Short Type 320

Type 320

National origin: United Kingdom
Manufacturer: Short Brothers, Sunbeam Motor Car Company
First flight: 1916
Introduced: 1917
Primary user: Royal Naval Air Service Royal Air Force
Number built: 127

The Short Type 320, also known as the Short Admiralty Type 320 was a British two-seat reconnaissance, bombing and torpedo-carrying "folder" seaplane designed by Short Brothers.

Design and development

The Short Type 320 was designed to meet an official requirement for a seaplane to carry a Mark IX torpedo. Larger than the earlier Short 184 it was a typical Short folder design of the time, with two-bay uneven span wings. Two prototypes were built powered by a 310 hp Sunbeam Cossack engine, and initially known as the Short 310 Type A from the engine fitted to the prototypes. When the torpedo bomber went into production it was powered by a 320 hp (238kW) Cossack engine which was the origin of the name the Type 320.

At the same time as Shorts were designing the 310 Type A torpedo bomber, they produced a similar design for a patrol floatplane, powered by the same Cossack engine and using the same fuselage, but with equal span three-bay wings instead of the uneven span wings of the torpedo bomber, known as the Short 310 Type B or North Sea Scout, with two prototypes ordered.

Priority was given to the torpedo bomber, the first being ready in July 1916 and the second in August that year, with the prototypes being rushed to the Adriatic The first prototype patrol aircraft was finished in September 1916, but proved to be little better than the Short 184 already in service, and was not ordered into production. The second prototype Type B was completed as a type A torpedo bomber.

A conventional biplane floatplane the torpedo was carried between the bottom of the fuselage and the floats. Unusually the aircraft was flown from the rear cockpit although this did cause a problem for an observer in the front seat. The observer had to stand on the coaming to use the machine-gun which was level with the top wing. When a torpedo was carried the aircraft could not fly with an observer at the same time.

The first order placed with Shorts was for 30 aircraft, followed by orders for a further 24 and 20 aircraft, together with orders for a further 30 and 20 placed at Sunbeam. Together with the three prototypes, this gave a total production of 127 Short Type 320s.

Operational history

Twenty-five aircraft were ordered in February 1917 and examples were delivered to the Royal Naval Air Service in Italy before the end of April 1917. Two accidents with the aircraft when the fuselage collapsed after the torpedo was released delayed the use of the aircraft on operations. The cause was later found to be the method of securing the fuselage bracing wires.

The first operational use was on 2 September 1917 when six aircraft (five with torpedoes and one with bombs) were towed towed on rafts fifty miles south of Traste Bay to enable them to attack enemy submarines lying off Cattaro. They had to be towed into position as they could not carry enough fuel and a torpedo for the mission. The operation did not go well; with a gale force wind and heavy seas two of the aircraft failed to take off so the operation was abandoned. On the return journey one aircraft was lost and the others were damaged. It appears that the Type 320 never launched a torpedo in action.

Due to the lack of operational experience in February 1918 four aircraft were operated from Calshot for experiments with launching the torpedoes. Forty drops were made and proved a valuable source of information about torpedoes entering the water when dropped at different heights and speeds. The aircraft continued to be used as a reconnaissance seaplane until the end of the war.

Operators

Japan

Imperial Japanese Navy, one only

United Kingdom

Royal Air Force
No. 229 Squadron RAF
No. 240 Squadron RAF
No. 248 Squadron RAF
No. 263 Squadron RAF
No. 266 Squadron RAF
No. 268 Squadron RAF
Royal Naval Air Service
No. 6 Wing - Italy

Specifications

Data from The Short Seaplanes

General characteristics

Crew: 2
Length: 45 ft 9 in (13.95 m)
Wingspan: 75 ft 0 in (22.86 m)
Height: 17 ft 6 in (5.34 m)
Wing area: 810 ft² (75.3 m²)
Empty weight: 4,933 lb (2.242 kg)
Gross weight: 7,014 lb (3,188 kg)
Powerplant: 1 x— Sunbeam Cossack 12 cylinder inline water-cooled piston engine, 320 hp (240 kW)

Performance

Maximum speed: 72.5 mph (117 km/h)
Endurance: 6 hours
Service ceiling: 3,000 ft (915 m)

Armament

1 x— 1,000lb (450 kg) Torpedo or
2 x— 230 lb bombs
1 machine gun

Barnes, C.H. (1967). Shorts Aircraft since 1900. London: Putnam.
Bruce, J.M. "The Short Seaplanes: Historic Military Aircraft No. 14 Part III". Flight (28 December 1956): pp.999-1004. http://www.flightglobal.com/pdfarchive/view/1956/1956%20-%201835.html.
Bruce, J.M. "The Short Seaplanes: Historic Military Aircraft No. 14 Part 4". Flight (4 January 1957): pp.23-24. http://www.flightglobal.com/pdfarchive/view/1957/1957%20-%200023.html.
Bruce, J.M. (1957). British Aeroplanes 1914-18. London: Putnam.
Jefford, C.G. (1988). RAF Squadrons. Airlife Publishing Ltd. ISBN 1 85310 053 6.
Taylor, Michael J. H. (1989). Jane's Encyclopedia of Aviation. London: Studio Editions. ISBN 0710607105.

Short Type 320 Pictures

Living Warbirds: The best warbirds DVD series.

Source: WikiPedia