The Old Engine House, comprises two buildings which at one time housed the main steam engines which provided the power for the mill replacing water wheels.
The engines were Musgrave engines which took water from a well in the Courtyard, which still exists (however is now covered by a glass lid) and using coal as the heat source converted the water to steam which powered the engines. Power was delivered to the mil buildings and the machines within them, by systems of drive shafts and belt pulleys.
The old bolt positions which held the high level brackets on which the drive shafts rotated, can still be seen on the exterior of Archibald Hope House at high level in vertical pairs between the windows.
The two story facade of the Engine House is in the South East corner of the Courtyard. It had three long windows on the upper level, with a date carved in the keystones of the left and right windows, giving date of construction as 1857.
To put into context 1857 was also the date of the Indian Mutiny and the “Black Hole of Calcutta”, the American Civil War was 1861 – 65.