ODDS’N’SODS — Tram lines did their job

The tram line was a most effective system for transporting ore, supplies and personnel between the mine and the mill in bygone days. Usually, they were used at inaccessible mine sites or if the cost of building a road was prohibitively high.

The general arrangement was standard. Two heavy-duty “standing” cables were strung between the mine terminal and the mill terminal and suspended from prominent vantage points on towers so that the moving buckets would clear the ground. The wheel assembly, with its suspended bucket, travelled on these standing lines.

A “travelling” cable, much smaller in diameter and more flexible, formed a continuous circuit between the bull-wheel, or drive-wheel, at the mine and the anchor wheel at the mill site.

The buckets and travel wheel assembly were attached by a clamp mechanism to this “running” cable, which passed over guide sheaves at each tower. The buckets were side-dump in design and a specific number of buckets were attached to the line.

Once the complex was in operation, with loaded buckets proceeding down hill, the drive wheel could be used to generate electricity to sustain the system. The braking mechanism was attached to the drive sheave. Tension on the “running” cable was sustained by mounting the anchor sheave at the bottom on a moving track assembly, with removable counterweights added to achieve the desired tension.

The Red Rose mine at Hazelton, B.C., used a small but effective tram line system rising some 3,800 ft. vertically above the mill to the mine (more than 8,000 ft. of installation). Usually, only 5-10 buckets were employed to transport ore and supplies, and on day shift only.

The camp and mine at the upper terminal were totally serviced by this arrangement; crew, food supplies, mine supplies and ore movement depended on utilization of the tram buckets. It was a unique experience to sit in the bucket and travel up or down the mountain making the journey to the mine. At times, there were shortages of water at the mine site, in which case the returning buckets were filled with water at the mill end. Altogether, this was a most useful system.

The Premier mine, north of Stewart, B.C., operated a much more sophisticated setup. The tram line there was some 20 miles long and there were many bends or turns in the suspended cable that transported concentrates between the mine-mill complex and the dock at Hyder, Alaska. This was a heavy-duty tram line capable of handling 300 tons per day and transporting supplies as well. Winds and heavy snowfalls distressed operators throughout the year, yet the system sustained the mine continuously for more than 35 years without serious mishap. Today, some 70 years hence, many of the towers are still standing. During the Second World War, the Emerald mine, east of Salmon, B.C., installed a tram line to transport run-of-mine ore from the mine at an elevation of 4,500 ft. (atop Iron Mountain) to the mill, 2,500 ft. below in the Salmon River Valley.

This, too, was an effective line, even when subjected to violent winds in winter and fierce lightning storms in summer. The line could handle more than 300 tons per day. The weakness, if any, was in the location of the break-over or transition towers from which there was an abrupt drop, to the valley below, of some 1,500 vertical ft. Many buckets were lost in this section and it could be said that the profile was too severe at the mill end. In general, tram lines responded to the maintenance and running concerns as well as to shortfalls in design. They were not labor-intense systems, once installed. In fact, they were possibly the forebearer of today’s ski-slope installations, which are also noted for their reliability.

In review, the main idea was to adjust to proper tensions in the standing and running lines. Once this was accomplished, the system delivered. — S.J. Hunter, a retired mining engineer and regular contributor, resides in Vancouver.