Caterpillar Performance Handbook, January 2017, SEBD0351-47

Bucket Selection

Hydraulic Mining Shovels

BUCKET SELECTION For the durability and life expectancy of hydraulic mining shovels, it is important to choose the correct bucket size based on the maximum loose density of the mate- rial to be loaded. Different bucket volumes for common material densities are available for most models. A lose density of 1.8 t/m³ (3030 lb/yd³) is considered standard density and the respective bucket volume is suitable for the majority of applications. Additional volumes are offered in staggered increments of 0.2 t/m³ (340 lb/yd³) and most of them are for heavier material. Rated Bucket Capacity Basically, the total volume is a combination of the struck capacity plus a heap on top of it. On hydraulic mining shovels, the rated bucket capacity is calculated with a different angle of repose for the heap of backhoe buckets versus that of face shovel buckets. As the kine- matics on backhoe machines allow for larger bucket tilt angles, steaper heaps are achieved compared to face shovel buckets. Therefore, the nominal bucket capac- ity is calulated on backhoe buckets with a heap of 1:1, and on face shovel buckets with a heap of 2:1 as shown exemplary in the adjacent sketch. The following standards have been used to determine the rated bucket capacity:

Practical Bucket Capacity Under real working conditions, the actual achieved bucket volume, over time, is generally lower when com- pared to the rated capacity. This is dependent upon various factors, such as fragmentation, bench or face height and humidity. An experienced, well-trained operator achieves between 90 to 95% in reasonably blasted material.

ISO 7451 for backhoe buckets ISO 7546 for face shovel buckets

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Edition 47 16-79