WINNING
T
he average life of a tyre for
equipment on a quarry is
9 000 hours of operation. This
figure, however, will be reduced
substantially if the haul roads from the pit
to the plant are in a poor condition.
According to Pete Holman, senior
consultant at Caterpillar Global Mining,
the primary cause of damage to tyres
used on equipment in quarries is related
to poor haul road maintenance. “About
80% of all large tyres fail before they wear
out. Cuts are responsible for about 45% of
failures, with impacts causing nearly 30%,”
says Holman.
Not only maintenance of the haul roles
plays a role in extending or reducing the
life of tyres on a quarry; the actual design
of the haul roads also has a significant
impact. The best haul roads have crowned
straight sections, super-elevated curves,
safety berms and drainage ditches on both
sides. The profile of the haul roads, such
as length, width, camber and elevation of
curves and gradients has a considerable
effect on dynamic overloading and on
tyre scrub. Well-designed haul roads also
increase fuel efficiency and operator safety.
Operating at consistent speeds
Super-elevation is the difference in height
between the inside and outside edges
of the bed of a banked road. Properly
designed, super-elevation keeps loads
QUARRY SA | MAY/JUNE 2018 _ 15