Analysis of U-boat Operations, Convoys SC 121, HX 228, SC 122 and HX 229

This Convoy sailed on the first of the month and it was not until the early hours of the 10th that the Convoy, then in 33° West, had been seen; later in the day a U-boat was sighted by an aircraft from USS Bogue, which sailed with this Convoy. Bogue was stationed in a lane seven cables wide between the 5th and 6th columns when not engaged on flying operations. The Carrier had an escort of two U.S. destroyers and this screen was reinforced by one destroyer from the escort during flying operations which took her clear of the Convoy. She patrolled with her screen p.m. on the 10th, after having put up two aircraft in the air on the 7th and two on the 10th. During the latter sortie a U-boat was sighted, but the value of this encounter to the escort was reduced by the fact that the aircraft's depth charges jammed; and by delays and inaccuracies in reporting the U-boat's position.

B 3 Group escorted the Convoy and consisted of Harvester (Senior Officer), plus three destroyers and four corvettes. Two destroyers were Polish, three corvettes were Free French.

The first attack on the Convoy was at evening twilight on the 10th March in 29° West, with visibility about four miles; a submerged attack was suspected. This was followed by a second attack shortly after midnight, which led to one of the dramatic incidents of the war. As a result of the escorts' search, Harvester sighted a U-boat and attacked with one fourteen charge pattern. The U-boat then surfaced and moved off at hight speed. Harvester, however, was after it at once and rammed it at about 26 knots. The ship slid over the casing and the U-boat hung under the stern and could not be dislodged for about ten minutes. It was last seen off Harvester's stern at an angle estimated at 40° with all abaft the conning tower below water. There were many survivors in the water - some were seen to be abandoning ship before the U-boat was struck, but Harvester, pre-occupied with her own damage, only recovered one. It is now known that this survivor came from U-444.

While all this was happening Aconit obtained an R.D.F. contact, which was probably Harvester, and, while approaching to investigate, obtained another contact. This second contact was found to be a U-boat, proceeding slowly on the surface, which was then rammed. Aconit picked up a few survivors and these also were from U-444. It appears, however, that they were already in the water when Aconit hit the U-boat.

In spite of considerable damage Harvester was able to proceed at 11 knots on one engine and accordingly Aconit was ordered to rejoin the Convoy. Unfortunately, at about 0800/11 Harvester's remaining shaft broke and she became disabled. Aconit came back to her but was unable to reach her before Harvester was torpedoed. However, Aconit depth charged and rammed U-432, which had just disposed of Harvester. It is very much regretted that Commander Tait, an oustanding Group Leader and very highly respected in his mixed group of British, Poles and Free French, lost his life in HMS Harvester.

Good air cover was provided on the 11th March and there were some promising attacks by aircraft and no more attacks by U-boats.

To Convoy SC 121	To SC 121 Analysis + charts/all convoys
To Convoy HX 228
To Convoy SC 122	To SC 122 Analysis
To Convoy HX 229	To HX 229 Analysis
See also the Statistical Analysis

Analysis of U-boat Attacks on Convoy HX 228 (text very blurry, numbers hard to decipher)
Attacks on Convoy	Detection of U-boat(s) before attack	Time	Ships torpedoed	Time	No. of escorts present	Action taken after attack	Time
1st	–	–	Tucurinca (61*) port side	2029/10	6	Escorts proceeding to take up night stations at time of attack. Operation Artichoke ordered by Harvester (S.O.). Roselys ordered to pick up survivors from No. 61.	2036?/10
			Andrea F. Luckenbach (64*) port side	2030/10		Harvester obtained asdic contact while screening No. 64.	2045/10 appr.
2nd	–	–	William C. Gorgas (121*) starboard side	0115/11	6	Half Raspberry ordered. Harvester, resuming station on starboard beam, sighted and rammed U-444.	0120/11 appr.
			Jamaica Producer (13*) felt heavy explosion. Able to proceed with convoy	0116/11
3rd	–	–	Brant County (125*) probably starboard side	0350/11	5	Half Raspberry ordered by Escapade (now S.O.). Renoncule (starboard beam) obtained contact and attacked.	0401/11
* The station numbers given here do not correspond to those given on the A 1 form, which has the ships in the following stations (the discrepancy might be due to the fact that there are no ships in column 1): Tucurinca - station 71 Andrea F. Luckenback - station 74 William C. Gorgas - station 131 Jamaica Producer - station 23 Brant County - station 135 Please note that these were not the only ships torpedoed in this convoy - see my 3 pages about HX 228.

Analysis of Detection of U-boats by Ships - Convoy HX 228
Time/Date	Ship	Position of ship (relative to Convoy)	Position of U-boat (relative to Convoy)	Method of Detection		Weapons used	Remarks
2045/10 approx.	Harvester	astern screening No. 64	astern 2 1/4'	Asdic	–	14 D/C's	No.'s 61 & 64 torpedoed
0120/11 approx.	"	starboard beam 5,000x	starboard beam 3'	R.D.F. 1,000x	Sighting	14 D/C's - gunfire	U-444 rammed
0125/11	Aconit	astern	about 2 1/2' astern	R.D.F. 5,500x	Sighting 300x	Gunfire	U-444 rammed and sunk
0401/11	Renoncule	1,500x abeam rear ship, starb. column	starboard beam 3,000x	Asdic 2,000x	–	10 D/C's	No. 125 torpedoed at 0340
0428/11	Garland	starboard bow 3,000x	starboard bow 3 1/2'	H/F D/F R.D.F. 5,100x	Asdic 2,250x	10 D/C's	–
1212/11	Aconit	astern	about 60' astern	Sighting (horizon)	Asdic 1,300x	10 D/C's 10 D/C's Hedgehog Gunfire	No explosions after Hedgehog attack. U-432 rammed and sunk
1400/11	No.'s 124, 125, 123 & 115	–	in convoy	Sighting	–	Gunfire	–
1630/11	Roselys	astern	about 30' on starb. quarter	Sighting 14,000x	–	–	U-boat disappeared
Again, please note that the station numbers of torpedoed ships do not correspond to A 1 form - see table above. This probably also means that the ships referred to as being in stations 124, 125, 123 and 115 are not the same as those on A 1 form.

Analysis of Detection of U-boats by Aircraft - Convoy HX 228
Time/Date	Aircraft	Position of U-boat (relative to Convoy)	Method of Detection	Weapons used	Remarks
1226/10	Aircraft from USS Bogue	10' on port bow	Sighting	–	D/C's jammed
0905/11	Liberator B / 120	20' on starboard quarter	Sighting	4 D/C's	Escort
0941/11	Liberator B / 120	20' on starboard bow	Sighting	–	Escort
1122/11	Liberator B / 120	26' on starboard quarter	Sighting	2 D/C's	Escort
1128/11	Liberator B / 120	40' ahead	Sighting	–	Escort No D/C's left
1254/11	Liberator R / 86	8' - 10' ahaed	Sighting	–	Escort

Aa–Al	An–Ar	As–Av	Ba	Be	Bi–Bl	Bo	Br–Bu	C	D
E	F	G	Ha	He	Hi–Hy	Hø	I	J	K
L	M	N	O	PQ	R	Sa–Sc	Se–Sj	Sk–Sn	So
Sp–St	Su–Sø	Ta–Te	Th–Ti	To	Tr–Tø	U	V	W	Ø