A compound steam engine unit is a type of steam engine where steam is expanded in two or more stages. A typical arrangement for a compound engine is that the steam is first expanded in a high-pressure
Cutaway of triple expansion compound steam engine, 1888
Robey horizontal cross-compound steam engine: small high-pressure cylinder (left) and large low-pressure cylinder (right)
The Coldharbour Mill Pollit and Wigzell cross-compound engine, which drives the rope race seen in the background, transmitting power to line shafts on all five levels of the mill
A Marchent & Morley horizontal tandem compound engine built 1914, at Craven Mills, Cole. The air pump and jet condenser are nearest with the LP cylinder beyond. It is fitted with Morley's patent piston drop valves
A marine steam engine is a steam engine that is used to power a ship or boat. This article deals mainly with marine steam engines of the reciprocating type, which were in use from the inception of the
Compound steam engine
…of compounding was widespread for stationary industrial units where the need was for increased power at decreasing cost, and almost universal for marine engines after 1880. It was not widely used in railway locomotives where it was often perceived as complicated and unsuitable for the harsh railway operating…
Period cutaway diagram of a triple-expansion steam engine installation, circa 1918. This particular diagram illustrates possible engine cutoff locations, after the Lusitania disaster and others made it clear that this was an important safety feature.
Side-lever engine of SS Pacific (1849)
Side-lever engine of RMS Persia (1855)
Model of the twin side-lever engines of the 1836 Thames River steamboat Ruby