The hydraulically driven spur planetary gear units for the travel gear of a transport crawler in a Chinese open pit mine (Fig.), ordered by a German plant construction company at the gear specialists of SGS Sonder Getriebe Service GmbH, are exceedingly compact and have a high load capacity. Both gear units are hydraulically driven via two adjustable axial piston motors each. At the output side the gear units are connected to the transport crawler via a flange shaft. Delivery is planned for the end of April 2011. The gear units are designed for transport crawlers, which lift head and base stations of conveyor systems with a weight of up to 1250 t, mobile and semi-mobile crushing plants and other open pit mining devices, in order to take them to their new site of operation. Temporary peak loads, like they occur in bends and slopes, can reach up to 2.3 times the nominal output torque. Both spur planetary gear units will be used in a Chinese open pit mine and are designed for an operation period of at least 15 years.