H.J. O’Connell (HJOC), a division of Bird, has completed the contract to supply and construct shoreline electrodes at L’Anse au Diable in Labrador, and Dowden’s Point in Newfoundland. Each electrode site location will be connected to a converter station at Muskrat Falls and Soldiers Pond respectively, as part of the Muskrat Falls hydroelectric project. The electrode sites are high-capacity grounding systems that are installed at each end of a high voltage direct current (HVdc) transmission system.

HJOC completed the civil and marine portion of the electrode sites on time and on budget. Each electrode system was comprised of 80 perforated HDPE wells (approximately 15 metres long) placed vertically to accept electrode element rods and buried in porous rocks of a breakwater for protection against ice and ocean waves. Major components of the civil scope included rock drilling, blasting and hauling over 150,000 tonnes of rock materials to each electrode location, construction of access roads, 80 electrode wells, buried cable duct banks, pull boxes, trenches and junction boxes.

Each electrode location involved the construction of the breakwater structure, which required approximately 90,000 tonnes of core material, 10,000 tonnes of filter, and 50,000 tonnes of six- to eight-tonne armour stone in the Atlantic Ocean, in water depths up to six metres.