from operator, at same time applying digging brake
pedal to prevent cable overrunning drum.
maintenance checks and services (para 3-6).
2-34. Operation of Jib Boom Front End Attachment
e. Wrap a heavy chain around pile and leads to
hold pile within leads, then remove pile handling cable
from pile.
a. When jib boom is installed to crane boom (fig.
24) and reeved (fig. 2-7), the job hoist line (or whip line)
Note
is operated as described below.
the chain should be sufficiently
b. Position boom with jib over center of load (by
loose not to bird pile when driving
swinging revolving frame, para 2-12b above, or
begins.
traveling, para. 2-12d above).
f. Lower hammer and pile follower by releasing
c. Lower weighted hook by releasing hoist brake
hoist brake lock and pressure on hoist brake pedal
lock (fig. 2-23) and allowing hook to drop by gravity,
Allowing hammer and pile follower to drop slowly to top
controlling rate of descent by varying pressure on hoist
of pile. Position pile in follower then remove pile
brake pedal.
follower cables from hooks on hammer.
d. After load is attached to hook, lift load by
g. To drive the pile, raise hammer by pulling hoist
moving hoist clutch and propel brake lever (fig. 2-23)
clutch lever toward operator. As hammer reaches top of
toward operator.
pile leads, return hoist clutch to neutral, and apply hoist
brake pedal immediately after hammer hits pile follower
e. When load is at proper height to clear all
to prevent hammer cable overrunning the drum. Repeat
obstacles, move hoist clutch and propel brake lever to
this step until pile is driven.
neutral and apply hoist brake pedal and lock with hoist
brake lock.
h. Position another pile and repeat the above
operating cycle as often as necessary.
f. Complete handling of load in similar manner to
crane operation (para 2-28 above).
i. When work is through for the day, lower
hammer to rest on pile follower, and disengage engine
clutch (fig. 2-24).
2-38
