Vertical boiler

Detail of vertical boiler and associated steam engine in a working model steam launch
Taffy a replica of Chaloner, a de Winton vertical-boilered narrow gauge railway locomotive

A vertical boiler is a type of fire-tube or water-tube boiler where the boiler barrel is oriented vertically instead of the more common horizontal orientation. Vertical boilers were used for a variety of steam-powered vehicles and other mobile machines, including early steam locomotives.