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 ship is an acronym for catapult aircraft merchant ship.[1]

They were equipped with a rocket-propelled catapult launching a single Hawker Hurricane, dubbed a "Hurricat" or "Catafighter" to destroy or drive away an attacking bomber. Normally the Hurricane fighter would be lost when the pilot then bailed out or ditched in the ocean near the convoy.[2] 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 – but the CAM ships were merchant vessels, commanded and crewed by the Merchant Navy.

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


Hawker Hurricane on CAM ship catapult c1941
A Hurricane IA before launch during trials at Greenock, in 1941

The German Luftwaffe had Focke-Wulf Fw 200 Condor aircraft with a range of nearly 2,000 nautical miles (3,700 km – 2,300 miles). 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.[1]

To counter this threat, the Admiralty developed the fighter catapult ship – a converted freighter, manned by a naval crew, carrying a single Hawker 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.[1]

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.[1]

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.[1] 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.[1]

MSFU crews signed ship's articles as civilian crew members 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 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 four or five ships were taken into Royal Navy service as "auxiliary fighter catapult ships", and later conversions were officially named CAMs manned by merchant crews. 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. She was sunk by U-108 on 2 June.[3] The first RAF trial CAM launch was from Empire Rainbow, at Greenock on the River Clyde on 31 May 1941; the Hurricane landed at Abbotsinch. Six CAM ships joined convoys in June 1941. 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.[3]

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 1942 after it proved impossible to maintain the catapult-mounted aircraft in flying order during the North Atlantic winter. CAM sailings resumed on 6 March 1942 on North Atlantic convoys and in April on the Arctic Russian convoys with an RAF aircraft maintenance unit in Archangelsk.[3]

CAM ships

Eight CAM ships were requisitioned from private owners, two of which were sunk: Daghestan, Daltonhall, Eastern City, Helencrest, Kafiristan, Michael E (sunk), Novelist, Primrose Hill (sunk).[4]

27 CAM ships were Ministry of War Transport owned Empire ships, ten of which were sunk: Empire Burton (sunk), Empire Clive, Empire Darwin, Empire Day, Empire Dell (sunk), Empire Eve (sunk), Empire Faith, Empire Flame, Empire Foam, Empire Franklin, Empire Gale, Empire Heath, Empire Hudson (sunk), Empire Lawrence (sunk), Empire Moon, Empire Morn, Empire Ocean, Empire Rainbow (sunk), Empire Ray, Empire Rowan (sunk), Empire Shackleton (sunk), Empire Spray, Empire Spring (sunk), Empire Stanley, Empire Sun, Empire Tide, Empire Wave (sunk).[4]

Take-off procedure

Hawker Hurricane launched from CAM ship c1941
Test launch of a Hurricane at Greenock, Scotland, 31 May 1941
  • The trolley receiving bar was removed at dawn.
  • The airmen started the aircraft and warmed up the engine at intervals.
  • The pilot climbed into the aircraft when enemy aircraft were reported.
  • The ship hoisted the international flag code F when the 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.)
  • An airman removed the pins, showed them to the pilot, and took them to the Catapult Duty Officer (CDO).
  • The pilot applied 30 degree flaps and 1/3 right rudder.
  • The CDO raised a blue flag above his head to inform the ship's master of his readiness to launch.
  • The ship's master manoeuvred the ship into the wind and raised a blue flag above his head to authorise the 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.)
  • The CDO waved his blue flag indicating he was ready to launch upon a signal from the pilot.
  • The pilot opened full throttle, tightened the throttle friction nut, pressed his head back into the head-rest, pressed his right elbow tightly against his hip, and lowered his left hand as a signal to launch.
  • The 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]

CAM combat launches

Date Ship/convoy Pilot Outcome
3 Aug 41 HMS Maplin / OG 17 Lt. R. Everett RNVR Focke-Wulf Fw 200 Condor shot down; pilot recovered by a destroyer[5]
1 Nov 41 SS Empire Foam FO Varley Focke-Wulf Fw 200 chased off; pilot recovered by HMS Broke[1][6]
26 Apr 42 SS Empire Morn / QP 12 FO JB Kendal Blohm & Voss BV 138 chased off and Junkers Ju 88 shot down (a Ju 88A-4 "4D+IT" of III./KG 30); Kendal died from injuries received while bailing out[1][6]
26 May 42 SS Empire Lawrence / PQ 16 PO Hay Two Heinkel He 111s shot down; Hurricane shot down, pilot wounded and recovered by HMS Volunteer[1][6]
14 Jun 42 SS Empire Moon / HG 84 PO Sanders Focke-Wulf Fw 200 chased off; pilot recovered by HMS Stork[1][6]
18 Sep 42 SS Empire Morn FO AH Burr Two Heinkel He 111s destroyed; pilot flew to the Russian Keg Ostrov aerodrome[1][6]
1 Nov 42 SS Empire Heath / HG 91 FO N Taylor Focke-Wulf Fw 200 shot down; pilot nearly drowned before recovery[1][6]
28 Jul 43 SS Empire Darwin / SL 133 FO JA Stewart Focke-Wulf Fw 200 destroyed; pilot recovered by HMS Leith[1][6]
28 Jul 43 MV Empire Tide / SL 133 FO PJR Flynn Focke-Wulf Fw 200 destroyed; pilot recovered by HMS Enchantress[1][6]

In total, there were nine combat launches. Nine German aircraft were destroyed (four Condors, four Heinkels and a Junkers 88), one damaged and three chased away. Eight Hurricanes were ditched and only one pilot lost.

Programme termination

As adequate numbers of escort carriers became available, CAM sailings on North American and Arctic Russian convoys were discontinued in August 1942. The aircraft maintenance unit was withdrawn from Archangelsk in September 1942. Catapults were removed from 10 of the 26 surviving CAM ships while the remaining 16 continued to sail with the Mediterranean and Freetown convoys.[3] Headquarters RAF Fighter Command ordered all MSFUs to be disbanded commencing 8 June 1943. The combat launches from homeward bound convoy SL 133 were from the last two operational CAM ships to sail; the last MSFU was disbanded on 7 September 1943. 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.[6]

See also



  1. ^ a b c d e f g h i j k l m n o p q r Wise, pp. 70–77
  2. ^ Although in one case the pilot was close enough to an airfield to land there instead
  3. ^ a b c d Hague, p. 78
  4. ^ a b Mitchell and Sawyer
  5. ^ "The first Condor shot down by a Hurricat". World War II Today. Retrieved 25 February 2016.
  6. ^ a b c d e f g h i Hague, p. 79


  • Barker, Ralph (1978). The Hurricats. London: Pelham Books. ISBN 0-7207-0994-6.
  • Hague, Arnold (2000). The Allied Convoy System 1939–1945. Naval Institute Press. ISBN 1-55750-019-3.
  • Mitchell, W H, and Sawyer, L A (1990). The Empire Ships. London, New York, Hamburg, Hong Kong: Lloyd's of London Press Ltd. ISBN 1-85044-275-4.
  • Wise, James E. Jr. (1974). "Catapult Off – Parachute Back". United States Naval Institute Proceedings.

External links

Convoy HX 156

Convoy HX 156 was the 156th of the numbered series of World War II HX convoys of merchant ships from Halifax, Nova Scotia to Liverpool. Forty-three ships departed Halifax on 22 October 1941, and were met two days later by United States Navy Task Unit 4.1.3 consisting of Gleaves-class destroyer Niblack, Clemson-class destroyer Reuben James, Wickes-class destroyer Tarbell, and Benson-class destroyers Benson and Hilary P. Jones.

Convoy OG 82

OG 82 was an Allied convoy of the OG (Outward to Gibraltar) series during World War II.

The action involving this convoy resulted in the destruction of a U-boat, and also had consequences for German U-boat strategy.

List of escort carriers of the Royal Navy

The escort aircraft carrier, also called a "jeep carrier" or "baby flattop" in the USN or "Woolworth Carrier" by the RN, was a small and slow type of aircraft carrier used by the Royal Navy in the Second World War. They were typically half the length and one-third the displacement of the larger fleet carriers. While they were slower, less armed, unarmoured and carried fewer aircraft, they were less expensive and could be built more quickly. This was their principal advantage, as escort carriers could be completed in greater numbers as a stop-gap when fleet carriers were scarce. However, the lack of protection made escort carriers particularly vulnerable and several were sunk with great loss of life. The light carrier (hull classification symbol CVL) was a similar concept to escort carriers in most respects, but they were designed for higher speeds for deployment with fleet carriers.

Escort carriers were too slow to keep up with the main forces consisting of fleet carriers, battleships, and cruisers. Instead, they were used to defend convoys from enemy threats such as submarines and planes. In the invasions of mainland Europe and Pacific islands, escort carriers provided air support to ground forces during amphibious operations. Escort carriers also served as backup aircraft transports for fleet carriers and ferried aircraft of all military services to points of delivery.

In addition, escort carriers such as HMS Vindex and HMS Nairana played an important role in hunter-killer anti-submarine sweeps in company with RN and RCN destroyers, frigates and corvettes (e.g. 6th Canadian Escort Group and 2nd British Escort Group). HMS Vindex is credited with the sinking, or taking part in the sinking, of four U-boats (U344, U653, U765, U394). Escort carriers should not be confused with the Merchant Aircraft Carrier or CAM ship.

List of ship launches in 1941

The list of ship launches in 1941 includes a chronological list of ships launched in 1941. In cases where no official launching ceremony was held, the date built or completed may be used instead.

MV Empire Day

Empire Day was a 7,241 GRT cargo ship that was built in 1941 as a CAM ship by William Doxford & Sons Ltd, Sunderland, Co Durham, United Kingdom for the Ministry of War Transport (MoWT). In 1943, she was converted to a standard cargo ship. She served until August 1944 when she was torpedoed and sunk by U-198.

MV Empire Faith

Empire Faith was a 7,061 GRT CAM ship that was built in 1941 by Barclay Curle & Co, Glasgow, Renfrewshire, United Kingdom for the Ministry of War Transport (MoWT). Converted to a cargo ship in 1943, she was sold to a British company in 1946 and renamed Jessmore. In 1958, she was sold to a Panamanian company and renamed Antiope. A further sale in 1964 saw her renamed Global Venture. She served until 1971, when she was scrapped.

Merchant Ship Fighter Unit

The Merchant Ship Fighter Unit (MSFU) was a Royal Air Force operational aircraft unit based at RAF Speke, in south Liverpool, {{now Liverpool John Lennon Airport]] during World War II. The role of the MSFU was to provide pilots, crews, support personnel and aircraft to operate from 35 merchant ships outfitted with a catapult on the bow, referred to as Catapult Aircraft Merchant ships (CAM ships), a stop-gap initiative to provide air support to convoys out of reach of land in the early part of the war when aircraft carriers were scarce. The aircraft operated by the MSFU were converted Mk1 Hawker Hurricanes that were near the end of their useful lives and were often Battle of Britain veterans. The alterations included catapult fixing points and the addition of a naval radio. The MSFU was formed at Speke on 5 May 1941 and provided detachments to the CAM ships, each vessel being equipped with one Sea Hurricane plus an RAF pilot and support crew.The single catapult consisted of an eighty-five-foot rail, along which a trolley carrying a Hurricane (later Hurricats were used for this) would be propelled by a battery of three-inch rockets over a distance of sixty feet. Using thirty-degree wing flaps, a pilot could make a successful takeoff while losing minimal height.

Most notable was the inability of the CAM ship to recover the aircraft, and as a result launches out of reach of land were one way flights that required the pilot to bail out or ditch in the sea when the aircraft's fuel was exhausted. While every effort was made to pick up the pilot, operational factors such as the convoy being under U-boat attack could mean that a ship may not be detached to pick up the pilot. On the convoys to Russia the low sea temperatures meant that the pilot had a low potential survival rate unless picked up very soon after landing in the sea.

Eventually CAM ships were replaced beginning in 1943 with the introduction into service of escort carriers.

CAM fighters were credited with seven kills and their presence was rumoured to discourage the Focke-Wulf Fw 200 Condor aircraft from pressing home attacks on convoys.


A minehunter is a naval vessel that seeks, detects, and destroys individual naval mines. Minesweepers, on the other hand, clear mined areas as a whole, without prior detection of mines. A vessel that combines both of these roles is known as a mine countermeasures vessel (MCMV).

Repair ship

A repair ship is a naval auxiliary ship designed to provide maintenance support to warships. Repair ships provide similar services to destroyer, submarine and seaplane tenders or depot ships, but may offer a broader range of repair capability including equipment and personnel for repair of more significant machinery failures or battle damage.

SS Empire Burton

Empire Burton was a 6,966 GRT CAM Ship which was built in 1941 for the Ministry of War Transport (MoWT). Completed in August 1941, she was torpedoed on 20 September 1941 by U-74 and sunk.

SS Empire Clive

Empire Clive was a 7,069 GRT cargo ship which was built in 1941 by Cammell Laird & Co Ltd, Birkenhead for the Ministry of War Transport (MoWT). During the Second World War, she served as a CAM ship, armed with a Hawker Hurricane aircraft. In 1946 she was sold and renamed Charlebury. In 1958, she was sold to Hong Kong and renamed Isabel Erica. She served until 1969 when she was scrapped.

SS Empire Darwin

Empire Darwin was a British 6,765 GRT CAM ship built in 1941 by William Gray & Co. Ltd., West Hartlepool, United Kingdom for the Ministry of War Transport (MoWT). Her Hawker Sea Hurricane was involved in the last action by an aircraft flown off a CAM ship, shooting down a Focke-Wulf Fw 200 Condor on 28 July 1943.

She was sold into merchant service in 1945 and renamed Culrain in 1946. In 1953, she was in collision with a Spanish ship in the Strait of Gibraltar, sinking her. In 1959, she was sold to Lebanon and renamed Mersinidi, operating under the Liberian flag. She served until 1966, and was scrapped in 1967.

SS Empire Dell

Empire Dell was a 7,065 GRT CAM ship that was built in 1941 by Lithgows Ltd, Port Glasgow, United Kingdom for the Ministry of War Transport (MoWT). She served until May 1942, when she was torpedoed and sunk by U-124 whilst a member of Convoy ONS 92.

SS Empire Eve

Empire Eve was a 5,979 GRT CAM ship that was built in 1941 by William Pickersgill & Sons Ltd, Sunderland, Co Durham, United Kingdom for the Ministry of War Transport (MoWT). She served until 1943, when she was torpedoed and sunk by U-414 off Algeria.

SS Empire Flame

Empire Flame was a 7,069 GRT CAM ship that was built in 1941 by Cammell Laird & Co Ltd, Birkenhead, United Kingdom for the Ministry of War Transport (MoWT). She was sold in 1945 and renamed Dunkery Beacon. A further sale to Finland in 1955 saw her renamed Rissa. Following a sale in 1961, she was renamed Augusta Paulin. She served until 1969 when she was scrapped.

SS Empire Morn

SS Empire Morn was a 7,092-ton CAM ship that was built in 1941. She saw service on a number of trade routes during the Second World War, making several crossings of the North Atlantic as well as voyages to Russia and Africa. She was badly damaged after hitting a mine in 1943, and spent the rest of the war laid up as a hulk. She was subsequently sold and repaired, returning to service for several companies after the war, under the names San Antonio and Rio Pas before being sold for scrapping in 1973.

Empire Morn is known for the death of the second youngest person in the British services to die in the war, 14-year-old galley boy Raymond Steed. She is also the only CAM ship whose fighter pilot died in action after his aircraft was launched from the ship.

SS Graigaur

Graigaur was a 7,047 GRT cargo ship that was built in 1941 by Swan, Hunter & Wigham Richardson Ltd, Newcastle upon Tyne, Northumberland, United Kingdom as the CAM ship Empire Foam for the Ministry of War Transport (MoWT). She was sold in 1946 to Graigaur Shipping Co Ltd and renamed Graigaur. She was sold in 1957 to Marinos & Frangos Ltd and renamed Maltezana. She was sold to the Great Southern Steamship Co Ltd., Hong Kong in 1958 and renamed Johore Bahru, serving until she was scrapped in 1963.

SS Hazelbank

Hazelbank was a 6,140 GRT cargo ship built in 1942 as Empire Franklin by John Readhead and Sons Ltd, South Shields, County Durham, United Kingdom for the Ministry of War Transport (MoWT). She was converted to a CAM ship shortly after completion. She was sold to Bank Line in 1945 and was renamed Hazelbank. She was sold Compagnia Navigazione Nuevo Mundo SA, Panama in 1957 and renamed Irinicos. She was sold to Paleocrassos Bros, Greece in 1962 then to Salinas Compagnia Navigazione SA, Panama in 1963 and was renamed Iris II, serving until 1967 when she was scrapped in Hong Kong.

SS Primrose Hill

SS Primrose Hill was a British CAM ship that saw action in World War II, armed with a catapult on her bow to launch a Hawker Sea Hurricane. She was completed by William Hamilton & Co in Port Glasgow on the Firth of Clyde in September 1941.Primrose Hill was managed by Counties Ship Management Ltd of London (CSM), an offshoot of the Rethymnis & Kulukundis shipbroking company. Primrose Hill was CSM's second CAM ship, in effect replacing Michael E that had been torpedoed and sunk three months previously on her maiden voyage.

Primrose Hill's navigation equipment included an echo sounding device and a gyrocompass.

CAM ships
The ships
Aircraft carriers
Patrol craft
Fast attack craft
Mine warfare
Command and support


This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.