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 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 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.
— Webster's Revised Unabridged Dictionary, C&G Merriam, 1913. [1]
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 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 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.
— [2]
In War and the Future, Wells acknowledged Diplock's pedrail as the origin for his idea of an all-terrain armoured vehicle: [3]
The idea was suggested to me by the contrivances of a certain Mr. Diplock, whose "ped-rail" notion, 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
— [4]
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 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. [5] It was a complicated and high-maintenance system, and in 1914 Diplock eventually produced a version on a simpler, single wide track. [6] 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.
An armoured fighting vehicle or armored fighting vehicle (AFV) is an armed combat vehicle protected by armour, generally combining operational mobility with offensive and defensive capabilities. AFVs can be wheeled or tracked. Examples of AFVs are tanks, armoured cars, assault guns, self-propelled artilleries, infantry fighting vehicles (IFV), and armoured personnel carriers (APC).
A military engineering vehicle is a vehicle built for construction work or for the transportation of combat engineers on the battlefield. These vehicles may be modified civilian equipment or purpose-built military vehicles. The first appearance of such vehicles coincided with the appearance of the first tanks, these vehicles were modified Mark V tanks for bridging and mine clearance. Modern military engineering vehicles are expected to fulfill numerous roles, as such they undertake numerous forms, examples of roles include; bulldozers, cranes, graders, excavators, dump trucks, breaching vehicles, bridging vehicles, military ferries, amphibious crossing vehicles, and combat engineer section carriers.
A tank is an armoured fighting vehicle intended as a primary offensive weapon in front-line ground combat. Tank designs are a balance of heavy firepower, strong armour, and battlefield mobility provided by tracks and a powerful engine; their main armament is often mounted within a turret. They are a mainstay of modern 20th and 21st century ground forces and a key part of combined arms combat.
Continuous track or tracked treads are a system of vehicle propulsion used in tracked vehicles, running on a continuous band of treads or track plates driven by two or more wheels. The large surface area of the tracks distributes the weight of the vehicle better than steel or rubber tyres on an equivalent vehicle, enabling continuous tracked vehicles to traverse soft ground with less likelihood of becoming stuck due to sinking.
An amphibious vehicle is a vehicle that is a means of transport viable on land as well as on or under water. Amphibious vehicles include amphibious bicycles, ATVs, cars, buses, trucks, railway vehicles, combat vehicles and hovercraft.
The history of the tank includes all vehicles intended to advance under enemy fire while remaining protected.
A bulldozer or dozer is a large, motorized machine equipped with a metal blade to the front for pushing material: soil, sand, snow, rubble, or rock during construction work. It travels most commonly on continuous tracks, though specialized models riding on large off-road tires are also produced. Its most popular accessory is a ripper, a large hook-like device mounted singly or in multiples in the rear to loosen dense materials.
"The Land Ironclads" is a short story by British writer H. G. Wells, which originally appeared in the December 1903 issue of the Strand Magazine. It features tank-like "land ironclads," 80-to-100-foot-long armoured fighting vehicles that carry riflemen, engineers, and a captain, and are armed with semi-automatic rifles.
The Tsar Tank, also known as the Netopyr' or Lebedenko Tank, was a Russian armoured vehicle developed by Nikolai Lebedenko, Nikolay Yegorovich Zhukovsky, Boris Stechkin, and Alexander Mikulin from 1914 onwards. The project was cancelled in 1915 after initial tests deemed the vehicle to be underpowered and vulnerable to artillery fire.
The development of tanks in World War I was a response to the stalemate that developed on the Western Front. Although vehicles that incorporated the basic principles of the tank had been projected in the decade or so before the War, it was the alarmingly heavy casualties of the start of its trench warfare that stimulated development. Research took place in both Great Britain and France, with Germany only belatedly following the Allies' lead.
A landship is a large land vehicle that travels exclusively on land. Its name is meant to distinguish it from vehicles that travel through other mediums such as conventional ships, airships, and spaceships.
The rocker-bogie system is the suspension arrangement developed in 1988 for use in NASA's Mars rover Sojourner, and which has since become NASA's favored design for rovers. It has been used in the 2003 Mars Exploration Rover mission robots Spirit and Opportunity, on the 2012 Mars Science Laboratory (MSL) mission's rover Curiosity, the Mars 2020 rover Perseverance and ISRO's Chandrayaan-3 rover Pragyan in 2023.
The Henschel Wehrtechnik TH-200, TH-400, and TH-800 are a family of wheeled armoured fighting vehicles by Thyssen-Henschel. Their development was loosely related to the Spähpanzer Luchs.
The Steam Wheel Tank was a U.S.-produced, prototype armoured fighting vehicle built by the Holt Manufacturing Company. Developed sometime between late 1916 and early 1917, it was the third tank to be designed in the U.S. The prototype was completed in February 1918 and was evaluated between March and May 1918 at Aberdeen Proving Ground. It performed poorly and was not developed further.
Bramah Joseph Diplock was an English inventor who invented the pedrail wheel in 1899 and the pedrail chaintrack, a type of caterpillar track, in 1907.
The Breton-Prétot machine was an experimental wire-cutting device developed in France from November 1914. It was developed by Mr. Prétot, engineer, and Jules-Louis Breton, member of the French National Assembly.
A dreadnaught wheel is a wheel with articulated rails attached at the rim to provide a firm footing for the wheel to roll over. These wheels have also been known as "endless railway wheels" when fitted to road locomotives, and were commonly fitted to steam traction engines. They are very similar to pedrail wheels, differing primarily in that their rails are not connected to the wheel directly, but articulated to each other.
The year 1903 was marked, in science fiction, by the following events.
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.
The Killen-Strait armoured tractor was an experimental armoured tractor constructed by the United Kingdom in 1915. The vehicle consisted of the superstructure from a Delaunay-Belleville armoured car, with the turret removed, fitted on a tractor produced by the American company Killen-Strait. A predecessor to the Little Willie, the vehicle is sometimes described as the first tracked armoured vehicle.