The AP1-88 was developed jointly by British manufacturer Hoverwork, BHC (British Hovercraft Corporation) and the NRDC (National Research Development Council) from 1981, with the first pre-production prototype being built and tested in 1982 [Barton, 2006]. Hoverwork, the engineering company associated with Hovertravel is still producing hovercraft today, its latest production model being the 130 seater BHT-130, used on the same route as AP1-88's today. Located on the Isle of Wight this firm was founded in 1966 [Hoverwork, 2004] and has produced various models of the AP1-88 including the "Well deck" variety used as an industrial amphibious transporter for various companies around the world, and the AP1-88/400 industrial variety (as seen here).
The AP1-88 replaced the SRN6 for the Southsea to Ryde route (Portsmouth to the Isle of Wight) which had started operation in 1965 by Hovertravel [Hovercraft Museum, 2007]. The craft were quieter, more efficient, had more capacity (88 seats and later 100 seats as opposed to SRN6's 38 seats) and were a revolutionary design change from the previous craft produced by BHC. Various AP1-88s have been used worldwide such as in the USA, Scandinavia, Australia and Canada [Leonard et al., 1981]. The Southsea to Ryde crossing normally takes about 7 minutes, weather and traffic permitting. Visit Hovertravel's website for a schedule of operations.
A photo gallery follows below, and you can also visit the AP1-88 Videos page.
Performance specifications for AP1-88 hovercraft
Source: Hoverwork, 2004
Feature
Specification
Length (m)
21.50
Beam (m)
10.06
Height (hovering) (m)
8.90
Height (landed) (m)
7.92
Rated cruise speed (kts)
45
Max Speed (Freedom 90) (kts)
~ 60
Propulsion Engines (Original version)
2 x Deutz BF12L 513FC air-cooled turbo-diesels
Engine max. efficiency speed (RPM)
2,300
Engine power at max efficiency (kW)
392
No. of Passengers (x/88, x/100)
88, 100
Propulsion Engines (Enhanced Freedom 90)
2 x MTU V12 water-cooled turbo-diesels, 800 h.p.
Engine power (Freedom 90) (kW)
597
Propellers
2 x Hoffmann 2.755 m dia. fixed pitch, Type HO-E-214P/D275BS
Lift Engines
2 x Deutz BF12L 513FC air-cooled turbo diesels, rated for continuous cruise.
Lift Engine max. efficiency speed (RPM)
2,300
Lift Engine power at max efficiency speed (kW)
392
Drive system
Geared belt drive from engine gearbox to propeller
Steering system
2 x forward bow thrusters, each with 360° freedom; Rudders on each ducted main propeller.
Video of AP1-88 Freedom 90 arriving at Hovershow 2009
Video used with permission from YouTube user UKWMO (YouTube channel)
Paul Brett, ex-engineer with Hovertravel, the Canadian Northern Transportation Company Ltd., and the Canadian Coastguard, sends me these photographs of the AP1-88s in action for the Canadian Coastguard out of Sea Island, Vancouver. See Paul's other gallery from Canada here.
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