Page 57 - Theory and Design of Air Cushion Craft

Applications for ACV/SES 41

deck utility API-88 constructed at NQEA in Queensland (the fifth built by NQEA)
was put into service for coastal oil field supply in Angola at the end of 1995; this has
subsequently been transferred to Peru for oilfield logistics operations supporting a
drilling programme. Griffon Hovercraft and Slingsby Hovercraft both have capable
designs for utility passenger ACVs. Griffon's range extends to 50 passengers,
Slingsbys' to 22. This technology has matured over the last decade, and the potential
operators appear more realistic about their expectations. While the order stream is not
large, it is steady, suggesting that the market is slowly developing.

What are the potential uses of a modern ACV or SES? To identify the applications
which ACV or SES may fulfill more efficiently than other vehicles, we need to review
the characteristics which set them apart. Some key ACV/SES performance character-
istics may be identified as follows:

Amphibious capabilities

Due to the light footprint pressure, as shown in Table 1.7 below, the ACV possesses
excellent amphibious capability. The footprint is about the same as a cross country
skier, and so can safely traverse most flattish terrain.

The cushion as noise and shock damper

The low and uniform cushion pressure (< 500 Pa), use of air propellers or ducted fans
for ACV propulsion, and waterjet propulsion for SES make these craft insensitive to
underwater mines. It is evident that both ACV and SES are suitable for applications
as mine sweeper and anti-submarine vessels.

Deck area and cabin volume

The ACV and SES both give spacious deck area and cabin volume. These vessels need
to be large relative to their displacement, to keep cushion pressure realistic. They are
therefore suited to applications where volume is the most important parameter:

Table 1.7 The footprint pressure of various forms of transport

The configuration of transport forms Footprint pressure (Pa)
Human footprint 60 000
Amphibious tank version 60 56 000
Light tank version 1KV91 40 000
British reconnaissance tank 35 000
Car type footprint 10 000
Skier 4000
ACV/SES 1000-5000