Editing Model engineering (section)

==Model live steam locomotives==
[[File:Livesteamtrain.jpg|thumb|right|230px|A more demanding model engineering project, a propane fired 1:8 scale live steam train, running on the [[Finnish Railway Museum]]'s miniature {{convert|7.25|in|mm|abbr=on}} track.]]

Model [[live steam]] locomotives predominate as the most popular modelling subject in model engineering.<ref>{{cite journal|title=Reader Survey|journal=Model Engineer|date=25 Jul 2003|volume=191|issue=4200|page=71|quote="...&nbsp;nearly 60% of [survey respondents] enjoy the articles on locomotives, almost 50% admitting to current involvement in a locomotive project."}}</ref> As such they deserve special mention. Live steam refers to the use of pressurised steam, heated in the model locomotive's own [[boiler]], to turn the wheels via miniature [[Cylinder (steam locomotive)|steam cylinders]]. Not all locomotives are live steam - some model engineers make model locomotives powered by electricity or internal combustion engines. The criteria however is that the model is self-propelled, hence requiring an engine to be made or motor to be installed, as opposed to the (usually much smaller) [[model train]]s that rely on an electrified track to run.

Live steam (and other self-propelled) locomotives are made in a range of sizes, or scales, according to track gauge. The smaller gauges, sometimes called 'garden gauges' because they can be set up in the owner's own garden,<ref>{{cite book|last1=Jones|first1=Peter|title=Building Small Steam Locomotives: a practical guide to making engines for garden gauges|date=2009|publisher=Crowood|location=Ramsbury, UK|isbn=9781847970299}}</ref> or in the US called a [[backyard railroad]], are sufficient to run by themselves but usually cannot haul the driver or passengers. The larger gauges are usually found on club tracks or [[List of ridable miniature railways|miniature railways]], and are intended to haul the driver and passengers.

Popular 'garden gauges' are '0' gauge, '1' gauge and 2½" gauge (ridable). Usual club track gauges are 3½", 5" and 7¼", and 4¾" and 7½" in North America. Larger miniature railway gauges such as 10¼" and 15" gauge are more common in zoo and park settings or as public passenger-hauling lines such as the [[Romney, Hythe & Dymchurch Railway]]. Various gauges have existed over time. 3½" and 5" gauge were proposed in 1898 as standard model gauges, although 5" gauge only became popular after the Second World War, along with 7¼" gauge.<ref>{{cite journal|last1=Monk|first1=Dennis|title=A brief history of the gauges|journal=Model Engineer|date=16 January 1998|volume=180|issue=4059|pages=77–80}}</ref>

Not all model live steam locomotive enthusiasts are model engineers (and ''vice versa''). There are many live steam enthusiasts who prefer running the models on a track rather than spending long hours building them in a workshop, and so purchase a ready made model locomotive. However, for many the joy of the hobby lies in the manufacturing process, ending in the great satisfaction of a running engine of any sort, which can be immense.