Snorkel A46JRT, Operator'S Manual

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Chapter 8 – Operation
A46JRT – 0261169 35
The value for actual gradeability will always be lower
than the theoretical gradeability value. The perception
then is that the machine can not climb a slope as steep
as it should.
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
angle of the slope in degrees not the percent slope.
Because of that, it may be useful to understand the re-
lationship between percent slope and the degree of the
slope angle as shown in Figure 8.4.
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 40 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 40 percent grade capability of the
aerial platform.
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 di-
vided by the length (run) times 100. Refer to Figure 8.5.
Figure 8.5 – 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.
2. Holding the downhill end, raise the 2 x 4 until the
level indicates that the board is level (refer to Figure
8.6).
Figure 8.6 – Percent Grade Calculation
3. Use the tape measure to measure the distance
(height) from the end of the 2 x 4 to the ground.
Record the height distance.
4. Measure the length of the 2 x 4 and record this mea-
surement.
5. Use the formula in Figure 8.5 to calculate the percent
of the grade.
Machine Gradeability
The gradeability specification for the AB46JRT aerial
platforms is listed below.
Gradeability – theoretical..........................................45%
Theoretically, when all contributing factors are optimal,
the machine can be driven on a slope of 45%. A slope
with a percent grade of 45% is a slope with an angle of
24.2 degrees.
Gradeability – actual.................................................40%
An actual gradeability of 40%, indicates that in most nor-
mal working conditions the machine can be driven on a
slope with an angle of 21.8 degrees.
Length
Height
Length
Height
% of Grade = x 100
Length
Height
Ground Slope