World War II Database

Contributor: Alan Chanter

ww2dbaseThe Short S.25 Sunderland, in spite of being one of the last flying-boats designed, was durable enough to remain in service for some twenty-one years, and is generally considered to have been one of the finest flying boats ever built.

ww2dbaseTo meet the requirements of the Air Ministry Specification R.2/33 Short's Chief Designer, Arthur (later Sir Arthur) George, prepared a tender which was submitted to the Ministry in 1934. The Design was based on the Company's C Class "Empire" flying boats which had been operated by Imperial Airways in the 1930s. The Air Ministry, already sufficiently familiar with the aircraft's civilian counterpart, accepted the proposal and placed an order in March of 1936, a full eighteen months before the prototype (K4774) made its maiden flight (16 October 1937). Deliveries to the Royal Air Force began in June 1938 with the first batch of production Sunderland Mk Is being delivered to No.230 Squadron based in Singapore. These Sunderlands would replace the RAF's mixed fleet of biplane flying boats and represented a huge leap forward in capability.

ww2dbaseInitially two squadrons were equipped with the Sunderland Mk.1 during 1938, but by the outbreak of war in the following year a further two squadrons had converted to the type (with a further three being formed within the opening months of the war). Sunderland 1 production would eventually total 90 machines (15 of which were built by the Blackburn Aircraft Company). These first machines were powered by four 1,010 hp Bristol Pegasus XXII radial engines.

ww2dbaseThroughout the Second World War the Short Sunderland would play a decisive role in the defeat of German U-boats in the Battle of the Atlantic. The first confirmed U-Boat kill by aircraft was achieved on January 30, 1940 when British destroyer HMS Whitshed, British sloop HMS Fowey, French destroyer Valmy, French destroyer Guépard, and a British No. 228 Squadron S.25 Sunderland aircraft sank German submarine U-55 by depth charges. The large Sunderland was also much in demand for convoy escort work, due not only to its striking power but its ability to land on the water for immediate rescue. The Sunderland was a very welcome sight to the many seamen from sunken vessels and airmen who had had to ditch (When the British Merchant ship Kensington Court was torpedoed, 70 miles of the Scillies on September 18, 1939 two patrolling Sunderlands had the entire crew of thirty-four personnel back on dry land within an hour of the vessel sinking). In this, and during many subsequent desperate evacuation operations early in the war, Sunderlands were regularly found carrying a large number of personnel in an almost continuous stream without ever needing the use of a land airfield.

ww2dbaseAs more capability was added to the airframe, anti-shipping strikes were undertaken across the globe. With their great endurance, Sunderlands could easily spot German ship movements when other types were forced back to base due to lack of fuel. In addition the aircraft's excellent defensive armament became so notorious perilous to the Germans that it gained the nickname of the 'Flying Porcupine'.

ww2dbaseIn 1941 production switched to the improved the Sunderland Mk.II. This model differed from its predecessor in having 1,050hp Bristol Pegasus XVIII engines; a two gun dorsal turret (replacing the single guns in the waist (beam) position of the Sunderland I); and the addition of a surface search radar. 58 Sunderland IIs were built.

ww2dbaseThe Sunderland III was first flown in June 1942. This was basically similar to the Sunderland II but with a revised planing bottom. The Sunderland III would become the major production version with some 407 machines being manufactured until late 1943. Six Sunderland IIIs would be converted for use as long range passenger aircraft, operated by BAOC from 1943 (firstly from Poole to Lagos, West Africa and to Calcutta, India, and from then on gradually extending their routes).

ww2dbaseThe final model of the Sunderland was the G.R. Mk.V, of which 143 would be completed by the time that production finally ended in 1946 (Bringing total Sunderland aircraft built to a total of 739 machines), The G.R.Mk.V switched to the 1,200 hp Pratt and Whitney R-1830-90B Twin Wasp engines. It also had better armament and other detail modifications.

ww2dbaseOften overshadowed by more glamorous aircraft, the Sunderland served throughout the war, and would later deliver nearly 5,000 tons of essential supplies during the Berlin airlift. It was also the only RAF aircraft to be used from the beginning to the end of the Korean War. The last Sunderland was finally retired from RAF service on the 20th May 1959 after an extensive and notable career.

S.25 Sunderland Timeline

SPECIFICATIONS

Sunderland I

Machinery	Four Bristol Pegasus XXII 9-cyl radial engines rated at 1,110hp each
Armament	2x7.62mm trainable bow turret machine guns, 4x7.62mm trainable tail turret machine guns, 2x7.62mm trainable beam machine guns, 907kg of ordnance
Crew	10
Span	34.39 m
Length	26.00 m
Height	10.00 m
Wing Area	138.00 m²
Weight, Empty	13,875 kg
Weight, Maximum	22,226 kg
Speed, Cruising	336 km/h
Rate of Climb	3.67 m/s
Service Ceiling	4,570 m
Range, Normal	4,023 km

Photographs

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6.  Alan Chanter says:
10 Aug 2013 05:28:39 AM

Manned by a mixed British, Dominion and Colonial crew "Z for Zebra" a RAF Coastal Command Sunderland flying boat carried out the the Royal Navy's last convoy escort of the war. At one minute past midnight on 4th June 1945, while on patrol some 500 miles northwest of Ireland "Z for Zebra" received the "cease patrol" order with gratitude for a job well done.