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Built: 1968 / 69
Manufacturer: Vosper Thornycroft

Dimensions & Performance

Length: 29.11 m
Width: 13.56 m
Hovering Draught: 1.14 m
Floating Draught: 2.97 m
Cushion Depth: 1.68 m
Car Bay Length (between ramps): 24.20 m
Car Bay Width: 5.18 m
Car Bay Height: 2.97 m
Bottom of Skegs to Masthead (craft level): 9.45 m
Calm Water Level to Masthead (on hover): 8.31 m

Weight: 77 tonnes

Power: Two Lycoming TF20 Marine Gas Turbines
Range: 320 nm (593 Km)

Cruise speed: 40 knots

Payload: 148 seated passengers & 10 average sized cars

History

In the 1960s, the hovercraft seemed to be a new vehicle with enormous potential for the future. Although there have been many developments since then, and new machines are still improving, the number of craft in use today is insignificant compared with what seemed probable then. Vosper Thornycroft also envisaged a big market, and considered that a development programme would probably yield big returns. A hovercraft department was formed in 1967 and the first hovercraft began trials in 1969.

The VT1 was 95 feet long with a beam of 45 feet. The payload of about 30 tonnes permitted it to carry a mixture of passengers and cars. It possessed a number of novel features, the principal one being - for a hovercraft - the means of propulsion. Although possessed of a fully peripheral flexible skirt (also of novel design), the vessel was propelled by water screws, mounted on two skegs beneath the main raft structure. Normal water rudders were also fitted. VT1 was therefore "semi-amphibious": she could drive through shallow water and ground her bow on a slipway, thus allowing loading or unloading of vehicles with relative ease. When underway, the water propellers were quieter and more efficient than airscrews and speeds up to 40 knots could be achieved with relatively small, light and economical Lycoming gas turbines. Having skegs in the water also made the problem of manoeuvring much easier by producing a side force relatively simply. In other words, VT1, unlike fully amphibious hovercraft, could corner without struggling to avoid skidding sideways.

The craft performed well up to expectations, and turned out to have remarkably good sea keeping characteristics. In conjunction with the Department of Trade and Industry (DTI), who were encouraging the hovercraft industry with sundry financial support, Vosper Thornycroft carried out a series of trials during the winter of 1970-71. Based in the Channel Islands, these encountered a good proportion of rough weather, and it was shown that the VT1 could maintain a speed of 26 knots in 12 foot waves.

The VT1 was designed specifically for commercial use, but the company also had an eye on military applications. The steadiness of the VT1 at speed in a rough sea, compared with a conventional boat, had obvious attractions when applied to a weapon platform. This could be convincingly, if frivolously, demonstrated to potential customers by inviting them to drink a glass of gin and tonic (or mineral water for followers of the Prophet) whilst proceeding at speed in conditions which, in a conventional patrol boat would have required both hands to hang on.

There also seemed to be plenty of potential for civil hovercraft. Technically, the performance of the VT1 prototype was promising, and two production craft were laid down on the strength of active interest displayed by Hovertravel Ltd, who were building up a lot of operating experience with the smaller SR.N5s and SR.N6s built by the British Hovercraft Corporation.

Unfortunately, despite various schemes, Hovertravel never acquired a VT hovercraft. A draft agreement to charter VT1 number 001 (the prototype) for operation in the Channel Islands came to nought, and efforts were redoubled to sell the craft elsewhere. In April 1971 the board were discussing the possibility of selling the two production craft (002 and 003) in the USA, in conjunction with a licensing agreement for building more craft in the States, but this too failed to materialise, and by May a hard look was being taken at halting further expenditure on development work; for example, on running the VT1(M), a man-carrying model which was used for various experiments including, latterly, trials with water jet propulsion.

Towards the autumn, proposals for a joint operation involving Rederi Aktibolaget Centrumlinjen of Sweden were beginning to crystallise at last. VT was urgently in need of some solid operational experience with the craft, and there was a clear intention to subsidise the operation with a view to achieving this as soon as possible.

At the same time, there was a firm policy statement to "go equally hard for both commercial and military applications of hovercraft", and there was a proposal to allow the Interservices Hovercraft Unit (IHU) to evaluate VT1.

In October John Rix went to Malmo to sign the promotion agreement with Rederi Centrumlinjen and thereafter things moved ahead. Vosper Limited, as VT's parent company, agreed to the subsidising of the operation, and a joint operating company, Centrumsvavarna AB, was set up to operate VT1 002 and 003 between Malmo and Copenhagen, fitted out to carry passengers only. The craft themselves were sold to a finance company and leased back for this purpose.

The service began in March 1972, and technically was a great success, the craft performing well and reliably, The first week or so of operation showed an encouraging load factor of 50 to 60%, but then the state owned opposition, operating in direct competition with hydrofoils and conventional ferries, cut its fares, The battle was on. A glance at the statistics tells the story only too plainly: the regular commuters could not afford to refuse the cheaper fares, and the average load factor dropped quickly to around 30% during the week, but regularly shot back up again at weekends when Centrumsvavarna seemed to get a better share of the market. Weekend trippers were presumably prepared to pay more for a faster, more spacious and comfortable ride. But despite running two craft and twenty eight scheduled trips per day, the statistics improved only slightly. With the end of summer in sight, and a probable reduction in the weekend demand, Hovertravel were asked to survey profitability and advise. By October the operation was at an end and the two craft back at Portchester, having ferried nearly 200,000 people over the route.

A loss of about £500,000 resulted from the ferry operations, but a great deal of good experience and confidence was gained. The board was, not surprisingly, unwilling to repeat a similar operation which could have provided very little more in the way of worthwhile experience, and one or two such projects were abandoned in the early stages of discussion. It was agreed that further ferry operations could only be contemplated if the craft were actually sold.

Negotiations in April 1973 with British Rail, aimed at operating the craft on the latter's Isle of Wight route, were not promising; calculations suggested that even at the sale price proposed  (£600,000, per craft; not a particularly high figure) an operating loss would result. The board considered lowering the price still further, but in the end decided against it.

The salesmen continued to try very hard to find homes for the two VT1 passenger craft, and in the autumn of 1973 there were still hopes of doing so, either on a route between Southampton and Cherbourg; or from the mainland of Italy to Sardinia; or in Hong Kong. Alas, none of these ever materialised and eventually the craft were scrapped. People driving down the newly opened M27 spur motorway into Portsmouth were for some months able to view the sad remains in Harry Pound's scrap yard.

But in 1972 hopes for hovercraft were still high. Considerable importance was attached to the future of military hovercraft designs since the board recognised that, whereas Vosper had once enjoyed a significant technical lead, which almost amounted to a monopoly, in the design of the fast gas-turbine powered torpedo boats, there was much more competition in the patrol boat markets now being addressed. Investing in hovercraft development was seen as one way of re-establishing a niche. Although hovercraft eventually turned out to be a dead end, it is hard to see how this could have been foreseen at the time.

Just before Christmas 1972, therefore, the Vosper board agreed on expenditure to convert the prototype VT1-001 to a fully amphibious craft, which was to be known as "VT2". The new craft was a VT1 with the skegs and water screws removed, and above-water propulsion substituted. The latter was novel, a good deal of thought having gone into its design.

 (Quote from book Warships for the World)

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