Hydraulically controlled clearing blade fitted to 385-hp Allis Chalmers HD 21 crawler. Allis Chalmers, Milwaukee 1, Wis. 532, U.S.A. Ohrn tractor. For farming or industrial applications, particularly lumbering and on rough terrain. Virtually impossible to overturn. Can be stripped down and reassembled in few hours.
Hydrodynamic transmission eliminates conventional gearbox, differential, and braking system.
Steered by lever which, through a clutch of new design, disengages inner track synchronized with steering system at rear. Speed controlled by accelerator, tractor stops when pressure removed from fuel pedal. Three speeds - low, high and reverse. F. Perkins Limited, Eastfield Factory, Peterborough., Northants., England. AK 5000 crane.