High velocity challenges: McKeil’s project team was contracted to assist in the demolition and partial removal of three in-water piers that supported a bridge from Cornwall to Cornwall Island at a time when the St. Lawrence River was experiencing unprecedented water currents. The job was completed safely and on budget.
Customer: Bronte Construction
Location: Cornwall, ON
Date: May to September 2019
The Challenge: With record high water volumes in the Great Lakes, the velocity of the current at the jobsite exceeded anticipated levels, reaching eight knots in places. This forced a re-evaluation of methodology and the ultimate execution plan differed significantly from the original concept.
Our Solution: McKeil positioned the MM142 barge alongside the abandoned high-level bridge abutments, which were to be cut up into 40-tonne blocks. These blocks would be cast onto the deck of a smaller barge and transported to the Port of Cornwall.
The original tug chosen for the work had a light draft and previous experience at this site in 2010. However, once the river flow increased beyond the maximum safe navigation flow rate, McKeil replaced this tug with the higher-powered Jarrett M. This increased the job’s complexity as the Jarrett’s draft restricted where she could travel on the site.
The concept for the mooring system was also changed, from three spuds to be used as the primary means and mooring wires to be used for redundancy, to the opposite: mooring wires became the primary means and spuds were used for redundancy.
The project team’s adaptability and experience ensured the piers were removed and transported safely.
Services: Project Cargo