The Supermarine Walrus was a single-engine amphibious biplane reconnaissance aircraft designed by R. J. Mitchell and operated by the Fleet Air Arm. It also served with the Royal Air Force, RAAF, RNZN, RCAF, and RNZAF.
The Walrus was initially developed for service from cruisers at the request of Australia, and was called the Seagull V; although there was little resemblance to the earlier Supermarine Seagull III. It was designed to be launched from ship-borne catapults, and was the first amphibious aircraft in the world to be launched by catapult with a full military load.
The lower wings of this biplane were set in the shoulder position with a stabilising float mounted under each one, and its horizontal tail-surfaces were positioned high on the tail-fin. The single Bristol Pegasus VI radial engine was housed in a nacelle slung from the upper wing and powered a four-blade propeller in pusher configuration. The wings could be folded on ship, giving a stowage width of 17 ft 11 in (5.5 m). One of the more unusual characteristics of the aircraft was that the control column was not a fixed fitting in the usual way, but could be unplugged from either of two sockets at floor level. It became a habit for only one column to be in use; and when control was passed from the pilot to co-pilot or vice-versa, the control column would simply be unplugged and handed over.
As the Walrus was stressed to a level suitable for catapult-launching, rather surprisingly for such an ungainly-looking machine, it could be looped and bunted, whereupon any water in the bilges would make its presence felt. This usually discouraged the pilot from any future aerobatics on this type.
Armament usually consisted of two Vickers K machine guns, with the capability of carrying 760 lb (345 kg) of bombs or depth charges mounted beneath the lower wings.
The Royal Australian Air Force ordered 24 examples directly off the drawing boards, under the Seagull V 'A2' designation, which were delivered for service from cruisers from 1935; followed by orders from the Royal Air Force with the first production Walrus, K5772, flying on 16 March, 1936. It was also hoped to capitalise on the aircraft's successful exports to Japan, Spain, etc.
A total of 740 Walrus were built in three major variants: the metal-hulled Seagull V and Walrus I, and the wooden-hulled Walrus II. The Walrus was affectionately known as the "Shagbat" or sometimes "Steam-pigeon"; the latter name coming from the steam produced by water striking the hot Pegasus engine.
The first Seagull V, A2-1, was handed over to the Royal Australian Air Force in 1935, with the last, A2-24 delivered in 1937 and served aboard the HMA Ships Australia (MTO [Mediterranian Theatre of Operations]), Canberra (MTO, SWPA, lost at Guadalcanal in 1942), Sydney (MTO, SWPA, lost off the coast of Western Australia 1942), Perth and Hobart.
Walrus deliveries started in 1936 when the first example to be deployed was with the New Zealand division of the Royal Navy, on HMS Achilles (later a victor of the Battle of the River Plate). By the start of World War II the Walrus was in widespread use, and saw service in home waters, the Mediterranean and the Far East. Walrus are credited with sinking or damaging at least five enemy submarines, while RAF use in home waters was mainly in the air-sea rescue role. One Walrus, HD874, (Restored and exhibited at the RAAF Museum, Point Cook, Victoria) was still in service in 1947 with the Australian Antarctic Expedition.
The Irish Air Corps used the Walrus as a maritime patrol aircraft during World War II. One of the Walrus aircraft formerly flown by the Air Corps is preserved, albeit in Royal Navy colours. The aircraft was bought back by the Fleet Air Arm after the war as a training aircraft, and now resides in the RNAS museum in Yeovilton.
Length: 33 ft 7 in (10.2 m)
Wingspan: 45 ft 10 in (14.0 m)
Height: 15 ft 3 in (4.6 m)
Wing area: 610 ft² (56.7 m²)
Empty weight: 4,900 lb (2,220 kg)
Loaded weight: 7,200 lb (3,265 kg)
Powerplant: 1× Bristol Pegasus VI radial engine, 680 hp (510 kW)
Maximum speed: 135 mph (215 km/h) at 4,750 ft (1,450 m)
Range: 600 mi (965 km)
Service ceiling 18,500 ft (5,650 m)
Rate of climb: 1,050 ft/min (5.3 m/s)
Wing loading: 11.8 lb/ft² (57.6 kg/m²)
Power/mass: 0.094 hp/lb (0.16 kW/kg)
2 x Vickers K machine guns
760 lb (345 kg) of bombs and depth charges