Having ascertained that the slew ring on its 20-year-old cement unloader was in need of replacement, the management of Forth Ports, Leith, called in Metalock Engineering, Coventry, to machine the 3.28m diameter slew ring surfaces to a high degree of flatness. This enabled a new slew ring to be fitted and restore the unloader to efficient use.
Leith & Forth Ports contacted the original manufacturer, BMH, Sweden to obtain the necessary spare parts and also seek recommendations for a company to remachine the badly worn slew ring location faces to the necessary flatness laid down by BMH. Based on past experience with similar work BMH recommended Metalock Engineering.
Following a site meeting with Metalock to discuss the requirements, the Port engineering staff separated the cabin and turret sections from the main frame enabling Metalock to undertake a series of pre-machining laser inspections before setting up its purpose designed rotary facing machine. This comprises a hydraulically driven arm that revolves around the slew ring base centre point. At the outer end is a hydraulically driven milling head.