Cromarty: The Flying Boat That Started It All for Short Brothers

Video from the channel Rex's Hangar about Short Brothers, linked on its Above Ten Thousand entry. Duration: 12:24. Language: English. Video type: Documentary.

The story of the Short N.3 Cromarty, Short Brothers' first in-house flying-boat design and the starting point of the firm's flying-boat line. It was championed by Oswald Short, the youngest of the three brothers.

After Horace Short's death in 1917, the company focused on the Medway, and the Ministry of Munitions commissioned it to build other firms' designs: 100 DH9s and 50 Felixstowe F3 flying boats of Porte design. For these it set up a dedicated workshop. Short's first F3, N4000, was ready on 15 May 1918. Part of the order was completed as the improved F5, and some cancelled F5s ended up with the Imperial Japanese Navy. In 1918 the Admiralty issued specification N.3 for a fleet-cooperation flying boat and ordered three prototypes from Vickers, which produced the Valentia, and three more from Short.

The Cromarty was derived from the F5, but was larger: 113 feet 6 inches in span and 59 feet long. It was an unequal-span biplane with two Rolls-Royce Condor engines and a plywood hull on a spruce frame. It carried a 37 mm bow gun and a biplane tail with three rudders. Only the prototype N120 was completed, launched on 21 March 1921, which first flew on 19 April with John Lancaster Parker at the controls. In trials at Grain it climbed to 3,000 feet in 7 minutes at 19,800 lb and reached 83 knots. Water absorbed by the hull worsened the climb, and improved Condor engines had to be fitted. In 1922, during a tour of the British south coast, it rode out a storm in the Scilly Isles, but shortly afterwards was damaged crossing a reef and was scrapped. The experience pushed Oswald towards metal hulls, which would lead to the Singapore series.