The large cylindrical object is not a boiler but a "steam drum" which was a third full of boiling water. It was filled with steam from a stationary plant then the loco would use the steam as it moved around. As the pressure dropped in the drum the water would boil more fiercely (As the temperature at which water boils drops with lower pressure). These locos were extremely successful and were largely used in gasworks oil refineries and other places where naked flames could not be tolerated. Fireless locomotive
This image, which was originally posted to Flickr, was uploaded to Commons using Flickr upload bot on 5 October 2007, 00:17 by Morven. On that date, it was confirmed to be licensed under the terms of the license indicated.
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
https://creativecommons.org/licenses/by/2.0CC BY 2.0 Creative Commons Attribution 2.0 truetrue
Add a one-line explanation of what this file represents
Glasgow Museum of Transport<\/a>"}},"text\/plain":{"en":{"P180":"Glasgow Museum of Transport"}}}}" class="wbmi-entityview-statementsGroup wbmi-entityview-statementsGroup-P180 oo-ui-layout oo-ui-panelLayout oo-ui-panelLayout-framed">