Spacer dampers separate bundled conductors and control vibrations caused by wind and ice buildup. Hydro-Québec designed its own heavy-duty spacer damper.

Most high-voltage conductors used by Hydro-Québec are made of aluminum with a steel core that gives the cable its required strength. Curiously, these conductors are bare: the air around them provides insulation. Each conductor is stranded, meaning it consists of several wires twisted together. This makes a conductor more flexible and more exposed to air, a feature that helps cool the conductor and therefore increase its conductivity. Electricity meets resistance when passing through hot metal, a phenomenon that transforms part of the electrical energy into thermal energy, a type of energy loss.

Alternating current, which is generated by power stations and transmitted on high-voltage cables, is made up of three parts, or phases. Each phase is transmitted on one to four wires, or conductors, depending on the voltage level. Phases with more than one conductor are called conductor bundles. Three-phase currents ensure greater power transmission stability with fewer energy losses.

Wires strung between two transmission towers seem to sag towards the ground. If they were straight, the towers would probably collapse! The lines curve downward so that less force is needed to hold them in place. Otherwise, towers would have to be built even stronger... and they would cost more. For example, holding a big dictionary with your hands is easy because all the force is concentrated vertically. However, when two people try lifting that dictionary using a rope, it’s another matter: as the object is raised higher, more horizontal force is required and we risk pulling the other person towards us.