Percent Vs. Degree Of Slope; Driving On A Slope; Calculating Percent Grade - Snorkel 460SJ Operator's Manual

performance. For example, tire contact may not be the
same at each drive wheel or the slope conditions may not
be optimal, which would then allow for loss of traction.

Percent vs. Degree of Slope

Gradeability is most often referenced as a percentage.
That value is based on a slope angle of 45° representing
100% grade.
Angle indicators, or inclinometers, often measure the an-
gle of the slope in degrees not the percent slope. Because
of that, it may be useful to understand the relationship
between percent slope and the degree of the slope angle
as shown in Figure 8.6.

Driving on a Slope

The machine should only be driven on a slope or load-
ing ramp in the stowed position with the platform on the
downhill side.
Danger
The aerial platform can tip over if it becomes unstable.
Death or serious injury will result from a tip-over ac-
cident. Do not drive on slopes that exceed 45 percent
grade, or where conditions of the slope could cause
driving to be hazardous.
Place the drive range switch in the low position before
attempting to drive the machine on a slope.
Drive the aerial platform only on slopes, or loading ramps
that are within the 45 percent grade capability of the
aerial platform.
460SJ – 1433685
Angle of Slope
in Degrees
Figure 8.6 – Slope Percent/Degree Conversion
Calculate the percent grade:
• before attempting to climb an unknown grade
• if it is believed that there is a malfunction to determine
if the slope is within the actual grade capability of the
aerial platform.

Calculating Percent Grade

The percent grade equals the height (rise) of the slope
divided by the length (run) times 100. Refer to Figure 8.7.
Figure 8.7 – Percent Grade Formula
The grade can be measured with an inclinometer or by
using a tape measure, a level, and a straight 2 x 4. If
using an inclinometer, refer to the conversion diagram
if necessary.
To measure the grade without an inclinometer, use the
following procedure.
1. With the 2 x 4 laying parallel with the slope, lay the
level lengthwise on the 2 x 4.
45°
40°
35°
30°
25°
20°
15°
10°
5°
0
Chapter 8 – Operation
100%
95%
90%
85%
80%
75%
70%
65%
60%
Percent of
55%
50%
Grade
45%
40%
35%
30%
25%
20%
15%
10%
5%
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