The Steam Engine, built by Davy Brothers of Sheffield and installed in 1855.
It was an additional source of power to the grinding hull if the water levels fell too low to run the waterwheel. It could only operate the grinding machinery not the tilt shop.
The engine has a 15 inch (0.38m) cylinder and 24 inch (0.61m) stroke.
Adjacent is the excavated Lancashire Boiler House.