Puffing Billy (locomotive)
Template:Short description Template:Use dmy dates Template:Use British English Template:Italic title Template:Hatnote group Template:Infobox locomotive Puffing Billy is the world's oldest surviving steam locomotive,<ref>Template:Cite journal</ref><ref>Template:Cite web</ref> constructed in 1813–1814 by colliery viewer William Hedley, enginewright Jonathan Forster and blacksmith Timothy Hackworth for Christopher Blackett, the owner of Wylam Colliery near Newcastle upon Tyne, in the United Kingdom. It was employed to haul coal chaldron wagons from the mine at Wylam to the docks at Lemington in Northumberland.<ref>Template:Cite web</ref>
History
Precursors
The first steam-powered locomotive on rails was built by Richard Trevithick in either 1802 or 1804. He built several locomotives, and although the success of his 1802 locomotive at Coalbrookdale is questioned, his 1804 locomotive ran near the Pen-y-Darren Ironworks in Merthyr Tydfil, South Wales successfully enough to haul five wagons of iron for nine miles, winning a wager. Its excessive weight cracked the iron rails, rendering it impractical, and steam locomotives were not adopted at the time.<ref >Template:Cite web</ref><ref >Template:Cite ODNB</ref>
In 1810, the Durham Coalfield was disrupted by a major strike over the Bond system.<ref name="DRO, Bond" /><ref name="Webb, 1810" /> During this time Christopher Blackett, owner of the Wylam Colliery, took advantage of the pit's idleness to experiment with the idea of a locomotive-hauled tramway worked purely by adhesion, rather than the Blenkinsop rack system that would be used on the Middleton.Template:Sfnp These began with a simple hand-cranked wagon, converted from a coal wagon chassis with the addition of a central drive shaft and geared drives to the axles.Template:Sfnp
As this experiment was successful, by 1812 it was followed by Wylam's first prototype 'travelling engine', worked by steam. This was based on a combination of the test wagon, with a single cylinder engine and boiler atop it. Little is known of the design, although it has been said to have been inspired by Trevithick's Pen-y-darren locomotive. It is unclear whether the single cylinder was vertical or horizontal, and whether the boiler had a single straight flue or a return flue. It may have been nicknamed Grasshopper.Template:Sfnp The 'travelling engine' was successful as a prototype, but underpowered and prone to stalling when overloaded or faced by a gradient. It was however convincing enough as a demonstration to encourage Blackett to fund further locomotives.
Prototypes
Puffing Billy was one of three similar engines built by Hedley, the resident engineer at Wylam Colliery, to replace the horses used as motive power on the tramway. In 1813, Hedley built for Blackett's colliery business on the Wylam Colliery line the prototypes, Puffing Billy and Wylam Dilly. They were both rebuilt in 1815 with ten wheels, but were returned to their original condition in 1830 when the railway was relaid with stronger rails.<ref name=Cassereley >Template:Cite book</ref>
In the September 1814 edition of Annals of Philosophy two locomotives with rack wheels are mentioned (probably Salamanca and Blücher), then there is mention of "another steam locomotive at Newcastle, employed for a similar purpose [hauling coals], and moving along without any rack wheel, simply by its friction against the rail road". From the context, this is at a different location to Blücher, so is probably Puffing Billy.<ref >Template:Citation</ref>
Puffing Billy remained in service until 1862, when Edward Blackett, the owner of Wylam Colliery, lent it to the Patent Office Museum in South Kensington, London (later the Science Museum). He later sold it to the museum for £200. It is still on display there. Its sister locomotive, Wylam Dilly, is preserved in the National Museum of Scotland in Edinburgh.
Two replicas exist: one, built in a Royal Bavarian State Railways workshop in 1906, is at the German Museum, Munich; the other, at Beamish Museum, was first run in 2006.
Design
Puffing Billy incorporated a number of novel features, patented by Hedley, which were to prove important to the development of locomotives. It had two vertical cylinders, one on each side of the boiler, and partly enclosed by it, and drove a single crankshaft beneath the frames, from which gears drove and also coupled the wheels allowing better traction.<ref name=Science>Template:Cite book</ref>
The engine had a number of serious technical limitations. It was only capable of at most Template:Cvt and its eight-ton weight broke the cast-iron wagonway plates, resulting in criticism from locomotive opponents. This problem was resolved by doubling the number of axles to better distribute the weight. The engine was eventually rebuilt with two axles when improved edge rail track was introduced around 1830.
Legacy
Puffing Billy was an important influence on George Stephenson, who lived locally, and its success was a key factor in promoting the use of steam locomotives by other collieries in north-eastern England.
It has been suggested that Puffing Billy's name survives in the English language in the intensifier like billy-o, but there are several alternative explanations for that phrase's origin.<ref>Template:Cite web</ref>
References
Template:Commons category Template:Reflist