Maxim's twin engined Naptha/Steam machine ( in only a test-rig configuration) in 1894 generated so much lift in a trial run ( estimated at between 3000 and 10,000 lb)that it inadvertently broke its restraining rails and travelled a considerable distance through the air with four on board.
In this configuration it was not intended to fly. The planned configuration for this included additional wing panels , powered flying controls and a gyroscopically governed autopilot.
Maxim ran out of money on this project and lost interest, probably because he was coming to the realisation that the internal combustion engine made smaller machines more practicable.
Unlike the Wrights 1903 engine, one of Maxim's engines ( of 180 hp incidentally) is fortunately still with us and is in the bowels of the U.K. Science Museum. At least it was in 1978.
The other engine Maxim consigned to the Smithsonian in the U.S.A. by the safest means of transportation possible in 1912. He put it on the Titanic.
If I may quote Peter Lewis ( British Aircraft 1809 to 1914. Putnam).
Designed on a grand scale, construction of Hiram S. Maxim's first biplane commenced in 1891, and the enormous machine was completed in 1894. Power for the pair of 17.83 ft. diameter propellers was provided by two light-weight compound steam engines, which gave a total of 360 h.p. 320 lb./sq. in. steam was supplied by a Thorneycroft marine boiler fired by naphtha, total thrust being 2,100 lb.
Testing was carried out at Baldwyn's Park, Bexley, Kent, on a 9 ft. wide steel railway track 1,800 ft. in length, equipped with check rails of Georgia pine 35 ft. apart. With pilot and three passengers aboard, the machine took off after a run of 200 yds., when it reached 40 m.p.h., but broke the check rails and came to a halt. The measured lift was 4,000 lb. Owing to the illness of the inventor, and the fact that the grounds at Baldwyn's Park were required for use as a public institution, the whole project was abandoned. Span, 104 ft. Length, 120 ft. Wing area, 3,875 sq. ft. Weight loaded, 8,000 lb.
Last edited by Haraka; 1st Jun 2014 at 10:12.