Together with a world class rubber tyre gantry crane OEM, Engineered Machine Company (EMCO), has developed a unique solution for the replacement of bowls for mining trucks. This innovation significantly reduces the time and safety risks generally associated with a bowl change. The successful implementation of this solution at the Anglo Platinum Mogalakwena mine has minimised truck downtime and resulted in increased operations and improved efficiencies across the entire mining operation.
EMCO’s RTG design allows for improved safety benefits, such as eliminating the requirement of using a high risk tandem mobile crane lift. Additionally, precise manoeuvring of the bowl above the truck reduces the risk for the technicians working under the truck when replacing the hinge pins. There is also no risk of load instability as the crane straddles the complete truck and bowl. The crane can be controlled via a handheld remote control, enabling the crane driver to position himself safely away from the load while in close communication with the technicians and riggers. In addition, RTG cranes can also be safely operated in high wind conditions.
Not only does the design of the RTG provide greater safety features, it also saves on operating time. The set-up time before operation only takes a few minutes, in contrast with the availability and significantly longer set up time required for a tandem lift using mobile cranes. Furthermore, the load can be accurately tilted and shifted in the X, Y & Z directions to quickly align the bowl to the truck frame.
The RTG crane can travel with the load to any place in the yard, meaning several bowls can be fetched and stored as needed. The time to sling and lift the bowls is substantially less than with a mobile crane (±70%), allowing operators to offload and load the trucks that deliver the bowls simply and quickly. The workload on the truck workshop is thus substantially reduced and the available space in the truck workshops also increases significantly.
Thanks to the reduced turnaround time required for the bowl changes and increased availability of the workshops, the up-time of the dump trucks is increased, leading to an overall positive impact on the efficiency of the mine. An advantage of utilising an RTG is that the capital and running costs are substantially less than that of a mobile crane. Moreover, there are no additional infrastructure investments required (e.g. power, rails, flooring), other than clearing and compacting the area in which the crane will operate.
As a standard RTG cranes can operate with full load at an incline of 1-2%. For Mogalakwena, by way of example, the crane was designed to operate at a slope of 6%. This meant there was no need to level the available area.