Stephenson's Rocket and the 1829 Rainhill Trials

In October 1829, five machines were entered in a contest at Rainhill in Lancashire, England, to decide what should pull trains on a new railway. Only one finished the course: Robert Stephenson's Rocket. It averaged 12 mph, reached a top speed of 30 mph, won a £500 prize and won its makers the order to supply the railway's locomotives. This article explains why the contest was held, how it was run, what happened to each entrant and why Rocket is still remembered.

Why the trials were held

The Liverpool and Manchester Railway was nearly finished in 1829. Its directors had to choose how to move trains along it. According to the account of the trials on Wikipedia, George Stephenson argued that locomotives would be the best option, and the trials were a public test of that claim. The alternative at the time was fixed steam engines that pulled trains along by rope. Running a competition let the company compare machines on the same track under the same rules.

The prize was £500. The trials ran from 6 to 14 October 1829 on a level one-mile stretch of track at Rainhill. Three judges oversaw them: John Urpeth Rastrick, Nicholas Wood and John Kennedy.

The rules

The rules were demanding for the time. Each engine pulled a load of three times its own weight, and the tender (the wagon carrying fuel and water) counted as part of that load. The engine had to make ten trips each way along the track, giving 35 miles in each direction, with at least 30 miles at full speed. The average speed had to be at least 10 mph, and steam pressure had to reach 50 psi before the engine set off. The track gauge was 4 ft 8½ in, the width still used on much of the world's railways.

The five entrants

• Cycloped was powered by a horse on a treadmill. It was withdrawn after an accident in which the horse broke through the floor of the engine.
• Perseverance was damaged on the way to Rainhill and repaired over five days. It then failed to reach 10 mph and was withdrawn, receiving a £25 consolation prize.
• Sans Pareil was reported to be 300 lb overweight at the start. It completed eight trips before a cylinder cracked. The railway bought it afterwards.
• Novelty was the crowd favourite and reached 28 mph on the first day. A boiler pipe failed, and after a second failure it was withdrawn.
• Rocket, built by Robert Stephenson and Company in Newcastle upon Tyne, was the only engine to complete the course.

How Rocket performed

The Science Museum Group, which cares for the surviving locomotive, describes Rocket as the clear winner, averaging 12 mph with a top speed of 30 mph. Wikipedia's account quotes The Times of 12 October 1829: the engine ran 35 miles in 3 hours 10 minutes, then another 35 miles in 2 hours 52 minutes, including stops. Its speed under load was reported as 14 to 17 mph, with bursts to 18 mph, and it was said to have used no more than half a ton of coke over the 70 miles.

Afterwards, Rocket was tested on the Whiston incline, where it hauled 12 tons at 12½ mph up a gradient of 1 in 96, according to the same account.

What made the design effective

The Science Museum Group says the design combined a multi-tube boiler with a blast-pipe, and calls this a substantial advance over earlier locomotives. A multi-tube boiler passes hot gases through many small tubes surrounded by water, so more heat reaches the water than with a single large flue. A blast-pipe sends used steam up the chimney, which pulls more air through the fire and so makes it burn hotter. Together they let the engine make steam quickly, which is what a fast, sustained run needs. The museum lists the locomotive's weight as 3,000 kg.

What the win led to

The Stephensons won the £500 prize and the contract to build locomotives for the railway. The line opened in 1830. On the opening day, according to the Science Museum Group, Rocket, driven by John Locke, struck William Huskisson MP at Parkside station, and his injury proved fatal. The accident is a reminder that early railways had few of the safety systems taken for granted today.

What became of Rocket

The original did not stay in its Rainhill form for long. The Science Museum Group says it was rebuilt within 18 months and set aside within ten years. In 1862 it was preserved, in an incomplete and semi-derelict state, and given to the Patent Office Museum in London, which later became the Science Museum. In 1998 it went on display outside the United Kingdom for the first time, travelling to Japan for Festival UK 98. The museum has displayed it in a much-modified form, since the rebuilding changed the engine from its 1829 shape. Where it is shown now has changed over the years, so check the museum's own site before planning a visit.

Wikipedia notes that a restaging of the trials in 2002 with replica engines found that Rocket would still have won, while replicas of Sans Pareil and Novelty failed to finish the course in many runs. That does not prove what happened in 1829, but it suggests the result was not luck.

Why it matters

Rainhill was not the invention of the steam locomotive, and Rocket was not the first one. What the trials did was test several competing ideas side by side, under written rules and in front of crowds, and pick the one that worked. The winning combination of a multi-tube boiler and a blast-pipe became a pattern for later steam engines, and the Liverpool and Manchester Railway became an early example of a line built to run on steam locomotives from the start.

Sources

• Rocket locomotive, Science Museum Group Collection
• Rainhill Trials, Wikipedia