Steam locomotive

[1]: 80  It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the locomotive's boiler to the point where it becomes gaseous and its volume increases 1,700 times.

[21] On 21 February 1804, the first recorded steam-hauled railway journey took place as another of Trevithick's locomotives hauled a train along the 4 ft 4 in (1,321 mm)-wide tramway from the Pen-y-darren ironworks, near Merthyr Tydfil, to Abercynon in South Wales.

In Russia, the first steam locomotive was built in 1834 by Cherepanovs, however, it suffered from the lack of coal in the area and was replaced with horse traction after all the woods nearby had been cut down.

Periodic stops are required to refill the tanks; an alternative was a scoop installed under the tender that collected water as the train passed over a track pan located between the rails.

It is then collected either in a perforated tube fitted above the water level or by a dome that often houses the regulator valve, or throttle, the purpose of which is to control the amount of steam leaving the boiler.

The blastpipe is placed at a strategic point inside the smokebox that is at the same time traversed by the combustion gases drawn through the boiler and grate by the action of the steam blast.

In the past, a strong draught could lift the fire off the grate, or cause the ejection of unburnt particles of fuel, dirt and pollution for which steam locomotives had an unenviable reputation.

Designing the exhaust ejector became a specific science, with engineers such as Chapelon, Giesl and Porta making large improvements in thermal efficiency and a significant reduction in maintenance time[36] and pollution.

A trailing axle was able to support a huge firebox, hence most locomotives with the wheel arrangement of 4-4-2 (American Type Atlantic) were called free steamers and were able to maintain steam pressure regardless of throttle setting.

In the 1920s, with the introduction of "superpower", the cast-steel locomotive bed became the norm, incorporating frames, spring hangers, motion brackets, smokebox saddle and cylinder blocks into a single complex, sturdy but heavy casting.

During World War 2, a number of Swiss steam shunting locomotives were modified to use electrically heated boilers, consuming around 480 kW of power collected from an overhead line with a pantograph.

Early locomotives used lags, shaped wooden staves, fitted lengthways along the boiler barrel, and held in place by hoops, metal bands, the terms and methods are from cooperage.

Britain's Great Western Railway was a notable exception to this rule, retaining the direct-loaded type until the end of its separate existence, because it was considered that such a valve lost less pressure between opening and closing.

The promoters of the Rainhill trials urged that each contender have a proper mechanism for reading the boiler pressure, and Stephenson devised a nine-foot vertical tube of mercury with a sight-glass at the top, mounted alongside the chimney, for his Rocket.

Other British lines such as the London, Brighton & South Coast Railway fitted some locomotives with the top feed inside a separate dome forward of the main one.

These have feed pipes to the bearing surface that start above the normal fill level, or are kept closed by a loose-fitting pin, so that only when the locomotive is in motion does oil enter.

It is customary for a small capsule of pungent oil (aniseed or garlic) to be incorporated in the bearing metal to warn if the lubrication fails and excess heating or wear occurs.

Locomotive stopping distances were also normally much greater than the range of headlights, and the railways were well-signalled and fully fenced to prevent livestock and people from straying onto them, largely negating the need for bright lamps.

To compensate for this some locomotives are fitted with a latch that prevents the firedoor from closing completely whereas others have a small vent on the door that may be opened to allow secondary air to flow through.

Though it was considered to design a firedoor that opens inwards into the firebox thus preventing the inconvenience caused on the footplate, such a door would be exposed to the full heat of the fire and would likely deform, thus becoming useless.

Southern Pacific selected this design to provide air free of smoke for the engine driver to breathe as the locomotive passed through mountain tunnels and snow sheds.

[43] However, as the pressure grew to run faster goods and heavier passenger trains, tractive effort was seen to be an inadequate measure of performance because it did not take into account speed.

In the 1920s, the focus in the United States turned to horsepower, epitomised by the "super power" concept promoted by the Lima Locomotive Works, although tractive effort was still the prime consideration after World War I to the end of steam.

[96] Water is required at many points throughout a rail network, making it a major problem in desert areas, as are found in some regions of the United States, Australia and South Africa.

The reciprocating mechanism on the driving wheels of a two-cylinder single expansion steam locomotive tended to pound the rails (see hammer blow), thus requiring more maintenance.

The idea was formalised in 2001 by the formation of 5AT Project dedicated to developing and building the 5AT Advanced Technology Steam Locomotive, but it never received any major railway backing.

Locations where new builds are taking place include:[citation needed] In 2012, the Coalition for Sustainable Rail[114] project was started in the US with the goal of creating a modern higher-speed steam locomotive, incorporating the improvements proposed by Livio Dante Porta and others, and using torrefied biomass as solid fuel.

The small town of Wolsztyn, Poland, approximately 60 kilometres (37 miles) from the historic city of Poznań, is the last place in the world where one can ride a regularly scheduled passenger train pulled by steam power.

The same company also rebuilt a German DR Class 52.80 2-10-0 locomotive to new standards with modifications such as roller bearings, light oil firing and boiler insulation.

The 20 euro Biedermeier Period coin, minted 11 June 2003, shows on the obverse an early model steam locomotive (the Ajax) on Austria's first railway line, the Kaiser Ferdinands-Nordbahn.