Thursday, 13 February 2020

HMS Implacable

The aircraft carrier that the recently featured Sea Hornet was landing on in the 7th February 1950 photograph in THE TIMES was HMS Implacable. She was a member of a group of armoured aircraft carriers designed just before the Second World War and built between 1937 and 1944. The first four ships formed the Illustrious-class (HMS Illustrious, HMS Formidable, HMS Victorious, and HMS Indomitable) and the second group was the Implacable-class (HMS Implacable and HMS Indefatigable). The latter pair were a development of the Illustrious-class, and mainly differed in having two hanger levels rather than one. This enabled them to carry a larger number of aircraft, even though the height of the hangers was less.

HMS Implacable was commissioned in May 1944, but was not fully worked-up until the September of that year. Her first operation was to locate the German battleship Tirpitz, which had left her berth in Kaafjord. A flight of reconnaissance aircraft from HMS Implacable found Tirpitz off Håkøya Island near Tromsø on 18th October 1944, but the ship did not mount a strike against the German warship as she was still awaiting her complement of Supermarine Seafire fighters to fly aboard.

Between December 1944 and March 1945, HMS Implacable underwent a refit to prepare her for service in the Far East as part of the British Pacific Fleet. She had arrived at the Admiralty Islands by the end of May, and in June she took part in an attack on the island of Truk. She then took part in a number of attacks on the Japanese home islands.

Once the war was over, HMS Implacable sailed to Australia to disembark her aircraft and be refitted for the repatriation of prisoners of war who had been held in Japanese camps. She completed these duties in early 1946, re-embarked her aircraft, and by June that year she returned to the UK. She then became the deck-landing training and trials carrier for the Home Fleet, a role that she continued to fulfil until the end of 1949. Amongst the aircraft that flew onto and from her decks during this period were a jet-powered Gloster Meteor fighter, and the prototypes of the Westland Wyvern turboprop-powered strike aircraft and the Short Sturgeon torpedo-reconnaissance bomber.

HMS Implacable spent the first few months of 1950 taking part in training exercises in the Atlantic and the Mediterranean. She then returned to the UK to be refitted for duty as a training ship. On 16th January 1952 she was recommissioned as the flagship of the Home Fleet Training Squadron. She subsequently took part in the Coronation Fleet Review for Queen Elizabeth II on 15th June 1953 as well as acting as a troop transport to and from the Caribbean. HMS Implacable was decommissioned on 1st September 1954 and sold for breaking up on 27th October 1955.

At one stage HMS Implacable had been considered suitable for reconstruction along the lines of her half-sister, HMS Victorious. This would have combined her two limited-height hangars into a single hangar with a height of 17 feet 6 inches, and allowed her to operate larger and heavier jet-powered aircraft. She would also have been fitted with an angled flight deck and probably a new type 984 3D radar system. The cost of the proposed reconstruction was judged to be too high, and the project was cancelled.

HMS Implacable's characteristics were:
  • Displacement: 32,110 tons(deep load)
  • Dimensions:
    • Length: 766ft 6in (233.6m) (oa); 730ft (222.5m) (waterline)
    • Beam: 95ft 9in (29.2m)
    • Draught: 29ft 4in (8.9m) (deep load)
  • Propulsion: 8 x Admiralty 3-drum boilers providing steam for 4 x geared steam turbines producing 152,000shp, each turbine driving a separate shaft and propeller
  • Speed: 32.5 knots
  • Range: 6,720 nautical miles at 20 knots
  • Complement: 2,300 (1945)
  • Armament: 16 x 4.5-inch quick-firing, dual-purpose guns (8 x 2); 44 x 2-pdr quick-firing anti-aircraft guns (5 x 8 & 1 x 4); 61 x Oerlikon 20mm anti-aircraft guns (21 x 2 & 19 x 1) (Note: Some of the Oerlikon 20mm anti-aircraft guns were later replaced by Bofors 40mm anti-aircraft guns.)
  • Armour: 4.5-inch (114mm) waterline belt; 3-inch (76mm) flight deck; 2-inch (51mm) bulkheads and hanger sides; 2-inch to 3-inch (51mm to 76mm) magazines
  • Aircraft capacity (including deck park): 81 (1945)
HMS Victorious after she had been reconstructed. It is likely that HMS Implacable might have been reconstructed along similar lines.


  1. Interesting Bob, as my maternal grandfather (whom I never met) served as a CPO possibly on AA (he stands posed next to Poms Poms) on British Carriers in the Far East 44/45 - from the MOI RN Photos in an album somewhere (so official public domain) at home, they were mostly Formidable (sister of Victorious), with some interesting official Navy shots of clearing up after Kamikaze attacks May 44, flash hoods and firefighting, pushing the wrecks over the side and of ditched Seafires missing the deck etc. I was fascinated on the very few occasions I saw them as a child by the shoreside pics of Suez, Egypt, Trinco, Sydney etc but also of the airplanes Hellcats / Corsairs etc with folded wings.
    From what I understand, the British carriers had armour plated decks unlike the American ones so could withstand the kamikaze damage better.

    1. Mark, Man of TIN,

      Thanks for sharing your memories with everyone who reads this blog. The six armoured fleet carriers did sterling service, and their ability to absorb damage justified the RN’s decision to build them. Unlike the US and Japanese, who expected to fight their carrier battles in the Pacific, well away from land-based bombers, the RN expected that their carriers would be operating in areas where land-based bombers would be prevalent in large numbers.

      All the best,