HMS Tracker (D24)

A twin 40 mm Bofors anti-aircraft gun; such weapons were mounted on Tracker

All the ships had a complement of 646 men and an overall length of 495 feet 8 inches (151.1 m), a beam of 69 feet 6 inches (21.2 m) and a draught of 24 ft 8 in (7.5 m). Propulsion was provided by two boilers connected to a steam turbine, which drove one shaft giving 8,500 shaft horsepower (6,300 kW). This arrangement could propel the ship at 18 knots (33 km/h; 21 mph).[3]

Aircraft facilities were a small combined bridge/flight control on the starboard side, two aircraft lifts 43 by 34 feet (13.1 m × 10.4 m), one aircraft catapult and nine arrestor wires. Aircraft could be housed in the 260 by 62 feet (79.2 m × 18.9 m) hangar below the flight deck. Armament comprised: two 4"/50, 5"/38 or 5"/51 Dual Purpose guns in single mounts, sixteen 40 mm Bofors anti-aircraft guns in twin mounts and twenty 20 mm Oerlikon anti-aircraft cannons in single mounts. The ships had a maximum aircraft capacity of twenty-four which could be a mixture of Grumman Martlets, Vought F4U Corsairs or Hawker Sea Hurricane fighter aircraft and Fairey Swordfish or Grumman Avenger anti-submarine torpedo bombers.[4]

Tracker was laid down 3 November 1941, under a Maritime Commission (MARCOM) contract, MC hull 233, by Seattle-Tacoma Shipbuilding in Tacoma, Washington. She was originally intended to be the 2nd replacement merchant ship Mormacmail for Moore-McCormack Lines, Inc., however, before completion, the vessel was purchased by the US Navy. In 1942, she was given the designation BACV-6 and converted into an escort carrier at Willamette Iron & Steel, Portland, Oregon. She was launched on 7 March 1942, and commissioned 31 January 1943; she was transferred to the Royal Navy and renamed HMS Tracker.[3]

Black smoke rises after a Grumman Avenger crashes on the flight deck of Tracker whilst on Russian convoy duty

Tracker served as an escort during 1943–1944, for North Atlantic and Arctic convoys. She originally carried Swordfish torpedo-bombers and Seafire fighters of 816 Naval Air Squadron; in January 1944, switching to the Grumman Avengers and Grumman Wildcats of 846 Naval Air Squadron. In April 1944, her aircraft, together with those from HMS Activity were responsible for the sinking of the German U-boat U-288 east of Bear Island, during convoy JW 58.

On 10 June 1944, while part of the antisubmarine screen of the Western Approaches Command for the D-Day landings, she collided with a River-class frigate of the Royal Canadian Navy, HMCS Teme, causing damage to both ships. HMS Tracker continued operations despite stove-in bows until 12 June 1944. Thereafter, she was repaired and partially refitted in Liverpool, until 7 September 1944. On 8 December 1944, the ship sailed to the US to be used as an aircraft transport, and spent the remainder of the war ferrying aircraft and personnel in the Pacific.

In August 1945, she made a final trip to the UK, being returned to the US Navy in November 1945. She was sold in November 1946, and entered service as the merchant ship Corrientes, based in Argentina. She was scrapped in 1964.

• Cocker, Maurice (2008). Aircraft-Carrying Ships of the Royal Navy. Stroud, Gloucestershire: The History Press. ISBN 978-0-7524-4633-2.
• "No name assigned ex merchant Lend-Lease as HMS Tracker (D24 - R317) BAVG 6".
• "A History of HMS Tracker". 11 June 2020.
• Mason, Geoffrey B. (18 March 2010). "HMS Tracker (D 24) - Attacker-class Escort Aircraft Carrier". Service Histories of Royal Navy Warships in World War 2. naval-history.net.