In the demanding environment of open-pit mining, the double back-up loading technique stands out as a highly efficient method for loading haul trucks, offering significant advantages in productivity and cost-effectiveness. This method, where a shovel or excavator positions itself to load trucks from both sides, minimizes operational delays and maximizes the performance of the loading equipment [1].
The primary advantage of double back-up loading lies in its ability to significantly reduce the loading cycle time [2]. By having a truck ready to be loaded on one side as soon as the previous one departs from the other, the shovel experiences minimal downtime. This continuous operation is a stark contrast to single-sided loading, where the shovel must wait for the loaded truck to leave and a new one to position itself.
This reduction in wait time directly translates to a substantial increase in productivity. Studies have shown that implementing double-sided loading can boost productivity by as much as 16% [2]. For a large-scale mining operation, such an increase in material moved per hour can lead to considerable financial gains.
Furthermore, the optimized movement of both the shovel and the haul trucks contribute to lower operating costs. The reduced swing angle of the shovel as it moves between the digging face and the truck on either side leads to less fuel consumption and reduced wear and tear on the equipment. One study highlighted that the increased operational efficiency from this method could result in annual operating cost reductions of as much as $3 million [2].
Effective implementation of double back-up loading also enhances the overall utilization of the mining fleet. With the primary loading unit operating at peak efficiency, the entire haulage cycle is streamlined. This can lead to a more balanced and productive fleet, reducing the likelihood of bottlenecks at the loading point and ensuring a steady flow of material to the processing plant or waste dumps.
In essence, double back-up loading, often used synonymously with double-sided loading, is a strategic approach to a critical stage in the mining process. By minimizing idle time and optimizing the interaction between loading and hauling equipment, it offers a clear path to increased productivity, reduced costs, and improved overall efficiency of the mining operation [2].
Reference
[1] F. Arteaga, M. Nehring, P. Knights, and J. Camus, “Schemes of Exploitation in Open Pit Mining,” C. Drebenstedt and R. Singhal, Eds., Cham: Springer International Publishing, 2014, pp. 1307–1323. doi: 10.1007/978-3-319-02678-7_126.
[2] X. Bouton, “Single-Sided vs Double-Sided Truck Loading in Surface Mines,” Oct. 2017, Accessed: Oct. 14, 2025. [Online]. Available: https://espace.library.uq.edu.au/view/UQ:706636
