Stationary Stacker

Substructure
The substructure or undercarriage is the structural steelwork from above the equalizers up to the slew bearing. It comes in a plate box girder design, with welded constructions on all the major members. The stationary stacker is designed to transfer loads from the stationary stacker superstructure via the portal into the long travel system as efficiently as practicable.

Superstructure
The superstructure is the slewable upper structure mounted above the slew bearing and consisting of the boom, counterweight, masts, and suspension assemblies. The stationary stacker superstructure is designed to support the boom conveyor, luffing system, and counterweights, and to transfer the load into the slew bearing as efficiently as practicable, without excessive stress or instability under all applicable load combinations.

Cable reel
Power and control signal exchanges are supplied to the machine via a flexible trailing cable. When the stationary stacker is moved towards or away from the termination point at the center of the stockyard, this cable is reeled off or onto a reel assembly fitted to the stationary stacker.

Travel bogies
A stationary stacker's travel mechanism consists of travel wheels that are propelled along the rail track by electro-mechanical long travel drives. A stationary stacker requires these long travel assemblies for its travelling motion.

Boom
The stationary stacker boom carries the complete boom conveyor belt, conveyor drive, take-up assembly, and counterweight blocks. The stationary stacker boom conveyor carries material from the tail to the head end and discharges it onto the stockpile. The stationary stacker boom is luffed hydraulically and slewed hydraulically or electro-mechanically, enabling the conveyor to discharge at different heights and onto different stockpiles during the stockpile building operation.

Slew arrangement
Slew drives turn the stationary stacker's upper slew and boom assembly relative to the undercarriage on a slew bearing mounted between the two structures. The slew drive is mounted on the upper carriage. The slew pinion gear engages the slew bearing with an external gear attached to the undercarriage.

Boom luffing system
The luffing arrangement consists of one or two hydraulic cylinders and a hydraulic power pack. The cylinders are pin-connected between the slew structure and boom, while the power pack is located in a separate enclosure on the boom rear platform or slew structure. Boom luffing can also be effected using a winch rope system.

Tripper car
The tripper transfers material from the stockyard conveyor belt at ground level to the stationary stackerboom conveyor belt above the stockpile. To this end, the tripper structure progressively increases the yard conveyor angle of elevation. The tripper moves on the same rails as the stationary stacker.

E-house
The electrical house (e-house) is where all the electrical switchgear for the stationary stacker, e.g. motor control centers (MCCs), programmable logic controllers (PLCs), variable speed drives (VSDs), etc., is installed.