Supermarine Stranraer

Supermarine Aviation Works

Company type	Company
Industry	Aerospace, Aircraft manufacturing
Founder	R. J. Mitchell (designer)
Fate	Continued as subsidiary of Vickers-Armstrongs
Headquarters	Woolston, Southampton , United Kingdom
Area served	United Kingdom, Canada
Key people	R. J. Mitchell (lead designer)
Products	Aircraft, including Supermarine Stranraer flying boat
Owner	Vickers-Armstrongs (parent company)
Parent	Vickers-Armstrongs

Template:Good article Template:Infobox aircraft The Supermarine Stranraer was a British flying boat developed and constructed by the Supermarine Aviation Works located in Woolston, Southampton. Its creation took place during the 1930s specifically for its main operator, the Royal Air Force (RAF). Notably, it was the final biplane flying boat operated by the RAF and also their fastest of this type.

Based on the earlier Supermarine Scapa, the design of this aircraft was significantly influenced by the Air Ministry's Specification R.24/31, issued in 1931. Although initially dismissed by the Air Ministry, Supermarine continued refining the concept as a private project under the name Southampton V. In 1933, a contract for a single prototype was awarded, coinciding with the aircraft being named after the town of Stranraer. The Stranraer took to the skies for its maiden flight on 24 July 1934 and entered active service with the RAF in 1937. By the time World War II commenced, most units were operational.

During the early phase of World War II, Stranraers primarily conducted anti-submarine warfare and convoy escort missions. The type was removed from frontline duties in March 1941 but remained in use as a training platform until October 1942. Beyond those built in Britain, Canadian Vickers in Montreal produced 40 additional Stranraers under licence for the Royal Canadian Air Force (RCAF). These Canadian-operated aircraft performed coastal defence and anti-submarine patrols along both Atlantic and Pacific shores of Canada and remained active until 1946. After military retirement, numerous former RCAF Stranraers were acquired by emerging regional airlines, where they served as passenger and cargo aircraft into the 1950s.

Background

File:Supermarine Aviation Ltd, Woolston.jpg

Supermarine's manufacturing facility at Woolston, Southampton

The Supermarine Stranraer originated as a direct evolution of the Supermarine Scapa and represented the last flying boat design created by R. J. Mitchell for the Royal Air Force (RAF). Production occurred at Supermarine’s Woolston factory in Southampton between 1937 and 1939. The design process began in the early 1930s under Mitchell's leadership.

This initiative responded to the Air Ministry’s Specification R.24/31 issued in 1931, which sought a twin-engine general-purpose coastal reconnaissance flying boat for RAF service. The specification required an increased payload capacity—approximately 1,000 pounds (450 kg) more than that of the Scapa—and mandated that the aircraft be capable of maintaining level flight with only one engine operational, a capability absent in the Scapa. Supermarine initially proposed an enlarged version of the Scapa to meet these requirements, competing against a design submitted by Saunders-Roe.

Ultimately, Saunders-Roe’s design was preferred by the Air Ministry, leading to Supermarine’s rejection. Nevertheless, Supermarine elected to advance their design independently as a private venture, initially designated as Southampton V.

Prototypes and production

In 1933, an order was placed for a single prototype powered by two Bristol Pegasus IIIM engines, each delivering 820 horsepower, and the aircraft was designated the Stranraer. The maiden flight of the initial prototype, registered as K3973, occurred on 24 July 1934, with Joseph Summers as the pilot. Over the subsequent months, a comprehensive initial flight testing program was carried out. On 24 October 1934, the aircraft was handed over to the Marine Aircraft Experimental Establishment (MAEE) at RAF Felixstowe to undergo official evaluation trials.

Following the completion of these proving flights, the Air Ministry issued a first production order for 17 units on 29 August 1935, assigned serial numbers from K7287 to K7303, to meet Specification 17/35. A further order for six additional aircraft (serials K9676 to K9681) was placed in May 1936 but was later cancelled. The first production-standard Stranraer took to the air in December 1936 and officially entered RAF service on 16 April 1937. The final delivery of a Stranraer occurred on 3 April 1939. Additionally, Canadian Vickers Limited produced 40 Stranraers under licence in Canada; both Supermarine and Canadian Vickers operated as subsidiaries of Vickers-Armstrongs.

Description

File:Supermarine Stranraer - John Player.jpg

A 1935 cigarette card illustrating the Supermarine Stranraer

The Stranraer was a twin-engine biplane flying boat designed to accommodate a crew of six to seven personnel. It had an empty weight of approximately 11,250 pounds and a maximum takeoff weight reaching up to 19,000 pounds.

Throughout its development, the Stranraer evolved from the earlier Scapa design by adopting a two-bay wing configuration. Compared to its predecessor, the Stranraer featured a 12% increase in weight as well as wing surface area and span. The elevator area was expanded by around 7%, and the rudders incorporated trim tabs that enabled stable flight during single-engine operation. Power was provided by moderately supercharged Bristol Pegasus IIIM radial engines. The airframe predominantly utilized alclad materials, with stainless steel employed for detailed fittings; metal parts were anodised to prevent corrosion. To enhance structural integrity, an additional pair of interplane struts were installed. The hull was significantly enlarged with an 18% increase in cross-sectional area but maintained equivalent hydrodynamic characteristics. Design improvements included a retractable forward gun mount, lowering of the midship gunner position, and introduction of a tail gunner station located aft of the control surfaces featuring a hooded windshield. These modifications reflected operational insights gained from earlier Southampton flying boats.

The production variant differed from the prototype chiefly through installation of more powerful Pegasus X engines rated at 920 horsepower. Engines were mounted in nacelles beneath the upper wing to keep propellers clear of sea spray. Fuel was stored in two centre-section upper wing tanks, each holding 250 imperial gallons; fuel delivery primarily relied on gravity feed supplemented by fuel pumps. The original two-bladed wooden propellers were replaced in production models by three-bladed metal Fairey-Reed propellers. Wing structure was revised to incorporate a two-bay configuration.

Armament consisted of three .303 inch Lewis guns positioned in nose, dorsal, and tail locations. The aircraft had capability to carry up to 1,000 pounds of bombs.

Pre-September 1939 military deployment

The Stranraer, alongside its contemporary the Saro London, represented the final generation of multi-engine biplane flying boats to be utilized by the RAF. The Royal Air Force operated a total of 17 Stranraers starting in 1937, although by the time they were introduced, these aircraft were already deemed outdated. The RAF placed orders for these aircraft in August 1935, coinciding with the adoption of the Stranraer name. Prior to the outbreak of war, this model was primarily assigned to No. 228 Squadron, No. 209 Squadron, and No. 240 Squadron. The aircraft's reception among pilots was generally unfavorable, with many regarding its performance as borderline adequate. However, some acknowledged that it exhibited superior seaworthiness compared to other commonly used aircraft like the Consolidated PBY Catalina. By 1938, several squadrons operating Stranraers had begun transitioning to other flying boats such as the Short Sunderland and Short Singapore.

In its early operational phase, the Stranraer undertook several demanding long-distance flights; notably, one mission in September 1938 covered approximately 4,000 miles (6,400 km) during a single exercise.

RAF Stranraers SOC ("struck off charge") prior to September 1939

Serial	Delivery Date	Disposition	Remarks
K3973	October 1934	SOC (30 October 1938)	Prototype, rendered obsolete
K7288	September 1937	Crashed into sea during night exercise, caught fire and sank (28 March 1938)	Six fatalities
K7297	September 1938	Lost over the North Sea (19 August 1939)	Six fatalities

World War II operations

Throughout World War II, no Stranraers operated beyond UK territorial waters. Following the war’s commencement in September 1939, these aircraft conducted patrols over the North Sea, targeting enemy shipping lanes between Scotland and Norway. Typically, they were equipped with bombs under one wing and an auxiliary fuel tank on the other for extended range missions. These patrol duties with the Stranraer concluded on 17 March 1941. The aircraft served notably with No. 240 Squadron and were also present in small numbers at the No. 4 (Coastal) Operational Training Unit. The last recorded RAF flight of a Stranraer was carried out by K7303 at Felixstowe on 30 October 1942.

File:Supermarine Stranraer 2 ExCC.jpg

RCAF Stranraer sporting wartime camouflage

During its service tenure, the Stranraer was met with widespread criticism from both aircrew and ground personnel, leading to an array of unflattering nicknames. Among these was "whistling shithouse," a reference to its toilet design which vented directly into the airstream, causing a distinctive whistling noise when opened. Other colloquial monikers included "Flying Meccano Set," "The Marpole Bridge," "Seymour Seine Net," "Strainer," "Flying Centre Section of the Lion's Gate Bridge," and a more polite variation known as "Whistling Birdcage."

The Royal Canadian Air Force operated Stranraers identical to those used by the RAF. In Canadian service, they fulfilled similar coastal patrol roles aimed at countering submarine threats. Aviation historian Dirk Septer noted that no enemy engagements involving RCAF Stranraers were documented. Nevertheless, a notable incident involved a No. 5 Squadron RCAF Stranraer crew led by Flight Lieutenant Leonard Birchall, who played a key role in capturing an Italian merchant vessel, Capo Nola, in the Gulf of Saint Lawrence shortly after Canada declared war on Italy on 10 June 1940. Birchall had been assigned to identify any Italian ships remaining in Canadian waters as hostilities loomed; upon locating Capo Nola, he executed a low pass that simulated an attack, prompting the ship’s captain to run aground on a sandbank. Birchall then landed nearby and awaited Royal Canadian Navy forces, resulting in the first Italian prisoners captured by Allied forces during the conflict. The Canadian-built Vickers Stranraers remained active within the RCAF throughout World War II until their final withdrawal on 20 January 1946.

RAF Stranraers SOC or destroyed between 1939 and 1942

Serial	Delivery Date	Disposition	Remarks
K7287	April 1937	SOC (25 June 1941)
K7289	December 1937	Unknown post-June 1941
K7290	January 1938	Sank during storm (21 November 1940)
K7291	June 1938	Collided with light boat and sank (10 November 1940)
K7292	February 1938	SOC (13 May 1941)
K7293	March 1938	Lost in gale (17 February 1941)
K7294	May 1938	Damaged beyond repair after water impact (3 November 1939)
K7295	July 1938	Damaged beyond repair following water impact (4 September 1942)
K7296	August 1938	SOC (22 September 1939)
K7298	September 1938	Crashed into sea (12 June 1941)	Nine fatalities
K7299	October 1938	SOC (4 April 1941)
K7300	November 1938	Sank in storm (20 October 1941)
K7301	December 1938	Sank in storm (21 August 1940)
K7302	January 1939	Sank in storm (20 October 1941)
K7303	April 1939	SOC (31 October 1942)

Civilian use

Beginning in May 1935, the Stranraer was adapted for commercial purposes and redesignated as the Type 237. Roughly half of the 40 Stranraers operated by the RCAF remained sufficiently intact after the war to be considered for further use. Out of these, 13 were transferred to civilian entities via Crown Assets following the conclusion of hostilities, receiving registrations in both Canada and the United States. A number of these aircraft underwent modifications to the Super Stranraer standard, featuring upgraded 1,200 horsepower (890 kW) Wright GR-1820-G202GA engines that replaced the initial Pegasus powerplants.

Post-World War II, several Stranraers found service with Queen Charlotte Airlines (QCA) based in British Columbia, remaining operational until 1958. QCA, at one point Canada’s third-largest airline, was colloquially known as the Queer Collection of Aircraft due to its eclectic fleet composed largely of surplus aircraft acquired on limited budgets. Within this fleet, the Stranraer earned a reputation for being more apt and was reportedly "well liked" by its flight crews. Additionally, eight surplus Stranraers were sold to Aero Transport Ltd., located in Tampa, Florida.

Military

Canada

File:Supermarine Stranraer 912.jpg

Supermarine Stranraer 912 of the RCAF at RCAF Station Jericho Beach

• RCAF – Operational Squadrons within the Home War Establishment (HWE), stationed in Canada
  • Eastern Air Command
    • No. 5 Squadron RCAF Operated Supermarine Stranraer (Nov 1938 – Sep 1941)
    • No. 117 Squadron RCAF Operated Supermarine Stranraer (Sep 1941 – Oct 1941)
  • Western Air Command
    • No. 4 Squadron RCAF Operated Supermarine Stranraer (Jul 1939 – Sep 1943)
    • No. 6 Squadron RCAF Operated Supermarine Stranraer (Nov 1941 – May 1943)
    • No. 7 Squadron RCAF Operated Supermarine Stranraer (Feb 1943 – Mar 1944)
    • No. 9 Squadron RCAF Operated Supermarine Stranraer (Dec 1941 – Apr 1943)
    • No. 13 (OT) Squadron RCAF Operated Supermarine Stranraer (Oct 1941 – Nov 1942)
    • No. 120 Squadron RCAF Operated Supermarine Stranraer (Nov 1941 – Oct 1943)
    • (OT) - Operational Training;

United Kingdom

File:Aircraft of the Royal Air Force 1939-1945- Supermarine Stranraer. CH2551.jpg

A Stranraer Mark I from No. 240 Squadron RAF landing on Loch Ryan

• Royal Air Force
  • No. 201 Squadron RAF
  • No. 209 Squadron RAF
  • No. 210 Squadron RAF
  • No. 228 Squadron RAF
  • No. 240 Squadron RAF

Civilian

United States

• Aero Transport Ltd.

Canada

• Pacific Western Airlines
• Queen Charlotte Airlines
• Wardair

Surviving aircraft

File:Supermarine Stranraer.jpg

The sole remaining Supermarine Stranraer, exhibited at the RAF Museum London, 2021

Only one Stranraer, designated 920/CF-BXO, is preserved within the collection of the Royal Air Force Museum London. Constructed in 1940 by Canadian Vickers as part of a batch of forty units, this aircraft served with the RCAF across multiple squadrons conducting anti-submarine missions, training roles, and passenger transport. After being retired from military service in 1944, it operated under Canadian Pacific Airlines until 1947. Subsequently acquired by Queen Charlotte Airlines, it was refitted with American Wright R-1820 Cyclone engines and used for passenger routes along British Columbia's Pacific coast until 1952. The aircraft changed hands among private owners before sustaining damage from a collision with a ship in 1966. Purchased by the RAF Museum in 1970, it was relocated to the United Kingdom.

The Shearwater Aviation Museum in Halifax, Nova Scotia holds components of a second Stranraer, serial number 915/CF-BYJ. This aircraft also flew with Queen Charlotte Airlines until it crashed on December 24, 1949, at Belize Inlet, British Columbia. Initial wreckage was recovered during the 1980s, with further parts transported to the museum in November 2008 for planned restoration—excluding the forward fuselage and cockpit sections. As of 2025, these remains are kept in storage pending restoration.

See also

• Short Knuckleduster

Additional resources

• Kightly, James; Wallsgrove, Roger. Supermarine Walrus & Stranraer. Mushroom Model Publications, 2004. Published in Sandomierz, Poland and Redbourn, UK. ISBN 978-83-917178-9-9.

External links

• Canadian Armed Forces: Supermarine Stranraer