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 (RAF).

Stranraer
Role Maritime Reconnaissance
National origin United Kingdom
Manufacturer Supermarine
Designer R. J. Mitchell
First flight 24 July 1934
Introduction 1937
Retired 1957 (civilian use)
Primary users Royal Air Force
Royal Canadian Air Force
Number built 57
Developed from Supermarine Scapa

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 During March 1941, it was withdrawn from frontline service, but continued to be operated in a training capacity until October 1942.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 Stranraers under licence for the Royal Canadian Air Force (RCAF). These Canadian Stranraers 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 Stranraers were sold off to fledgeling regional airlines, with whom they served in various commercial passenger and freighter operations into the 1950s.

Design and development

Background
Supermarine's works at Woolston, Southampton

The Supermarine Stranraer, which was directly derived from the Supermarine Scapa, was the final aircraft in a series of flying boats produced by Supermarine at Woolston, Southampton in southern England between 1925 and 1936.[1] Development of the series commenced during the early 1930s with Supermarine's design team, headed by its chief engineer and designer R. J. Mitchell. The project was pursued in a response to the Air Ministry's issuing of Specification R.24/31, which called for a general purpose coastal reconnaissance flying boat for the Royal Air Force (RAF).[2] This specification listed various requirements, including a payload capacity 1,000 pounds (450 kg) greater than that of the Scapa and the ability to maintain level flight on only a single engine, both of which were not within the capabilities of the Scapa without enlargement. Thus, Supermarine submitted its initial response to the specification as a larger model of the Scapa; the company competed against a rival bid from Saunders-Roe.[2]

The Air Ministry favoured Saunders-Roe's proposal and rejected Supermarine's design.[2] However, Supermarine opted to continue development work on the design as a private venture, which was first known as the Southampton V. As it progressed, the design deviated to a greater extent from the Scapa, opting for an alternative thin-wing arrangement around a two-bay structure.[2] The wing's span, area, and weight were 12 percent greater; the elevator was also 7 percent larger, while the rudders featured trim tabs capable of holding the aircraft straight under single-engine flight. While some consideration towards adopting the Rolls-Royce Kestrel was made, the moderately supercharged Bristol Pegasus IIIM radial engine was selected instead.[3]

While the airframe was broadly similar to the Scapa, its was cleaner in terms of its aerodynamics.[4] Much of the airframe was composed of alclad, while detailed fittings were fabricated from stainless steel; metallic objects were anodised as an anti-corrosion measure. While the hull a sheet metal covering, the wings were covered with fabric.[4] For additional structural strength over the preceding Scapa, a pair of interplane struts were introduced.[5] The hull was considerably larger, its cross-section being increased by 18 percent, yet still achieving virtually identical hydrodynamic performance. The forward gun was redesigned to be retractable, the middle gunner's position was lowered, and a tail gunner position was added just aft of the control surfaces, completed with a hooded windshield.[5] In general, the equipment of which the aircraft was to be fitted with were the result of lessons learnt from operations of the earlier Southamptons.[4]

Prototypes and production

During 1933,[6] a contract was placed for a single prototype powered by two 820 horsepower (610 kW) Bristol Pegasus IIIM engines and the type was named the Stranraer. On 27 July 1934, the first prototype, K3973, conducted its maiden flight, piloted by Joseph Summers.[4] Over the following months, a relatively intense initial flight test programme was conducted. On 24 October 1934, the Stranraer prototype was delivered to the Marine Aircraft Experimental Establishment (MAEE) at RAF Felixstowe for official trials.[7] On 29 August 1935, quickly after the completion of proving flights, an initial order was placed for 17 aircraft (serial numbers K7287 to K7303) was placed by the Air Ministry to fulfil Specification 17/35.[8]

The production model of the Stranraer different in a few aspects from the first prototype, chiefly of which being the installation of the more powerful 920 horsepower (690 kW) Pegasus X engine.[8] The first production standard aircraft made its first flight during December 1936, and entering service operation with the RAF on 16 April 1937. An additional order for six aircraft (K9676 to K9681) was placed in May 1936, but subsequently cancelled. The final Stranraer was delivered on 3 April 1939. In addition, a total of 40 Stranraers were manufactured under licence in Canada by Canadian Vickers Limited; Supermarine and Canadian Vickers being subsidiaries of Vickers-Armstrongs.

Operational history

Military use
RCAF Stranraer in wartime camouflage

The RAF operated 17 Stranaers from 1937; the type—which was already considered obsolete when it entered service[6][Note 1]—served primarily by No. 228, No, 209 and No. 240 Squadrons along with limited numbers at the No. 4 OTU.[8] Generally, the aircraft was not well-received, with numerous pilots considering its performance being typically marginal.[9] Others noted that it had superior seaworthiness to several aircraft in common use, such as the Consolidated PBY Catalina.[10] 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.[8] 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.[8]

No Stranraers saw action away from UK territorial waters during World War II.[6] Immediately following the outbreak of the war in September 1939, Stranraers 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.[8] The final Stranraer flight in RAF service was conducted by K7303 at Felixstowe on 30 October 1942.[8]

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".[11]

The Royal Canadian Air Force (RCAF) Stranraers 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 Stranraers. Aviation author Dirk Septer stated that no enemy action was ever recorded by the RCAF's Stranraers.[12]}} However, 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.[13][Note 2]

The Canadian Vickers-built Stranraers served with the RCAF throughout the war, the last example being withdrawn on 20 January 1946.[14]

Civilian use

From May 1935 the Stranraer was developed for civilian use into the Type 237.[6]

After the end of World War II, 13 examples were sold through Crown Assets (Canadian government) and passed into civilian use; several served with Queen Charlotte Airlines (QCA) in British Columbia, operating until 1958.[15] A re-engine project by the airline substituted 1,200 horsepower (890 kW) Wright GR-1820-G202GA engines in place of the original Pegasus units.[10]

Queen Charlotte Airlines became at one point the third largest airline in Canada; it was popularly known as the Queer Collection of Aircraft. With limited money, it flew an eclectic mixture of types that were often the cast-offs of other operators. However, in QCA use, the Stranraer gained a more suitable reputation and was "well liked" by its crews.[16] A total of eight surplus Stranraers were also sold to Aero Transport Ltd. of Tampa, Florida.[17]

Operators

Military
Canada
Supermarine Stranraer 912 of the RCAF at RCAF Station Jericho Beach
 United Kingdom
Stranraer. CH2551

Civilian
 United States
  • Aero Transport Ltd. (United States)
 Canada

Specifications (Stranraer)

Data from Supermarine aircraft since 1914,[27] Database: Supermarine Stranraer[28]

General characteristics

  • Crew: 6–7
  • Length: 54 ft 9 in (16.69 m)
  • Wingspan: 85 ft 0 in (25.91 m)
  • Height: 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)
  • Powerplant: 2 × Bristol Pegasus X nine-cylinder air-cooled radial piston engines, 920 hp (690 kW) each
  • Propellers: 3-bladed variable-pitch metal propellers

Performance

  • 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)
  • Range: 1,000 mi (1,600 km, 870 nmi) at 105 mph (91 kn; 169 km/h) and 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)
  • Power/mass: 0.097 hp/lb (0.159 kW/kg)

Armament

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

Surviving aircraft
The single surviving Supermarine Stranraer, on display at the RAF Museum London

A single intact Stranraer, 920/CF-BXO, survives in the collection of the Royal Air Force Museum London.[29][30] This aircraft was built in 1940, one of 40 produced by Canadian Vickers. In service with the RCAF, it flew with several squadrons, on anti-submarine patrols, as a training aircraft and carrying passengers. In 1944, it was disposed of. It was flown by the civilian airline Canadian Pacific Airlines until 1947, then by Queen Charlotte Airlines, who replaced its original engines with American Wright R-1820 Cyclone engines. Queen Charlotte Airlines flew the aircraft on passenger flights until 1952, flying from Vancouver along the Pacific coast of British Columbia. It flew with several other private owners until it was damaged by a ship in 1966. In 1970, it was bought by the RAF Museum and transported to the UK.[31]

Parts of a second Stranraer, 915/CF-BYJ, are owned by the Shearwater Aviation Museum, Halifax, Canada. This aircraft also operated with Queen Charlotte Airlines until it crashed on Christmas Eve 1949 at Belize Inlet, British Columbia. Most of the aircraft was recovered in the 1980s, with the exception of the forward fuselage and cockpit.[31]

See also

Related development

Aircraft of comparable role, configuration, and era

Related lists

Notes
  1. The RAF's Stranraers were ordered in August 1935.[6]
  2. Flight Lieutenant Birchall had been tasked with locating any Italian vessels still in Canadian waters as war became imminent. On 10 June, he located the Capo Nola, which had recently departed from Quebec. Birchall had been informed of the declaration of war by radio and so made a low pass over the freighter, as if making an attack. This panicked the captain into running his vessel aground against a sandbank. Birchall then touched down nearby and waited until Royal Canadian Navy vessels reached the scene. The Capo Nola's crew were the first Italian prisoners taken by the Allies during the war.

References
  1. Andrews & Morgan 1981, pp. 4, 134.
  2. Andrews & Morgan 1981, p. 134.
  3. Andrews & Morgan 1981, pp. 134–135.
  4. Andrews & Morgan 1981, p. 136.
  5. Andrews & Morgan 1981, p. 135.
  6. Pegram 2016, p. 137.
  7. Andrews & Morgan 1981, pp. 136–137.
  8. Andrews & Morgan 1981, p. 137.
  9. Morgan 2001, pp. 58–59.
  10. Andrews & Morgan 1981, p. 139.
  11. Septer 2001, p. 60.
  12. Septer 2001, pp. 60–61.
  13. Pigott 2003, p. 61.
  14. Andrews & Morgan 1981, pp. 137–139.
  15. Andrews & Morgan 1981, pp. 139–140.
  16. Septer 2001, pp. 62–63.
  17. Septer 2001, p. 62.
  18. Kostenuk & Griffin 1977, pp. 25–26.
  19. Kostenuk & Griffin 1977, p. 50.
  20. Kostenuk & Griffin 1977, pp. 24–25.
  21. Kostenuk & Griffin 1977, p. 27.
  22. Kostenuk & Griffin 1977, p. 28.
  23. Kostenuk & Griffin 1977, p. 31.
  24. Kostenuk & Griffin 1977, p. 36.
  25. Kostenuk & Griffin 1977, p. 55.
  26. Bowyer 1991, p. 161.
  27. Andrews & Morgan 1981, pp. 128–140.
  28. Morgan 2001, pp. 54–56.
  29. "Supermarine Stranraer". Royal Air Force Museum. Retrieved 23 November 2021.
  30. London 2003, p. 176.
  31. Simpson 2007.

Sources

Further reading
  • Kightly, James; Wallsgrove, Roger (2004). Supermarine Walrus & Stranraer. Sandomierz, Poland; Redbourn, UK: Mushroom Model Publications. ISBN 978-83-917178-9-9.
  • Shelton, John (2008). Schneider Trophy to Spitfire: the design career of R.J. Mitchell. Sparkford: Hayes Publishing. ISBN 978-1-84425-530-6.
  • Taylor, John W.R. (1969). Combat Aircraft of the World from 1909 to the Present. New York: G.P. Putnam's Sons. ISBN 978-0-425-03633-4.
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