Convoy OB 293

OB 293 was a North Atlantic convoy which ran during the battle of the Atlantic in World War II. It was notable for seeing the loss to the Kriegsmarine (KM) of GS U-47 (1938), with her commander KL Günther Prien, the person responsible for the sinking of HMS Royal Oak (08) two years previously.

Prelude
OB 293 was a west-bound convoy of 37 ships, either in ballast or carrying trade goods, and sailed from Liverpool on 2 March 1941 bound for ports in North America.

It was escorted by an escort group of two destroyers, HMS Wolverine (D78) and HMS Verity (D63), and two corvettes, HMS Arbutus (K86) and HMS Camellia (K31). They were led by LtCdr Rowlands of Wolverine, which would stay with them till they left the Western Approaches. (At this stage of the campaign escort groups were too scarce to provide "end-to-end" cover).

On 6 March 1941 the convoy was sighted by GS U-47 (1938) commanded by Prien. After sending a sighting report he set to shadowing the convoy, being joined throughout the day by three other boats. They were GS U-99 (1940) (Kretschmer), GS U-70 (1940) (Matz) and GS UA (1939) (Eckermann).

Action
The wolf pack launched its attack on the night of March 6-7.

In the early hours of 7 March U-99 slipped into the convoy from ahead, to attack on the surface. She torpedoed and sank the tanker Athelbeach, already damaged by U-47, and the whale factory ship Terje Viken. U-70 damaged a British tanker, Delilian, and a Dutch tanker, Mijdrecht. The latter rounded on U-70 and attempted to ram, forcing U-70 to crash-dive to escape. UA hit a freighter, but did not sink her.

The response of the escorts was swift and effective. The U-boats were subjected to a fierce bombardment as the warships chased down contacts. Over 100 depth charges were expended over a five-hour period. UA was damaged but was able to escape. U-99 only escaped by diving deep and waiting out the attack. U-70 was damaged in the onslaught and forced to the surface, where she was fired on and sunk by the corvettes Camellia and Arbutus.

U-47 avoided damage and was able to stay in contact with the convoy, sending further reports and requesting reinforcements. They had also been able to torpedo Terje Viken, which was straggling after being damaged, though she still remained afloat. The escorts attempted to bring her to port, but she finally sank on the 14th. Her loss was credited to both U-99 and U-47.

At about 1am on the night of March 7-8, Wolverine sighted a U-boat on the surface which she identified as U-47. She and  Verity attacked, and after four hours the U-boat was driven to the surface within yards of Wolverine, before diving again. The destroyer sent down a pattern of depth charges and was rewarded with an underwater explosion, marked by an orange glow, and flames that broke the surface.

Aftermath
Wolverine was credited with destroying U-47, and this featured in the official record until the late 1990s. However, after reviewing the available records modern historians regard this attack as being directed against UA, which was badly damaged, but survived to reach port.

No conclusion can be reached about the fate of U-47, and it is thought likely to be the result of a diving accident.

The success of the defence of OB 293, with the loss of Prien, coupled with the successful defence of Convoy HX 112, and the loss of two more aces, Kretschmer and Schepke, one week later, marks a minor turning point in the Atlantic campaign.