Page 15 - Equipment Echoes Issue #137

Sauerman Slackline Cableway Excavators

The beginning of a large pit. A 1-yard machine removing 500 to 600 tons a day opened this hole in the short space of three months.

perimeter of the area being excavated and, after 180 degrees of
such motion, relocating the mast’s guys and changing the positions
of the blocks to give access to the other 180 degrees.

Description and Rigging
A Sauerman Slackline Cableway Excavator normally had a wood
or steel mast 50 to 125 feet high set upon a concrete foundation,
although other headworks were also available as will be discussed
shortly. It was secured by four main guy cables and two lighter
auxiliary guys. A double-drum power unit, set on another concrete
slab at a distance of about 1½ times the mast height, operated the
bucket and carrier. Two single-sheave guide blocks and two tension The impressive height to which a slackline dragline could dump is demonstrated by this
blocks were atop the mast. The number of sheaves on the tension spoil bank, created from the excavation of a reservoir. The machine dug the 400 by 600-foot
blocks depended on the installation’s requirements. Three blocks reservoir from three working positions.
were attached to the mast: One tension block at the top; beneath The bucket and trolley carrier, along with chain mountings,
it, one guide block for the tension line; and beneath that, the other dump block and traveler block, was hung on the track cable. A
guide block, for the load line. The other tension block was held dump chain ran from the rear of the bucket up and over the sheaves
in place by the tension line, which ran from the hoist’s rear drum in the carrier, then forward and through the dump block, a separate
through the two tension blocks and the tension guide block. triangular sheave that was connected by a short piece of chain to
The track cable was attached to the lower tension block and the bridle or draught chains of the bucket. After passing over the
ran across the pit to a bridle cable stretched between two ground sheave in the dump block, the dump chain returned upward and
anchorages placed at right angles to the track cable. Just before it was attached freely on the track cable ahead of the carrier. The
reached the bridle, the track cable passed through a saddle sheave traveler block was attached only to the dump chain.
hung in a short tower or A-frame, and then was attached to the One corner of the dump block was connected to the bucket’s
bridle by means of a bridle frame. front chains. The load cable that pulled the bucket was attached

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