ee . eRe eS ERO peepee 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 — Og Saat ie eae Sat GR POLS OE me | agp ins : e St tae Be eh eS ak! oe . : ie se d eS » eae z ee SN Gey = See Soe nF se ee ae ae eg * — 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 — 94> =