Other work undertaken by the apprentices involved repairing some frost damage to the foundation brickwork , digging a drainage trench around the mill and moving the auxiliary engine into position . A concrete path around the tower was trapping moisture , leading to rising damp . A French drain was constructed around the mill to remedy these problem . A 21 horsepower ( 16 kW ) Ruston & Hornsby 4YHR diesel engine had been purchased in 1981 and was fitted onto a permanent concrete base with the aid of a mobile crane . After fitting it was then painted . Some missing or broken parts were made or repaired as necessary .