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Fifty years ago, giant hovercraft were the pride of Britain.
They were a new kind of machine that could go almost anywhere, on land, water, or just
about any other surface.
And they were fast, capable of reaching one hundred and thirty kilometers an hour.
The largest could transport sixty cars and as many passengers as a jumbo jet.
These giants once promised to revolutionize the way we travel.
But today, they’ve all but disappeared.
To understand what made hovercraft so revolutionary, consider that they're not like any other vehicle.
In fact, they share more in common with aircraft than boats.
That’s because hovercraft are essentially airborne.
They work using the principles of lift and thrust.
To lift off and hover, fans trap a cushion of air, while propellers generate thrust to
move forward.
And what it all means is that friction and water resistance are significantly reduced, allowing
a hovercraft to hit speeds well beyond that of any ship.
But speed isn’t the only advantage.
Because no other vehicle can match a hovercraft’s versatility.
Out at sea, in shallow water, on ice, or in a swamp, they can go where no other vehicle
can.
Where’s there’s no harbor, a hovercraft can simply crawl out of the water where a
ship would run aground.
Hovercraft were a brilliant innovation.
And in the 1960s, a hover transport revolution seemed just over the horizon.
When the first hovercraft debuted in the summer 1959, it stunned the world as it appeared
to almost magically float over any surface.
Its designer, a brilliant British engineer named Christipher Cockerell, wasn't the first
to dream up the idea of a hovercraft.
But modern hovercraft wouldn't be possible without Cockerell’s key innovation, called
the Momentum Curtain.
Earlier attempts at building hovercraft involved blowing air into an open hull, which didn't
work very well and required a lot of power.
Cockerell’s innovation was to direct a ring of air towards the outer edges of the hull,
trapping high pressure air.
Which allowed the craft to hover much higher off the ground.
In 1959, Cockerell and two others piloted the first practical hovercraft all the way
across the English Channel.
But it would take another key innovation to truly unlock the hovercraft’s potential.
In 1961, another British engineer proposed fitting the craft with a flexible skirt, which
would allow it to hover much higher off the ground to better handle uneven surfaces
With the flexible skirt, hovercraft could become a much more versatile machines.
And it sent British Aircraft builders racing to develop their own designs.
Almost overnight, the first small scale hovercraft transport services began popping up throughout
Britain.
In just few short years, hovercraft would go from small prototypes, to enormous craft
that could carry hundreds of passengers
By the mid-1960s a hovercraft craze had swept the world.
And countries like the United States and France poured millions into their development.
But the British were at the forefront, and the leading company in the world was Saunders-Roe
They had not only built Cockerell’s original prototype, but also a series of civilian and
military designs.
And in 1963, Saunders Roe set out to build a new kind of hovercraft.
One that would be four times larger than previous designs, and built to compete against conventional
ferries.
On the English Channel, a ferry needed about an hour and half to make a crossin.
A hovercraft would cut the trip down to just half an hour, allowing for twice as many daily
crossings.
The new giant hovercraft would be designated as the SR.N4.
And it would operate more like an airliner with a crew that would include a captain,
flight engineer and navigator, along with a deck and cabin crew of eleven.
In standard configuration, it would carry 30 cars and 254 passengers, or configured
for 609 passengers
No one had ever attempted to build a hovercraft this large.
The engineering and economic risks were enormous.
The world’s largest hovercraft debuted in the summer of 1968 with service connecting
Britain and France on the English Channel.
On board, high profile guests included Princess Magaret and Christopher Cockerell himself.
Passengers marveled at the all-British achievement as the 165-ton machine built up speed.
But what no one yet realized, was that the SR.N4’s rubber skirt was literally tearing
apart beneath them.
Attachments designed to contour to waves, were damaged or torn right off by rough seas,
sending repair crews scrambling to replace them after almost every trip.
And just three days into service a large wave damaged the craft, putting it out of commission
for nearly a week.
And was really just the start of problems.
Crossings were regularly canceled due to mechanical issues like hydraulic and gearbox failures.
But an even bigger issue was the weather.
The SR.N4 was rated for waves of just two and a half meters.
And on the English Channel, it didn’t take much to stir up those kind of conditions.
In its first three months of service, more than a third of the scheduled trips were canceled.
The debut hadn’t gone well.
And in October of 1968, the SR.N4 was pulled from service altogether to undergo extensive
modifications.
Unreliable and seemingly unsuitable for open water travel, the future of large passenger
hovercraft was in doubt.
Despite the disastrous debut, cross-Channel hovercraft proved incredibly popular with
the traveling public.
And by the time the SR.N4 was put back into service, many of the earlier issues had been
solved.
And the skirt had been redesigned to better withstand waves.
By mid-1970, there were two carriers operating iconic hovercraft on the English Channel.
And, they could barely keep up with demand, with trips fully booked weeks out in advance.
But there was still a problem.
Neither carrier, was actually making money.
Because the SR.N4’s burned a thousand gallons of aviation grade fuel every hour.
And maintenance costs were astronomical compared to conventional diesel ferries.
To offset high operating costs, both carriers had to modify their hovercraft to increase
passenger and vehicle capacity by widening and lengthening their hulls.
By 1978, the largest hovercraft could carry up to 418 passengers and 60 cars.
The increased capacity helped make giant hovercraft more competitive.
By the end of the decade, hovercraft were carrying nearly a third of cross-Channel passenger
traffic.
But as the 1980s approached, large civilian hovercraft would face a challenge that no
engineer could solve.
If the iconic hovercraft were in operation today, they would still be the fastest way
to cross the English Channel.
Faster than conventional diesel ferries, or high speed catamarans introduced in 1991.
Faster than even the Channel Tunnel which opened in ‘94.
But it wouldn't have mattered.
The hovercraft as a form of transport, really was doomed from the start.
In the early 1960s, they had captivated the public’s imagination with their incredible
speed.
But that speed came at the cost of just about everything else.
Compared to conventional ferries, hovercraft were less reliable, less efficient, less capable
in rough weather, and less comfortable.
And it meant that by the end of the 1960’s, excitement over hovercraft had largely worn
off.
And Britain's once booming hovercraft industry fell into recession.
To make matters worse, fuel prices skyrocketed in the 1970s.
Putting a final nail in the coffin, ensuring that fuel-thursty hovercraft could never be
widely adopted as transport.
And it meant that the enormous SR.N4’s would represent the pinnacle of passenger hovercraft
design.
But in the 1980’s they would face increasingly stiff competition from conventional ferries,
which had wide enough profit margins to continually lower fares and win back customers.
Giant hovercraft could no longer compete, especially after the Channel tunnel opened
in 1994.
But no vehicle can match a hovercraft’s versatility.
Which is why these awesome machines remain relevant today with the world’s militaries,
industry, and rescue services, even as the iconic SR.N4’s were entirely phased out
by the year 2000.
But many argue that hover technology never reached its full potential.
And in the 1960s, Cockerell and British engineers had a much bigger vision for a new form of
transport that would hover on a cushion of air and reach speeds of five hundred kilometers
an hour.
They were called Tracked Hovercraft, and they would’ve been faster than any train in the
world, even to this day.
By 1972, engineers had developed the necessary technologies and even constructed a test track
and prototype train.
They were seemingly on the cusp of reinventing railways.
But their efforts have almost entirely been forgotten.
You can learn more about the incredible story of the tracked hovercraft in my latest video
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