水缸
In Britain, locomotives working on roadside steam tramways were required by law to have condensers. Water tank condensers (as above) were sometimes used but air-condensers were more common. A steam tram engine usually had a full-length roof and this was surmounted by a nest of air-cooled copper tubes in which the exhaust steam was condensed. Kitson &amp; Co. made many engines of this type. The system was satisfactory for tram engines (which were very low-powered) but would not have worked for larger railway locomotives.