3.2 TRANSMISSION INFRASTRUCTURE Transmission lines transport electricity long distances as efficiently as possible. Introduction to Transmission Infrastructure Canada has migrated from what was once predominantly localized generation, to the current model of large-scale generation at centralized locations, thus requiring transmission infrastructure. The primary elements of the transmission infrastructure include transmission towers, rights-of-way, conductors, insulators, and ground wires.
Transmission Towers Transmission towers carry the conductors or transmission lines and are typically built from steel, wood, or composite materials. •
Tower heights range from 25 to 100 metres depending on the transmission voltage level, and the distance between towers ranges from 250 metres to 500 metres.
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Towers are built to be tall because high voltage requires high clearance from the ground and ample separation from other conductors. Height is also required to safely straddle rivers, roads, bridges, railways, and distribution lines.
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Given their height and their often-remote locations, building and maintaining these towers can be challenging. Many transmission companies utilize crane-size bucket trucks, specialized helicopters, and even drones to accomplish this.
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Where adverse weather prevents flight-based access for maintenance purposes, other devices such as snowmobiles and off-road vehicles are used.
Right-of-Way A right-of-way is a path where transmission towers and lines are placed. It is typically 30 to 100 metres wide, but can be wider to accommodate multiple tower lines, and to allow utility personnel faster access to the lines for inspection, maintenance, and repair. Corridors Rights-of-way corridors require a significant amount of land, and routes must be approved through established government processes. Utilities endeavour to use as direct a route as is feasible, with due regard to environmental and other values and land uses.
Electricity Canada | Electricity Fundamental in Canada: Student Handbook
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