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Supermarine Stranraer

The Supermarine Stranraer was a flying boat designed and built by the British Supermarine Aviation Works company at Woolston, Southampton.

It was developed during the 1930s on behalf of its principal operator, the Royal Air Force.

Derived from the Supermarine Scapa, the aircraft’s design was heavily shaped by Specification R.24/31.

Initially rejected by the Air Ministry, Supermarine persisted with development as a private venture under the designation Southampton V.

During 1933, a contract was placed for a single prototype, it was around this time that the type was named the Stranraer.

First flown on 24 July 1934, the Stranraer entered frontline service with the RAF during 1937, most examples of the type were in service by the outbreak of World War II.

The Stranraer’s typically undertook anti-submarine and convoy escort patrols during the early years of the conflict.

During March 1941, it was withdrawn from frontline service, but continued to be operated in a training capacity until October 1942.

In addition to the British-built aeroplanes, the Canadian Vickers company in Montreal, Quebec, also manufactured 40 Stranraer’s under license for the Royal Canadian Air Force.

These Canadian Stranraer’s served in anti-submarine and coastal defence capacities on both Canada’s Atlantic and Pacific coasts, and were in regular service until 1946.

Following their withdrawal from military service, many ex-RCAF Stranraer’s were sold off to fledgling regional airlines, with whom they served in various commercial passenger and freighter operations into the 1950s.

The RAF operated 17 Stranaer’s from 1937 although they were already considered obsolete when they entered service.

The type served primarily by No. 228, No, 209 and No. 240 Squadrons along with limited numbers at the No. 4 OTU.

Generally, the aircraft was not well-received, with numerous pilots considering its performance being typically marginal.

Others noted that it had superior seaworthiness to several aircraft in common use, such as the Consolidated PBY Catalina.

As early as 1938, some Stranraer squadrons had begun to reequip themselves with other aircraft, such as the Short Sunderland and Short Singapore flying boats. 

Early on in its career, the Stranraer performed several challenging long-distance flight, one such flight, covering 4,000 miles (6,400 km), was performed during a single exercise during September 1938.

No British Stranraer’s saw action away from UK territorial waters during World War II. 

Immediately following the outbreak of the war in September 1939, Stranraer’s patrolled the North Sea, intercepting enemy shipping between Scotland and Norway.

Aircraft assigned to such duties were typically armed with bombs underneath one wing and a single overload fuel tank underneath the other, use of the Stranraer for such patrols came to an end on 17 March 1941.

The final Stranraer flight in RAF service was conducted by K7303 at Felixstowe on 30 October 1942.

Having acquired a less than favourable reception by flight and ground crews alike, the Stranraer gained a large number of derisive nicknames during its service life.

It was sometimes referred to as a “whistling shithouse” because the toilet opened out directly to the air and when the seat was lifted, the airflow caused the toilet to whistle.

The Stranraer also acquired “Flying Meccano Set”, “The Marpole Bridge”, “Seymour Seine Net”, “Strainer”, “Flying Centre Section of the Lion’s Gate Bridge”, as well as a more genteel variant of its usual nickname, “Whistling Birdcage”.

The Royal Canadian Air Force Stranraer’s were exact equivalents of their RAF counterparts.

In Canadian service, they were usually employed in coastal patrol against submarine threats in a similar role to the British Stranraer’s.

The crew of a 5 Squadron Stranraer, flown by Flight Lieutenant Leonard Birchall, were responsible for the capture of an Italian merchant ship, the Capo Nola, in the Gulf of Saint Lawrence, hours after Canada issued its declaration of war on Italy on 10 June 1940.

The Canadian Vickers built Stranraer’s served with the RCAF throughout the war, the last example being withdrawn on 20 January 1946.





54 ft 9 in (16.69 m)


85 ft 0 in (25.91 m)


21 ft 9 in (6.63 m)

Wing area

1,457 sq ft (135.4 m2)

Empty weight

11,250 lb (5,103 kg)

Gross weight

19,000 lb (8,618 kg)


2 × Bristol Pegasus X, 

9 cylinder air cooled radial piston engines,

920 hp (690 kW) each


3 bladed variable pitch metal propellers


Maximum speed

165 mph (266 km/h, 143 kn) at 6,000 ft (1,800 m)

Alighting speed

58.5 mph (50.8 kn; 94.1 km/h)

Cruise speed

105 mph (169 km/h, 91 kn)


1,000 mi (1,600 km, 870 nmi) at 105 mph (91 kn; 169 km/h)


5,000 ft (1,500 m)

Service ceiling

18,500 ft (5,600 m)

Rate of climb

1,350 ft/min (6.9 m/s)

Time to altitude

10,000 ft (3,000 m) in 10 minutes

Wing loading

13 lb/sq ft (63 kg/m2)


0.097 hp/lb (0.159 kW/kg)



Three × 0.303 in (7.70 mm) Lewis guns


1,000 lb (454 kg) of bombs 


Depth charges on external racks under the mainplanes

8 × 20 lb (9 kg) bombs housed in internal bays in the lower mainplanes

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