SPECIFICATIONS
Powerplant: Three 525 h.p. Bristol Jupiter XI.F
Performance: Max Speed: 118 m.p.h.
Range: 650 miles
Weights: Weight (All-Up): 22,500 lb
Dimensions: Span: 93 ft  0 in
Length: 66 ft  0 in
Crew: 2
Passengers: 15
Cost: £18,000

In 1926 Imperial Airways ordered two Short S.8 Calcutta three-engined biplane flying boats to be powered by 540 hp (403 kW) Bristol Jupiter XI radial engines. The design of the Calcutta, which accommodated 15 passengers, was based closely on the military Singapore I, and when these aircraft were delivered to Imperial Airways in the late summer of 1928 they were the first stressed-skin metal hull flying boats to enter commercial service. Production for Imperial Airways totalled five, and Short Brothers built one other for the French government. A manufacturing licence was negotiated with Breguet, this company developing from the Calcutta the very similar Breguet 521 Bizerte.