Short S.25 Tasman Class Sandringham / Sunderland
The Sunderland maritime-patrol and reconnaissance flying-boat was designed to meet the requirements of Air Ministry Specification R.2/33 and was virtually a military version of the Empire boat. The prototype flew for the first time on 18 October 1937, just over a year after the first Empire began its trials.
Entering service in June 1938, by the outbreak of war there were three squadrons of RAF Coastal Command operational with it and others in the process of re-equipping or forming. The Sunderland was notable for being the first flying-boat to be equipped with power-operated gun turrets.
The first production version was the Sunderland I powered by Bristol Pegasus 22 engines and armed with eight 7.7mm machine-guns: two in a Fraser-Nash nose turret, four in a Fraser-Nash tail turret, and two on hand-operated mountings in the upper part of the hull aft of the wing trailing edge.
The Sunderland II had Pegasus XVIII engines, but was otherwise similar to the Mk I, although late models were fitted with a two-gun dorsal turret in place of the manually operated guns.
The Mk III used the same power plant as the Mk II, but had a modified hull with a stream-lined front step and a dorsal turret as standard.
The final military version was the Sunderland V, the IV having become the Seaford. The Mk.5 was used mainly as a maritime reconnaissance flying boat they were powered the more powerful l200hp Pratt & Whitney R-1830 Twin Wasp. Wing span remained the same, however, the aircraft was slightly longer at 85’ 4”. Due to the increased power, the MAUW was 65,000lbs, but the maximum speed remained relatively unchanged. Armed with six Browning .303 machine-guns carried in two turrets (four in the rear and two in the forward), and four .303s fixed, that were controlled by the pilot. There were also two 0.5 Browning, which were manually operated, positioned in the beam hatches. Eight depth charges were carried on racks which were run out from the bomb room, along rails which extended under the wings. As with all the guns, these could be reloaded in flight.
Production continued until October 1945 and seven hundred and forty-nine Sunderlands were built, and they served throughout the war. The final Coastal Command Sunderland operational mission was in June 1945 over four weeks after the German surrender. Long-range Sunderland operations also took place overseas from bases in Africa and the Far East.
In 1943 a number of Sunderlands were de-militarised, equipped to carry 20 passengers and turned over to BOAC.
Post-war the type took part in the Berlin Airlift carrying 4920 tonnes (4847 tons) of freight. During the Korean War Sunderlands based in Japan undertook nearly 900 operational sorties totally over 13350 hours of flying. The Sunderland finally retired from RAF service in 1959 when the last aircraft were scrapped at RAF Seletar, Singapore.
Engines: 4 x Bristol Pegasus XVIII
Cruise: 200 mph
Pax capacity: 16-24
Sunderland Mk. III
Engines: 4 x 1065hp Bristol Pegasus radials
Wing span: 112 ft 10 in
Length: 84 ft 4in
MAUW: 58, 000 lb
Top speed: 210mph at 7,000ft
Sunderland Mk V
Engines: 4 x Pratt-Whitney R-1830-90B Twin Wasp, 895kW / 1200 hp
Max take-off weight: 29480 kg / 64993 lb
Empty weight: 16740 kg / 36906 lb
Wingspan: 34.38 m / 113 ft 10 in
Length: 26 m / 85 ft 4 in
Height: 10.52 m / 35 ft 6 in
Wing area: 156.72 sq.m / 1686.92 sq ft
Max. speed: 185 kt / 343 km/h / 213 mph
Cruising speed: 116 kt / 214 km/h
Service Ceiling: 5455 m / 17900 ft
Range: 2337 nm / 4300 km / 2672 miles
Armament: 2 x .5in / 12.7mm Browning machine-guns, 10 x .303in / 7.7mm machine-guns
Bombload: 2250kg / 8 x depth charges