Hovercraft¹ are amphibious vehicles propelled by air screws and supported by a cushion of air. This air cushion lifts the hovercraft, making it hover, and so is able to travel over both land and sea, and because of the lack of friction, they are able to travel at quite high speeds.

Early Hovercraft

The first recorded design for an air cushion vehicle like a hovercraft was put forward by Swedish designer and philosopher, Emmanual Swedenborg in 1716. Swedenborg soon realised that his idea, which was to be man-powered, would not work, and so abandoned it.

Later, in the mid 1870s, Sir John Thornycroft was interested in the idea of hovercraft. He built a number of model craft, yet because the internal combustion engine had not yet been invented, his idea did not have a suitable power source.

Sir Christopher Cockerell And Saunders-Roe

In the mid 1950s Christopher Cockerell², a brilliant British radio engineer, started to think
about the possibilities of hovercraft. Cockerell, who ran a boatyard on the
Norfolk Broads, began by exploring the use of air lubrication to reduce
hydrodynamic drag. His early experiments included first a punt, and then a 20
knot ex-Naval launch as a test craft. Yet he soon realised that using air-
lubrication as an efficient means of transport would work with a purpose-
designed vehicle that used an air cushion to rise the craft above the water.
This would not only enable it to sail over the waves, but it would also be able
to sail on land.

To check his own theory Cockerell used little more than a couple of tins, an
air-blower and some scales. By inserting a cat food tin into a coffee tin, and
blowing a jet of air through the gap between the walls of the inner and outer
tins, he demonstrated the possibility of a machine that could one day travel on
a cushion of air.

Christopher Cockerell had a neighbouring boat builder produce a working
model hovercraft. His idea worked very well in model form, and so he decided to
pursue it. As, at the time, it was the duty of anyone who thought an invention
that could have military potential, he contacted the Service Ministries. The
model hovercraft soon flew over many Whitehall carpets in front of various
government experts and put on the secret list. Saunders-Roe, an Isle of Wight
aircraft company based at East Cowes, was contacted by the National Research
& Development Corporation to build a craft.

The SR.N1

In 1959, Saunders Roe³ started work on the hovercraft with great
enthusiasm. The world's first hovercraft, the SR.N1, was even completed two
months ahead of schedule, only eight months after it was started. The Cockerell
designed research vessel Saunders Roe Nautical One (SR.N1) appeared in May at
East Cowes, Isle of Wight - the first flight taking place on 11th June.

The press watched with astonishment as the model craft was demonstrated to
them on a lawn and over a small obstacle course. After that, the full-sized
craft was carried out on the concrete slipway, and soon into the East Cowes
yacht basin by a launch. This was a nervous time for its engineers as the
hovercraft had never been tried over water before. All went well, though, and
no problems were encountered. This, the first skirtless craft, could operate
only in calm seas with waves up to one and a half foot in height and negotiate
obstacles of 6 to 9 inches.

On the 25th July 1959, the SR.N1 crossed the channel between Calais and
Dover in 2 hours and 3 minutes. It had been shipped to France especially for
the occasion - it was 50 years to the day since Louis Bleriot made the first
crossing of the Dover Strait by aeroplane. Although the SR.N1 was the first
hovercraft to make the trip successfully, it was plagued with slow performance
and the inability to traverse even very small waves easily, as it only had a
hoverheight of only 23cm.

In December 1959 the Duke of Edinburgh visited Saunders Roe at East Cowes
and persuaded the chief test-pilot Commander Peter Lamb to allow him to take
over the SR.N1's controls. He flew her so fast that he was asked to slow down a
little. On examination of the craft afterwards, it was found that she had been
dished in the bow due to excessive speed - this damage was never allowed to be
repaired, and was affectionately referred to as the "Royal Dent".

Lahtimer-Needham

After reading about Cockerell's experiments, another inventor, C. H. Latimer-Needham thought about the size of the waves that hovercraft would likely encounter in the English Channel and the Atlantic. He was convinced that the way forward was to create a flexible skirt to contain the air cushion. This would let hovercraft travel during rougher weather and other surfaces. In
October 1961, Latimer-Needham sold his skirt patents to Westland, the parent company of Saunders Roe Ltd. The introduction of the skirt was a vital engineering breakthrough.

It meant that the total depth of the air cushion beneath the solid structure was now equal to the depth of the skirt. Engineers
soon discovered that the obstacle clearance height was ten times greater. Apart from being subjected to wear and tear, particularly at high speed over water, skirts had few operational problems. The skirt would even deflect on coming in to contact with waves, rocks and jetties, and since afterwards it would return promptly to its normal inflated shape, air leakage would be minimal.

The SR.N1 was now fitted with a Rolls Royce Viper jet engine for forward propulsion, and now made 50 knots with ease instead of its earlier piston-engined maximum of 35kt. With a 4 foot skirt fitted around the perimeter of the craft, the craft could cope with 6 to 7ft waves, cross marshland with gullies up to 4ft deep and traverse obstacles up to 3ft 6in high. Moreover, the craft
was now operating at twice its original weight, with no extra lift-power needed. ⁴.

Other Saunders-Roe Hovercraft

Other companies started building hovercraft, especially Vickers and Vosper
Thornycraft, but Saunders-Roe continued to lead the way.

In late 1959 it was decided to design and build the first passenger carrying
hovercraft. The craft, capable of carrying 59 passengers, was called the SR.N2.
It was finished by 1962, and soon was used in commercial travel, yet only one
was built. This was because by the time it was finished, it was possible to
build even better hovercraft.

The SR.N3

By the end of 1963, the Ministry of Technology asked for a larger version of
the SR.N2 for military purposes. This was the SR.N3, and it was capable of
carrying 92 fully equipped soldiers at speeds over 70 knots. It was launched in
December 1963, and was also designed to carry vehicles such as jeeps or medium
trucks. Again, only one was built. The IHTU, Interservice Hovercraft Trials
Unit, tested the SR.N3 at their facility at HMS Daedalus near Gosport to
ascertain whether hovercraft could have any military potential.

By 1974, after using the SR.N3 in a number of roles, the Ministry of Defence
decided to use the SR.N3 as a testbed to see how vulnerable hovercraft were to
under-water explosions. The SR.N3 was tethered and subjected to a series of
explosions, some actually under the craft, yet not only did the hovercraft
survive, it was still capable of returning to base under its own power.

The SR.N5 and SR.N6

Meanwhile, Saunders-Roe had started work on the SR.N5. This was the first
hovercraft to be designed from the start to be fitted with a deep, flexible
skirt. The SR.N5, known as the Warden⁵ class, was almost 40ft long and 23ft
wide, could carry 18 passengers and had a top speed of 66 knots. The first
craft hovered in April 1964, and fourteen were built.

As soon as the SR.N5 appeared in service, there was a demand for hovercraft
with greater carrying capacity. So, in 1964, the SR.N6 Winchester class was
designed, and it was essentially a SR.N5 but 10ft longer. The first SR.N6 was
launched in March 1965 and could carry 38 passengers. British Rail Hovercraft
Ltd., though, were not content with the SR.N6 and wanted an even bigger craft.
The SR.N6 was stretched by another 10ft in 1972 making the passenger capacity
58. Surprisingly, performance was not affected by the stretch.

The last in the SRN.5/6 series was one which had a drop in noise level, as
all of Saunders-Roe's hovercraft were quite noisy⁶.
This was in 1982. By which time 69 SRN5/6 craft had been built, including five
for the Iraqi Navy and eight for the Imperial Iranian Navy.

The SR.N4

Westlands had intended to follow the SR.N3 with a large craft, the SR.N4,
but this was delayed until the skirts equipped on the SR.N1 and SR.N5 had been
fully developed and tested. In 1965, the project was authorised and work was
started. Despite the Saunders-Roe company merging with Vickers Supermarine in
December 1966, forming the British Hovercraft Corporation Ltd and causing Sir
Christopher Cockerell's resignation, work continued, and the first began trials
in 1967. The SR.N4, known as the Mountbatten class, was the world's largest
hovercraft, capable of carrying 254 passengers and 30 cars across the channel
in half an hour. It was 200 tons, and had a top speed of 83
knots⁷. The SR.N4's propellers have a diameter of 21 feet, making them the largest driven propellers in the world. The hovercraft's fuel is kerosene, which is the same fuel as an airliner.

It cost £1.75 million and was fitted with a skirt that was 2.5 metres high, which was expected to cope with most conditions in the Channel. It underwent 2 hours 30 minutes of trials, covering a distance of 20 miles and reaching speeds approaching 50 knots - this in winds gusting to force 6. The world's first hovercraft car ferry made its maiden flight from Dover to Boulogne on 11th June, crossing in 35 minutes.

This not only captured the public imagination, but the British Government also instructed British Rail to set up a hovercraft subsidiary and introduce an Isle of Wight route prior to taking delivery of the first SR.N4 for cross-Channel services in 1968.

It was soon realised that the skirt system still had not been perfected, and by 1976 the skirts were replaced. The new skirt, when inflated, raised the craft 3 metres into the air. The SRN.4s were also stretched by 55 ft. This increased passenger accommodation to 418 and the car capacity increased to 60. It now had a displacement of 300 tons. The SR.N4 was now nicknamed "Super 4". It is the largest hovercraft in the world ever, and in 1978 the Cowes, Isle of Wight workcrew were awarded the 1978 Award for Innovation.

After the SRN.4

The Saunders-Roe team continued to make hovercraft, the next model, called the BH-7⁸ was started in 1969 and was called the Wellington class. Six were sold to the Imperial Iranian Navy.

In 1972 British Hovercraft Corporation bought another Isle of Wight company, Cushioncraft, which had specialised in sidewalls. This company had been created by John Britten and Desmond Norman, who designed the very succesful Islander aircraft.

The latest class of hovercraft to be built was the AP1-88 in 1982. So far, over 14 have been built including tank-landing hovercraft for the American Army, ones for the Canadian Coastguard as well as several passenger hovercraft, especially for the Isle of Wight route.

The Start Of Commercial Travel

Three years after the hovercraft's invention, hovercraft passenger routes soon started throughout Great Britain, but few lasted long.

Isle Of Wight Routes

In August 1962, a passenger service was started from Eastney beach, Southsea near Portsmouth
to Ryde, Isle of Wight, on weekday mornings using the newly-built 48 seat SR.N2 craft. A new company, Hovertransport, was
formed to carry passengers on the experimental Ryde to Eastney route starting on 17th June.

In 1965 Hovertravel Ltd. started their Southsea to Ryde service with Winchester Class, 38 seater SR.N6 hovercraft. This is now the world's oldest Hovercraft operator, and is still being run by Hovertravel. A Ryde to Stokes Bay, Gosport, service was also started but closed two years later. Before it closed, though,
it had carried over 500,000 passengers.

During March 1965, British Rail Hovercraft Ltd formed Seaspeed and the Southampton to Cowes service started in July with two 36 seat SR.N6 craft. In March 1967 Seaspeed's Cowes - Portsmouth Harbour link open using an SR.N6. The service continued before it closed in September 1969. April 1968 saw a third Seaspeed Isle of Wight service start, from Portsmouth to Ryde.

Considering the number of Hovercraft routes to the Isle of Wight, it is not surprising that a local singer, Lauri Say, wrote and sung a popular song about the Hovercraft on his "Songs For Singing Islanders" album in 1968:

What's this rumbling that I hear?
What's this roaring in my ear?
What's this racket driving everybody daft?
Well it's not artillery
Or the start of World War Three
It's the Westland SRN "Super-Noiseless" hovercraft.

Oh the hovercraft is coming,
Can't you hear that crazy humming?
You can see the fishes scatter fore and aft.
With it's mighty engine pushing
Floating on it's own air cushion
It's the Westland SRN "Super-Noiseless" hovercraft.

It's like a mobile goldfish bowl and
When it screams across the Solent,
The duration of your journey will be halved.
If you don't mind being cramped on
For your visit to Southampton
Take the Westland SRN "Super-Noiseless" hovercraft.

The directors made a statement
In the cause of noise abatement
When we said it made a row they only laughed.
"Anyone can stand the din
If he's got his earplugs in
On the Westland SRN "Super-Noiseless" hovercraft."

If this method of propulsion
Fills you with revulsion
You should travel on a dinghy or a raft.
Whatever you may take
You'll never hear the end
Of the Westland SRN "Super-Noiseless" hovercraft.

The folks who live in Cowes and
Gurnard tremble by the thousand,
And the peace of Ryde is shattered everyday.
So if you want a place that's silent,
You'd better leave the Island,
You can hear the bloody thing at Totland Bay.

Oh the hovercraft is coming,
Can't you hear that crazy humming?
You can see the fishes scatter fore and aft.
With it's mighty engine pushing
Floating on it's own air cushion
It's the Westland SRN "Super-Noiseless" hovercraft.

Before long, though, only the Hovertravel service to the Isle of Wight had survived. By 1976, Seaspeed, which had operated three services to the Isle of Wight, had transferred ownership of the Southampton - Cowes route to Hovertravel. It closed soon after.

After October 1st 2000, the Southsea - Isle of Wight hovercraft route will be the only remaining one in Europe.

International Routes

The prototype SR.N4, named Princess Margaret, entered commercial service for Seaspeed on the 26 mile route between Dover (Eastern Docks) and Boulogne on the 1st August 1968. This route was chosen so that customers could easily be switched to
British Rail's ship ferry service if anything went wrong. It had been named by HRH The Princess
Margaret on the previous day. Six daily return flights were advertised, the first leaving Dover at 08.20 and then every two hours. Wednesday was half-day - with three round trips followed by a period of maintenance. Fares were £3.10s.0d (£3.50) single with a
day excursion for £3.00.

During November 1967, Hoverlloyd Ltd⁹ was formed with the object of pioneering the world's first International Hovercraft service between Ramsgate and Calais, although in reality it became the second. Hoverlloyd operated two of the massive SR.N4s across the English Channel in 30 minutes. On 10th December 1968, Hoverlloyd's first SR.N4, the Swift was completed at East Cowes. It was the first craft with the new Mk II skirt which provided both a smoother ride and more protection to the bow. The second Hoverlloyd hovercraft, Sure was launched in 1969.

Hoverspeed was created on 25 October 1981 when Seaspeed and Hoverlloyd merged. The merged company initially operated a fleet of six hovercraft - two SRN4 MkIII hovercraft, The Princess Margaret and The Princess Anne, and four SRN4 MkII hovercraft, Swift, Sure, Sir Christopher, and The Prince
of Waleson services from Dover to both Calais and Boulogne.

Sadly, though, the hovercraft services are gradually being replaced by Sea Cats. Only The Princess Margaret and The Princess Anne are still in operation, yet both have a claim to fame. The Princess Anne holds the record for the fastest crossing of the English Channel, travelling the 23 miles between Calais and Dover on 14 September 1995 in just 22 minutes. The Princess Margaret featured in the James Bond film "Diamonds are Forever". Yet the Hovercraft are due to be withdrawn from service on the 1st October 2000, leaving the Southsea - Ryde, Isle of Wight route the only remaining hovercraft route in Europe, not far from where the hovercraft was invented.