The Dortmund factory designed and built many legendary hydraulic mining shovels, including the RH200, RH300 and RH400, the largest serial production hydraulic shovel produced to date. Here through a wide selection of images and informative text the technical details of O&K, Terex and Bucyrus hydraulic mining shovels are thoroughly explored. The book includes how the RH200's main and swing hydraulic systems worked and on which machine serial number innovative technical changes such as CMS were first installed, as well as the benefits of TriPower, why O&K favoured twin-engined operation and numerous on-site hourly production rates. Ex-Dortmund employee Rob Sinclair provides an unparalleled insight into these machines with many previously unpublished photographs.