Supermarine Type 316
| Industry | Aerospace, Defense |
|---|---|
| Founded | 1913 |
| Headquarters | Woolston , United Kingdom |
| Products | Aircraft |
The Supermarine B.12/36 was a British four-engine heavy bomber prototype that was lost due to enemy bombing before it could be completed during World War II.
Specification
In July 1936, the British Air Ministry released specification B12/36, seeking a high-speed, four-engine heavy bomber for the Royal Air Force. The requirement called for an aircraft capable of cruising at approximately 230 miles per hour (370 km/h) and reaching speeds up to 275 miles per hour (443 km/h). It needed to cover a range of 3,000 miles (4,800 km) while carrying either a bomb load of 14,000 pounds (6,400 kg) or transporting 24 troops. Additional criteria included the capability to be disassembled for transport via the British railway system, compatibility with catapult-assisted takeoff, and the ability to clear a height of 50 feet (15 m) after departing from a runway no longer than 500 feet (150 m). The wingspan was restricted to a maximum of 100 feet (30 m), and the design had to ensure buoyancy for several hours if forced down at sea.
Among the manufacturers invited to submit proposals were Supermarine, Armstrong-Whitworth, Handley Page, Fairey, Boulton Paul, Vickers, and Shorts. Supermarine's invitation likely stemmed from their expertise in designing water-resistant hulls and catapult-launch capable aircraft, as demonstrated by their work on the Supermarine Walrus.
Design
The Supermarine Type 316 featured a single-spar, mid-wing configuration, with a swept leading edge and a straight trailing edge.[1] Its bomb load was distributed between the wings and the fuselage, while defensive weaponry was arranged in three turrets.[2] Among the various engines proposed for the Type 316, three exceeded 1000 horsepower: the Rolls-Royce Merlin, the Bristol Hercules radial engine, and the Napier Dagger.[3] The aircraft’s projected top speed ranged from approximately 330 to 370 mph (530 to 595 km/h),[4] with an estimated cruising speed near 260 mph (420 km/h). It was expected to have an operational ceiling around 30,000 feet (9,144 meters) and a range close to 3,000 miles (4,828 kilometers).[3]
In October 1936, the Air Ministry reviewed several proposals. Initially, Supermarine’s design ranked lower than those from Vickers, Boulton Paul, and Armstrong Whitworth. However, after an interview with Supermarine’s chief designer R.J. Mitchell in November, the Air Ministry elevated Supermarine’s position. By January 1937, their design had been chosen as the preferred option.[4] Both Supermarine and the Air Ministry then undertook modifications that included enlarging the wing area and incorporating a twin-tail assembly.[5] This updated version was designated as the Type 317.[6] On 22 March 1937, two prototypes powered by Hercules engines were commissioned. Although the Short S.29 was initially considered as an alternative, redesign efforts were requested, leading to prototype orders for that model in June as well. Following Mitchell’s death, concerns about the Supermarine design increased. Meanwhile, Supermarine continued development on a Merlin-powered variant called the Type 318; however, in July 1937 they were instructed to halt work on this version to focus solely on the Type 317.Template:Fix/category[citation needed]
Cancellation
During construction, both prototypes were irreparably damaged when the Supermarine factory at Woolston was struck in a daytime Luftwaffe bombing raid on 26 September 1940.[7] The blueprints for their assembly were also destroyed. Subsequently, the Air Ministry officially terminated the order in November 1940.Template:Fix/category[citation needed]
The Short S.29 entered service as the Short Stirling and served as Britain’s primary four-engine heavy bomber until it was surpassed by the Handley Page Halifax and Avro Lancaster—both developed under specification B13/36 for twin-engine bombers.[8]
Specifications (Type 317 estimated performance)
Notes
References
- ↑ Pegram 2016, p. 201.
- ↑ Pegram 2016, pp. 202–203.
- ↑ 3.0 3.1 Andrews & Morgan 1987, p. 323.
- ↑ 4.0 4.1 Pegram 2016, p. 203.
- ↑ Andrews & Morgan 1987, p. 322.
- ↑ Buttler 2004b, p. 99.
- ↑ Andrews & Morgan 1987, p. 325.
- ↑ Norris 1966, p. 12.
Sources
- Andrews, C.F.; Morgan, E.B. (1987). Supermarine Aircraft Since 1914, Second Edition (Hardback). London: Putnam. ISBN 978-0-85177-800-6.
- Buttler, Tony (2004a). British Secret Projects: Jet Fighters Since 1950 (Hardback). Manchester: Crecy Publishing. ISBN 978-1-910-80905-1.
- Buttler, Tony (2004b). British Secret Projects: Fighters and Bombers 1935-1950 (Hardback). Manchester: Crecy Publishing. ISBN 978-1-85780-179-8.
- Mackay, Ron (1989). Short Stirling in Action. Carrollton, Texas: Signal Publications. ISBN 978-0-89747-228-9.
- Norris, Geoffrey (1966). The Short Stirling. Windsor, UK: Profile Publications Ltd. OCLC 45000607.
- Pegram, Ralph (2016). Beyond the Spitfire: The Unseen Designs of R.J. Mitchell. Cheltenham, UK: The History Press. pp. 200–205. ISBN 978-0-7509-6515-6.
- Shelton, John K. (2015). From Nighthawk to Spitfire: The Aircraft of R.J. Mitchell. Stroud, UK: History Press. pp. 162–166. ISBN 978-07509-6-550-7.
- Sinnott, Colin (2001). The RAF and Aircraft Design, 1923-1939: Air Staff Operational Requirements. London; Portland, Oregon: Frank Cass. ISBN 978-0-7146-5158-3.
Further reading
- Buttler, Tony (2012). ""30 Supermarine B.12/36"". British Experimental Combat Aircraft of World War II: Prototypes, Research Aircraft and Failed Production Designs. Manchester, UK: Hikoki Publications. ISBN 978-1-902109-24-4.
- Goulding, James (1975). RAF Bomber Command and its Aircraft. London: Ian Allan. ISBN 978-0-7110-0627-0.
External links
- John Dell's perspective on the Supermarine 318
- Additional details regarding the B.12/36 Specification provided by Secret Projects