Item: REMOTE AVALANCHE CONTROL SYSTEMS (RACS) ALONG THE TRANS-CANADA HIGHWAY - OPERATIONAL IMPROVEMENTS AND CHALLENGES DURING SIX WINTERS OF USE AT THREE VALLEY GAP, REVELSTOKE, CANADA
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Title: REMOTE AVALANCHE CONTROL SYSTEMS (RACS) ALONG THE TRANS-CANADA HIGHWAY - OPERATIONAL IMPROVEMENTS AND CHALLENGES DURING SIX WINTERS OF USE AT THREE VALLEY GAP, REVELSTOKE, CANADA
Proceedings: International Snow Science Workshop Proceedings 2023, Bend, Oregon
Authors:
- Walter Steinkogler [ Wyssen Avalanche Control, Revelstoke, BC, Canada ]
- Alan Jones [ Dynamic Avalanche Consulting Ltd., Revelstoke, BC, Canada ]
- Chad Hemphill [ Ministry of Transportation and Infrastructure, Revelstoke, British Columbia, Canada ]
Date: 2023-10-08
Abstract: Three Valley Gap, located 20 km west of Revelstoke, Canada is one of the highest priority avalanche areas on the Trans-Canada Highway (TCH). During 2007-2016, avalanche related closures averaged 46.5 hours per winter during 12 closure periods (average of 4 hours per closure), many of which exceeded 2 hours. These closures presented a major disruption to commercial traffic and the local economy. Increasing traffic volumes continue to increase avalanche risk in this corridor, and compound traffic flow problems. Starting in 2016 eleven remote avalanche control systems (RACS) had been installed at Three Valley Gap. This system reduces risk to public and commercial vehicles, risk to workers performing avalanche control, and the duration of avalanche related closures. This paper focuses on operational improvements and challenges experienced during the last 6 winters since the RACS were added to the program. Benefits of RACS during the first six winters included a reduction of average time for avalanche control from about 30-60 to 10-30 minutes, and the reduction of the average time per closure from 4 hours during 2007-2016 to 1.8 hours during 2017-2023. This is especially relevant as traffic volume has been steadily increasing on average by 2.9% each year, compounded. Additionally, shifting control missions to nighttime or early morning hours and reducing pre-mission preparation time frees up worker resources that allows avalanche personnel to manage other avalanche areas in the highway corridor. Recently, operations have been further optimized with the construction of a dedicated storage building nearby, where the deployment boxes can be stored over the summer and where maintenance and loading are carried out. Technical improvements and location-specific modification of the deployment boxes included snow roofs to avoid snow accumulation on top of the lid and a customized power-safe mode to address the limited solar gain at tower locations. In terms of evaluating the locations of the system, we review the chosen locations and the general effect of explosive airblasts in heavily forested terrain. The findings highlight operational challenges that are relevant to the planning and optimizing of RACS projects, especially in steep, forested, high frequency avalanche paths.
Object ID: ISSW2023_P3.61.pdf
Language of Article: English
Presenter(s): Walter Steinkogler
Keywords: avalanche control, highway, avalanche risk, explosives, RACS, Three Valley Gap
Page Number(s): 1569 - 1576
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