Editing George Stephenson (section)

===Locomotives===
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Cornishman [[Richard Trevithick]] is credited with steam engine research and development, leading to what has been variously described as "the first steam-powered passenger vehicle",<ref name="HISTORY 2009 b345"/> or "his first high-pressure steam locomotive",<ref name="Ricci 2012 n595"/> in both cases referring to his unveiling and testing of the "[[Puffing Devil]]" (or simply, "Puffer") on 24 December 1801.<ref name="HISTORY 2009 b345"/><ref name="Ricci 2012 n595"/> This was a result of his refinements of the steam engine of [[James Watt]] toward "strong [high pressure] steam",<ref name="HISTORY 2009 b345"/><ref name="Ricci 2012 n595"/> Watt believing this direction of development too dangerous.<ref name="Ricci 2012 n595"/> Evident from both accounts is that this first strong steam "locomotive" operated without tracks, because it was three years later that Trevithick was successful in producing a steam engine that operated on rails.<ref name="Ricci 2012 n595">{{cite web | author=Ricci, Tom | date=June 22, 2012 | title=Richard Trevithick: Biography | website= [[ASME]].org | location = New York, NY | publisher = [[American Society of Mechanical Engineers]] (ASME) | url=https://www.asme.org/topics-resources/content/richard-trevithick | access-date=April 5, 2024 | quote = <small>Trevithick's interests soon turned to designing high-pressure steam engines to power locomotives. On Christmas Eve in 1801, he unveiled his first high-pressure steam locomotive and took seven friends on a short journey. Known as the "Puffing Devil," the locomotive was able to keep up the steam pressure for short journeys. Three years later, Trevithick produced the world's first steam engine to run successfully on rails...</small>}}</ref><ref name="HISTORY 2009 b345">{{cite web | author = <nowiki>History.com Editors</nowiki> | date= January 31, 2025 | orig-date = November 13, 2009 | title=Richard Trevithick Introduces His "Puffing Devil" | website=History.com | url=https://www.history.com/this-day-in-history/richard-trevithick-introduces-his-puffing-devil | access-date=April 5, 2024 | quote = <small>British inventor Richard Trevithick takes seven of his friends for a test ride on his “Puffing Devil,” or “Puffer,” the first steam-powered passenger vehicle, on December 24, 1801. Unlike the steam engine pioneered by the Scotsman James Watt, Trevithick’s used “strong steam”—that is, steam at a very high pressure (145 pounds per square inch, or psi). Trevithick’s engines were extremely versatile...</small>}}</ref> Later, he visited [[Tyneside]] and built an engine there for a mine-owner.{{citation needed|date=May 2019}}<!--Not in History.com or Ricci-ASME citations.--> Several local men were inspired by this, and designed their own engines.{{citation needed|date=May 2019}}<!--Not in History.com or Ricci-ASME citations.-->

[[File:Killingworth-locomotive.jpg|thumb|234px|Early Stephenson locomotive in [[Samuel Smiles]]' ''Lives of the Engineers'' (1862).<ref name="Smiles, Lives of the Engineers, Stephenson, 43" /> Called an 1816 Killingworth Colliery locomotive (often claimed to be ''[[Blücher (locomotive)|Blücher]]''), it looks more like the slightly later [[Hetton colliery railway]] locomotives whose 1852 replica ''[[Lyons, Hetton colliery railway|Lyons]]'' was still operating in Smiles' time.<ref name="Smiles, Lives of the Engineers, Stephenson, 43" />]]
Stephenson designed his first locomotive in 1814, a travelling engine designed for hauling coal on the Killingworth wagonway named ''[[Blücher (locomotive)|Blücher]]'' after the [[Prussia]]n general [[Gebhard Leberecht von Blücher]] (It was suggested the name sprang from Blücher's rapid march of his army in support of Wellington at [[Battle of Waterloo|Waterloo]]).{{efn-lr|Recent scholarship holds that Stephenson's ''My Lord'' of 1814 pre-dated ''Blücher''<ref name="Bailey, Stephenson" />}} ''Blücher'' was modelled on [[Matthew Murray]]'s locomotive ''Willington'', which George studied at Kenton and Coxlodge colliery on Tyneside, and was constructed in the colliery workshop behind Stephenson's home, Dial Cottage, on Great Lime Road. The locomotive could haul 30 tons of coal up a hill at {{convert|4|mi/h|km/h|abbr=on}}, and was the first successful flanged-wheel adhesion locomotive: its traction depended on contact between its flanged wheels and the rail.

Altogether, Stephenson is said to have produced 16 locomotives at Killingworth,<ref name="Davies"/> although it has not proved possible to produce a convincing list of all 16. Of those identified, most were built for use at Killingworth or for the [[Hetton colliery railway]]. A six-wheeled locomotive was built for the [[Kilmarnock and Troon Railway]] in 1817 but was withdrawn from service because of damage to the cast-iron rails.<ref>Smiles (1857)</ref> Another locomotive was supplied to Scott's Pit railroad at [[Llansamlet]], near [[Swansea]], in 1819 but it too was withdrawn, apparently because it was under-boilered and again caused damage to the track.<ref>{{cite book|first=Paul |last=Reynolds |chapter=George Stephenson's 1819 Llansamlet locomotive | editor-first=M.J.T. |editor-last=Lewis |title=Early Railways 2: papers from the Second International Early Railways Conference |location=London |publisher=Newcomen Society |date=2003 |pages=165–76}}</ref>

[[File:stephenson-rail-patent.jpg|right|thumb|[[Fishbelly rail]] with half-lap joint, patented by Stephenson 1816]]
The new engines were too heavy to run on wooden rails or plate-way, and iron edge rails were in their infancy, with [[cast iron]] exhibiting excessive brittleness. Together with [[William Losh]], Stephenson improved the design of cast-iron edge rails to reduce breakage; rails were briefly made by [[Losh, Wilson and Bell]] at their Walker ironworks.

According to Rolt, Stephenson managed to solve the problem caused by the weight of the engine on the primitive rails. He experimented with a [[steam spring]] (to 'cushion' the weight using steam pressure acting on pistons to support the locomotive frame), but soon followed the practice of 'distributing' weight by using a number of wheels or bogies. For the [[Stockton and Darlington Railway]] Stephenson used [[wrought-iron]] malleable rails that he had found satisfactory, notwithstanding the financial loss he suffered by not using his own patented design.<ref>{{cite book|last=Nock|first=Oswald|author-link=O. S. Nock|title=The Railway Engineers|publisher=Batsford|location=London|year=1955|page=62|chapter=Building the first main lines}}</ref>