Snorkel TB85J Fixed Axle CE - Manual (Page 51)

Chapter 8 – Operation
TB80/TB85J Fixed Axle – 0112823EE 47
• Use low range (four wheel drive) for driving on load-
ing ramps or other steep grades and when safety
considerations demand slow deliberate machine
movement. Low range is for low speed, high torque
operation.
2. Determine the desired steer mode for the specific
driving conditions. Place the switch in the four wheel
coordinated, two wheel, or crab steer mode position
to achieve the desired machine movement. Refer to
Figure 8.5
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. Place the drive/boom selector switch in the drive position.
4. Step down on the platform foot switch.
5. Push the drive joystick forward to move the chassis
forward, the direction of the blue arrow. Pull the joy-
stick backward to move the chassis backward, the
direction of the yellow arrow. The drive speed is pro-
portional to the joystick position.
6. To stop drive motion, return the joystick to neutral.
7. Push the drive joystick to the right to steer to the
right, the direction of the yellow arrow. Push the joy-
stick 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.
8. 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 a limit switch
that senses the main boom position. When the boom is
elevated, only the slowest drive speed will work regard-
less of the drive range switch position. 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 1.0
km/h (0.6 miles per hour) [7.9 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 posi-
tion.
Platform Overload Sensing System
All functions are stopped from the upper and lower con-
trols, when the platform overload limit is exceeded. The
horn will sound intermittently and the red overload light
(refer to Figure 8.6) will blink until the excess load is
removed from the platform. At that time, the machine func-
tions are again operational.
Figure 8.6 – Upper Controls
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
Platform
Overload Light