In the years after Richard Trevithick invented the first high pressure steam engine in 1803, the locomotives that followed all had the problem of using too much coal and being slow and unreliable.
By 1829 it was clear that new ideas were needed; the directors of the Liverpool and Manchester Railway Company launched the Rainhill Trials, offering a purse of £500 to anyone who could improve efficiency on the railway line between Liverpool and Manchester.
The thought of winning such an amount was all the motivation locomotive builder George Stephenson and his son Robert needed. In designing the now-famous ‘Rocket’, Stephenson made three design innovations:
- A multi-tube boiler (25 copper tubes), instead of a single or twin flue, increased efficiency.
- Using a blast pipe increased the draught to the fire by concentrating exhaust steam at the base of the chimney, generating more power (steam), so Rocket could go faster.
- A simplified connecting rod system which linked the wheels and the cylinders improved the drive and reduced breakdowns.
Going like a rocket
When Stephenson's turn in the Trial came, Rocket went like a rocket, reaching speeds of 24mph (the average speed of locomotives was 10mph at that time). Most of the other competitors were forced to withdraw due to breakdowns and Stephenson received fame, fortune and future work far beyond the prize money.
For Rocket, her grand prize for winning turned out to be a few years’ service on the Liverpool and Manchester Railway before being sold to work as a freight engine. Having been built as a prototype the production models made soon after were more refined, but the basic design was ground-breaking and appeared in all subsequent steam locomotive designs. Rocket’s place in history was already secured.
In 1862 Rocket was donated to the Patent Office Museum and is now on display at the Science Museum in London.