Karrier 'Junior Cob' three-wheeled tractor, 1946.
© Science Museum / Science & Society Picture Library
Model (scale 1:10). The tractor is shown with a four-ton trailer. This type of vehicle was built to transport goods over short distances. The engine, which is integral with the gearbox, has four cylinders and develops 47 HP at 1000 revolutions per minute (rpm). The operating speed of the tractor-trailer combination is 20 mph, with a petrol consumption of 13 mpg. The single wheel at the front of the tractor is used for steering.