0-2-2

Locomotive wheel arrangement thumb|300px|Stephenson's Rocket, the first 0-2-2 locomotive. This is the condition after rebuilding, with the cylinders lowered from their original position An 0-2-2, in the Whyte notation for the classification of steam locomotives by wheel arrangement, is one that has no leading wheels, followed by two coupled driving wheels, with two trailing wheels. The configuration was briefly built by Robert Stephenson and Company for the Liverpool and Manchester Railway. Equivalent classifications Other equivalent classifications are: UIC classification: A1 (also known as German classification and Italian classification) French classification: 011 Turkish classification: 12 Swiss classification: 1/2 Liverpool & Manchester Railway thumb|Locomotive Northumbrian as depicted in the October 16, 1830 issue of Mechanics' Magazine. Rocket The 0-2-2 or Northumbrian wheel arrangement was first used for Stephenson's Rocket, their entry for the Rainhill Trials of 1829, a competition to choose a locomotive design for the new Liverpool and Manchester Railway.Loco Motion The Locomotive Comes Of Age 1828–1830: 'Rocket' 0-2-2 Bailey Michael R. 2014 The History Press 978-0-7524-9101-1 49–51 Stephenson recognised that the rules of the competition favoured a fast, light locomotive of only moderate hauling power.Snell J.B. Railways: Mechanical Engineering Arrow 1973 1971 0-09-908170-9 Snell 1971 59 Although George Stephenson's previous designs had been heavy four-coupled freight locomotives, Rocket was almost entirely new. Stephenson was an advocate of the adhesion railway, against the fashion of the time, and believed that the light loads for Rainhill would even allow just a single driving axle. This allowed the simplification of not requiring either a chain drive between the axles or Stephenson's invention of the external coupling rods. Achieving adequate traction required more of Rocket's weight to be over the driving axle than the carrying axle. The heavy boiler was placed forwards, with the axle beneath it, giving a 0-2-2 layout rather than 2-2-0. The cylinders were set at a steep angle, as used the year before for Lancashire Witch, rather than the typical vertical cylinders of this period. The cylinders were thus over the firebox and both driver and fireman shared a footplate at the same, rear, end of the engine. Previously they had often been separated to their own ends of the engine. Novelty Ericsson and Braithwaite's entry for the Trials, their Novelty, was an 0-2-2 well tank locomotive.The Science Museum Science Museum, London The British Railway Locomotive 1803-1853 HMSO 1958 5–6 Both the driving wheels and trailing wheels were the same size, and there may also have been the facility to fit a coupling chain drive to give better adhesion "when needed". Novelty has also been described as a [2-2-0 WT design,Bailey 2014 61–64 as there is no clear "front" or "rear" to this design. Northumbrian Rocket was the only locomotive to complete the trials successfully and Stephenson became the supplier of locomotives to the L&MR. The 0-2-2 arrangement was subsequently used by Robert Stephenson and Company on eight locomotives supplied to the Liverpool and Manchester Railway after 1829:, Meteor, Comet, Dart, Arrow, Phoenix, North Star, Northumbrian, and Majestic. Like the rebuilt Rocket, these had their cylinders set low in a near-horizontal position. The Northumbrian type was superseded by the 2-2-0 Planet type. These reversed the layout, placing the cylinders inside, between the frames, and below the smokebox at the front. The inside cylinders were closer together, giving less of a rocking couple and so were less prone to yawing oscillation at speed. Placing the cylinders below the smokebox also permitted shorter steampipes and exhaust pipes to the blastpipe, giving better efficiency. Northumbrians were the last, and only, production locomotives with this wheel arrangement. After the Planets, most passenger locomotives began to use a 2-2-2 arrangement, with an additional front carrying axle to give better riding at speed. Tank engines thumb|left|Railmotor with 0-2-2 locomotive unit c.1905 In the early 20th Century a number of railmotors were built by various railway companies in the UK where the locomotive section had an 0-2-2 wheel arrangement, but they were designed to operate semi-permanently coupled to a coach unit. The LSWR C14 class used a similar layout, but reversed as a 2-2-0 T. Their low adhesive weight gave them a poor performance and half of them were rebuilt as the 0-4-0 T S14. Preserved examples and Replicas LocationAddressRailroadRoad number/NameTrack gaugebuilder Year(s) builtNotesNational Railway MuseumYork EnglandBrampton RailwayRocketuksgRobert Stephenson and Company1829was originally at the Science Museum, London now permanently at the National Railway MuseumHenry Ford MuseumDearborn, Michigan USLiverpool and Manchester RailwayRocketuksgRobert Stephenson and Company1929ReplicaMuseum of Science and Industry, ChicagoChicago, Illinois USLiverpool and Manchester RailwayRocketuksgR. & W. Hawthorn, Leslie and Company1929ReplicaNational Railway MuseumYork EnglandLiverpool and Manchester RailwayRocketuksgRobert Stephenson and Company1935A cut away replica of Stephenson's Rocket located in the Great Hall at the National Railway Museum in York originally at the Science Museum, London on display with the originalNational Railway MuseumYork EnglandLiverpool and Manchester RailwayRocketuksgLocomotion Enterprises1979a working replica of Stephenson's Rocket located in the Great Hall at the National Railway Museum in York References collapsed Category:0-2-2 locomotives 2,0-2-2