Intelligence and radar set the trap at Ushant

Enigma intelligence and the Headache radio-listening system warned Allied commanders that German destroyers and a large torpedo boat were moving toward the invasion area. The 10th Destroyer Flotilla then used radar to make contact before the Germans had an equally clear tactical picture. A line-abreast leading division reduced vulnerability to a single torpedo spread and widened the interception front, while smoke and minefields later split the battle into separate encounters. HMS Tartar and HMS Ashanti destroyed the captured Dutch destroyer ZH1, while HMCS Haida and HMCS Huron drove Z32 ashore after it had first escaped the Polish destroyers of the 20th Division. Z24 and T24 escaped badly damaged. The result illustrates how intelligence, formation, radar, and aggressive gunnery reinforced one another at night.