loads, and parking heavy equipment on a steep slope
requires detailed planning and is work for competent
and experienced supervisors and operators who possess
a specific knowledge and skill set, as described in this
article.
The worksites and access roads on slopes are distant
from management offices and supervision and usually
vehicle drivers and heavy equipment operators find
themselves facing steep slopes alone. Identifying and
managing the risk of ascending or descending these
isolated slopes requires adherence to a safe work
procedure which, in its preparation, has considered the
hazards and details a system of controls to mitigate the
risks in the absence of supervisory control.
In mountainous terrain, each slope should be measured
separately to identify how steep it is. Slopes are measured
in two ways, not to be interchanged: degrees of slope (as
an angle of inclination to the horizontal), or percentage
of grade, (which is in terms of length of rise or drop, per
length of horizontal distance).
Once the slopes are measured, a safe work procedure
will require the classification of the different degrees
of slope from zero to extreme. A simple system, which
works well, is to colour code the different classifications
of slopes on a project road access and ROW map. Onsite,
colour coded physical markers are erected at the top and
bottom of the slopes:
)
)
0 - 7° normal slope – classified green.
)
)
7 - 15° medium slope – classified yellow.
)
)
Above 15 - 25° steep slope – classified blue.
)
)
Above 25° extreme slope – classified red.
The defining degrees for each classification of
slope varies from project to project, at the discretion,
experience and confidence of the contractor’s
Figure 2.
Blocking of tracks with skids when parking on slope.
Figure 4.
Retractable device to secure the load close to boom
when ascending or descending a slope.
Figure 3.
Strung pipe joints prevented from sliding down slope.
162
World Pipelines
/
AUGUST 2015
