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You are here: Home / Article topics / Publications / Naval Historical Review / U-Boat Battle – Convoy ONS5

U-Boat Battle – Convoy ONS5

Downes, A.M., Captain · Sep 10, 2010 · Print This Page

Author
Downes, A.M., Captain
Subjects
Biographies and personal histories, WWII operations, History - WW2
Tags
U Boats, HMS Tay, HMS Duncan, Anti-submarine operations
RAN Ships
None noted.
Publication
September 2010 edition of the Naval Historical Review (all rights reserved)

’25 U-boats in contact . . .’

The Admiralty had instructed the 3rd Support Group to come and assist us and they joined on 2nd May, but most of the ships had to leave a few hours later as the weather was too rough for them to refuel and they were also running out. Only HM Ships Offa and Oribi remained for the final night. On the evening of the 5th, we received a signal from the Admiralty saying ‘25 U-boats in contact with your convoy, 40 in immediate vicinity closing, 70 in general area’. In fact, we now know from German records that 51 subs were deployed to trap ONS 5 and that Dönitz had called for a final effort.

One of the U-boat skippers who survived the war has since said that the U‑boats thought that they could wipe out the entire convoy during that night. But at last the weather was changing in our favour with near calm conditions and thick fog. This meant that the U-boats on the surface had trouble finding the convoy whereas we could pick them up easily on radar. But now we only had HM Ships Vidette, Loosestrife, Sunflower and Snowflake as effective close escorts with Tay in control but no A/S. Offa and Oribi were all that were left of the support group and they were stationed 3 – 5 miles further out on each bow. We were all running out of depth charges.

Escort Group attacks

The signals coming in were exciting: ‘Oribi – ramming’; ‘Vidette – sank one U-boat with Hedgehog’; ‘Loosestrife – 3 contacts am engaging’. Then ‘one dived dropped 5 charge pattern’. Then ‘one dived, dropped charges’ and finally, ‘third contact dived, dropped 10 charge pattern. U-boat surfaced alongside and blew up’. Snowflake signalled ‘3 echoes bearing 185 degrees’, then, ‘U-boat sighted turned away’. Then ‘second U-boat sighted engaged with 4” gun until dived’ then ‘third U-boat -sighted, dived, dropped 1 charge. No charges left.’ Although this left Snowflake largely impotent she was not yet finished. She came across the U-boat which had been rammed by Oribi but which had not yet sunk and both vessels had a brief gun duel. The U-boat eventually sank or scuttled herself and, in the confusion and fog, Snowflake turned to ram a radar echo, which she thought was the sub and instead almost rammed the Sunflower which was coming to assist her. Snowflake then made the signal ‘Lights in water, interrogative save’, to which we had to reply, ‘Negative, resume station’, because we were so short-handed. And that turned out to be the end of the battle as far as B7 was concerned, four hours later the U-boats withdrew.

That night, we escorts claimed seven U‑boats sunk, four very probably sunk, two probable and many damaged. In fact the Germans later confirmed that they had lost 11 U-boats that 24 hours (one by aircraft attack). Dönitz called off the attack and thereafter the German skippers seemed to have lost their nerve. B7’s next convoy, eastbound, was attacked by twenty U-boats, but the attacks were not pushed home. We did not lose a single ship but we sank five of the attackers.

Incidentally, many of you know the skipper of Snowflake, Harold Chesterman, who now lives in Caloundra and was for years in the Queensland Lighthouse Service ships. I spoke to him the other day and he sent me a photograph of his empty depth charge rails with a notice ‘Sold out’.

Britain nearing starvation levels

Gentlemen, just think of this. Britain was the forward base for the Second Front and troops were pouring into the country. We lost 97 ships in the Atlantic in the first twenty days of March 1943. Britain was nearing starvation levels and the Navy, whilst their ready use tanks were full, had a reserve supply of only thirty days of oil fuel. Quite clearly we could not have sustained these losses. But in May, a total of 41 U‑boats were sunk for the loss of 17 ships. Our own escorts were increasing in numbers and in skill whereas the U-boats had lost their ace skippers and their ability to attack on the surface due to radar and H/F D/F. They had lost the initiative and never regained it. The Wolf Packs, which were so nearly successful, had failed and were never really tried again.

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Naval Historical Review, Biographies and personal histories, WWII operations, History - WW2 U Boats, HMS Tay, HMS Duncan, Anti-submarine operations

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