TM 5-3810-289-12
2-20.
Operation of Backhoe
2-19.
Operation of Clamshell
a. General.
a
General.
(1) Keep the boom as high as conditions
(1) Be sure that the dipper teeth are kept
permit, but be careful not to let the bucket swing against
sharp and built up to proper size.
the underside of the boom.
(2) When dragging in the dipper, keep a
(2) Keep sufficient tension on the bucket
slight pressure on the hoist brake; this will insure that the
tagline so that the bucket will not spin and the cables.
weight of the boom is not transferred to the dipper.
(3) When transferring material from
(3) Don't swing into trench walls. Be sure
stockpile, always excavate the center of it so that the
to clear bank or trench wall when hoisting out of the cut
material falls inwards, and helps to insure a full bucket
before attempting to swing.
every time.
(4) Do not allow the machine to stand at
(4) Start and stop the swing motion slowly
the end of the trench or near the edge of other
so that the loaded bucket will not swing excessively.
excavation during the shutdown hours.
(5) Do not disengage the main clutch
(5) Do not propel the machine back over a
leave the cab when the bucket is off the ground.
partly excavated trench.
b. Operation.
b. Operation.
(1) Start the crane-shovel (para 2-15).
(1) Start the crane-shovel (para 2-15).
(2) Refer to figure 2-46 to operate the clam
(2) Refer to figure 2-47 to operate the
shell.
backhoe,
A. RAISING OPEN BUCKET
B. LOWERING OPEN BUCKET
STEP 1.
HOIST OPEN BUCKET BY RELEASING
HOLD AND HOIST BRAKES AND
STEP 3.
SWING MACHINE (FIGURE 2-42) TO
PUSHING HOLD-LOWER CLUTCH LEVER
DIGGING AREA.
FORWARD, HOIST UNTIL BUCKET IS
STEP 4.
LOWER OPEN BUCKET BY RELEASING
CLEAR OF OBSTRUCTIONS.
HOLD AND HOIST BRAKES.
STEP 2.
DISENGAGE HOLD-LOWER CLUTCH
NOTE:
DO NOT ALLOW BUCKET TO BOUNCE
AND ENGAGE HOIST AND HOLD BRAKES.
ON GROUND. THIS MAY CAUSE THE
CABLES TO FOUL.
ME 3810-289-12/2-46 (1)
Figure 2-46. Operating the clamshell (sheet 1 of 2).
2-53
