Feasibility Study and Technical Report - Pretivm

Figure 18.7Photo of Typical Slopes in the Salmon River Valley18.7.2 TRANSMISSION LINE DESIGN AND CONSTRUCTIONGiven the preferred route and terrain for the proposed Brucejack Transmission Line,various options were investigated for conductor selection, tower design, and constructionapproach. While the vast majority of transmission lines in BC and elsewhere areconstructed using wood poles, the use of steel towers were considered more suitable tothe terrain and construction requirements for the Project.Engineering and construction constraints for the Project include:• the moderate to steep slopes immediately above the existing road to theGranduc Mine, limiting the suitability of this corridor for a transmission due toimpacts and significant risk of upslope hazards (tree fall, debris slides, etc)• the lack of road access from the Granduc Mine site to the Knipple Glacier,significantly increasing the access costs (on a per-structure basis)• the snow avalanches on many slopes in the area, limiting the technically viableroutes – particularly in the Knipple Glacier area• the movement of the Knipple Glacier, presenting foundation conditions notsuitable for transmission towersPretium Resources Inc. 18-25 1291990200-REP-R0012-02Feasibility Study and Technical Report on the BrucejackProject, Stewart, BC