been used with this combination.
"DACKEL" Consists of Cuba aerial + Borkum + Hela + headphones + oscillograph.
      The combination was given by another prisoner as Cuba + Hela I + Borkum covering 5-12 cm.  Range 20-30 Km.  Bearing of contact cannot be obtained.
      One man kept a joint watch on the "SPITZ" and "DAKEL" combinations.
      Borkum, used in normal boats as a G.S.R. set, was used in U 473 only as a rectifier.  Two were carried and were only used with "DACKEL" and "SPITZ".  Another prisoner stated that four Borkum rectifiers were carried and were used with all combinations except "FLEIGE".
  8. "FLEIGE" This combination consists of Fliege aerial + Hela + amplifier + headphones.  Contacts were always obtained whenever "SPITZ" and "DACKEL" were receiving them.
      Requires a 220 Volt A.C. supply.  Contacts strength 2, were obtained from a Rotterdam set at a distance of 70 Km.
      The FLIEGE" was said to have picked up transmissions off Northern Ireland (R) and after research it was thought that the Allies were probably working on 2 to 4 cm. as it was believed that certain contacts were not fundamentals but higher harmonics.  A new cable
- 9 -


      for the "FLIEGE" aerial was used in U 473 and U 765.  The cable, which was armored, was 1-1/2 cms. in diameter and was blue in color.  It increased the range from 35 Km. to 45 Km.  The cable was brought from Berlin by Professor SCHWARZ just before U 765 left Kiel on 18th March.  (N.I.D. Note:  According to a captured document "FLIEGE" is identical with Cuba 1.a  See C.B. 03122, S.N.,I.P. (M.P.) 81/44).
  9. "KRAHWINKEL" Set Tried out experimentally but not carried.  Designed for obtaining a continuous note from a passing contact.
          (c)  Testing Sets
  1. Famulus Two Famulus sets were carried.  The test set consisted of a small box with a buzzer inside.  It was never used.
  2. Bug Bug was a small box containing a buzzer similar to Famulus.  Was used exclusively for testing the sets, by holding it near the aerial.  Two of these sets were carried.
          (d)  Hela Amplifiers
                Amplifiers known as Hela I and Hela II were carried in addition to four others.  Hela I and Hela II were 6 or 8 valve low-frequency amplifiers with E.F. 13 steel valves.
          (e)  Oscillographs
                  Two prisoners said that U 473 carried four cathode ray tubes.  One Telegraphist said that she carried six.  
            (f)  Frequency Meter  
                  An accurate Phillips instrument was carried but was not used.  Operators preferred to guess the frequency by the pitch of the contact.  It was intended for use with "DACKEL" and "SPITZ" combinations.  
            (g)  Polarization Switches  
                  Horizontal and vertical polarization switches were fitted and kept mostly in vertical position.  They were never used.  
            (h)  Fitting of G.S.R. Equipment in U 473 and Trials  
                  In October U 473 went to Kiel where the experimental G.S.R. and infra-red equipment was fitted.  From Kiel she proceeded to Neustadt and Pelzerhaken, spending a night at each.  At Pelzerhaken Dr. KRAHWINKEL came on board.  
                  Sometime in November 1943, U 473 proceeded to Stolpmünde, where she carried out two trials with the experimental ships "ANNA" and "KATE" and one aircraft, which were fitted with Rotterdam radar sets.  These sets were a copy of apparatus taken from a crashed British aircraft.  The trials lasted about three weeks.  She then went to Hel and Gdynia, and finally to Kiel where more experimental apparatus was fitted.  She then returned to Stolpmünde once more, where further trials, lasting about a fortnight, were carried out.  
            (i)  Results obtained on Patrol  
                  Good and accurate G.S.R. contacts were obtained during the patrol with the experimental gear and the C.O. himself supervised the work and even operated some of the sets.  Regular reports on results obtained were sent to Control and some prisoners believed that these signals were picked up by Allied forces, which led to their sinking.  
            (ii)  Flamingo Infra-Red Detection Equipment  
                  The aerial, which is pressure tight and stated by one prisoner to be tested to withstand a pressure of 30 atmospheres, consists of a glass container.  Inside the container is a detector unit which rotates continuously  
- 10 -


and is connected via a circuit to a cathode ray oscillograph with a circular trace.  The Flamingo did not set up any interference on other sets.  (See also C.B. 04051(99), page 9).
(iii)    Emergency Transmitters
        A prisoner mentioned a new automatic emergency transmitter with a range of 200 Km. for fitting to dinghies.  It sends out S.O.S. followed by 5 dots.  There is also a key but it may only be used for making S.O.S. signals.  Two aphrodite balloons (R.D.E.) may be adapted for an aerial or if there is sufficient wind a box kite, which takes about one hour to assemble, can be used.  The kite is carried in a large metal container.
        Another prisoner spoke of a similar transmitter which is being developed by Oberleutnant KUGELMEIER and the C.P.O. Telegraphist of the 2nd Flotilla in Lorient.  It is to work automatically on 600 m.
(iv)   Very Long-wave Transmitters
        In addition to the very long-wave transmitters at Nauen and Kootwijk, there is one near Warsaw.  The Kootwijk transmitter has a strength of rather more that 350 kilowatts and Nauen is more powerful; it is not however equal to Goliath.
(v)    U-boat Wavelengths
          U 473 used the 'Diana' wavelength during her first patrol and this gave the best reception.  It is thought that the 'Diana' wavelength is not used now for orders to U-boats to attack convoys.  
          (N.I.D. Note:  "Diana" = Series 8 is at present (August 1944) in use for U-boats operating in the English Channel.)  
  (vi)    "Electra Sonne" Beacons  
          The range of "Electra Sonne" beacons used by U-boats is 350 miles and reception is said to be good.  Prisoners considered considered them an invaluable aid to navigation.  U 473 used them a great deal when on passage to Lorient.  
  (vii)  Steel of U 473's Pressure Hull  
          U 473 was the last U-boat to be built at Kiel the steel of whose pressure hull had a small copper content.  
  (viii)  Reversing Gear  
          U 765 was the last of the U-boats built at Wilhelmshaven to be fitted with Diesels with reversing gear.  No new U-boats are being fitted with it in order to economise in material and reduce weight.  
  (ix)   200-watt short-wave Transmitters  
          Type VII F boats are being fitted with the normal 200-watt short-wave transmitter and the F. K.W. 200-watt transmitter which is air cooled.  
  (x)    Construction of Pre-fabricated U-boats.  
          A prisoner from U 473 said that no more U-boats were to be laid down in Kiel after 1st January and the yards were to work entirely on the construction of pre-fabricated parts of U-boats which would be sent to Gdynia due to damage caused by air raids on Kiel, and at least 1500 workmen had been transferred.  The assembly of U-boats at Gdynia has been delayed as several trains carrying the pre-fabricated parts from different parts of Germany have been destroyed or wrongly routed.  The prisoner had heard that the pre-fabricated bows were manufactured somewhere in Sileia.  He believed the boats built in this way were Type VII C.  
          A prisoner from U 765 said that building of 740-ton U-boats will continue, but construction will be from pre-fabricated sections.  
- 11 -


(xi)   Small U-boat
        A prisoner from U 473 knew of three small U-boats, two at Hel and one at Swinemünde, with a complement consisting of the captain and eight C.P.O.s and P.O.s.  They never left the harbor except at night and during the day were heavily camouflaged and quite inaccessible.  The boat in Swinemünde was about 25 m. long (82 feet) with a glass cupola.  Part of the rudder projected above water about 8 feet from the visible stern.
        (N.I.D. Note:  Probably refers to prototypes of 110' type of small U-boat building at Hamburg, of which none is believed (July/August 1944) yet in operation.)
(xii)  Japanese Submarine
        When U 473 was in Lorient from 20th-27th April, 1944, a large 2,200 ton Japanese submarine was in one of the shelters for part of the time.  It sailed a few days before U 473.  The boat was so long that it protruded from the shelter and there was only a 6ft. 6 ins. clearance between the boat and the wall of the pen.  Two guns were mounted, one forward and one aft, and she had a folding aerial.  Other who had seen the boat said there was an electric cable wound round the hull.  She was unloading rubber and gold.  She left with a cargo of high tension cable and some medical stores.  She was also said to be taking eight Japanese students back to Japan.  When U 473 was at sea on her last patrol a signal was intercepted from this submarine reporting her safe passage through the Bay of Biscay.
(xiii)  Camouflage
        U 473 was camouflaged with special dark grey paint which was intended to absorb infra-red.
  (xiv)  Weather Reporting  
          There were thought to be eight new U-boats which had sailed straight from Kiel to operate off Ireland as weather reporting boats.  A signal was intercepted by U 473 which was believed to be intended for these boats, instructing them to report weather regardless of their own safety.  
          The U-boats acting as weather boats off Ireland did not carry meteorologists.  Boats which do carry meteorologists do not send out weather reports as they are used purely for experimental purposes.  
- 12 -


(i)     France
        (a)    Brest
                There is an enormous G.S.R. station near Brest, which is said to be the largest shore station of its kind.  Its main purpose is to watch for Allied aircraft crossing the coast.
(ii)    Germany
        (a)   Hamburg
                In the Howaldtswerke there is a U-boat shelter which can accommodate six boats.  It is divided into two pens, the roof of which is 16 ft. thick; it is entered through steel doors.  U-boats undergoing final adjustments lie here.  Inside the shelter is a complicated electric generating station.  Two fire engines are kept outside and at night the shelter is used as an A.R.P. shelter by the public.  Railway trucks can be brought right into it.
          (b)   Kiel  
                  A similar shelter to the one at Hamburg is being constructed in the Howaldtswerke at Kiel.  
          (c)   Königsberg  
                  New slips are being built at the Schichauwerft Königsberg.  
- 13 -


(i)    Commissioning
        U 473 was built at the Deutsche Werke, Kiel.  She was commissioned at the beginning of June 1943.
(ii)    Working-up
        On leaving Kiel she proceeded to Swinemünde where the ship's company received Flak instruction.  From there she went to Hel for about six weeks "Agru-front" exercises and then to Libau for about three weeks torpedo firing.  After calling at Pillau for degaussing and to go over the measured mile, she carried out three days silent running trials at Rönne and returned in October to Kiel, where the 37 mm. was mounted.  At Kiel the G.S.R. and infra-red equipment was fitted.
        From Kiel U 473 proceeded to Neustadt and Pelzerhaken, spending one night at each.  At Pelserhaken Dr. KRAHWINKEL came on board.
  (iii)  Trials at Stolpmünde  
          Sometime in November 1943, U 473 proceeded to Stolpmünde, where trials were carried out with the new G.S.R. (See Section V (i)).  After the completion of these trials and the normal working-up programe U 473 returned to the Deutsche Werke, Kiel for adjustments.  
          In January 1944 U 473 returned to Stolpmünde for further trials and after their completion proceeded to Kiel.  On 19th March she left Kiel for Bergen, where she stayed six to eight days, sailing on 1st April for Lorient.  U 473 sank nothing on passage and arrived at Lorient on 18th or 19th April.  
          U 765 was commissioned on 19th July, 1943, at the Deutsche Werke, Wilhelmshaven.  After the usual tactical exercises at Gdynia and Pillau she arrived in Hamburg for working-up.  
          She appears to have visited a large number of the Baltic ports during her working-up period.  In mid-February 1944 she returned to Kiel where she embarked provisions and torpedoes.  
- 14 -


PREPARATIONS FOR SEA OF U 473, 12th to 15th MARCH, 1944, AT KIEL.
                                                                                 (From a Captured Document)
Instruction and Tests
March Time
Instruction of W/T personnel and W/T officer   14th 0800   By Flotilla Officer
G.S.R. instruction.  Compulsory for all officers, W/T personnel and auxiliary (G.S.R.) operators   15th 1400   In W/T office St. Louis
Gunnery instruction for Second Watch Keeping officer, Boatmans Mate and Ordnance rating A   12th     Deck A Cabin 64
C.O.'s Instruction   14th 0815   St. Louis, Operations Office.
Preparations and Trials before going on patrol
D/F calibration   15th 0900   Lying near Buoy A 13.
Embarking Torpedoes   12th 0900   Berth 13.
Embarking Ammunition   13th 1600   Inside Shelter.
Embarking tinned provisions; including bread and potatoes.   19th 0600   Berth 33
Embarking fresh provisions   15th 1200   Berth 33
Embarkation of armament and dinghies   14th 1000   Berth 33
Wiping.  Pilot   12th 1600   Old lock.  5 short blasts.
Compass Adjustment.  Unscrewing caps of mirror system.   14th 1400   Lying in B-system near Monkeberg steamer landing stage 5 short blasts on hooter
Hydrophone Trials   14th 1600   Near buoy 13.  Prepare for diving.
- 15 -


March Time
Final Trimming Test.  Engineer Officer report U-boat base Office for orders two days before trials.   15th 0800   At this time boat to be 300 m. off Tirpitz Mole.
(i  Celebration   15th 1700   Smoking Room St. Louis
(ii  Leave on patrol.   16th     As per special orders.
C.Bs. and Secret Documents   13th 1500   Deck E, cabin 113
        Boat to be in the shelter of Howaldt Dockyard from 12th to 15th March 1944.  In the shelter diesels must not be warmed up and no charging is to be done by Diesel.  Caution when maneuvering.  Beware of hydrophones and propellers.
        Refill and top up all diving and inner tanks with oil.  Ventilate.  Type VII C boats to keep regulating tanks full for final trimming test.
- 16 -



Nominal Roll of U 473
(i)  Survivors:
English Equivalent
GRAMMS, Wilhelm Oberleutnant (Ing.) Sub-Lieutenant (E) 19.5.06.
Chief & Petty Officers  
(ii)  Casualties:
English Equivalent
STERNBERG, Heinz Kapitänleutnant Lieutenant  
SCHULZE, Heinz Leutnant zur See Junior Sub-Lieutenant  
STROHM,       - do -       - do -  
Chief & Petty Officers  
  (iii)  Total Crew:  
Chief & Petty Officers  
Nominal Roll of U 765
  (i)  Survivors:  
English Equivalent
WENDT, Werner Oberleutnant zur See Sub-Lieutenant 6. 2. 16
GELHAUS, Alexander Leutnant zur See Junior Sub-Lieutenant 2. 8. 22
Chief & Petty Officers  
  (ii)  Casualties:  
English Equivalent
TÖLLE, Heinz Leutnant (Ing.) Junior Sub-Lieutenant (E)  
Chief & Petty Officers  
  (iii)  Total Crew:  
Chief & Petty Officers  
- 17 -



Click the icons to view the associated records

Return to the British Interrogation Reports page