The Swiss cross-country Metrac - a six-wheeled vehicle that climbs wall, lifts itself over high obstacles and descends steep slopes on an even keel.
The Swiss cross-country Metrac - a six-wheeled vehicle that climbs wall, lifts itself over high obstacles and descends steep slopes on an even keel. Designed by Ernst Meili, the Metrac has potentialities as a military, expedition or building site vehicle.
All six wheels are powered, by chain, from the front engine. The front and rare wheels are carried on hollow swinging arms pivoted on a central axle. There are four hydraulic jacks, connected to the front and rear wheels, which increase or decrease ground clearance.
When the lorry is confronted by an obstacle the front wheels and cab are hydraulically lifted onto the wall or hill. The rear wheels drive the vehicle forward until the central wheels are on the obstacle, then the hydraulic jacks lift them; the central wheels, gripping the obstacle, then pull the rear wheels onto the wall. While this takes place the front wheels are lowered to the ground on the other side of the obstacle and the lorry drives forward slowly until the rear wheels are clear of the wall or hill and then lowered also.
For deep ditches the procedure is reversed; with a narrow ditch in front the chassis is locked horizontally and the lorry drives across. Descending or ascending steep slopes, one set of wheels is lifted or lowered to keep the Metrac on an even keel.
There are two versions of the Metrac. The larger one, with cab, is powered by a Chevrolet 100 hp engine and has a top speed of about 70mph. The smaller version has a 60 hp Porsche engine and its maximum speed is 40mph.