Designed to the same specification, R. 24/31, as the Saro London, the Supermarine Stranraer twin-engine biplane flying-boat prototype, originally known as the Singapore V, was powered by Bristol Pegasus HIM radials driving two-blade wooden propellers and first flew in mid-1935, but was immediately renamed Stranraer.
A production contract was placed in August 1935 for seventeen aircraft. It also underwent comparative trials with the London on No. 210 Squadron in October and November 1935, during which it was found to be somewhat underpowered.
Production deliveries of aircraft powered by a pair of Pegasus X radials driving a three-blade Fairey Reed metal propeller started December 1936, and the type was declared operational in April 1937 with No. 228 Squadron at Pembroke Dock, remaining with this squadron until April 1939.
In December 1938 Stranraers joined No. 209 Squadron at Felixstowe, and later moving to Invergordon and Oban for patrols over the North Sea until supplanted by the Lerwick the following year.
No, 240 Squadron was the only other RAF Coastal Command squadron to fly the Stranraer, converting to the aircraft in June 1940 at Pembroke Dock for short-range patrol work over the Western Approaches. The Stranraers were eventually replaced by Catalina 'boats in March 1941, continuing to serve in a training capacity until October 1942.
Although RAF Stranraers did not serve at overseas stations, a total of 40 aircraft was licence-built by Canadian-Vickers between 1939 and 1941, and served in the coastal reconnaissance/anti-submarine role with the RCAF until finally replaced by the Consolidated Canso (Catalina) from 1943.
Eight were in service with the Canadians at the outbreak of war. Hese aircraft were used for patrol duties both on the Atlantic and Pacific coasts. They were finally retired from service in February 1945.
After retirement from service use, several Stranraers were registered for civil use. Queen Charlotte Airlines continued to use Stranraers into the 1950s, operating from Vancouver and providing a service along the pacific coast of British Columbia.
Engine: 2 x Bristol Pegasus X, 652kW
Max take-off weight: 8600 kg / 18960 lb
Empty weight: 5100 kg / 11244 lb
Wingspan: 25.91 m / 85 ft 0 in
Length: 16.71 m / 55 ft 10 in
Height: 6.63 m / 22 ft 9 in
Wing area: 135.36 sq.m / 1457.00 sq ft
Max. speed: 266 km/h / 165 mph
Cruise speed: 169 km/h / 105 mph
Ceiling: 5640 m / 18500 ft
Range: 1600 km / 994 miles
Armament: 3 x 7.7mm machine-guns