*JimH* wrote:

One cylinder @ 125 hp!

Not to be confused with internal combustion engines. Apples and
oranges.

The largest ever single cylinder steam engine was designed by mathew
Loam of Cornwall and built by the Hayle Foundry Co. in 1849 for land
draining at Haarlem, Netherlands. The cylinder was 3.6 m 12 ft in
diameter and each stroke also of 3.65 m 12 ft, lifted 61.096 liters
13440 gal of water.


And if you notice, this 150 hp only had a 16" bore, 30" stroke: They
did, however need huge flywheels!

This engine was designed and built by the William A. Harris Steam
Engine Company, corner of Park and Promenade Streets, Providence, RI.
It has a 16" bore and 30" stroke. It has a Tangye bed and Brown Valve
gear. William A. Harris was the plant superintendant at the Corliss
Steam Engine Company until 1869, when the Corliss patent ran out. He
then started his own company using the Corliss valve design. This
engine was first installed in a shoe factory in Brockton, MA in 1911