Operation Raspberry (ii)

'Raspberry' (ii) was a British tactical manoeuvre designed for employment against U-boats attacking a convoy (1942/45).

Developed under the auspices of Captain R. Roberts of the Western Approaches Tactical Unit, the tactic used some of the convoy escorts to illuminate the entire area with star shells while others undertook triangular sweeps of the surrounding area using their radar and sonar equipments to detect U-boats for otherwise conventional attack.

In greater detail, this meant that as soon as a merchant vessel in one of a convoys inner columns was torpedoed by a U-boat inside the convoy, the warships protecting the convoys outer flanks reversed course and steamed to the rear of the convoy even as the U-boat dived and waited for the convoy to pass ahead of it even as the crew reloaded the boat’s torpedo tubes. On reaching a position astern of the convoy, the warships reversed course once again and advanced in line abreast to cover the rear of the convoy even as they carried out a sonar search for the attacking U-boat as the strength of its possible echo improved in the less turbulent water astern of the convoy.