1192 / 2440
Edition 47 16-79
Hydraulic
Mining Shovels
16
Bucket Selection
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:
ISO 7451 for backhoe buckets
ISO 7546 for face shovel buckets
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.