CAM ship

CAM ships were World War II–era British merchant ships used in convoys as a stop-gap until sufficient escort carriers became available. CAM ship is an acronym for catapult aircraft merchant ship.

The ships carried a rocket-propelled catapult to launch a Hawker Hurricane, dubbed a "Hurricat" or "Catafighter" to attack Luftwaffe aircraft. Normally the Hurricane fighter would be lost when the pilot bailed out or ditched in the ocean near the convoy. CAM ships continued to carry their normal cargoes after conversion.

The concept was developed and tested by the five fighter catapult ships, commissioned as warships and commanded and crewed by the Royal Navy – the CAM ships were ordinary merchant vessels, commanded and crewed by the Merchant Navy.

The Luftwaffe had Focke-Wulf Fw 200 Condor aircraft with a range of nearly 2,000 nmi (3,700 km; 2,300 mi). After the Fall of France, these aircraft could operate from western France against British merchant ships in the Atlantic. Flying from Bordeaux–Mérignac Airport, Fw 200s of I/KG40 could reach the convoy lanes west of Britain while staying outside the range of British land-based fighters. The Royal Navy had no aircraft carriers available to provide close air cover for the convoys. The Fw 200s could shadow convoys, directing U-boat attacks on them, or drop bombs on convoy ships, without opposition and to deadly effect.

To counter this threat, the Admiralty developed the fighter catapult ship – a converted freighter, crewed by naval sailors, carrying a Hurricane fighter. When an enemy bomber was sighted, the fighter would be launched into the air with rockets, and fly up to destroy or drive away the bomber. Being large and slow, the Fw 200 became a rather vulnerable target. After the combat, the fighter pilot would bail out or ditch in the ocean near the convoy, and be picked up if all went well.

The Admiralty had already experimented with this system. They ordered 50 rocket-propelled aircraft catapults to be fitted to merchant ships. The planes were Hurricane Mark Is, converted to Sea Hurricane IAs.

The pilots for these aircraft were drawn from the Royal Air Force (RAF). The RAF formed the Merchant Ship Fighter Unit (MSFU) on 5 May 1941 in RAF Speke by the River Mersey in Liverpool. Wing Commander E.S. Moulton-Barrett commanded the unit providing training for volunteer pilots, fighter direction officers (FDOs), and airmen. After training, MSFU crews were posted to Liverpool, Glasgow, or Avonmouth where they assisted in loading their Hurricanes onto the catapults. Each team consisted of one pilot for Atlantic runs (or two pilots for voyages to Russia, Gibraltar, or the Mediterranean Sea), with one fitter, one rigger, one radio-telephone operator, one FDO, and a seaman torpedoman who worked on the catapult as an electrician.

MSFU crews signed ship's articles as civilian crew under the authority of the civilian ship's master. The ship's chief engineer became responsible for the catapult, and the first mate acted as catapult duty officer (CDO), responsible for firing the catapult when directed. The Hurricane fighter was launched only when enemy aircraft were sighted and agreement was reached using hand and flag signals between the pilot, CDO and ship's master.