Safe Quarry - Health and Safety Authority

PART 3
GENERAL SAFETY PROVISIONS
Figure 7:
Recommended haul road width
(two-way traffic)
Figure 9: Grade as an angle
10 o Slope
6 ft 12 ft
6 ft
Two Times
12 ft 6 ft
10 o Angle = Slope in Degrees
Three and one / half Times
Now if we have traffic going both ways (as we usually do)
we would take the width of the widest vehicle, and have a
lane for it. Again we would have 6 feet (1.85 metres) on each
side for a 12-foot (3.7 metres)-wide vehicle. Now the area in
the middle, 6 feet (1.85 metres) in this circumstance, can be
shared. So for a two lane road you would have to have a
road 3½ times the width of the widest vehicle (42 feet (12.9
metres) wide in this case).
The minimum width of the bench, and the type of
machinery,which can be safely used on it,should be
considered during the design, appraisal and where
appropriate, the geotechnical assessment of the
excavation, tip or lagoon. They should be reviewed
as the working methods and the excavation, tip or
lagoon develop. Benches need to be wide enough
for the type and volume of traffic using them and
take account of the traffic systems in force, for
example, one-way systems.
Benches and haul roads must be designed to avoid
dangerous sharp bends and gradients. They must
also be maintained so that they do not develop
bumps, ruts or potholes that may make vehicles
Figure 8: Grade as a percentage
difficult to control or cause health problems due to
whole-body vibration.The maximum gradient upon
which vehicles can operate should be specified by
the 1 supplier but is also dependent on maintenance,
the quality of the haul roads,the weather conditions
and the condition of the braking system. As a rule
of thumb, and to avoid excessive wear on vehicles,
the grade should P not exceed 10% (1 in 10) except
for short periods.
Figure 10: Comparison percent v degrees
Percent Vs Degrees
1.0 0.6
5.0 3.0
10.0 5.7
15.0 8.5
17.06 10.0
20.0 11.0
Figure 11: Excessive gradients
10% Slope
X Percent Slope
X ft
10’
26%
100 ft
SAFE QUARRY GUIDELINES TO THE SAFETY, HEALTH AND WELFARE AT WORK (QUARRIES) REGULATIONS 2008 33