hammer, then lift hammer and pile follower by moving
h. Position another pile and repeat the above
hoist clutch lever toward operator. When hammer
operating cycle as often as necessary.
reaches top of hammer guides, return hoist clutch lever
i. When work is through for the day, lower
to neutral, apply hoist brake pedal, and set hoist brake
hammer to rest on pile follower, and disengage engine
lock (fig. 2-23) to hold hammer in raised position.
clutch (fig. 2-24).
c. Run pile handling cable off drum by moving
crowd and retract clutch lever away from operator, and
maintenance checks and services (para 3-6).
at same time applying pressure to digging brake pedal
to prevent pile cable from overrunning. Attach pile
2-34.
Operation of Jib Boom Front End
handling cable to upper end of a pile and raise it into
Attachment
position within pile leads by moving crowd and retract
clutch lever toward operator, return clutch to neutral and
apply digging brake when pile is within pile leads.
is operated as described below.
d. Position pile in desired location by moving crane
b. Position boom with jib over center of load (by
as required (swing para 2-12b, travel para 2-12d), then
swinging revolving frame, paragraph 2-12b above, or
lower point of pile to ground by slowly moving crowd and
traveling, paragraph 2-12d above).
retract lever away from operator, at same time applying
c. Lower weighted hook by releasing hoist brake
digging brake pedal to prevent cable overrunning drum.
lock (fig. 2-23) and allowing hook to drop by gravity,
e. Wrap a heavy chain around pile and leads to
controlling rate of descent by varying pressure on hoist
hold pile within leads.
brake pedal.
Note. The chain should be sufficiently loose not to
d. After load is attached to hook, lift load by
bind pile when driving begins.
moving hoist clutch and propel brake lever (fig. 2-23)
f. Lower hammer and pile follower by releasing
toward operator.
hoist brake lock and pressure on hoist brake pedal
e. When load is at proper height to clear all
allowing hammer and pile follower to drop slowly to top
obstacles, move hoist clutch and propel brake lever to
of pile. Position pile in follower then remove pile
neutral and apply hoist brake pedal and lock with hoist
follower cables from hooks on hammer.
brake lock.
g. To drive the pile, raise hammer by pulling
f. Complete handling of load in similar manner to
reaches top of pile leads, return hoist clutch to neutral,
crane operation (para 2-28 above).
and apply hoist brake pedal immediately after hammer
its pile follower to prevent hammer cable overrunning
the drum.
2-40
