One of the most significant locomotives of all times was the „Rocket”, built in 1929 by George and Robert Stephenson for the Rainhill Trials which were held by the Liverpool & Manchester Railway. In these trials, the L&MR wanted to determine the design for a locomotive that could successfully operate light passenger trains over longer distances. The new locomotive had to achieve an average speed of 10 mph (16 km/h) over the 70 miles from Liverpool to Manchester and back. The limit for four-wheeled locomotives was set to four and a half tons, while six-wheeled locomotives were limited to six tons.

Since the Stephensons recognized that a single driving axle would be enough for the light trains, they chose the 0-2-2 wheel arrangement for the first time. In this case the driving axle was at the front and the cylinders were mounted behind it at an angle of 38 degrees. The rear wheels were not connected to the driving wheels and only carried the weight of the firebox. 

The boiler had many features which could be found on later steam locomotives. Instead of a single or two flues, it had 25 tubes which created more surface for the smoke to heat the water. These worked great in conjunction with the blast pipe to provide enough draught. Additionally, the firebox had a water jacket to utilize the direct radiant heat from the hottest part of the boiler.

The original with changed cylinder position in the Science Museum, London

Irid Escent

“Rocket” easily won against its rivals in October 1829 and so the Stephensons could share the £500 prize with Henry Booth from the L&MR, who had provided valuable input for the design. It took part in the opening of the railway on September 15, 1830 when the Stephensons had already built the even more advanced “Northumbrian”. The event was overshadowed from an accident in which “Rocket” struck and killed William Huskisson, the MP for Liverpool.

In 1831, when some similar locomotives had already been built, the cylinders of “Rocket” were mounted in a more horizontal way to match “Northumbrian”. It was used on the L&MR until 1834 and then it was unsuccessfully used by Thomas Cochrane to test steam turbines. Rebuilt back to conventional cylinders, it was sold to the Brampton Railway in 1836 and used there until 1840.

After a period of storage, it was donated to the Patent Office Museum (Science Museum) at London in 1862, where it rested until 2018. After some time in the NRM at York, it came to Shildon in 2023. Over the years, several working and stationary replicas have been built. The most popular replica was built for the 150th anniversary in 1979. The original locomotive can today be seen with its nearly horizontal cylinders, while this replica still has them inclined by 38 degrees.