Page 49 - Theory and Design of Air Cushion Craft

ACV and SES development in China 33

model was constructed in both wood and aluminium alloy, and used an aviation type
electric motor for lift power. Because of the lack of high speed towing tank facilities
at that time the towing model experiments were carried out in a natural lake and were
towed by hydrofoil craft to decrease the wavemaking interference.
A manned test craft, version '33' weighing I.It, was designed by HSEI in 1958, fol-
lowed by detailed design and construction at the Wei-Jian aeroplane manufacturing
plant of Harbin. The craft was launched on Soon Hua river on 1 August 1958. Static
hovering tests were carried out successfully on Soon Hua river, but the craft failed to
take off above 'hump speed' onto planing mode. After several modifications, it took
off smoothly and successfully operated on the coast close to Port Lu Shun (Fig. 1.10).
It reached a speed of 50 km/h during tests, and completed its first long range sea trial
on 12 July, 1959. Seakeeping tests were also carried out.
During 1960 ACV research and development in China reached a climax. The Sheng
Yang Aviation Engineering Industry School joined with the Sheng Yang Aeroplane
Manufacture Plant to carry out research and development and finally completed an
amphibious hovercraft in that year. The first domestic conference for air cushion tech-
nology was held in a tanker training school in the outskirts of Beijing in August 1960.
About forty experts from Universities, Institutes and industrial plants with their
manned or self-propelled models attended the conference. There was some demon-
stration of ACV carried out at the conference. Most models couldn't run straight due
to their poor manoeuvrability and directional stability. The conference resolved to
develop air cushion technology vigorously.
Unfortunately owing to the famine which lasted for three years in China, air cushion
technology research was now interrupted. Then in 1963, under very difficult circum-
stances, the Marine Design & Research Institute of China (MARIC) re-commenced
ACV research and development. Through theoretical study, model experimental
research and development, and in spite of all sorts of difficulties encountered and fail-
ures met, eventually the first manned amphibious hovercraft version 711-1 (Fig. 1.30)
was completed in June 1965, and operated steadily at Jin Sah Lake at a speed of 90
km/h. The same year the craft was modified with flexible extending nozzles, and suc-
cessfully completed its sea trials in this form. The flexible skirt greatly reduced the
drag peak, and the time interval for taking off through hump speed was reduced from
several minutes to just under twenty seconds. The craft could be operated steadily for

Fig. 1.30 First Chinese amphibious prototype hovercraft 711-1.