You’ve heard of Christmas tree farms, but is there such a thing as a hydro pole tree farm? It’s a question we hear often, from both kids and adults alike – so we asked our experts.
The use of wooden utility poles dates back to the mid-19th century, when they were first erected by inventor Samuel Morse to hold up telegraph systems wiring, after burying the lines proved unsuccessful. Morse was successfully able to transmit a message across 40 miles, from the U.S. Capitol in Washington D.C to Baltimore, and within a few years, utility poles began popping up all over the continental United States and around the world.
Over the next several decades, utility poles became more prevalent and, ultimately, an integral part of distributing telephone signals and electricity across the country. But just where do these poles come from? How does a tree go from a forest to supporting vital service lines to our neighbourhoods? And, what about those taller poles that are not made of wood?
To answer these questions, we spoke to some of our engineering experts. At Hydro Ottawa, we opt for wooden poles made from Canadian-grown Western Red Cedar or Red Pine trees, although other types of trees that grow in North America can also be used (including Douglas Fir or Southern Yellow Pine – but these are typically found south of the border). As it turns out, not all trees are suitable to be made into utility poles. To be selected, trees have to reach a certain height and diameter, and grow in a relatively straight manner. In fact, it’s thought that only about 7% of trees meet the proper criteria!
Once the trees are chosen, they go through a process that transforms them into the hydro poles you see around the city today: they’re air or kiln-dried and pressure-treated so that they can withstand the elements – like our harsh winters – before being delivered to their future locations. Once we install them, wooden poles have a lifespan of up to 40 years, but they can be prone to damage from things like lightning strikes, termites, and woodpeckers (you can read more about woodpeckers and hydro poles in an earlier blog post). Because of this, we regularly inspect our poles in 10-year intervals in an attempt to identify damage and make repairs before outages occur.
After years of dealing with damage to wooden poles, and in response to the need for taller, more sustainable solutions, composite poles were introduced. Composite poles are made of specially-woven fibreglass, resins, and UV protection, making them less likely to corrode or be damaged over time. They are lighter, more durable and have a significantly longer lifespan than their wooden counterparts – twice as long to be exact! Although not always as easy to install, composite poles come with many additional benefits; they are fabricated in sections and can be assembled during installation, meaning they can be easier to transport, more suitable in uneven or rugged terrain, and can be made to reach higher heights than most wooden poles. Due to their longer lifespan of up to 80 years, they don’t need to be replaced as often – although we still perform regular inspections on them, just to be on the safe side.
If you keep an eye out around town, you can spot composite poles used in some areas, like along the Innes Road bypass or Hawthorne Road, where an entire line of 26 wooden poles were replaced with composite poles in 2017 using 13 double-bucket trucks, three radial boom derrick trucks, two 90-tonne cranes, and a stone-slinger truck – it was a big job!
Hydro poles, whether they’re made of wood or composite materials, are an integral part of transmitting and distributing electricity to hospitals, schools, homes and businesses across our service territory. And even though there’s no such thing as a dedicated farm of future hydro poles, there is a lot of thought and care that goes into selecting, preparing, installing, and maintaining them each and every day.