Page 27 - Theory and Design of Air Cushion Craft

12 Introduction to hovercraft

Fig. 1.11 The world's largest commercial amphibious hovercraft, the SR.N4.

Fig. 1.12 British ACV SR.N3 on underwater explosion tests.

CC1, 2, and 5 and H.D.L. designed and built its own HD-1. The basic craft perfor-
mance problems encountered during the early 60s encouraged continued develop-
ment, especially in the application of flexible skirts. Nevertheless, as operating
experience was gained, researchers, designers and manufacturers all faced many diffi-
culties along the way. Various practical problems had to be solved, for instance improv-
ing skirt life from a few hours to thousands of hours, so as to meet the commercial
user's requirements; designing filters to prevent accumulation of salt, which is very
harmful for engines, especially gas turbines, due to the significant spray caused by hov-
ercraft; anti erosion design for air propellers and lift fans; and internal/external noise