F.d.U./B.d.U.'S War Log

16 - 31 March 1941

PG30285

	Date Position, Wind, Weather   and Sea State, Illumination, Events Time Air Pressure, Moonlight etc.
	16.3.   U 552 put into St. Nazaire.  The Commander carried out his first operational trip with the new boat extremely well.  Owing to numerous torpedo failures, the total result is only two steamers of altogether 13,000 GRT.     Convoy U 106:   U 106 maintained contact until 1056.  From a U-boat warning at 1700 in EJ 69, it was conjectured that there was a least one boat in the area at this time.  U 105 reported being in the convoy area.       Convoy U 110:     U 99 requested beacon signal from contact; it is therefore in the immediate vicinity.     U 110 temporarily lost contact between 0205 and 0405 and then remained with the convoy until 0810 which was reported to consist of 15 ships and two destroyers.  At 0830 the boat reported breakdown and requested a relief contact boat.  For the time being contact appeared to be lost.  In the meantime U 74 which was to relieve U 95 as south weather boat, reported its position as AM 11; far to the north, therefore, and in the vicinity of the convoy.  This boat was also detailed for operations on the convoy.  The reasons for not carrying out the order to relieve U 95 will be examined later.  At present the following may be presumed to be in the convoy area.  U 110, 99, 37, 100 and 74.  At 1220 U 37 sighted the enemy in AE 8793 and sent beacon signal.  At 1720 U 110 was again up to the convoy and at 1920 U 99 reported on request that it was in contact with the convoy.  During the course of the evening a wireless message was received from U 37, reporting having been rammed beneath the surface.  It received orders to return.         17.3.   U 48 put out of St. Nazaire for the operational area.             Italian U-boats are to be detailed temporarily for duties as weather boats, as our own boats are lacking.  On the whole, the reports received are prompt and adequate.           Convoy U 106:     U 106 regained contact at 0700.  No further messages were picked up during the day.         In the evening further messages were received; according to these U 106 was still up to the convoy, while U 105 lost contact at 2209.
	- 35 -

 

	Date Position, Wind, Weather   and Sea State, Illumination, Events Time Air Pressure, Moonlight etc.
	Recent messages from the boats reporting numerous unexplained failures, and surface runners, give rise to deep anxiety as regards the torpedo question.  The following report thus: a) U 37,  9 unexplained misses and failures between the 8 and 10.2. b) U 107,  3 unexplained failures and a surface runner between 3 and 23.2. c) U 69,  3 unexplained failures and two surface runners between 12 and 24.2. d) U 97,5 unexplained misses on 24.2. e) U 73,  a surface runner on 24.2. f) U 552,7 unexplained failures on 23.2. g) U 147, 2 unexplained misses at the end of February.   After a thorough examination of the existing battle and firing conditions on the return of the boats, and on the grounds of my personal knowledge of the capabilities and achievements of the Commanders, I am convinced that for the most part the misses referred to were simply failures.  The Torpedo Inspection (Department) and Torpedo Ordnance Department have so far given no explanation for the torpedo failures.  That these failures should suddenly appear after an uneventful six months in torpedo situation, must in my opinion, be significant.   As all the boats concerned, with the exception of U 37, were fitted out in home waters during the cold weather, the suspicion that the low temperature was in some way responsible, may not be unfounded.   I requested Professor Cornelius to come to Lorient for further enquiry and an intensive examination of the situation on the spot.  Boats putting out from home waters have received orders to maintain and check torpedoes with particular care.   Fitting out depots have received instructions not, if possible, to give boats torpedoes which had been exposed to extreme temperatures after ranging.  Recently received reports of successes from boats fitted out in Lorient stress the observation that the torpedoes belonging to these boats are in order.  As a conclusion to the inquiry made by Professor Cornelius in conjunction with the Director of Torpedoes, Lorient, a conference took place today at which the Inspector of Torpedoes was present.     The inquiry has not resulted in an exact confirmation with regard to the cause of the failures, however the material available was examined and put in order, so that practical tests for the discovery and the circumventing of the cause may be started upon.  There is,
	- 36 -

 

	Date Position, Wind, Weather   and Sea State, Illumination, Events Time Air Pressure, Moonlight etc.
	however, complete agreement that torpedo failures are the cause of the increased number of misses by U-boats from German ports, and that B.d.U.'s conjecture that the cold had influenced this, was the most likely explanation.  The question arises whether the oil used for torpedoes is cold resisting.  B.d.U. must demand that the Torpedo Technical Department must test the torpedo in all conditions it is likely to experience (also the effect of cold), before it is used in action.  It must not be, in this connection, that boats in action take the initiative, after a number of valuable enemy ships have been missed.   18.3.   Convoy U 110:   At 0321 U 110 reported the convoy changing course to the SE.  At 0503 the boat reported that the convoy had scattered.  Contact was not reestablished, even with a section of the convoy.  The attack therefore came to an end.  Apart from U 110 which reported the sinking of two tankers, no reports of successes were received from the boats.  Radio Intercept Service reported the torpedoing of three ships.  Boats were requested to report as soon as circumstances allow.       Convoy U 106:     It may be presumed from the two U-boat warnings, that at least two attacks took place on it on 17.March.  At 0203 U 106 lost contact.  U 105 was also silent and was therefore probably not on the scene.  In the evening both boats received instructions to proceed to the south if they were not in contact with the enemy.             UA has put into Lorient.  One steamer of 8,000 GRT was sunk.  The Commander was forced to break off operations prematurely as the boat sustained heavy damage in a depth charge attack and further operations were complicated.  He carried out duties well and with determination.           There was a conference - B.d.U. with the newly appointed Fliegerführer Atlantic; KG 40 (previously operationally under B.d.U.) and other Luftwaffe Groups for operational duties over sea are now under him.  Questions of cooperation and the form it should take in the near future were clarified.             U 69 put out of Lorient and U 551 out of Bergen for the operational area in the Western North Channel.         19.3.   It appears from a message from U 99, picked up by U 37, that the crew have been obliged to abandon the boat and scuttle it.         The lack of any kind of news of U 100, in spite of repeated requests, since the passage report from the North Sea, also increases the anxiety with regard to this boat.  At the moment, I can only reckon with certainty on three boats in the northern area.
	- 37 -

 

	Date Position, Wind, Weather   and Sea State, Illumination, Events Time Air Pressure, Moonlight etc.
	U 76 put out of Kiel for the operational area.     U 95 has put in to St. Nazaire from a long-distance voyage.   Convoy U 106:   U 106 reported the sinking of three steamers of approximately 21,000 GRT from the convoy and two isolated steamers of altogether 14,316 GRT.  U 105 regained contact with the enemy at 0240 and was again beaten off at 0306.  It may be assumed from Radio Intercept reports that it had sunk 2 steamers, including a 6,000 ton tanker.  Contact was again temporarily lost during the day and was reestablished by U 106 at 1602.  The boat reported that a battleship of the Malaya Class was acting as escort.  This lengthy pursuit of the enemy makes it questionable whether my intention to permit both these boats to replenish supplies from ship 41 on about 25 March can be carried out.  It is possible that by reason of insufficient fuel, the boats could no longer return from so far south.  A forewarning for the replenishment of supplies in Culebra is therefore necessary.         A message from U 124, the first boat to take on supplies from the ship on 15 and 17 March, has not yet been received.           Convoy U 46:     Aerial reconnaissance reported an outward-bound convoy consisting of more than 25 ships and 6 destroyers, course 270 degrees, in AM 4649, at 0835.  U 46, outward bound in the vicinity, and the Italian boats to the west have been informed of the enemy sighting.     U 46 gained contact with the convoy at 1100, and maintained it until 1945.  None of our own boats were in the area.  4 Italian boats were detailed for action, also several aircraft which are to be directed to the convoy by the boats.           A further convoy, putting in to port, was confirmed by the Luftwaffe at 0905 in AM 4616.  There are no boats available for deployment.           A third convoy was also reported by the Luftwaffe at 1130 in AM 3364.  Course 2700.   An immediate U-boat operation is impossible here too.  After repeated consultation with the Fliegerführer, an intensified air reconnaissance was planned for the following day in the convoy area, which can be reached by then, while the available U-boats - 3 altogether - are brought up, far enough to the west however, so that they are certain of being ahead of the outward-bound convoy when the Luftwaffe reconnoiters the area.
	- 38 -

 

	Date Position, Wind, Weather   and Sea State, Illumination, Events Time Air Pressure, Moonlight etc.
	20.3.   U 97 put out of Lorient for the operational area.     U 124 reported having replenished supplies from Ship 41.  The boat is returning to the area west of Freetown as instructed.       The Commander of U 95 reports having sunk 5 steamers of altogether 33,000 GRT.  Duties well and efficiently carried out, result very gratifying.         Convoy U 106:     U 106 continues to send messages at long intervals.  According to this boat the enemy deviated first in a northwesterly, later in a southwesterly direction.     U 105 appears to have kept up with the enemy, as it reported at 2358: "contact lost, request beacon signal".           U 46, which lost contact with its convoy the previous evening, reported its position in the forenoon.  From this it would appear not to have found the convoy again.  The Italian U-boats have presumably also passed by.  Altogether 2 FW 200s from Stavanger and 1 FW 200 from Bordeaux were sent out against the north-bound convoy confirmed by the Luftwaffe at 1130 on 19.3.     The aircraft were not able to locate it in the medium visibility.  The three U-boats brought up to action positions to the east, were left in their positions until evening, then, when it was no longer considered possible to intercept the convoy by day, they were ordered, together with the remaining boats still coming up, to the following operational areas:     a) Lines between 10 and 190 W. in the vicinity of the grids:   U 551 - AE 84   U 74 - AE 87   U 98 - AM 11   U 46 - AM 13 b)   U 110 west of Ireland as far as 250 W., research into traffic to Reykjavik.   U 48 - grid AE 74 and 75 and 77 and 78.   U 69 - grid AL 12 and 14 and 21 to 24.         21.3.   At 1201, U 69 outward bound, reported a convoy in sight in AL 8822.  Easterly course.  U 48 also outward bound in the vicinity was detailed for action as were 4 returning Italian boats.  It appeared possible from the probable
	- 39 -

 

	Date Position, Wind, Weather   and Sea State, Illumination, Events Time Air Pressure, Moonlight etc.