Supermarine Southampton

The Vickers Supermarine Southampton reconnaissance flying boat was one of the most successful of such aircraft operated by the Royal Air Force (RAF). In addition to its intended duties, the type took part in many long-distance overseas flights leading to the development of overseas airways routes.

 

By the mid-twenties the RAF needed to replace their First World War vintage Felixstowe F3 flying boats and the civil Supermarine Swan was well received in its certification trials.  As a result, Vickers Supermarine received an order off the drawing board for six Vickers Supermarine Southampton flying boats (a military derivative of the Vickers Supermarine Swan) against Specification R.18/24. The first of these (N9896) was flown for the first time on 10th March 1925.

 

The Vickers Supermarine Southampton was a twin engine tractor biplane flying boat with diagonal (Warren truss) bracing of the wing centre section. The distinctive empennage featured three shapely fins and rudders. Power was provided by Napier Lion engines and in the first version, the Vickers Supermarine Southampton I, the hull and wings were of wooden construction. The crew comprised pilot and navigator / wireless operator and two gunners.

 

The type was an immediate success and a series of production orders followed, the final production figures being 83 production aircraft, plus a single example of the three-engine Vickers Supermarine Southampton X. A series of notable flights were undertaken by the RAF, including a 10,000 mile flight around the British Isles (a 7,000 mile flight to Egypt and back) and the flight to the Far East of four Vickers Supermarine Southampton IIs covering nearly 27,000 miles, including a circumnavigation of Australia.

 

 

The first eighteen Vickers Supermarine Southampton aircraft delivered were Mk.Is, with wooden hulls. However, a research programme had convinced the Royal Air Force of the superior qualities of 'metal over wood' and so the final forty-eight were delivered as Vickers Supermarine Southampton Mk.IIs, with metal hulls. In a programme begun in 1929, all surviving wooden-hulled Vickers Supermarine Southamptons were re-built with metal hulls.

 

The metal hull is stated to have resulted in a direct weight saving of 540lb, with an additional benefit of avoiding water soakage, which could account for up to aa 400 lb weight growth of the wooden-hulled machines. The combination of this direct weight saving, with the resultant ability to carry additional fuel, allowed a maximum range of 900 miles for the vickers Supermarine Southampton II, compared with 600 miles for the Vickers Supermarine Southampton I.

 

 

The first Vickers Supermarine Southampton II (N218) flew with Napier Lion engines, and later experimentally fitted with Bristol Jupiter engines. 24 new metal hulls were also built to be retro-fitted to the wooden-hulled Southampton I, and to act as spares.

 

Metal wings were also developed, offering a further 200 lb benefit in terms of weight saving. The metal winged aircraft were known as Vickers Supermarine Southampton Mk.IIIs.

 

The vickers Supermarine Southampton remained in RAF service until December 1936.

 

 

The type was exported to Argentina, Japan, Turkey and Australia whilst 8 aircraft were sold also to Argentina, for use by their naval air arm. These aircraft were powered by two 450 hp Lorraine 12E engines, whilst of the 5 Argentine aircraft, 2 had wooden hulls and three were metal-hulled.

 

Two Ex-RAF Singapore I aircraft were sold to Australia (S1158, S1159 becoming A11-1 and A11-2, respectively) and these aircraft were intended to take part in the RAF Far East Flight’s circumnavigation of Australia. One aircraft (A11-1) was pre-positioned to greet the RAF Far East Flight at Adelaide SA in June 1928. Sadly however, a freak gust of wind overturned the aircraft as it was about to leave to meet up with the RAF flight.

 

 

One Vickers Supermarine Southampton (A11-2) subsequently set off on a tour of the major cities of the eastern Australian States, an expedition which generated very positive publicity for the RAAF. Consequently, similar recruitment tours became a regular occurrence during 1929-33 period, with one of the aircraft undertaking such a task every six months or so.

 

In Australian service, the type proved to be very popular with aircrews due to the combination of a galley and sleeping area. It also found favour as a reliable, stable flying platform that earned high praise from those undertaking long range flights as well as those who maintained them.

 

The Vickers Supermarine Southampton main role was undertaking aerial surveys and long-range, search and rescue missions at sea. A secondary and almost unexpected usage was for aircrew parachute training.

 

 

The single Vicker Supermarine Southampton II sold to Japan in 1928 (J-BAID) was later converted to an 18-passenger civil configuration. 6 Vickers Supermarine Southampton II aircraft were also sold to Turkey, being deliveredas N3 to N8 under ‘Class B’ markings.

 

One Vickers Supermarine Southampton IV (S1648) was fitted with a 525 hp Rolls-Royce Kestrel III engine and this aircraft became the prototype for the Supermarine Scapa.

 

An aircraft known as the 'Southampton X' was created as a three engine sesquiplane (a biplane with one wing of less than half the area of the other). This all-metal flying boat had no connection to the original Vickers Supermarine Southampton other than the re-use of Southampton name. Whilst the hull was produced by Supermarine at Woolston, whilst the wings were the responsibility of Vickers Ltd at Weybridge. Both components markedly exceeded their planned structural weights (by some 30%).

 

 

As a result, the sole example built (N252) proved to be underpowered when first tested in March 1930 and subsequently at the  Seaplane Experimental Station at Felixstowe. This led to a number of engine changes, with the initial Jaguar Vis being replaced by Bristol Jupiter XBFM / Bristol Jupiter XIF as well as Panther engines.

Southampton I - Hull only (N9899)

RAF Museum Hendon, London              www.rafmuseum.org.uk