The Pedrail Machine was an experimental British armoured fighting vehicle of the First World War . It was intended initially to be used as an armoured personnel carrier on the Western Front , but the idea was dropped in favour of other projects. Work on the machine was re-directed so that it could be used as the basis of a mobile flamethrower, but it was never completed and saw no action.
21-502: The pedrail wheel is a type of all-terrain wheel developed in the late 19th and early 20th century by Londoner Bramah Joseph Diplock . It consists of a series of "feet" ( pedes in Latin ) connected to pivots on a wheel. As the wheel travels, pressure exerted by springs within it increases the number of feet in contact with the ground, thus reducing ground pressure and allowing the wheel to negotiate obstacles and uneven ground. According to
42-551: A 12-pdr gun. Protection was 8 mm (0.31 in) of armour to the sides and 6 mm (0.24 in) on top. Two 46 hp (34 kW) Rolls-Royce engines drove the machine. This led to an order for twelve machines being placed with the Metropolitan Carriage and Wagon Company in Birmingham. The Committee realised the design as supplied would not be able to readily manoeuvre through French villages and it
63-531: A capability that attracted the attention of the War Office. The practical realisation of this was the Pedrail Tractor made by Fosters of Lincoln, from which an account in 1904 of a trial attended by members of the War Office proved its ability to tow a heavy load over rough ground, climbs hills and turn with ease, and show a 2 ton drawbar pull. In 1902 he published a book about his pedrail system and
84-539: A short pivoted rail controlled by a powerful set of springs. This arrangement permits the feet to accommodate themselves to obstacles even such as steps or stairs. H. G. Wells , in his short story The Land Ironclads , published in The Strand Magazine in December 1903, described the use of large, armoured cross-country vehicles, armed with automatic rifles and moving on pedrail wheels, to break through
105-414: A system of fortified trenches, disrupting the defence and clearing the way for an infantry advance: They were essentially long, narrow and very strong steel frameworks carrying the engines, and borne upon eight pairs of big pedrail wheels, each about ten feet in diameter, each a driving wheel and set upon long axles free to swivel round a common axis. This arrangement gave them the maximum of adaptability to
126-404: A version on a simpler, single wide track. With a body fitted, the machine could carry a ton of cargo and be pulled with minimal effort by a horse. It demonstrated the attributes of the caterpillar track: low friction and low ground pressure. Bramah Joseph Diplock Bramah Joseph Diplock (27 April 1857 – 9 August 1918) was an English inventor who invented the pedrail wheel in 1899 and
147-438: The 1913 Webster's Revised Unabridged Dictionary , a pedrail is: A device intended to replace the wheel of a self-propelled vehicle for use on rough roads and to approximate to the smoothness in running of a wheel on a metal track. The tread consists of a number of rubber shod feet which are connected by ball-and-socket joints to the ends of sliding spokes. Each spoke has attached to it a small roller which in its turn runs under
168-583: The building of a single Pedrail was cancelled by the authorities. In July 1916 the machine was transferred to Stothert & Pitt in Bath , for completion as a mobile flamethrower . The finished chassis was handed over to the Trench Warfare Department in August, and sent for trials to the government research centre at Porton Down . It was deemed too heavy to be practical, and at the end of
189-547: The contours of the ground. They crawled level along the ground with one foot high upon a hillock and another deep in a depression, and they could hold themselves erect and steady sideways upon even a steep hillside. In War and the Future , Wells acknowledged Diplock's pedrail as the origin for his idea of an all-terrain armoured vehicle: The idea was suggested to me by the contrivances of a certain Mr. Diplock , whose "ped-rail" notion,
210-543: The end only one prototype was created (see Pedrail Machine ). The pedrail system, with rollers in the tracks and rails on the chassis, lost out to the simpler system with linked tracks forming a temporary road way for numerous wheels on the chassis. Diplock founded the Pedrail Transport Company of Fulham in 1911, and at the outbreak of World War I it was the only British company still manufacturing "caterpillar" continuous tracks . A demonstration of
231-439: The experiments and experience with two traction engines fitted with it. Publisher Longman, Green and Company, entitled "A New System of Heavy Goods Transport on Common Roads". In 1907 Bramah applied for a patent for the pedrail system where the track was laid in a chain link. However, a similar looking tracked system had already been patented in 1904 by David Roberts, Chief Engineer of Richard Hornsby & Sons Ltd, and reports in
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#1732783719504252-480: The need to steer the vehicle. His patents date back to 1893 when he was living in Falmouth, Cornwall. This desire for greater traction in road locomotives (traction engines) probably led directly to the pedrail system which he patented in 1899. In this design the continuously laid tracks contain rollers and the rails roll over them, which gave it the capability for crossing banks and ditches, as well as soft ground;
273-420: The notion of a wheel that was something more than a wheel, a wheel that would take locomotives up hill-sides and across ploughed fields, was public property nearly twenty years ago Although Wells describes the pedrail wheels in detail, a number of authors have mistakenly taken his description to be of some form of caterpillar track . Diplock's version of an endless track was not designed until some ten years after
294-653: The pedrail chaintrack, a type of caterpillar track, in 1907. Diplock was born in Chelsea, London to Thomas Bramah Diplock, a coroner, and Eleanor Diplock. He died suddenly on 9 August 1918 of brain hemorrhage at 21 Heathfield Close, Chiswick, aged 62. Diplock Glacier in Antarctica is named after him due to his contribution to the development of tracked vehicles. Diplock's first inventions were related to improving traction in geared locomotives (both road and rail) by driving all wheels, this presenting problems due to
315-455: The press of the time appear to sometimes confuse the two systems. The term 'pedrail' becoming more generic in application, as was 'caterpillar track'. There are reports that Pedrail chaintrack tractors, and towed trailers, using this principle were under evaluation by the War Office by early 1909, though the pictured vehicle bears a remarkable similarity to the Hornsby vehicle under evaluation at
336-521: The publication of Wells' story. The pedrail wheel played no part in the design of the first British tanks . In 1910, Diplock abandoned the Pedrail Wheel and began developing what he called the Chaintrack, in which fixed wheels ran on a moving belt, very like the caterpillar track as it is now understood. It was a complicated and high-maintenance system, and in 1914 Diplock eventually produced
357-542: The system's ability to support a large load for trench warfare was made on 16 February 1915 to Winston Churchill , and may have been influential in the development of the tank . The company went into liquidation in 1921. Pedrail Machine Following discussions by Captain Murray Sueter of the Royal Naval Air Service and Bramah Diplock of the Pedrail Transport Company, the machine
378-429: The time. The pedrail chaintrack system was to have an important influence on tank development, although it was not the pedrail tracked system that was adopted. Faced with trench warfare there were ideas supported by Winston Churchill and Lord Fisher (First Sea Lord) for land battleships, however Sir Percy Scott argued that these huge slow moving devices would be destroyed by artillery fire before they could be effective. It
399-569: Was designed by the British engineer Colonel R.E.B. Crompton on behalf of the Landship Committee . The brief was for a vehicle that could carry a unit of troops - a "trench storming party of 50 men with machine guns and ammunition"- under protection across No Man's Land . Crompton's design as presented to the committee used two sets of continuous tracks in a vehicle around 40 feet (12 m) long, weighing around 25 tons and armed with
420-429: Was reworked to articulate it in the middle. At the same time the armour protection was increased to 12 mm (0.47 in). The original order for 12 was reduced to one, and then Metropolitan asked to be removed from the project to concentrate on other war work. The task of finishing the single vehicle went to William Foster and Co. at Lincoln but with other, more promising, armoured vehicle projects coming along, even
441-447: Was then that Commodore Murray Sueter suggested adapting the pedrail chaintrack system. A demonstration of the pedrail chaintrack was hastily arranged before Lloyd George, Winston Churchill and other senior War Office staff, where "a demonstration was given of the powers of the caterpillar in forcing wire entaglements and surmounting obstacles". As a result of these trials 18 pedrail equipped armoured tracked vehicles were ordered, however in
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