Steam locomotive components

Main components found on a typical steam locomotive include: The diagram, which is not to scale, is a composite of various designs in the late steam era.

Some components shown are not the same as, or are not present, on some locomotives – for example, on smaller or articulated types.

Conversely, some locomotives have components not listed here.

Alternative names shown below are often, but not always, reflective of differences in terminology in the United Kingdom and some of its former colonies (shown as UK+) and in countries that follow Northern American practice (shown as US+).

A slash ( / ) indicates alternative terms in use within the same jurisdiction.Numbers in parentheses (e.g. 20) point to numbers of related entries, both in this list and in the main diagram.