Model of Stephenson's "long boiler" locomotive (scale 1:8).

This is a model of a Stephenson 'long boiler' locomotive. Robert Stephenson patented this design of steam locomotive in 1841. By placing all three axles under the boiler barrel it was possible to use a large boiler, while retaining a wheelbase of normal dimensions. The driving wheels were without flanges, to obviate lateral stresses on the crank axle; this feature had been patented by Stephenson in 1833. The model is believed to have been made in about 1845, but the builder's identity is unknown. It it possible that it was commissioned by Robert Stephenson himself, as it was given to the Science Museum by a descendant in 1914.