Supermarine Stranraer Reconnaissance Flying Boat
The Supermarine Stranraer was the last of the line of biplane flying boats to be accepted into service with the RAF.
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The Supermarine Stranraer was the final evolution of the Supermarine Southampton which debuted in March of 1925. The original Southampton went on to have a highly successful flying career and was utilized by both military parties (Royal Air Force (RAF)) and civilian passenger airliners. The type saw some 83 examples built with service stemming into the 1930s before being replaced by modern types. The Stranraer itself was developed to Air Ministry R.24/31 Specification (as was the Saro London flying boat) which required a maritime coastal patrol platform to serve the RAF. Supermarine then secured a contract for a single prototype in 1933. The Stranraer became one of the last flying boats constructed with biplane wings.
Supermarine engineers produced a twin-engined, biplane wing design fitted atop a long fuselage with a boat-like hull for water landings. Pontoons were set under the lower wing assemblies to assist in keeping the vessel upright in choppy waters. The cockpit was completely enclosed with windows dotting the sides of the fuselage. An open-air gun emplacement was fitted at the front of the design with a second at amidships along the fuselage spine aft of the wings. Bombs, naval mines or depth charges could be held under the wings (up to 1,000lbs) for engaging sea-based targets. The empennage was capped by a single horizontal plane supporting a pair of vertical tail fins. The original prototype was given a pair of Bristol Pegasus IIIM series radial piston engines outputting at 820 horsepower each and engines were set high in the design along the leading edge of the upper wing assembly. Each engine drove a two-bladed wooden propeller. The fuselage was constructed of metal while wings were covered over in fabric - consistent with aircraft manufacture of the time, a period seeing increased use of all-metal skinned aircraft prior to World War 2. At this point in its development, the aircraft became known as the "Stranraer" after a town in southwest Scotland. First flight of the Stranraer was recorded on July 24th, 1934 to which the RAF then received a working example for formal trials.
After some requested changes were completed, the Royal Air Force officially introduced the type into service in 1937. The initial order numbered 17 aircraft and first deliveries formed with No.228 Squadron at Pembroke Dock in 1937. Production forms differed from the original prototype in that they were fielded with Bristol Pegasus X series 9-cylinder air-cooled radial piston engines of 920 horsepower each due to the underpowered nature of the prototype's engine installations. The engines now drove more modern three-bladed metal propellers. The Stranraer was crewed by up to seven personnel and armed with 2 x 7.7mm Lewis machine guns. She held a wingspan of 85 feet with a length of 54 feet, 9 inches. Maximum speed was 165 miles per hour with a range of 1,000 miles - able to operate at ceilings of 18,500 feet. Once in circulation, RAF crews found the type to be slow and many unappealing nicknames for the mount soon emerged. Regardless, the new aircraft served in the all-important anti-submarine coastal patrol role though none would ever see combat action in World War 2 (1939-1945). The type was withdrawn from frontline service as early as March 1941 though several remained on station as training platforms into October of 1942. British Stranraers were eventually replaced in service by the excellent American PBY Catalina series flying boats.
It was in Canadian hands (Royal Canadian Air Force) that the Stranraer would establish its more noted history as 40 examples were produced locally by Canadian Vickers Ltd and serve in a longer tenure than those of the RAF. Like the British marks, Canadian Stranraers were utilized in the anti-submarine patrol role though fielded locally along both Canadian coastlines during World War 2 (with eight being in service at the outbreak of war). Again, none were destined to see direct combat action in the conflict. Canadian Stranraers were fielded in this capacity up until February of 1945 to which examples were then passed on to interested civilian parties in Canada and the United States beginning in 1946. Militarily, the Stranraer only ever served with British and Canadian forces during her tenure and the last civilian Stranraer was retired from service in 1957. Canadian Stranraers were also replaced by American Catalinas before the end of the war.
Only a single complete Stranraer survived time and this example can be seen at the Royal Air Force Museum (London) in its full glory. The example on display is Canadian in origin - having served as a trainer, anti-submarine platform and passenger airliner throughout her long career. In all, 57 Stranraers were produced.