Page 20 - Equipment Echoes Issue #137

Sauerman Slackline Cableway Excavators

The moveable self-supporting tower, equipped with a gravity backhaul bucket and rigging,
predated the tower machines. This one is building a levee for a copper company.

Eighty cycles an hour was possible on a 100-foot span, and
Sauerman also offered specialized implements for the Power Drag Scraper. Clockwise from
upper left: Rock scraper; “Slusher” scraper; Hoe scraper for surface mining; and V-Type scraper. operation was continuous until grade had been reached in the cut;
then the tail tower or tail sheave was moved to set the bucket on
a new path, and work resumed. Maximum span was 1,000 feet,
but 500 was the recommended limit for smaller machines. The
Power Drag Scraper could work under water, and in everything
from sand to shot rock; Sauerman offered a variety of tooth and
bucket designs for various needs.
In the 1920s or 1930s, Sauerman also marketed this bucket
for two other applications. One was for use with a conventional
dragline serving as a mobile mast, and the other was a conversion
to a hydraulic drag scraper for use behind crawler tractors. These
Crescent Hydraulic Scrapers ranged from 1¼ to 3½ yards struck,
and the largest scrapers were recommended for Cat Seventys and
RD-8s and Cletrac FDs and FGs. When the scraper was full, it
simply stopped loading and glided on the surface. The back wall,
floor and cutting edge pivoted against the walls; the single hydraulic
This 2½ yard Power Drag Scraper with 50-foot moveable steel head tower is clearing rock cylinder pulled the top of this assembly forward for rear dumping,
and earth from a reservoir and placing the spoil on the containing embankment. Why the and the operator controlled the speed of dumping. It returned to
vertical side of the tower faces the cut on some installations but not others is not explained.
the cut in the dump position, riding on its front endwalls.
Scraper Tower Machines
weight, and imparted a tendency to travel in a straight line without Sauerman also adapted the power drag scraper concept to
spillage. Capacities ran from 1/3 to 12 cubic yards. the construction of long, continuous cuts and fills through
The other was the operation and rigging of the bucket. It was
propelled by two cables attached to it, one each fore and aft; the
forward cable drew it in to the mast, and the rear cable drew
it back. This pull-back cable, as it was called, passed through a
sheave on the tail tower or the bridle cable at the anchorages, then
directly across the span to the top of the mast, and finally down
to the power unit on the ground. The bucket was not hoisted to
dump as with the slackline dragline; it merely gathered the load
and pulled it forward along the ground. When the dumping point
was reached, the operator reversed the hoist and the bucket was
withdrawn, leaving the load behind. The pull-back cable also lifted Sauerman also marked the Power Drag Scraper for use with a conventional dragline as a
the back of the bucket to facilitate dumping and to increase speed mobile mast. This arrangement, with a tree serving as an anchorage, was proposed for
cutting a trench across a riverbed. (Sauerman brochure, How to Convert Your Dragline into a
and reduce drag on the return trip. Long Range Machine, n. d., HCEA Archives)

18 | Equipment Echoes Summer 2020 | #137