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Stephenson's Rocket
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Stephenson's Rocket was an early steam locomotive of 0-2-2 wheel arrangement, built in Newcastle at the Forth Street Works of Robert Stephenson and Company in 1829.
Design innovations A common misconception is that Rocket was the first steam locomotive. In fact the first steam locomotive to run on tracks was built by Richard Trevithick 25 years earlier, but his designs were not developed beyond the experimental stage. Then followed the first commercially successful twin cylinder steam locomotives built by Matthew Murray in Holbeck for the Middleton Railway between Middleton and Leeds, West Yorkshire. George Stephenson, as well as a number of other engineers, had built steam locomotives before. Rocket was in some ways an evolution, not a revolution.
Rocket's claim to fame is that it was the first 'modern' locomotive, drawing together several recent strands of technological improvement, some tried elsewhere and some still experimental, to produce the most advanced locomotive of its day, and the template for most steam locomotives since. In fact, the standard steam locomotive design is often called the "Stephensonian" locomotive.
Rocket used a multi-tubular boiler, which made for much more efficient and effective heat transfer between the exhaust gases and the water. Previous locomotive boilers consisted of a single pipe surrounded by water. Rocket had 25 copper tubes running the length of the boiler to carry the hot exhaust gases from the firebox. This was a significant development, as it greatly increased the amount of steam produced, and subsequent designs used increased numbers of boiler tubes. Rocket also used a blastpipe, feeding the exhaust steam from the cylinders into the base of the chimney so as to induce a partial vacuum and pull air through the fire. Credit for the invention of the blastpipe is disputed between Sir Goldsworthy Gurney and Timothy Hackworth. The blastpipe worked well on the multi-tube boiler of Rocket but on earlier designs with a single pipe through the boiler it created so much suction that it tended to rip the top off the fire and throw burning cinders out of the chimney, vastly increasing the fuel consumption.
Rocket had two cylinders set at 35 degrees from the horizontal, with the pistons driving a pair of 4 ft 8 ins diameter wheels. Most previous designs had the cylinders positioned vertically, which gave the engines an uneven swaying motion as they progressed along the track. Subsequently Rocket was modified so that the cylinders were set horizontally, a layout used on nearly all designs that followed. The second pair of wheels was 2 ft 6 ins in diameter, and uncoupled from the driving wheels, giving an 0-2-2 wheel arrangement. The firebox was separate from the boiler and was double thickness, being surrounded with water. Copper pipes led the heated water into the boiler.
There have been differences in opinion on who should be given the credit for designing Rocket. George Stephenson had designed several locomotives before but none as advanced as Rocket. At the time that Rocket was being designed and built at the Forth Banks Works, he was living in Liverpool overseeing the building of the Liverpool and Manchester Railway. His son Robert had recently returned from a stint working in South America and resumed as managing director of Robert Stephenson and Company. He was in daily charge of designing and constructing the new locomotive. Although he was in frequent contact with his father in Liverpool and probably received advice from him, it is difficult not to give the majority of the credit for the design to Robert. A third person who deserves a significant amount of credit is Henry Booth, the treasurer of the Liverpool and Manchester Railway. He is believed to have suggested to Robert Stephenson that a multi-tube boiler should be used.
History Rainhill trials Rocket was designed and built to compete in the Rainhill Trials, St. Helens, Merseyside, a competition to select the locomotive type for the Liverpool and Manchester Railway, on 6 to 14 October 1829. Of the five entrants, only three of them were seen as serious contenders. All of the other competitors broke down and Rocket was declared the winner. Rocket fulfilled the key requirement of the contest that a full simulated 50 mile (80km) round trip under load be completed with satisfactory fuel consumption. It averaged 12 miles per hour while hauling 13 tons and 29 miles per hour running light.
Opening-day accident The opening ceremony of the L&MR, on 15 September 1830, was a considerable event, drawing luminaries from the government and industry, including the Prime Minister, the Duke of Wellington. The day started with a procession of eight trains setting out from Liverpool. The parade was led by Northumbrian driven by George Stephenson, and included Phoenix driven by his son Robert, North Star driven by his brother Robert Sr. and Rocket driven by assistant engineer Joseph Locke. The day was marred by the death of William Huskisson, the Member of Parliament for Liverpool, who was struck and killed by Rocket at Parkside.
Subsequent service In 1834, the engine was selected for modifications to test a newly-developed rotary steam engine designed by Lord Dundonald (Thomas Cochrane). At a cost of nearly £80, Rockets cylinders and driving rods were removed and two of the engines were installed directly on its driving axle with a feedwater pump in between. On October 22, of that year, an operational trial was held with disappointing results; one witness observing, that "the engine could not be made to draw a train of empty carriages". Due to inherent design flaws and engineering difficulties associated with their design, Dundonald's engines were simply too feeble for the task.
After service on the Liverpool and Manchester Railway, Rocket was used near Tindale village on Lord Carlisle's Railway in Cumberland (now Cumbria), England.
Preservation In 1862 Rocket was donated to the Patent Office Museum in London by the Thompsons of Milton Hall, near Brampton, in Cumbria.
The locomotive still exists, in the Science Museum (London), in much modified form compared to its state at the Rainhill Trials. The cylinders were altered to the horizontal position, compared to the angled arrangement as new, and the locomotive was given a proper smokebox. Such are the changes in the engine from 1829 that The Engineer magazine, circa 1884, concluded that "it seems to us indisputable that the Rocket of 1829 and 1830 were totally different engines".
The Replica In 1979 a replica Rocket was built by Locomotion Enterprises for the 150th anniversary celebrations. It has a shorter chimney than the original in order to the clear the bridge at Rainhill: the trackbed is deeper than in the 19th century, giving less headroom. This replica is based at the National Railway Museum, York.
See also
External links -
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- by Reiner Knizia
- magazine examines the differences between the 1829 and 1830 Rocket, as reprinted in Scientific American Supplement, No. 460, October 25, 1884.
- 1:26 Scale model of Rocket.
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