Radar and the U-Boat Killers

On 17 March 1941 HMS Vanoc, under the command of by Lieutenant Commander James Deneys, became the first ship to detect and sink a German U-boat using radar.

HMS Vanoc, V Class Destroyer

HMS Vanoc was a British V Class destroyer that was launched in 1917. In March 1941 the ship was deployed with the 5th Escort Group in the North Western Approaches to escort Convoy HX112.

She was accompanied by the destroyers HMS Walker, HMS Volunteer, HMS Sardonyx and HMS Scimitar, with the corvettes HMS Bluebell and HMS Hydrangea also in the group.

On the evening of 16 March 1941 the convoy was attacked by U-boat U-100 and the tanker Erodana was badly damaged. HMS Walker, commanded by Captain Donald MacIntyre, Senior Office Escort, launched a series of counter-attacks against the submarine. Later that night U-100 was joined by U-37 and U-99. Together they launched another attack on the convoy and sank five merchant ships.

HMS Walker, V Class Destroyer

The escorts maintained an intense search and at 1.30 am on 17 March HMS Walker got a firm sonar contact on U-100. Following a series of depth-charge attacks U-100 was badly damaged and forced to the surface. HMS Vanoc was hen able to use its pioneering Type 286 surface radar to quickly locate the submarine. The destroyer turned to engage her at high speed and rammed and sank the submarine. U-100 had a compliment of 44 officers and ratings, of which six were rescued.

The detection and sinking of the U-boat U-100 by HMS Vanoc was the first of the Second World War to be achieved with radar. Type 286 radar was first used by British convoy escort vessels in 1941 and initially could detect a submarine on the surface at a distance of 1 ¼ miles. Later variants were able to detect objects as small as a periscope on the surface and submarines as far away as 5 ¼ miles.

German U-boat U-100

U-boat U-100 was commanded by Kapitänleutnant Joachim Schepke and was one of the Nazi’s most successful submarines of the Second World War.

Her sinking off the south-east coast of Iceland brought an end a career that included six patrols, during which the she sank 25 vessels. U-100 was a Type VIIB U-boat and was armed with 14 torpedoes and with a 3.5 inch deck gun that had 220 rounds.

Following the attack U-99 attempted to make her escape and surfaced a short distance away. The U-boat was detected by HMS Walker, which quickly intercepted her. U-99 was under the command of Kapitänleutnant Otto Kretschmer who realised that they could not evade a further engagement and ordered his crew to abandon ship. Of a compliment of 43 officers and ratings 40 were taken prisoner.