Adams axle

The Adams axle is a form of radial axle for rail locomotives that enable them to negotiate curves more easily. It was invented by William Bridges Adams and patented in 1865. The invention uses axle boxes that slide on an arc in shaped horn blocks, so allowing the axle to slide out to either side. This is similar to the movement of a Bissell truck, but with the notional centre point of the curve being where the pivot of the truck would be. This design, using slide bearings, is more expensive than one employing a shaft, but takes up less space.