Short Type 320 The Short Type 320 , also known as the Short Admiralty Type 320 , was a 1910s British two - seat reconnaissance , bombing and torpedo - carrying " folder " seaplane . Design and development . The Short Type 320 was designed to meet an official requirement for a seaplane to carry a Mark IX torpedo . It was larger than the earlier Short 184 , and 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 ( 238 kW ) Cossack engine which was the origin of the name the Type 320 . At the same time as Shorts was designing the 310 Type A torpedo bomber , it 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 , and two prototypes were ordered . Priority was given to the torpedo bomber ; the first was ready in July 1916 , and the second in August that year , and the prototypes were rushed to the Adriatic . In September 1916 , the first prototype patrol aircraft was finished , but it 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 . As with conventional biplane floatplane s , 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 . In February 1917 , 25 aircraft were ordered , and before the end of April 1917 , examples were delivered to the Royal Naval Air Service in Italy . Two accidents with the aircraft , when the fuselage collapsed after the torpedo was released , delayed its use 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 . In February 1918 , due to the lack of operational experience , 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 .