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FIGURE 1 — Winter-time operations at the Cassiar pit.

tunately, the pit configuration allows very limited
stockpiling of low-grade ore, with the result that
maximum in-pit blending must be utilized.

Because a hot change is practiced on the equipment
at the mine and the operators report on shift at the
mine dry, situated at the mill/plant complex, the on-
going-offcoming shift foremen have only a few minu-
tes to discuss problem areas. To alleviate this as much
as possible, a detailed log is written out by the general
foreman, prior to the afternoon shift reporting. The
general foreman normally also verbally instructs the
ongoing foreman. The offgoing foreman will telephone
the ongoing foreman at the mine dry, detailing the
situation regarding equipment and problems at the
end of his shift.

The pickups supplied to supervisory personnel are
equipped with a two-way radio system, enabling them
_ to maintain contact with all loading equipment, drills,
the crusher, the pit maintenance shop and the mill/
plant complex.

A shift report, recording equipment hours, truck
loads and equipment availability, is filled in by each
mine shift foreman. An equipment availability report
compiled by the maintenance department at the mine
is countersigned by the mine shift foreman. Equip-
ment operators’ time cards, the shift report and the
availability report are scrutinized daily by the mine
clerk to ensure that equipment operating hours and
loads are compatible from the various information
sources. These are then entered into a Hewlett
Packard desk computer. This information is invaluable
for compiling availability and performance statistics
on equipment for future planning and can be quickly
recalled at any time.

Total mine labour force is 160 persons, including
mine production supervision. At the present time, the
waste crews work six days on, followed by two rest
days, the ore crew works five days on, with two rest
days. Supervisors rotate with their own crews of

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approximately 30 persons. The drill and blast foreman
and the crushing plant foreman work dayshift, Monday
to Friday.

High labour turnover necessitates the employment
of two training foremen to ensure that an adequate
supply of trained operators are available for produc-
tion requirements.

Drilling

Drilling was originally carried out using Ingersoll-
Rand Drill Masters, with 5-in. or 614-in. down-the-
hole hammers, on ore and waste benches. The major
waste drilling was carried out using a Bucyrus-Erie
30R rotary drill with 634-in. bits. A Bucyrus-Erie
40R rotary drill, using 9-in. bits, was introduced in
1964. In 1970, the Bucyrus-Erie 80R was retired and
an additional Bucyrus-Erie 40R was introduced. Both
BE 40R drills were diesel-electric powered.

A new 24-kv powerline to the pit was installed in
October, 1974, and the following drills are now used
for primary waste drilling:

1 Gardner-Denver GD80 electirc................. 54-ft single-pass drill
steel, 9-7/8-in hole

1 Bucyrus-Erie 45R electric.................... 324 -ft drill steel,
9-7/8-in. hole

The single-pass GD80 drill is equipped with a GD
SJWG 1750-cfm compressor, derated to 1400 cfm at
55 psi; the BE 45R has an Allis-Chalmers 17-L 1310-
efm compressor at 40 psi. Because both units are
equipped with oversized compressors, no difficulty
has been encountered in clearing drill cuttings in
55-ft-deep holes, even in fractured rock. The drill pipe
used on the GD80 is 8%-in. diameter, single-pass, 54-
ft (16.5-m) long with 51%4-in. A.P.J. thread ,driven
from the drill deck, using hydraulic rotary drive, em-
ploying two wedges which fit into machined slots on
the drill pipe. The BE 45R has standard 8*-in.-dia-
meter pipe, using 6-in. B.E.C.O. thread. A swivel-
mount shock sub is used on the BE 45R to reduce

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