All-terrain 6x6 on test
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by Bryan Jarvis • The Defence Evaluation & Research Agency (DERA) is about to begin evaluating a new I-ILMC high mobility 6x6 logistics concept vehicle, designed to demonstrate technologies for military all-terrain use.
The purposeful-looking vehicle is intended to test techniques as much as components: it was designed by DERA's Chertsey unit as a project to build confidence in computer-aided modelling systems, which promise to shorten development times considerably.
The prototype's cab was built by Glover Webb; the chassis largely by Ricardo Specialist Vehicles, with advanced components from a number of suppliers. The vehicle is rated at around 20 tonnes GVW with a nine-tonne flat-rack payload on a smaller 10ft body based on the existing DROPS system, provided by Cargotec; the swap-body interface allows other body systems to be used. An Atlas crane is also fitted.
Hydro-pneumatic suspension struts by Airlog will replace the early coilspring design, enabling the suspension rates to be adjusted according to payload and on or off-road conditions.
Power is supplied by a 350hp (261kW) Cummins L10 diesel driving through a nine-speed Eaton transmission with a lock-up torque converter, a special Rockwell transfer case and axles to achieve all-wheel drive and steering.
Two ZF Servocom operating chambers are fitted to deliver the high output needed for off-road steering. An engine-driven pump powers ZF assist rams on the first two axles with emergency assistance coming from a pump at the rear of the transfer box.
The steering installation also allows the driving position to be altered from left-hand to right-hand drive for extra flexibility. Wall-to-wall turning circles are 17.8m with two-axle steering, but GINAF of Holland has supplied a rear-steer system which comes in at low speeds. Opposed steering in this case reduces the turning circle to 14.7m.
Rockwell/Timoney axles are fitted with Rockwell's in-board, air-operated disc brakes, controlled by Wabco-supplied components and ABS. The chassis rails are box section for enhanced torsional stiffness.
Michelin 475/80R 20in tyres are used; design speed limit is 70mph.