PRINCIPLES OF OPERATION
The All-Terrain Crane (ATEC) incorporates an all welded steel frame and is fully self-
contained. All crane functions are either electrically or hydraulically controlled, and hydraulically
operated. The crane is equipped with two cabs, a carrier cab and a superstructure cab. The
carrier cab contains all controls and indicators necessary for crane travel. The superstructure cab
contains all controls and indicators necessary to perform craning operations. Both cabs utilize
international symbols to label the various crane controls. A symbol identification decal is located in
Both front and rear axles are drive/steer axles. Only the front axle is used for steering
during normal travel operation which is accomplished by the carrier cab steering wheel. When
additional maneuverability is needed for parking or other special conditions, the rear axle can also
be steered from the carrier cab by a rear steer control switch.
Steering can also be performed from the superstructure cab during craning operations. Job
site travel is normally with the boom over-the-rear. Hence, the steering wheel in the superstructure
cab steers the rear axle and a switch steers the front axle. The engine is mounted in front of the
carrier and provides power through a six-speed forward and reverse, electrically shifted
The main operating functions of the superstructure are raising and lowering the boom,
swinging the boom, extending or retracting the boom, raising and lowering loads with the hoists,
and extending and retracting the outriggers. Hydraulic cylinders activate the elevation, telescope,
and outrigger systems. The hoist and swing systems are driven by hydraulic motors.
A diesel engine provides drive power for the main hydraulic pump and the primary steering
pump. The diesel engine also drives an alternator which supplies electrical power for control,
accessory, and lighting systems and an air compressor which supplies pressure for operating the
service/parking brakes, the trailer supply lines, and the tire inflation system. The engine also
provides power through a transmission, to drive the crane.
Hydraulic flow, air, and electrical power are transferred from the carrier to the superstructure
by an air/hydraulic swivel and electrical collector ring located at the center of rotation.
MAJOR COMPONENTS AND SYSTEMS.
Carrier Cab Assembly. The carrier cab contains all the controls and indicators
necessary for traveling and parking functions. The cab is all-steel, acoustically
treated, fully enclosed with tinted safety glass windows throughout. Access to the
cab is via a hinged left side door which features a latch handle and keyed lock. A
grab handrail is provided to aid the operator in getting in and out of the cab. A
suspension seat installed in the cab is adjustable both vertically and horizontally.
The seat is also equipped with a seat belt.