HMS Attacker (D02) - Design and Description

Design and Description

She had been laid down on 17 April 1941 as the merchantman Steel Artisan (hull 160) under Maritime Commission contract by Western Pipe and Steel Company, San Francisco, California for the Ithanian Steamship Company and was launched in late September. She was then requisitioned for conversion to a carrier in December 1941 to be named USS Barnes but selected for transfer under Lend-Lease to the British.

HMS Attacker was the lead ship in the Attacker class of eight escort carriers, just one of the 38 escort carriers built in the United States for the Royal Navy during the Second World War. She was built at the Western Pipe & Steel shipyards, who also built three other ships in the class. Once completed she was supplied under the terms of Lend-Lease agreement to the Royal Navy. There was a ships complement of 646 men, who lived in crew accommodation that was significantly different from the arrangements that were normal for the Royal Navy at the time. The separate messes no longer had to prepare their own food, as everything was cooked in the galley and served cafeteria style in a central dining area. They were also equipped with a modern laundry and a barber shop. The traditional hammocks were replaced by three-tier bunk-beds, 18 to a cabin which were hinged and could be tied up to provide extra space when not in use.

Attackers dimensions were: an overall length of 492.25 feet (150.04 m), a beam of 69.5 feet (21.2 m) and a height of 23.25 ft (7.09 m). They displaced 11,420 long tons (11,600 t) at deep load. Propulsion was provided by four diesel engines connected to one shaft giving 8,500 brake horsepower (BHP), which could propel the ship at 17 knots (31 km/h; 20 mph).

She had the capacity for up to 24 anti-submarine or fighter aircraft, which could be made up of a mixture of the British Hawker Sea Hurricane, Supermarine Seafire, Fairey Swordfish or the American Grumman Wildcat, Vought F4U Corsair or Grumman Avenger. The exact composition of the embarked squadrons depended upon the mission. Some squadrons were composite squadrons for convoy defence and would be equipped with anti-submarine and fighter aircraft, while other squadrons working in a strike carrier role would only be equipped with fighter aircraft. Aircraft facilities were a small combined bridge–flight control on the starboard side and above the 450 feet (140 m) x 120 feet (37 m) flight deck, two aircraft lifts 42 feet (13 m) by 34 feet (10 m), and nine arrestor wires. Aircraft could be housed in the 260 feet (79 m) by 62 feet (19 m) hangar below the flight deck.

The ships armament concentrated on anti-aircraft (AA) defence and comprised two 4 inch dual purpose, AA guns in single mounts, eight 40 mm AA guns in twin mounts and twenty-one 20 mm AA cannons, in single and twin mounts.

Before entering service with the Royal Navy she was sent to Burrards shipbuilders in British Columbia for some modifications. These modifications, 150 of them in total, were paid for by the Canadian government. Further modifications to turn her into an assault carrier were undertaken by the Caledon Shipbuilding & Engineering Company in Dundee, Scotland. This work included installing an operational telephone system with over 100 telephones. A new briefing room with an army plot was installed and extra cabins were built providing an additional 140 bunks.

Attacker was designed to accompany other ships forming the escort for convoys. The anti-submarine aircraft employed were initially the Fairey Swordfish and later the Grumman Avenger, which could be armed with torpedoes, depth charges, 250 pounds (110 kg) bombs or the RP-3 rocket projectile. As well as carrying out their own attacks on U-Boats, these aircraft identified their locations for the convoy's escorts to mount an attack. Typically anti-submarine patrols would be flown between dawn and dusk. One aircraft would fly about 10 miles (16 km) ahead of the convoy, while another patrolled astern. Patrols would last between two and three hours, using both Radar and visual observation in their search for U-Boats. Attacker also had a secondary role, providing oil and provisions for her accompanying destroyers. This could be a lengthy process and was done on the move. It took 40 minutes from firing a line across to the destroyer to start pumping oil, while it took another two hours to pump 98 tons of oil and a further 35 minutes to disconnect the hose pipe and secure the equipment.