Stephenson’s ‘Long Boiler’ locomotive and the dawn of railway vehicle dynamics

Stephenson’s ‘Long Boiler’ locomotive of 1843, though commercially successful, acquired a reputation for bad riding. The problem was only partially understood at the time, but it stimulated the first attempt to analyse the dynamics of the railway vehicle in a scientific manner. Le Chatelier’s investigations resulted in his book of 1849 that contains a comprehensive account of the effects of the driving motion forces, which was subsequently applied generally to locomotive design. Le Chatelier could be said to have initiated the science of railway vehicle dynamics. However, his analysis of the lateral motions of locomotives was not correct and it was many years before a proper understanding was achieved. Modern knowledge of railway vehicle dynamics and computer simulation is applied to the complex behaviour of the ‘Long Boiler’ locomotive, giving insight to an important, but generally neglected, aspect of railway engineering of its day.