Updated: 5 June 2009
Steamroller diwheel added
Dicycles and Diwheels. |
Updated: 5 June 2009 |
 | Left: The Otto Dicycle: 1870s.
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 |  | Artist's impressions of the Bryant diwheel on the cover and inside Popular Science: 1938.
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THE GRAND PANJANDRUM
An unassailable contender for the title of the most dangerous diwheel of all time is the British Grand Panjandrum. This World War 2 weapons system was designed by Barnes Wallis, the inventor of the Dambusters' bouncing bomb, and was intended for attacking beaches. The Panjandrum consisted of two 10-foot wooden wheels with 1-foot wide steel treads, joined by a central drum, and propelled by small powder rockets attached to the rims. The central drum was intended to be fitted with a massive explosive payload- no less than 4000 pounds.
The intention was to carry the Panjandrum close inshore in a landing craft, drop the front ramp, and ignite the rockets. The great wheel would then plunge through the shallows and roll up the beach at 60mph, crushing barbed wire until it encountered a suitable enemy obstacle, when it would explode. How detonation would be triggered at the right time is currently unknown.
In reality the rockets fired unevenly, the direction of travel was completely unpredictable, and it was much a danger to its own side as to the enemy. At least one demonstration saw the onlookers fleeing for their lives before the Panjandrum toppled over on its side and stopped careering about.
The prototype was built in great secrecy at Leytonstone, in East London, not a mile from where I sit and type. It was transported with similiar secrecy to Devon, travelling at night, but once there all security evaporated.
Testing was done on the beach at Westward Ho, a seaside resort in Devon. This "secret weapon" was tested several times in full view of holidaymakers, leading to some interesting speculation as to its real purpose- see below.
 | The Panjandrum just before a test: 1943/4
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A film of this thing in operation exists but I have not been able to track it down so far.
 | The Panjandrum: 1943/4
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The final trial was in early January 1944, and was ludicrously unsuccessful. The idea was dropped.
But was there a little more to it than that? It has been suggested several times that in view of the very public trials it was actually a piece of misdirection, and part of FORTITUDE SOUTH, the ambitious and highly successful operation to convince the Germans that the D-day invasion would be in the Pas de Calais. This was the most formidable part of the "Atlantic Wall" where the Great Panjandrum might just conceivably have been useful; the actual landings were made on the less heavily fortified Normandy beaches. The astonishing lack of security at the Westward Ho tests makes this a tempting hypothesis- after all, the technology so disclosed would not exactly useful be useful to the Germans.
However, nobody seems to know the real answer to this one.
THE VEREYCKEN/FRAQUELLI DIWHEEL: 1947
 | The Vereycken Diwheel: 1947
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 | The Vereycken Diwheel: 1947
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 | The Drivetrain of the Vereycken Diwheel: 1947
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 | Or was it invented by an Italian after all?
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 | This is called "Ezekiel's Wheel,"
The current owner is Warren Hunting of Lone Jack, Missouri, who I have tried to contact without success. I hope he doesn't mind me using the picture. |
 | This machine was built by some Swedish students at Gothenburg, and has taken part in Summer parades since 1999.
Engine: 2-cyl 2-stroke snowscooter engine of 400cc Diameter: 1.96m Width: 1.3m |
 | Note the large number of idler wheels around the circumference compared with other designs on this page.
The designer's explanation regarding the large number of idler wheels: "think 'ball-bearing'. In Gothenburg we have an quite well known manufacturer, SKF." |
 | This amphibious concept machine has been produced by GBO Design in Holland.
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 | Do-It-Yourself diwheel with dual pedal drive.
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