TM 5-3810-288-12
dragging (filling) the bucket, raising the loaded bucket,
Caution: Do not attempt to raise the boom by
swinging, and dumping. The boom angle position is set
means of the boom hoist lines if the boom tip is
before beginning operations in the same manner as for
below the level of the ground which supports the
the crane (fig. 2-40). Start the engine (para 2-16), and
carrier. The angle of pull on the boom will be such
operate the dragline as shown on figure 2-42.
that the boom may collapse before it can be pulled
into the operating position.
2-23.
Piledriver Operation
2-21.
Clamshell Operation
a. General. The Model M320T truck crane,
with the crane boom and a piledriver attachment in-
a. General. The Model M320T truck crane,
stalled and reeved for piledrive operation, is used for
with the crane boom and a clam bucket installed and
driving piles for bridges, piers, and foundations.
reeved for clamshell operation, is used to handle
material which is relatively loose or soft and must be
b. Positioning the Carrier. Back the carrier to
accurately dumped at a higher level than would be
the work site so that most of the work will be performed
possible with a shovel attachment.
The
clamshell
over the rear of the carrier. Set the carrier brakes, and
attachment is used widely for loading and unloading
extend and set the outriggers (fig. 2-4).
loose material from ships and open freight cars, and for
digging deep pits or shafts where the digging point is
c. Operating cycle. The piledriver operating
accessible only to a vertically operated bucket.
cycle consists of four steps: positioning the pile-driver,
setting the pile, lifting the hammer, and dropping the
b. Load Limits. Refer to paragraph 1-4 for
hammer. Start the engine (para 2-16), and operate the
load limits before starting operation.
piledriver as shown on figure 2-43.
c.
Positioning the Carrier. Refer to paragraph
2-24.
Backhoe Operation
2-20.
a. General. The Model M320T truck crane,
d. Operating cycle. The clamshell operating
with the backhoe attachment installed and reeved as
cycle consists of four steps; filling the clam bucket
described in paragraph 2-9, is used where the digging
(closing) ; raising the load bucket, swinging, and
level is below machine grade, the area to be worked is
dumping.
The boom angle position is set before
relatively small, requires the movement of a minimum
beginning operations in the same manner as for the
amount of material, and the material must be dumped
crane (fig. 2-40). Start the engine (para 2-16) and
accurately.
The backhoe attachment is used in
operate the clamshell as shown on figure 2-41.
preference to the dragline attachment when precise
control is re-quired, and when it is required that the walls
2-22.
Dragline Operation
of the excavation be straight.
a. General. The Model M320T truck crane,
b.
Positioning the Carrier. Refer to paragraph
with the crane boom and a dragline bucket installed and
2-20.
reeved for dragline operation, is used to handle material
which is soft, muddy, sticky, or medium hard, and where
c. Operating cycle. The backhoe operating
the loading and dumping points are far apart, both
cycle consists of four steps: filling the dipper, hoisting,
horizontally, and vertically, where digging is below
swinging, and dumping. During backhoe op-eration,
machine grade, and where the material must be dumped
tension must be maintained in both the front and rear
accurately. The dragline attachment is used for digging
drum lines at all times, since they are interdependent.
canals, trenches, and levees, making em-bankments,
Start the engine (para 2-16), and operate the backhoe as
and skimming of top soil.
shown on figure 2-44.
b. Load Limits. Refer to paragraph 1-4 for
load limits before starting operation.
2-25.
Shovel Operation
c.
Positioning the Carrier. Refer to paragraph
a. General. The Model M320T truck crane,
2-20.
with the shovel attachment installed and reeved as de-
d. Operating cycle. The dragline operating cy-
cle
consists of five steps: casting the bucket,
2-36
