Page 177 - Failure Analysis Case Studies II

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Fig. 4. Exploded view of the drive head assembly.

hole. The 119 m of rock had been reamed over a period of a few months at almost the full working
capacity of the equipment. Mains water was used as the flushing medium.
The torque and thrust capabilities of the raise borer are as follows:
0 maximum torque capacity: 494,876 N m (365,000 ft lb)
0 maximum thrust capacity: 4454 kN (1,000,000 lb)

Fig. 5. Cutaway diagram of the drive head installation.