Designed by the Sopwith Aviation Company, originally for service with the RNAS, the 1½ Strutter was so nicknamed because each of the upper wings (there was no true centre section) were connected to the fuselage by a pair of short (half) struts and a pair of longer struts, forming a "W" when viewed from the front .[1] The aircraft had airbrakes on the lower wings and was powered by a 130-hp (97 kW) Clerget rotary engine. Some early production aircraft were initially built without pilot's guns - at the time Vickers guns, as well as the necessary synchronisation gears, were in short supply. The Scarff ring mounting was also very new, and production was at first slower than that of the aircraft requiring them - so that various makeshift Lewis mountings, as well as the older Nieuport ring mounting, were fitted to some early 1½ Strutters as an interim measure. From the beginning, a dedicated light bomber version was planned, with the observer's cockpit eliminated to allow for more fuel and bombs to be carried.