Biting Back: Success Against The Wolf Packs

January 15, 2014 by Marc Milner
HMCS Wetaskiwin, while in port. [PHOTO: CANADIAN WAR MUSEUM—20070003-048]

HMCS Wetaskiwin, while in port.
PHOTO: CANADIAN WAR MUSEUM—20070003-048

The mid-Atlantic convoy battles of May and June 1942 were a test.

In these two months the real damage to Allied fortunes in the Atlantic came off the east coast of the United States and in the Gulf of Mexico, where a U-boat rampage resulted in nearly one million tons of lost shipping.

But as a result of Wolf Pack Hecht’s operations (The Wolf Pack Attacks, September/October 2013), Karl Dönitz knew that the transatlantic convoys were cleaving closely to the Great Circle route and were no better defended than the year before. Much of Hecht’s effort had directly tested the Royal Canadian Navy, either as individual ships in the token American group A.3, or the notionally Canadian C.1, or in the latter stages of the battle for ONS 102 as largely an RCN operation.

Although British staffs found reason to complain about these Canadian efforts, the mid-ocean battles that followed in July, August and September produced a string of clear Canadian successes: proof that the RCN could sink U-boats at the very least.

This latest test of Canadian mettle began in mid-July, when U-boat Group Wolf, composed of nine submarines all commanded by new captains, formed west of Ireland. The group’s job was to sweep west in transit for the happy hunting ground off the U.S. coast. After chasing phantoms for a week, it was directed onto convoy ON 113. The escort was C.2, composed of two Town-class destroyers, His Majesty’s Ship Burnham and the RCN’s venerable St. Croix, and one British and three RCN corvettes.

HMCS Skeena, May 31, 1940. [PHOTO: CANADIAN WAR MUSEUM—19900321-009]

HMCS Skeena, May 31, 1940.
PHOTO: CANADIAN WAR MUSEUM—19900321-009

By the time Group Wolf made firm contact on July 24, ON 113 had brushed aside two U-boats in transit. The result of U-552’s contact report on the 24th was a short, sharp and balanced battle.

Warned of the imminent contact with Group Wolf, C.2’s senior escort officer, Commander T. Taylor of the RN, ordered his two destroyers to distant screening positions 10 miles ahead of the convoy. At 3:30 p.m., Lieutenant-Commander A.H. Dobson, the commanding officer of St. Croix, reported two U-boats on the surface.

The destroyers split up to deal with the pair, but the U-boat sought by Burnham dove and could not be found. U-90 was not so lucky. The U-boat’s captain was a novice in command and it is generally considered that he handled the crucial first few minutes of contact with St. Croix poorly.

When St. Croix closed within 6,000 yards, U-90 dove. Dobson made an educated guess of the U-boat’s underwater course and his asdic (sonar) operator soon had a solid contact. Within a few minutes, St. Croix made three quick depth-charge attacks.

We will never know with certainty what transpired aboard the U-boat, it was all over very quickly and there were no survivors. Although oil and debris littered the surface, it was not quite enough to confirm a kill so Dobson attacked a fourth time, and got what he—more precisely what the staff at Western Approaches Command and the British Admiralty—really wanted: human remains, evidence that U-90 and some of its crew had been torn apart. This proof was duly collected and preserved in jars for delivery in port. As far as anyone at the time knew, the RCN had just claimed its second U-boat kill of the war.

The contact with Group Wolf on the 24th resulted in an order from Taylor to divert the convoy’s track north, away from the waiting subs. As this was underway the convoy received orders to change course to the south after dark and hold that course for 12 hours before turning west. Both Taylor and the convoy commodore knew that the ordered course change would bring them back on the waiting U-boats, so they made a compromise with the brass in Washington who issued the order: they turned ON 113 east at dusk and then at midnight turned south, as ordered.

A half hour after the southerly course was assumed, in high winds and mounting seas, U-552 torpedoed two ships. At 10:55 a.m. the next morning, ON 113 turned westward again: it had turned a complete circle in the mid-ocean, lost a day’s advance and steered right back into Group Wolf. Deteriorating weather, however, frustrated subsequent attempts to attack ON 113. One more ship was torpedoed: sunk while limping alone into St. John’s. Another merchant ship, damaged in the night attack on the 24th, sank while in tow.

Aerial photo of a convoy at sea. [PHOTO: CANADIAN WAR MUSEUM—20020090-054]

Aerial photo of a convoy at sea.
PHOTO: CANADIAN WAR MUSEUM—20020090-054

The final score from ON 113, two merchant ships for one U-boat kill, left Western Approaches staff with little to complain about. No particular praise was heaped on Dobson for his destruction of U-90, although it was due.

A week later, six U-boats intercepted ON 115, and the ensuing battle had the potential to be one of the great RCN success stories of the war, had the ships been fitted with modern equipment. As it was, C.3—the original Barber Pole Group with their distinct funnel band—fought the U-boats to a stalemate for most of the passage, and the senior officer of the escort group, Commander D.C. Wallace, made innovative use of what he had. By this stage the British were using shipborne high-frequency direction finders to locate the U-boats as they sighted the convoy and sent their contact reports. These HF/DF fixes not only provided a clear indication of how many U-boats were in contact and where they lurked, they allowed the escort to drive down each U-boat as it arrived. With luck, contact would then be broken. Either way, shipborne HF/DF was the key to making sensible battle plans and disrupting a pack attack.

While Canadian escorts—with the single exception of Restigouche—lacked HF/DF, all of them were fitted with medium-frequency direction finders (MF/DF) as a navigational aid. These are present in almost every photo of the period: two large circles set at 90 degrees from each other on a prominent mounting near the bridge. The MF/DF was much less precise than HF/DF, but it provided enough general information to help ships find their way. U-boats in contact with convoys used MF homing transmissions to help other U-boats find the convoy. Wallace knew this, and used it to direct aggressive patrolling by Canadian ships Saguenay and Skeena around ON 115. These patrols not only kept the pack at bay, they led to a contact with U-558 on July 31.

At St. John’s, Nfld., Rear Admiral L.W. Murray (rear centre) congratulates the ship’s company of HMCS St. Croix for sinking U-90 on July 24, 1942. [PHOTO: LIBRARY AND ARCHIVES CANADA—PA169228]

At St. John’s, Nfld., Rear Admiral L.W. Murray (rear centre) congratulates the ship’s company of HMCS St. Croix for sinking U-90 on July 24, 1942.
PHOTO: LIBRARY AND ARCHIVES CANADA—PA169228

On the night of July 30, after several days of pushing back contacts and dodging U-boats, Wallace ordered Skeena to take up a distant screen seven miles north of the convoy, where MF/DF transmissions suggested the pack was gathering. At 6:36 a.m., Lt.-Cmdr. Ken Dyer, RCN, the destroyer’s captain, signalled Wallace that they had spotted three U-boats on the surface. Wallace ordered the corvette Wetaskiwin, Lt.-Cmdr. Guy Windeyer, RCN, off to help. Not only were Dyer and Windeyer professional naval officers, they had recently conducted a prolonged hunt for a U-boat which had gone deep, and had discussed how they might improve their tactics. On July 31, 1942, they got their chance. Hearing that Windeyer was on his way, Dyer signalled “ACTS 16, V.9.” When Windeyer found the passage in his Bible it read, “And a vision appeared to Paul in the night: there stood a man of Macedonia and prayed him saying, ‘Come over into Macedonia and help us.’”

What followed was one of the finest U-boat hunts of the war. Skeena had already made two attacks on U-588 and U-511 by the time Wetaskiwin arrived, then lost contact. A deliberate search resulted in firm contact with U-588. A series of attacks followed, alternating between the destroyer and the corvette. When contact was lost again Windeyer’s careful plot allowed U-588 to be relocated. By late morning, Dyer and Windeyer concluded that U-588 had gone deep, perhaps over 300 feet, too deep for the asdic of the attacking ships to retain a useful contact as they swept in to drop depth charges.

So it was decided to direct Skeena’s next attack from Wetaskiwin. The corvette would stand off and maintain asdic contact and direct the destroyer over the target so its precise position was known at the moment the charges were released. In short, Windeyer used Skeena herself as a weapon. This would later be the standard practice for dealing with deep U-boats.

As Skeena began her final approach—the destroyer was down to her last five depth charges—Windeyer and Dyer made two crucial decisions. The first was that the U-boat had gone beyond its normal safety limit of 350 feet and was probably at its crush depth of 550. Settings on Skeena’s charges were changed accordingly. Then, to compensate for the much longer descent time to 550 feet and the likelihood of U-588 taking evasive action at that depth, the interval between firing the charges was lengthened. This gave the final pattern a much wider area. With the U-boat at the limit of her ability to handle water pressure, even a more dispersed pattern of depth charge explosions could prove fatal.

From left: Murray poses with Lieutenant-Commander Guy Windeyer, commanding officer of Wetaskiwin; Vice-Admiral Percy Nelles and Lt.-Cmdr. Ken Dyer, CO of HMCS Skeena. [PHOTO: LIBRARY AND ARCHIVES CANADA—PA198510]

From left: Murray poses with Lieutenant-Commander Guy Windeyer, commanding officer of Wetaskiwin; Vice-Admiral Percy Nelles and Lt.-Cmdr. Ken Dyer, CO of HMCS Skeena.
PHOTO: LIBRARY AND ARCHIVES CANADA—PA198510

And so it did, but not immediately. Skeena’s attack produced no immediate results, and Wetaskiwin was already moving in for the next depth charge attack when two rending explosions were heard. Debris began to appear on the surface, and Windeyer radioed that there was “Plenty of wreckage over this way,” and added Revelations 13.V.1 for good measure. Boats were lowered to collect the grisly remains, later confirmed by Surgeon Captain Archie McCallum in St. John’s as human. It had taken four hours of skilled hunting to sink U-588: there were no survivors. It seems likely that Skeena’s final attack had sent U-588 on a plunge to depths that burst it like a balloon.

The battle for ON 115, however, was not over. The U-boats of Group Pirate would exact revenge for U-588 from the convoy as it steamed into the fog of the Grand Banks, and HMCS Sackville, the little corvette that would become Canada’s National Naval Memorial, would have her greatest moment.

 

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