Monday, July 20, 2015
Supermarine Seafire Mk 1B
In late 1941 and early 1942, the Admiralty assessed the Spitfire for possible conversion. In late 1941, a total of 48 Spitfire Mk Vb were converted by Air Training Service Ltd. at Hamble to become "hooked Spitfires". This was the Seafire Mk Ib and would be the first of several Seafire variants to reach the Royal Navy's Fleet Air Arm. This version of the Seafire was mainly used to allow the Royal Navy to gain experience in operating the Spitfire on aircraft carriers. The main structural change was made to the lower rear fuselage which incorporated an A-frame style arrestor hook and strengthened lower longerons. It was soon discovered that the fuselage, especially around hatches, was too weak for carrier operations. In an attempt to alleviate this condition, reinforcing strips were riveted around hatch openings and along the main fuselage longerons. A further 118 Seafire Mk Ib's incorporating the fuselage reinforcements were modified from Spitfire Vbs by Cunliffe-Owen at Eastleigh and Air Training Service. These aircraft were equipped with Naval HF radio equipment and IFF equipment as well as a Type 72 homing beacon. In these and all subsequent Seafires the instruments were re-calibrated to read kn and nmi rather than mph and mi. The fixed armament was the same as that of the Spitfire Vb; two 20 mm (.79 in) Hispano Mk II cannon with 60 rpg fed from a "drum" magazine and four .303 in (7.7 mm) Browning machine guns with 350 rpg. Provision was also made to carry a 30 gal (136 l) "slipper" fuel tank under the fuselage. In June 1942, the first deliveries of the Seafire took place to 807 Squadron. Another front line unit, 801 Squadron operated this version on board HMS Furious from October 1942 through to September 1944.