Snorkel AB85RJ CE - Manual (Page 53)

Chapter 8 – Operation
AB80J/AB85J – 0420453EE 49
Figure 8.5 – Steer Modes
• Use two wheel steer for most machine operation
such as travel between jobs and to position the
machine near the job location.
• Use four wheel coordinated steer when a tight turn-
ing radius is desired for positioning the machine.
• Use crab steer to travel in a diagonal motion in the
direction of the wheels.
Note
The steering wheels are not self-centering. Set the steer-
ing wheels straight ahead after completing a turn and
before switching from one steer mode to another.
3. Step down on the platform foot switch.
4. Push the drive joystick forward to move the chas-
sis forward, the direction of the blue arrow. Pull the
joystick backward to move the chassis backward,
the direction of the yellow arrow. The drive speed is
proportional to the joystick position.
5. To stop drive motion, return the joystick to neutral.
6. Push the drive joystick to the right to steer to the right,
the direction of the yellow arrow. Push the joystick
to the left to steer to the left, the direction of the blue
arrow. The wheels will steer only when the drive
joystick is in the forward or reverse drive position, or
when the booms are stowed.
Note
The steering wheels are not self-centering. Set the steer-
ing wheels straight ahead after completing a turn.
7. After driving to the desired location, release the foot
switch, or push the emergency stop button to apply
the parking brakes.
Drive Speeds
The drive speed is proportional to the joystick position.
The farther the joystick is moved, the faster the travel
speed.
Always slow down and shift the drive system to low
range before traveling over rough terrain or any sloped
surface.
Drive speed ranges are interlocked through limit switches
that sense the main and riser boom position. When either
boom is elevated or extended, only the slowest drive
speed will work regardless of the drive range switch posi-
tion. To avoid a sudden speed change from high to low
elevated boom speed, always bring the machine to a stop
before raising the booms from the stowed position.
A Warning
The potential for an accident increases when safety
devices do not function properly. Death or serious
injury can result from such accidents. Do not alter,
disable, or override any safety device.
Do not use the aerial platform if it drives faster than  km/h
(0.6 mph) [8 m (26 feet) in 30 seconds] when the booms
are elevated from the stowed position.
Motion Warning Alarm
The motion warning alarm sounds loud intermittent beeps
when the drive joystick is in the forward or reverse position.
Gradeability
Gradeability refers to the maximum slope that the aerial
platform is capable of travel. Gradeability can be de-
scribed as “theoretical” or “actual” with the slope, or grade,
measured in percent of slope or degree of slope.
Theoretical Gradeability
Theoretical machine gradeability refers to the maximum
slope that the machine is capable of travel under perfect,
or theoretical, conditions. It is based on mathematical
calculation, not practical application.
Some of the factors taken into consideration when cal-
culating theoretical gradeability include:
• Drive motor efficiency
• Machine weight
• Machine center of gravity
• Tire traction
• Tire contact
• Condition of slope
The value for theoretical gradeability will most always be
high when compared to the actual gradeability value. The
perception then is that the machine can climb a steeper
slope than is actually practical.
Actual Gradeability
Actual machine gradeability refers to the maximum slope
that the machine is capable of travel under practical condi-
tions. It, too, is based on mathematical calculation, but it
also takes into account the practical application.
Steer Modes
Crab
• Front and rear
wheels turn in
steer direction
Four Wheel
Coordinated
• Front wheels turn
in steer direction
• Rear wheels turn
in the opposite
direction
Two Wheel
• Front wheels turn
in steer direction
• Rear wheels do
not turn