Distribution River Crossing Inspection

In July 2020, BC Hydro’s Distribution Engineering was planning an upgrade project on one of their 25kV distribution lines. This line is a bit unusual as it crosses one of the arms of the Fraser River to Westham Island. There are 4 poles that make up this 300m crossing, which have no road access.

In order to better understand the condition of the poles and equipment, as part of their project planning process BC Hydro wanted to conduct a detailed inspection on the distribution line.

To date, the task has been performed by pole climbing inspectors from a boat. This kind of inspection can be daunting and comes with substantial safety risks, not to mention all the logistics and scheduling challenges presented by the currents and tides.

Aeriosense has worked with BC Hydro on a number of previous inspection projects and this was a perfect opportunity to demonstrate the effectiveness of automated drone inspections on a challenging section of a distribution line.

The inspection site was near C class designated airspace. This meant co-ordination was required with Nav Canada and BC Hydro’s Aeronautical Operations Department to ensure air safety in compliance with Transport Canada’s air regulations.

In preparation for the inspection, we reviewed inspection requirements with BC Hydro, performed a location survey, and performed hazard assessment. We then generated pre-set flight plans, using drone automation software, to be used for data collection.

With a bit of planning ahead the field inspection took under 1 hour. In addition to inspecting the distribution structures themselves, we also inspected the conductors and conducted a survey of the crossing location generating a detailed map.

The deliverable of the detailed inspection of the individual components and the pole structure from the base to the pole top were a quick win for the BC Hydro distribution team in utilizing the drone based inspections. There was also value for multiple departments in generating a detailed site survey, which will be used for project planning, environmental assessment, and remediation.

This inspection saved the considerable cost and effort of using a boat and a multi person crew, along with a complex safety plan. It also avoided the inconvenience to the customers of an outage.

You did very good work at Westham Island

— Zoran Maletic, Electrical Engineer, Distribution Asset Management Planning at BC Hydro