Editing Train (section)

=== Other types ===
[[File:Union_Pacific_third_generation_GTEL_locomotive.JPG|thumb|A [[gas turbine locomotive]] operated by the [[Union Pacific Railroad]]]]
{{See also|Alternative fuel locomotive}}
Various other types of train propulsion have been tried, some more successful than others.

In the mid 1900s, [[gas turbine locomotive]]s were developed and successfully used, though most were retired due to high fuel costs and poor reliability.<ref>{{Cite web|title=About Gas Turbine Locomotives|url=http://www.up.com/up/aboutup/special_trains/gas-turbine/index.htm|access-date=2021-11-05|website=www.up.com|language=en}}</ref>

In the 21st century, alternative fuels for locomotives are under development, due to increasing costs for diesel and a desire to reduce greenhouse gas emissions from trains. Examples include [[hydrail]] (trains powered by hydrogen fuel cells) and the use of compressed or [[liquefied natural gas]].<ref>{{Cite web|last=Clinnick|first=Robert|date=October 21, 2021|title=Worldwide hydrogen projects gain traction|url=https://www.railjournal.com/in_depth/worldwide-hydrogen-projects-gain-traction/|access-date=2021-11-07|website=International Railway Journal|language=en}}</ref><ref>{{Cite web|last=Vantuono|first=William C.|date=2021-11-01|title=CP: Green 'Gas 'n Go' Gets Grant|url=https://www.railwayage.com/mechanical/locomotives/cp-green-gas-n-go-gets-grant/|access-date=2021-11-07|website=Railway Age|language=en-US}}</ref>