A pile gate, able to accommodate up to 18-inch (45.7 cm) diameter piles, is attached to the bottom lead
section to assist in properly aligning the piles during operation. The pile gate consists of a pile gate
frame, swing arm, and latch. Weight data is stenciled on the sides of the pile gate and warning and lift
point location decals are also located on the pile gate.
An impact hammer stop, installed near the top of the lead tower by removable bolts, replaces the anti-
two block function of the Load Moment Indicator (LMI) system for pile driving operations. The impact
hammer stop physically prevents the impact hammer from colliding with the boom nose by limiting its
The anti-two block function of the Load Moment Indicator (LMI) system is
disabled and not used during pile driving operations.
Weight, impact hammer orientation (UP), and center-of-gravity location data is stenciled on the
individual lead tower sections.
The spotter is a hydraulically-operated, adjustable, mechanical link attached to the bottom lead section
and the crane superstructure to provide stability to and control the location and pitch of the lead tower.
The spotter is attached to the bottom lead section via the spotter slide and to mounting lugs on the front
of the crane superstructure via brackets and two support pins. The hydraulic connections are provided
by the boom hose reel on the crane and connected to two hydraulic connections (spotter manifold)
located on the right-hand side of the spotter base (at crane superstructure mounting bracket). A
hydraulic hose retention chain, attached to the base of the spotter, is used to secure the hydraulic hose
reel lines. The spotter is extended and retracted by the telescope/clamshell control pedal in the
superstructure cab (when the TELE/CLAMSHELL selector switch is in the CLAMSHELL position).
The spotter consists of two telescoping inner and outer boxes with short and long wear pads on each, a
hydraulic cylinder (3-inch (7.6 cm) diameter x 96-inch (2.4 m) stroke), and spotter slide.
The spotter slide, connected to rails on the rear of the lead tower, allows vertical adjustment of the
spotter connection to the lead tower. A pin on the spotter slide engages holes on the rear of the lead
tower to hold the spotter slide in place along the rails. A manual release on the spotter slide can be
operated by a tag line and enables the pin to be disengaged to allow vertical movement of the spotter
slide along the rails. A retainer pin can be used to hold the manual release (and spotter slide pin) in the
disengaged position during height adjustment. Two lubrication fittings, located on each side of the
spotter slide, enable lubrication of the spotter slide.
Warning and weight data is stenciled on top of the spotter. Warning, lubrication location, and lift point
location decals are located on the spotter. In addition, a decal illustrating crane signals and additional
pile driving hand signals is attached to the left-hand side of the spotter.
The impact hammer is a self-contained, diesel engine-driven, direct drive-type pile driving hammer
operating on compression/ignition, two-cycle operation. The impact hammer utilizes an air-activated,
high pressure fuel injection system with a fuel tank and air-activated, pressurized lubrication system
with attached oil tank. Startup of the impact hammer is controlled by an integrated hammer trip system
with trip safety lock.
The main components of the impact hammer are the piston and impact block, upper and lower
cylinders, hammer trip assembly (mechanical starting device), fuel injection system, lubrication system,
and direct drive system that houses a recoil dampening system and striker plate (driving head).