Geared steam locomotive

The geared steam locomotives that have been built have been for conventional track, relying on the adhesion between wheels and rail.

The steam locomotive, as commonly employed, has its pistons directly attached to cranks on the driving wheels; thus, there is no gearing, one revolution of the driving wheels is equivalent to one revolution of the crank and thus two power strokes per piston (steam locomotives are almost universally double-acting, unlike the more familiar internal combustion engine).

Many industrial applications require a low speed locomotive with ample starting tractive effort.

There was also an earlier Class A Climax with a vertically mounted marine-type steam engine, working through a similar drive-line, via a two-speed gearbox.

The Heisler locomotive has a 'V-twin' style steam engine, one cylinder each side of the boiler, affixed to a centrally located longitudinal driveshaft, again geared to the wheels.

Some geared steam locomotives are still at work in the sugar plantations of Indonesia, and no doubt elsewhere too,[citation needed] but in most countries they may now be seen only on tourist lines, preservation sites and museums.

Most are long wheelbase 0-10-0 locomotives that use an articulation technique incorporating a geared drive to the outer-most axles, the inner pair being direct-drive.

The Alishan Forest Railway in Taiwan operated 22 Shay locomotives in the past, with the oldest dating to 1910 Archived 2016-04-17 at the Wayback Machine.