TM 5-3810-231-12
drum to wrap the line on the drum. Push this lever away
m. Boom Hoist Pawl Control (2). When the control
from the operator to reverse the direction of the drum
is down the pawl is engaged in the ratchet of the boom.
rotation to run off the line.
hoist drum. To release the pawl from the ratchet, raise
e. Secondary Hoist and Swing Brake Lever (5).
the boom slightly by pulling the boom hoist lever toward
the operator. Depress the button in the center of the
Pull this lever toward the operator to rotate the rear
handle and pull up on the control.
drum to wrap the line on the drum. Push this lever away
from the operator to apply the swing brake.
Note
f. Boom Hoist Lever (6). Pull this lever toward the
Keep pawl engaged at all times
operator to rotate the boom hoist line drum and raise the
boom (or auxiliary gantry where used) Push this lever
except when lowering boom.
away from the operator to release the boom hoist brake
and allow the boom to lower by gravity.
n. Main Hoist Brake Lock (3). Push this handle
down to engage the pressure retaining valve connected
g. Boom Hoist Hydraulic Control (7). Squeeze this
to the main hoist brake hydraulic line. This retains the
handle toward the boom hoist lever to close the
pressure applied to the main hoist brake when the brake
pressure retaining valve connected to the boom hoist
is pushed down. To release the pressure retaining
hydraulic line. The boom hoist lever can then be
valve, apply pressure to the brake pedal then raise the
"pumped" (pulled toward the operator more than once)
handle and gradually release pressure on the brake.
to engage the boom hoist clutch more firmly on the
drum.
o. Magnetic Clutch Switch (4). This switch is used
to increase the excitation to the clutch fields to decrease
h. Propel Lever (8). When this lever is in a neutral
the amount of "slip" when swinging with an extremely
position the propel brakes are set. Push this lever
long boom.
forward away from the operator, which will release the
spring set brakes and engage the travel clutch. Th e
p. Engine Hand Throttle (5). Pull back to increase
machine will travel forward. Bringing the lever back to
engine speed. Push forward to idle engine.
the neutral position will disengage the travel clutch and
q. Engine Clutch Lever (6). The engine clutch is
set the propel brakes. Push lever to left and pull back to
disengaged with the lever in the rear position as shown.
travel in reverse motion.
Push the lever forward to engage the engine clutch and
i. Main Hoist Brake Pedal (9). Push this pedal
start the machinery in motion.
down to apply the main hoist brake.
r. Swing Lock Lever (7). With the lever in the
j. Secondary Hoist Brake Pedal (10). Push this
upper position as shown, the swing lock is disengaged.
pedal down to apply the hoist brake.
Move the lever forward or away from the operator to
engage t he swing lock and prevent the upper from
k. Foot Throttle (11) Press down on the throttle
turning or swinging.
plate for desired speed. Release foot pressure on
throttle plate to reduce speed.
s. Quick Release Valve (8). This valve is used as
a quick release of the air to the propel brakes. Push
down to actuate valve.
valve controls the air pressure applied to the air
hydraulic booster system on the secondary hoist brake
t. Steering Control Lever (9). When this is in the
and the main hoist brake. (Refer to Hydraulic Section
center position both crawlers are engaged and the
for additional information concerning this control).
machine will travel straight forward or backward. Push
the lever forward toward the operator to engage the left-
hand crawler and the machine will travel to t he right.
When the lever is back away from the operator, the
machine will travel to the left.
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