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- Herausgeber: The History Press
- Kategorie: Lebensstil
- Sprache: Englisch
Motoring journalist Ashley Hollebone reveals for the first time the full story behind the hovercraft, a wonderful British invention that was created in a back shed from a rusty food tin and an old hair dryer – simple yet remarkable! Christopher Cockerell's 1950s invention has found a multitude of uses across numerous arenas, from cross-Channel ferries and leisure cruising to racing at up to 80mph; it has modernised travel and has an impressive safety record, yet despite this little has been written about this, one of the most innovative modes of transport.This colourful book decisively redresses the balance and comprehensively reveals the history of the hovercraft, through photographs and diagrams, making it an invaluable addition to every enthusiast's library.
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Veröffentlichungsjahr: 2012
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The Hovercraft Story
Ashley Hollebone
First published in 2011
The History Press
The Mill, Brimscombe Port
Stroud, Gloucestershire, GL5 2QG
www.thehistorypress.co.uk
This ebook edition first published in 2014
All rights reserved
© Ashley Hollebone 2011, 2012, 2014
Ashley Hollebone has asserted his moral right to be identified as the author of this work.
This ebook is copyright material and must not be copied, reproduced, transferred, distributed, leased, licensed or publicly performed or used in any way except as specifically permitted in writing by the publishers, as allowed under the terms and conditions under which it was purchased or as strictly permitted by applicable copyright law. Any unauthorised distribution or use of this text may be a direct infringement of the author’s and publisher’s rights, and those responsible may be liable in law accordingly.
EPUB ISBN 978 0 7524 8512 6
MOBI ISBN 978 0 7524 8511 9
Original typesetting by The History Press
CONTENTS
Acknowledgements
1 What is a Hovercraft?
2 Where it all Began
3 The First Hovercraft – The SRN-1
4 The Next Step
5 The SRN-5/6 – The Most Successful Early Hovercraft
6 The SRN-4 – Mountbatten Class
7 The New Era
8 Military Times
9 Hovercraft for You
10 Hovercraft Today
11 Back to the Future
Appendix 1 – Hovercraft Timeline
Appendix 2 – Glossary
ACKNOWLEDGEMENTS
To the memory of:
Sir Christopher Sydney Cockerell CBE The Englishman that made the hovercraft a practical reality. 4 June 1910 – 1 June 1999
Lord Mountbatten of Burma An avid supporter of the hovercraft in his capacity as First Sea Lord during the crucial development period of hovercraft. 25 June 1900 – 27 August 1979
I would like to express my personal gratitude to Warwick Jacobs of the Hovercraft Museum Trust for his assistance with my work on this publication. Without Warwick and the team of volunteers at the Hovercraft Museum there would be a huge gap in place of their superb commemoration of the link between our aviation and maritime heritage.
WHAT IS A HOVERCRAFT?
The very idea that man could one day fly was conjured up not long after hairy Neanderthals were rolling stones and forming the wheel. While countless efforts were made and lives lost as pioneers tried to be birds there was another creation that would unfold decades later.
What if you could hover like a humming-bird and glide like a bird of prey? Yes this was the hovercraft, a schoolboy’s futuristic fantasy, a playground icon and a truly British engineering success story that would one day inspire the world. The hovercraft represents all that Britain was in its postwar industrial boom. It’s also a gentle reminder today, as the microchip continues to dominate our lives, that the simpler an idea then the better it stands the test of time. This book is a look at the global contribution this back shed creation has made, as well as its renaissance.
Is it a boat? Is it a plane? Well in fact it’s both of those and more. The hovercraft is the only truly amphibious vehicle that is in a class of its own. It can hover over landmines and can go where other vehicles cannot. It can fly up a river with vital aid supplies and when that river runs dry it will keep going. Technically a hovercraft is an aircraft; it is not in contact with the ground as it floats on a cushion of air. However, today hovercraft have a mainly nautical reference despite their amphibious roles.
WHERE IT ALL BEGAN
Although the hovercraft wouldn’t look out of place in the Star Wars movies, the principle of its engagement is actually centuries old. Leonardo da Vinci was well known for his highly advanced method of thinking in the fifteenth century, and looking back at his designs today it is clear that he was keen for man to one day fly. In fact, da Vinci designed a concept for a helicopter and even theories for frictionless boats. The basic principle of hovering can therefore be traced back as early as the 1400s.
However, the Renaissance aside, it would not be until the industrial age of the mighty Victorian era that the hovercraft could claim to have made its first step. In 1877, Englishman John Isaac Thornycroft designed and built a series of models to test his new theory of reducing the friction of a boat’s hull as it passes through the water. A layer of air would be created and his idea was to pump air under the bottom of the hull. The air would act as buoyancy, in effect pushing the water aside and reducing drag. The benefits of this would mean less energy would be needed to row the boat, achieving an increase in speed for less effort.
Thornycroft was a famous shipbuilder of the era and in later years his company would go on to produce fast tenders, RAF air/sea rescue launches, and even fire engines and trucks.
While the idea worked and Thornycroft’s patent protected him, he was not taken up as the technology needed was not at a stage where the desired effect could be achieved to make it worthwhile past the model stage. He did, however, prove that the theory of air under a boat’s hull can have positive effects.
From that time up until the 1950s there had been various attempts to create a frictionless craft but none have achieved success more than that of Sir Christopher Cockerell in 1954. Cockerell was an engineer and came from a family of talented and forward-thinking people. Born in 1910, he joined the Marconi Wireless Telegram Company in 1935 and during the Second World War he worked within an elite team of boffins that would go on to create the first ever practical radar system, a creation that Winston Churchill believed had a significant impact on the outcome of the conflict. Radar was, however, only one of Cockerell’s many outstanding personal achievements – he patented over thirty-six ideas whilst at Marconi alone.
When Cockerell retired in 1950 he bought a small boatyard in Norfolk, although it never really raised any money and it wasn’t long before his buzzing brain sought further pursuits with invention. One of these ideas would change his life forever. Cockerell was totally convinced that it was possible to create a hovering vessel, putting a lot of thought into the matter. Over time he would produce his calculations and drawings before constructing several models to test the concept. Cockerell knew that merely blowing air under an object would not be enough to cope with anything practical in the real world.
Dates go down in history for notable occasions and breakthroughs and the relevant one here was a Saturday evening in 1954, when Christopher Cockerell would gain the title of inventor of the hovercraft. On this night Cockerell realised that the machine could work if the lift air was retained within a fixed curtain on the craft, thus reducing the amount of power required to achieve lift.
Like many great inventions, the development of the hovercraft owes its origins to household items: in this case, a Kit-Kat tin, a Lyons coffee tin and an air blower. Cockerell built a simple test rig to work on his theory. Simply put, if you place an empty tin can bottom-side-up on a table with a hole at the top, blowing air directly from a vented hairdryer into that old tin will cause it to lift. However, the tin will move around, but it won’t stay hovering as the air will escape quicker than it can be created to form lift. This is exactly what Cockerell did, but it was what he did next that provided the breakthrough. He placed a smaller tin inside the first one and replicated the experiment. The idea was that air entering the can would have a smaller area to fill and a higher pressure would therefore be created inside the chamber of the inner tin. This form of kinetic (movement) energy is known as an annular jet, as the exiting air is forced to repel against itself inside the chamber (the larger coffee tin). The tins joined together now lifted higher than before and used less energy. The experiment proved that it was possible to retain air, and that air pressure was vital if the machine would have any chance. Christopher Cockerell had invented and patented a crucial part of hovercraft design that would make it a viable vehicle of the future. The momentum chamber, or plenum chamber, meant that the craft was able to hover in a controlled manner.
Now Cockerell had to win over the men in suits. He was no stranger to Government departments as he had spent his career working with such types, but one wonders if he really thought he would meet with such opposition as he did. After the coffee tin test, Cockerell would go on to produce many working models that would actively demonstrate the hovercraft’s capabilities, with test flights across lawns and obstructions placed in their path, obstructions which the craft would merely float over and continue on its hovering journey.
By 1955, after much work, Cockerell had managed to win over the Ministry of Supply to back his hovercraft project. You would think the most interested party would naturally be the military; in fact they were the least interested. The Air Ministry said it was a boat, the Navy said it was an aircraft and as for the Army, well they just were just undecided. How ironic it is then that today most of the world’s key hovercraft are operated by the Marines!
The 1950s were dark times for the British Government; the threat of an ever-looming Cold War was never far away and the nation’s defence and research commitment was at an all-time high. In this decade some of Britain’s greatest developments in aviation would be achieved, including the V-force and nuclear armoured deterrents. It was therefore inevitable that Cockerell’s patented hovercraft would be held on a secret project list, preventing the inventor from doing anything with it until the authorities would allow him to do so. This naturally made Cockerell restless as he wanted to move forwards.
Thankfully by 1958 the patent was eventually declassified and Cockerell was able to continue. The National Research Development Corporation – a Government-financed organisation that finances the development of promising new technology – pledged time and funds to the hovercraft project.
Saunders Roe on the Isle of Wight, a firm with a background in building seaplanes, was selected by the NRDC to design and build the world’s first full-size person-carrying amphibious hovercraft. The SRN-1 (SRN standing for Saunders Roe – Nautical) was born. Most British hovercraft in the first decades were constructed by Saunders Roe.
The SRN-1 was completed on 28 May 1959 and flew for the first time on 31 May 1959, ahead of schedule. It was not until the summer, on 11 June, that the SRN-1, nicknamed the ‘Flying Saucer’, was demonstrated to the world’s media. Journalists and members of the public were so taken aback by its futuristic appearance that many refused to leave until they had witnessed it hover across water.
This strange object was not from Mars but the Isle of Wight. It had a large fan in the centre of the craft that sucked air down and dispersed it underneath. On either side the craft had vented ducts that could be opened and closed to provide thrust and steering for the machine.
On 25 July the SRN-1 entered the history books as it made its first cross-Channel flight from Calais to Dover with Cockerell on board as a form of human ballast. This date was significant as it also marked fifty years since the first cross-Channel aeroplane flight by French aviator Louis Bleriot. Schoolboys across the world now craved a new toy and rightly Dinky Toys produced a model that would satisfy their needs of a futuristic world.
While there is an excellent hovercraft museum at the former HMS Daedalus site in Hampshire, England, on the site of the former Hovercraft Trials Unit in Hampshire, the original SRN-1 now lies in the back of a storage facility in Wiltshire owned by the Science Museum and is rarely open for public viewing. The Hovercraft Museum at Daedalus is the only one of its type in the world and has a vast collection of preserved craft, including the two cross-Channel Hoverspeed giants the SRN-4s.
We now see that Sir Christopher Cockerell’s vision made the hovercraft a reality. His ambition to invent, combined with the efficient use of simple technology, meant that at last the frictionless vehicle could move.
