The Hawker Sea Hurricane W9182 on the catapult of a CAM ship

CAM ships were World War II-era British merchant ships used in convoys as an emergency stop-gap until sufficient escort carriers became available. "CAM" was an acronym for "Catapult Aircraft Merchantman"^[1] and a CAM ship was equipped with a rocket-propelled catapult launching a single Hawker Sea Hurricane, dubbed a "Hurricat" or "Catafighter". CAM ships continued to carry their normal cargoes after conversion.

[edit] Origin

After the fall of France in June 1940, long range German Focke-Wulf Fw 200 reconnaissance aircraft of I/KG40 shadowed and bombed merchant shipping from the French airfield at Bordeaux-Merignac.^[1] The Admiralty had already tried Fighter Catapult Armed Auxiliary Ships, converted freighters equipped with a single rocket launched fighter, manned by Naval crews, and they ordered 50 more rocket-propelled catapults for fitting aboard merchant ships. These were equipped with fifty Hawker Hurricane Mark I aircraft, converted to Sea Hurricane IAs as a temporary measure to provide fighter protection beyond the range of bases on the British Isles. The ship was not fitted for aircraft recovery, so, unless close to land, the pilot would bail out or ditch in the sea at the end of the flight and the plane would be lost.^[1]

The RAF formed the Merchant Ship Fighter Unit (MSFU) on 5 May 1941 at RAF Speke by the River Mersey at Liverpool.^[1] Wing Commander E.S. Moulton-Barrett commanded the unit providing training for volunteer pilots, Fighter Direction Officers (FDOs) and airmen.^[1] After training, MSFU crews were posted to Liverpool, Glasgow or Avonmouth to assist loading their Hurricanes onto the catapults.^[1] 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.^[1]

MSFU crews signed ships articles as civilian crew members under the authority of the civilian ship's master.^[1] 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.^[1] The single Hurricane fighter was launched only when enemy aircraft were sighted and agreement was reached via hand and flag signals between the pilot, CDO, and ship's master.^[1]

The first CAM ship, Michael E, was sponsored by the Royal Navy while the RAF MSFUs were working up. After a trial launch off Belfast, Michael E sailed with convoy OB 327 on 28 May 1941 and was sunk by U-108 on 2 June.^[2] The first RAF trial CAM launch was from Empire Rainbow at Greenock on the River Clyde on 31 May 1941 and the Hurricane landed at Abbotsinch.^[1] Six CAM ships joined convoys in June 1941.^[1] When a CAM ship arrived at its destination, the pilot usually launched and landed at a nearby airfield to get in as much flight time as possible before his return trip.^[1] Pilots were rotated out of CAM assignments after two round-trip voyages to avoid the deterioration of flying skills from the lack of flying time during the assignment.^[2]

CAM sailings were initially limited to North American convoys with aircraft maintenance performed by the Royal Canadian Air Force at Dartmouth, Nova Scotia. CAM ships sailed on Gibraltar and Freetown convoys beginning in September, 1941, after an aircraft maintenance unit was established at the RAF base at North Front, Gibraltar. No CAM aircraft were provided during January and February of 1942 after it proved impossible to maintain the catapult-mounted aircraft in flying order during North Atlantic winters. CAM sailings resumed on 6 March 1942 on North Atlantic convoys and in April on the Arctic Russian convoys with a RAF aircraft maintenance unit in Archangelsk.^[2]

[edit] CAM ships

Eight CAM ships were requisitioned from private owners, two of which were lost in service: Daghestan, Daltonhall, Eastern City, Helencrest, Kafiristan, Michael E (lost in service), Novelist, Primrose Hill (lost in service).^[3]

The majority of CAM ships were Ministry of War Transport owned Empire ships: Empire Burton (lost in service), Empire Clive, Empire Darwin, Empire Day, Empire Dell (lost in service), Empire Eve (lost in service), Empire Faith, Empire Flame, Empire Foam, Empire Franklin, Empire Gale, Empire Heath, Empire Hudson (lost in service), Empire Lawrence (lost in service), Empire Moon, Empire Morn, Empire Ocean, Empire Rainbow (lost in service), Empire Ray, Empire Rowan (lost in service), Empire Shackleton (lost in service), Empire Spray, Empire Spring (lost in service), Empire Stanley, Empire Sun, Empire Tide, Empire Wave (lost in service).^[3]

[edit] Take-off procedure

• Trolley receiving bar was removed at dawn.
• Aircrew started and warmed up engine at intervals.
• Pilot climbed into aircraft when enemy aircraft were reported.
• Ship hoisted international flag code F when decision was made to launch. (CAM ships were usually stationed at the head of the outboard port column of a convoy so they could manoeuvre into the wind for launch.)
• Aircrew removed pins, showed them to the pilot, and took them to the CDO.
• Pilot applied 30 degree flaps and 1/3 right rudder.
• CDO raised blue flag above head to inform ship's master of readiness to launch.
• Ship's master manoeuvred ship into the wind and raised blue flag above head to authorise launch. (The ship's master stood on the starboard bridge wing to avoid the catapult rocket blast which sometimes damaged the port side of the bridge
• CDO waved his blue flag indicating ready to launch upon signal from pilot.
• Pilot opened full throttle, tightened throttle friction nut, pressed head back into the head rest, pressed right elbow tightly against hip, and lowered left hand as signal to launch.
• CDO counted to three, waited for the bow to rise from the trough of a swell, and moved the switch to fire the catapult rockets.^[1]

[edit] CAM combat launches

In total, there were nine combat launches, eight aircraft and one pilot were lost for eight German aircraft destroyed and one damaged.

[edit] Programme termination

As adequate numbers of escort carriers became available, CAM sailing on North American and Arctic Russian convoys were discontinued in August 1942. The aircraft maintenance unit was withdrawn from Archangel in September 1942. Catapults were removed from ten of the 26 surviving CAM ships while the remaining 16 continued to sail with Mediterranean and Freetown convoys.^[2] RAF Headquarters Fighter Command ordered all MSFUs disbanded commencing 8 June 1943.^[1] The combat launches from homeward bound convoy SL 133 were from the last two operational CAM ships to sail, and the last MSFU was disbanded 7 September 1943.^[1] Twelve of the 35 CAM ships had been sunk while sailing on 170 round trip voyages.^[1] Two more ships, Cape Clear and City of Johannesburg, were briefly fitted with dummy catapults and aircraft for deception purposes in late 1941.^[5]

[edit] See also

• Merchant aircraft carrier
• Fighter catapult armed auxiliary ship

[edit] References