Convoy Rescue Ship - Service

Service

Each merchant ship in convoy was typically assigned a station so the convoy formation consisted of several columns of three to five ships. The lead ships of the columns were spaced at intervals of 1,000 yards (910 m) along a line perpendicular to the convoy course. Each ship in the column followed the ship ahead at a distance of 800 yards (730 m). The typical convoy would be approximately 8 to 10 kilometers (5.0 to 6.2 mi) wide and 3 kilometers (1.9 mi) long. The rescue plan for early convoys was to have the last ship of each column rescue survivors of other ships in that column. If the last ship in column was hit, the rescue task fell to the escorting warships. In practice, the escorting warships performed rescue tasks more often than the 25% suggested by random hits on a four-ship column; because some merchant ships refused to leave the protection of the convoy formation to fall back and remain a stationary target while rescuing survivors. Merchant ships were not well suited to maneuver to pick up survivors, and those attempting rescue were hampered by lack of suitable rescue equipment.

Warships attempting rescue were diverted from the task of defending the rest of the convoy from the attacking U-boats or aircraft. The first specially equipped rescue vessel went into service in January 1941. When rescue ships were unavailable, large, ocean-going tugboats or converted trawlers were sometimes designated to perform rescue duty.

The rescue ship was normally assigned a convoy position at the rear of one of the central columns of ships. From this position it could observe damaged ships falling astern of the convoy and quickly rendezvous to transfer survivors.

In addition to equipment for rescuing and treating survivors, rescue ships carried High Frequency radio Direction Finding equipment (abbreviated to HF/DF and known as "Huff-Duff") to assist in the location of U-boats. The rescue ship position at the rear of the convoy provided good triangulation with the HF/DF installation on the escort leader typically patrolling in front of the convoy.

By the end of the war 30 rescue ships had been built or converted, taking part in 797 convoys and had rescued 4,194 survivors from 119 ships. Six rescue ships were sunk.