Shipping dock replacement project is completed in sub-arctic conditions.
Located in a demanding sub-arctic environment where the water temperature barely rise above freezing, tides change in excess of 15 feet and storms pound the wharf, the old wooden pier used on a daily basis needed to be replaced. As part of a $25-million contract, Pierre Gagne Construc-tion of Thunder Bay, Ontario, had the difficult task of installing steel piles for a new dock. Construction of the new dock required rock sockets to be drilled to install 24-inch steel H beams cast in place to support a sheet piling wall. The entire project called for 140 piles to be drilled along the existing wooden dock that will be demolished when the new one is completed.
For all the drilling, Pierre Gagne Construction utilized a Foremost DR40 drill rig outfitted with a Numa Champion RC300 reverse circulation hammer and 34-inch reverse circulation bits. Keeping tight control over any environmental impact on the Hudson Bay was of great concern on this project. With the large number of polar bears, beluga whales and other marine life, there could not be any drilling fluids or cuttings deposited back into the bay. Utilizing reverse circulation products offered the ability for all drilling by-products to be collected at the point of drilling and exhausted up through the hammer and drill string to be safely collected in a cement truck at the surface.