U 575

10. war patrol


February 29 to March 13, 1944



U 575

The battle was lossed for the U-Boates. The enemies are to much and had two considerable advantages. The locations technical and the crack in the Enigma code. The U-Boat forces had yet only two important functions. That was the reason, why the U-Boat forced battled continued. They must to take care, that the Allied forces furthermore used the convoy system. The convoy system commit heavy transport capacity. And the second reason, to absorb the U-Boat hunter Air forces with hundred of big airplanes like Fortress, Wellington etc. Every U-Boat-Hunter plane can not bomb the German towns.  

In the three month of the past dock yard time get U 575 as second Atlantic-boat a Snorkel built-in. On this journey they shall reported her experiences by the snorkeling and used as weather-boat.

With the group “Preußen” operated U 575 from March 9th on the convoy SL 150/MKS41. As ordered they must give a 25 min. radar report about her experiences by the snorkeling. After that, they were directly localized and at the same evening the had enemy contact with a search group. At March 10th they run across to the English Corvette HMS Aphodel (Flower class) with 1.015 GRT on position 45°24´N/18°09´W. U 575 shot a acoustic-target-search-torpedo T 5 (“Zaunkönig”) at 1.54 a.m. and sank with that the Asphodel (grid square BE 5887).

Now follows a 18hours depth charge hunting, they survived it well good. Next enemy contact at the March 13th, shortly after midnight. A attacked Fortress  (R) of the 206.Sq (RAF) with „Leigh-Lights“ were shot down, so the report of the crew. A official validation doesn’t exist. This was the last success of U 575. At the same day sinks U 575 after a hunting of a hunting-killer-group of the USS Bogue. See different sinking reports.



HMS Asphodel


1 x 10,2 cm gun

1 x 4 cm anti air-craft

2 x 2 cm anti air-craft

1 Hedgehog

4 depth-charge

Radar 271 M, Asdic

85 men crew

KTB des BdU
(summery of war diary of the commander of the U-Boats)


29.February 1944

Sailed:  U 575 - St. Nazaire; U 741 - 625 - 392 - Brest;  U 537 - 541 - Lorient.

4. March 1944.

575 - BF 84 (grid square)

Current Operations:

  1. 1) U 741 - 625 - 575 - 653 - 415 have been given AL 70 as new approach point, and later are to join Group "Preussen".

2) Group "Preussen" is manning the attack areas allocated. Its transfer to the N. is planned.

5.March 1944.

575 - BF 76

6.March 1944.

575 - BF 74

7.March 1944.

575 - BE 93

8.March 1944

575 - BE 92

9.March 1944.

  1. On Return Passage:  U 168 - 178 - 183 - 188 - 212 - 257 - 441 - 532 - 539 - 764 - 845 - 985.

Entered Port:  - . –
Sailed:  U 629 - 311 - Brest;  U 766 - 993 - Kiel to Northern Waters.

  1. Air Reconnaissance:  None.
  2. Reports on the Enemy:
    1. U 575 reported when she made her passage report that she had sighted 2 steamers and 2 destroyers at 2300 in BE 8284, course 100, 12 knots.  At 0154 on 9.3. boat fired a T 5 at a destroyer, detonation after 12 1/2 minutes, then "Naxos" location and starshell fired by second destroyer.  Bow T 5 miss was fired at approaching destroyer at a range of 800 meters.  Submarine was pursued for 18 hours by und  and depth charges (destroyer was possibly sunk, clarification impossible until submarine returns).
    2. None.
      1. Periscope sighted in CG 9555, 1 ASV location in unspecified position. 
      2. Radio guardships were located as follows:  "BLX" in BD 4748; "142" in BE 51, BE 34, BE 19.
      3. Enemy units were located in: AL 6780 - AM 6190 - AM 6175 - BE 6110 - 3870 - BF 2294.
    4. None.


  1. Current Operations:
    1. U 255 has joined Group "Preussen" and is manning AK 3869, to a depth of 40 miles.
    2. None.
    3. U JT 24 is to wait for "Brake" to arrive in JC 5451, and refuel for return journey.   U 183 has been given the same square for refueling and according to dead reckoning should arrive there about 19.3.
    4. None.

       V.        Reports of Success:  None.

           10.March 1944.

         575 - BE 57

U 575 sighted a destroyer at 2217 in BE 4956, course NE.

11.March 1944.

575 -  BE 48

U 575 reported her experience with Schnorchel: In areas with strong patrols of search groups it is not possible to run on the Schnorchel as it is impossible to listen. It is also inadvisable because smoke is made. Periscope observation is perfectly feasible. When running on the Schnorchel "Wanze" location (radar) has been observed.

12.March 1944

575- BE 47

13.March 1944.

575- BD 68

Reports on the Enemy: a) 1) U 575 was attacked by a plane in BD 6824 at 0855.

14.March 1944.

575- BD 59

15.March 1944

575 - BD 58

16.March 1944

575 - Op(BD 40)

17.March 1944

IV. Current Operations:
U 575: Last report on 13.3. concerning attack by aircraft. Orders to report weather and position on 15 and 16.3. were not answered. Possibly lost by air attack.


Summary of the Interrogation Report (O.N.I.)


In the period of two and a half months preceding U-575's departure for her tenth and last patrol, complete overhaul and new installations were made.  The Diesel engines, being well worn out by this time were replaced with completely new engines.  A new type 37-mm. automatic gun was installed on Platform II, and the two twin 20-mm. guns were removed, completely overhauled and repaired, and remounted on Platform I.  The conning tower was somewhat altered, the air-raid shelters, which had been installed for the ninth patrol, being removed, and the narrower shape of the conning tower being restored.  A protracted spot for one man, on port side, was all that was retained in the way of shelter.  Wanz G-2 and Borkum were installed in the listening room, and the extensible Diesel intake and exhaust (Schnorchel) was fitted.  The HF/DF gear was installed in the listening room, as was also a second all-wave receiver for the exclusive use of the meteorologist.  Normal trials and tests were then made.

        The purpose of this patrol was primarily to study weather conditions and make weather charts of an area northwest of the Azores.  An officer with silver stripes (rank equivalent to lieutenant junior grade) came aboard for this purpose.  For a description of his activities on board see Chapter III.

        Officers for the tenth and final patrol were:

                Captain:  Oberleutnant Wolfgang Boehmer.

                Executive Officer:  Leutnant Helmut Gramlow.
Second Watch Officer:  Leutnant Harald Mayer.

                Engineer Officer:  Oberleutnant (Ing.) Gerhard Lob (Promoted 1 November 1943).

                Meteorologist:  Marinewetterdienstreferendar Willi Brogmus.

        U-575 sailed from St. Nazaire at 1700 on 29 February 1944, escorted by two mine-destructor vessels.  No other U-boats accompanied her.  At dawn on 1 March 1944, U-575 made her first dive and the escort vessels turned back.

        U-575 traveled on the surface from morning until evening of this first day.  Toward evening she submerged for a while, came again to the surface long enough to launch an R.D.S., then submerged again.  It was during the early morning hours of 2 March 1944 that U-575 for the first time raised her extensible Diesel intake and exhaust (Schnorchel) and proceeded on Diesels at periscope depth.  At dawn she submerged.

        General practice on succeeding days was as follows:  U-575 proceeded through the Bay of Biscay submerged on her electric motors during daylight hours.  At dusk she came to periscope depth, raised her Schnorchel and proceeded in this fashion until about 2300.  She then surfaced for three or four hours to complete charging batteries.  When the batteries were full, she submerged.  (Further details given under Schnorchel in Chapter II.)  

        Each night during the time that U-575 was completely surface, one or two R.D.S. were assembled and set adrift.  The actual distance apart of the R.D.S. set out was estimated by two officers as roughly one every 35 to 40 miles.  R.D.B. were released only when a warning was received on the G.S.R.  This happened only once on the passage of the Bay of Biscay.

        Late in the evening of 8 March 1944, while U-575 was submerged, propeller noises were heard on the hydrophones, and the Captain decided to surface and investigate.  Visibility was poor, so he took his boat down again.  Once more sounds were picked up to starboard.  U-575 surfaced and this time a large shadow was sighted bearing green 30 to 40 degrees.  Again U-575 submerged and continued listening, changing course and gradually moving closer to the origin of the sounds.  When U-575 surfaced, the bridge watch could see bearing 3500 relative a large ship, which they believed to be a carrier, escorted by two destroyers, one a considerable distance ahead and the other close astern.  The three ships turned to port and U-575 maneuvered into position ahead of them.  Before she could get into firing position, the leading destroyer turned towards her.  U-575 turned about and made ready to fire a T-5 at the pursuing destroyer.  Before long, however, the destroyer made off to join the other ships.  U-575 now followed, then attempted to get into firing position to attack the carrier; but the leading destroyer again turned towards her and continued to pursue her.  The captain decided that he must either sink the destroyer or be sunk himself.  He quickly fired a T-5 from the stern tube at a range of 3,000 meters.  After about 12 minutes, during which time U-575 remained on the surface, changing course more than once, an explosion was heard, which indicated that the destroyer had probably been hit.  This view was confirmed in the Captain's mind by the fact that he did not see the destroyer again.

        Immediately after the explosion the second destroyer started firing star-shells and the U-boat picked up with her Naxos steady Radar transmissions lasting fully half an hour.  R.D.B. were released, and the Captain ordered the U-boat turned to starboard.  In the excitement the U-boat was turned to port, and suddenly the destroyer was seen close to and bearing down on the U-boat.  U-575 fired a second T-5, this time from tube 2 forward.  The destroyer may have picked up the torpedo with her hydrophones, one officer believes, for she stopped and later altered course.  The torpedo failed to hit.  U-575 had dived immediately after firing, and the officer's belief may be largely guesswork, however.  A little later, four or five badly placed depth-charges exploded, and the destroyer was heard circling overhead.  According to prisoners, the destroyer then dropped noise-buoys which made a whirring sound and retired to await the arrival of other escort vessels.  U-575 gradually left the whirring sounds behind and was undisturbed for a period possibly as long as two hours.  (O.N.I. Note:  The whirring noises were not caused by sonobuoys.)

        Then for another two hours three or four vessels were heard scouting around overhead.  Then depth-charges started exploding.  The Captain took his boat to 140 meters at first, then, as the patterns began exploding ever closer to the boat, he went to 160 meters.  The lights were put out by the explosions again and again.  The hydrophones went out of order and had to be worked by hand.

The batteries began to reach the exhaustion point, and the air in the boat was foul.  Trim became increasingly difficult to maintain.  Conditions within the boat gradually became more and more serious, although emergency repairs were made as fast as damage occurred.  Then, probably about 1930 on 9 March 1944, the attack abruptly ceased.  Prisoners declared that if one more well-placed pattern had been dropped, it would have been necessary to surface and abandon ship.  To the relief of the crew, the escort vessels now gave up the hunt and no more was heard from them.  U-575 remained submerged and made repairs.

        (O.N.I. Note:  It is probable that H.M.S. STRIKER was the carrier sighted at the beginning of this attack, and that her escorts, H.M.S. BAYNTON (DE) and H.M.S. CLOVER (DE) were the vessels which dropped the depth charges.  On 9 March at 1035 two attacks were reported by these vessels in position 45024' N., 18009' W.  The torpedoed escort may very likely have been H.M.S. ASPHODEL, sunk at 0130 on 9 March 1944 in position 45024' N., 18009' W.)

        No further incident took place until early on 13 March 1944.  Until then, U-575 continued on her course, surfaced at night, submerged by day.  When she crossed the twentieth meridian a report to this effect was radioed to control.  The Schnorchel was used only once in this period.

        On 12 March 1944 at about 2100 U-575 came to the surface.  A shadow was seen, and U-575 moved off without being detected.  Another shadow, then later three more were sighted.  U-575 maneuvered toward them on the surface at flank speed.  At 0145 on 13 March 1944 a four-motored plane with searchlight suddenly appeared coming very low toward the U-boat.  An officer stated the it was so low that he thought it was a surface ship with a light showing.  The plane attacked, raking the U-boat with machine-gun fire.  Fire was returned by the bridge watch, who opened fire at 500 meters.  During this attack the 37-mm. gun was not used, as the plane was already too near when the nature of the attacker was recognized.  The Executive Officer thinks he may have shot this plane down with 20-mm. fire.  (Some prisoners discounted this as boasting; several others, however, claim to have heard something hit the water soon after, and think it may have been the plane, which had circled and returned to drop bombs.)  (O.N.I. Note:  This attack is believed to have been delivered by a Wellington Aircraft B-172 which reported firing on a U-boat at this time and in this approximate position.  This plane was not shot down, so far as could be ascertained.)

        U-575 submerged immediately and heard no more from the plane.  No damage was apparent within the boat, but prisoners believe that a fuel tank had been punctured by the machine-gun fire and that U-575 left an oil trace from this time on.  The attack was reported to Control by "short signal."

        About 0800, U-575 again surfaced.  Within a matter of seconds she found herself again under attack by a four-motored plane.  (O.N.I. Note:  This is believed to have been an Azores-based Flying Fortress, which reported an attack at 0805 on 13 March 1944.)  Again U-575 engaged the plane with gun fire from her 20-mm. guns, and this time also with the 37-mm. gun.  Fire was opened at about 3,000 meters.  The U-boat maneuvered to present as small a target as possible, and the plane circled twice before being able to make its run-in.  The automatic feed mechanism of the 37-mm. gun jammed after only a few rounds were fired.  The gun crew continued to fire single shots until the U-boat dived.  The plane began its run-in from 90 degrees relative to the U-boat and dropped its bombs.  One fell possibly on the U-boat's starboard side, the other two off the port beam.  The U-boat was shaken by the bombs, but again no damage was visible.  The order to crash dive was given at the very moment that the plane flew overhead.  The U-boat submerged and no more was heard from the attacking plane.  She remained submerged until the end of the final attack, which began some six hours later.





detailed informations in German available

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