Yates and Ross shaft rehab continues

The Yates and Ross shafts, each 5,000 feet deep, are the main access routes to the underground, and major rehabilitation projects are under way in each shaft. Last week, Sanford Lab crews and Heavy Constructors Inc. of Rapid City, S.D., reached significant milestones in those projects.

In the Ross Shaft, the multi-year project to replace the steel supports in the shaft has begun with preparation of the shaft itself. Infrastructure techs, for example, have removed interior ?lacing? in the shaft down to the 3650 Level. The lacing?either wood (in the photo at right) or corrugated steel?provides a barrier between the skips and the other internal shaft compartments. The old lacing is being hoisted to the surface for disposal. (Skips hoisted rock out of Homestake during mining.)

Infrastructure techs also have made preparations at the 5000 Level for removing muck from the sump at the bottom of the Ross Shaft. A clamshell excavator will be hung underneath the service cage and lowered to the sump, where it will scoop up the gravel and rust that has accumulated there. The muck will be dumped into 3-ton rail cars for transport to underground storage locations.

Next month the Ross Shaft will be shut down (except for emergency egress) for reconstruction. The Yates Shaft will provide primary access to the underground. But first a new ?rope dog? safety system must be installed.  (See the Jan. 17 edition of Deep Thoughts.) On Friday, Heavy Constructors installed the first steel beam of the rope-dog tower (below) which will secure the system?s two 5,200-foot wire ropes that will run the length of the Yates Shaft.