Stephenson's Rocket was an early steam locomotive of 0-2-2 wheel arrangement. It
was built for, and won, the Rainhill Trials held by the Liverpool & Manchester
Railway in 1829 to choose the best design to power the railway.
Rocket was designed by Robert Stephenson in 1829, and built at the Forth Street
Works of his company in Newcastle upon Tyne.
Though the Rocket was not the first steam locomotive, it was the first to bring
together several innovations to produce the most advanced locomotive of its day.
It is the most famous example of an evolving design of locomotives by Stephenson
that became the template for most steam engines in the following 150 years.
The locomotive was preserved and is now on display in the Science Museum in
London.
The locomotive had a tall smokestack chimney at the front, a cylindrical boiler
in the middle, and a separate firebox at the rear. The large front pair of wooden
wheels was driven by two external cylinders set at an angle. The smaller rear
wheels were not coupled to the driving wheels, giving an 0-2-2 wheel arrangement.
Stephenson designed Rocket for the Rainhill trials, and the specific rules of
that contest.
As the first railway intended for passengers more than freight, the rules
emphasised speed and would require reliability, but the weight of the locomotive
was also tightly restricted. Six-wheeled locomotives were limited to six tons,
four-wheeled locomotives to four and a half tons. In particular, the weight of
the train expected to be hauled was to be no more than three times the actual
weight of the locomotive. Stephenson realised that whatever the size of
previously successful locomotives, this new contest would favour a fast, light
locomotive of only moderate hauling power.
