Poles Collapse Driven by Unique Combination of Factors
Utilities Kingston is releasing the report provided by industry experts UTS Consultants regarding the hydro poles collapse on John Counter Boulevard June 17. The report identifies at least seven separate factors that created a unique circumstance and contributed to the event.
“This was an isolated incident, driven by a number of unrelated factors. We are very confident in our ongoing investments to ensure the safety and reliability of the local electricity distribution system,” says Jim Keech, president and CEO of Utilities Kingston.
Data collection and calculations by UTS indicate the following factors contributed:
- An electric service wire to a commercial customer was hit two days prior to the pole-line collapse, likely inducing tension pull on the poles.
- Machinery from construction activity in the vicinity may have come in contact with poles.
- The base of Pole #3284 was exposed due to excavation.
- The anchor to Pole #3226, at the west end of the pole line, pulled from the ground.
- Pole #3280 was set to an insufficient depth when originally installed.
- A third-party communications cable added to the pole line contributed stress and load.
- Deterioration of poles due to age and insects.
The affected pole line had been identified for replacement during regular pole inspection. Utilities Kingston had built a new pole line and, at the time of the collapse, removal of the affected pole line was nearly complete. The end-of-life pole line was scheduled to be transferred to the new poles on the north side of the road the Monday following the collapse.
“Our community can continue to have confidence in the safety of the electricity distribution system. Utilities Kingston adheres to industry standards and regulations, and we exercise due diligence in managing the system,” says Keech.
In accordance with industry code, Utilities Kingston inspects poles and related equipment through an annual preventative maintenance program and prioritizes them for replacement.
As part of its preventative maintenance program, Utilities Kingston had begun investigating new pole-testing technology to help assess the internal strength of the poles before the event. The assessment of this new technology continues.
By the end of 2016, more than 1,000 poles will have been replaced (since 2011) representing 15 per cent of the total. More than $11 million will have been invested to renew overhead infrastructure, including poles, transformers, wires and other components. With plans approved by the Ontario Energy Board for 2017-2020, there will be an additional $5.6 million invested to renew overhead infrastructure, including the replacement of approximately 550 poles.
Luckily, while the pole collapse disrupted traffic and caused widespread power outages, no one was injured.
“Public and worker safety is our number one concern. Knowing what to do in case of downed power lines can save your life. We are so thankful that bystanders and vehicle occupants did exactly the right thing by keeping clear or staying in their vehicles until Utilities Kingston staff told them it was safe,” says Keech.
Watch for an upcoming powerline safety campaign from Utilities Kingston.