Blackburn GP Seaplane 1415 prototype on slipway
The prototype Blackburn GP 1415 in 1916.
The Blackburn GP (General Purpose) was a large twin-engine seaplane built as a private venture by Blackburn Aeroplane and Motor Company  and was partly in response to the poor performance of the earlier Blackburn TB seaplane.
The initial design, created by the Team at the Brough Works, alongside the River Humber, was intended for use as a long-range, anti-submarine patrol aircraft. Two prototype Blackburn GP Seaplanes were built, the first of which (1415) was completed in July 1916. The type was a three-bay biplane featuring a long, slim fuselage, with a biplane tail unit and twin rudders. The wings were of unequal span, with the upper wing span (at nearly 75 ft) being some 22 ft greater than that of the lower. Power was supplied by two 150 hp Sunbeam Nubian engines, which were mounted on the lower wing, driving opposite-handed propellers. The three crew comprised a Gunner / Bomb-aimer accommodated in a nose cockpit with the Pilot sitting to the rear. A third cockpit was also provided behind the wings for a Rear Gunner and armament on the GP Seaplane initially comprised of two defensive Lewis guns, with the alternative provision for the carriage of four 230 lb bombs mounted beneath the wings.
A pair of pontoon floats were used, mounted directly beneath each engine for stability with the gap between the floats clear of struts, thus enabling the carriage of a torpedo (although it is not thought that the type ever flew with one fitted).
The prototype aircraft was the subject of 'Sea-Keeping Trials' at the Isle of Grain, which were followed by a significantly modified second aircraft (1416), which is sometimes referred to as the Blackburn SP (or Special Purpose) seaplane. This type is reported to have been seen 'under test' on the Humber during the winter of 1916, before being delivered to the Great Yarmouth Air Station for Service Trials.
Blackburn GP Seaplane 1416 on slipway ready for launch 1916
The second Blackburn GP (1416) ready for launching from the slipway.
The second aircraft was powered by two opposite-handed, 190 hp Rolls-Royce Falcon engines, mounted on struts mid-way between the upper and lower wings. Ailerons were fitted on all four wings and heavier gauge steel fittings were also used. Additionally, wire trailing edges were fitted to all wings and control surfaces.
Sadly, whilst no production of the Blackburn GP resulted, a landplane variant was created and named the Blackburn RT1 Kangaroo. This proved more successful, with 20 aircraft being built.
Blackburn GP 1416 raised nacelles
The second Blackburn GP (1416) at Brough, showing its raised engine nacelles.


Variants & Number Built

Two prototypes (1415 and 1416)



Two 150 hp Sunbeam Nubian (1415) or two190 hp  Rolls-Royce Falcon (1416)
74 ft 10.25 in
Maximum Weight
8,100 lb (1415), 8,000 lb (f1416)
Capacity & Armament
Three crew; two defensive Lewis guns, four 230 lb bombs carried on racks beneath the wings.
Maximum Speed
97 mph (serial 1416)
8 hours




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