Factory capacity narrows Britain's design choices

Supermarine's focus on the Spitfire and the limited capacity of smaller manufacturers mattered as much as aerodynamic merit. Supermarine was only one specialized part of the larger Vickers organization and had finite designers, workers, and facilities available for parallel programs. Britain was expanding aircraft output from 1937 through measures such as the shadow-factory program, but the new capacity had not yet matured in 1938-39. Officials could therefore set aside an innovative proposal simply because its manufacturer could not plausibly produce it in useful numbers. Although S.24/37 expressed a preference for an air-cooled engine, none of the air-cooled proposals advanced, another sign that the selected path diverged from the paper brief. The fact that Blackburn later built most wartime Swordfish illustrates how work could eventually be redistributed once factories and jigs were available. This passage turns the competition into a lesson in production feasibility: selecting a paper design without a credible manufacturing path would not create an operational aircraft.