Condensing steam locomotive

The apparatus takes the exhaust steam that would normally be used to produce a draft for the firebox, and routes it through a heat exchanger, into the boiler water tanks.

In many conditions the temperature gradient is often much worse due to using air instead of having an abundant source of cooling water as naval or stationary steam power plants have.

Because of the relatively high temperature in a locomotive condenser and the rejection of the heat to the air, the potential improvement in thermal efficiency expected from including the condenser in the cycle is not usually realised within the space constraints of a typical locomotive.

A non-return system must be fitted, to prevent water from the tanks being drawn into the cylinders when the steam is shut off.

Here, the exhaust steam is blown into an air-cooled radiator, similar to that used for the cooling system of an internal combustion engine.

[4] There are two usual reasons for fitting condensing equipment - reducing exhaust emissions and increasing range.

[5] The water in the tanks could quickly heat up near boiling point, reducing the condensing effect on the exhaust steam.

In Britain, locomotives working on roadside steam tramways were required by law to have condensers.

Generally this was a more sophisticated installation that used forced air cooling to condense the exhaust steam.

The system was intended to reduce the problems of getting enough water to steam locomotives running through desert and very arid areas, e.g. South Africa.