The Big Lift
In 2010, planning began that would see the entire suspended structure of the Macdonald Bridge replaced over the course of several years. With the size and scope of such a monumental task, it was dubbed the Big Lift.
But it wasn’t just the size of the project that made it historical, it was also the engineering. The Big Lift was only the second time in history the suspended spans of a suspension bridge were replaced while keeping the bridge open to traffic. Interestingly enough, the first time this feat was completed was on the Lion’s Gate Bridge — the Macdonald Bridge’s sister bridge in Vancouver — 15 years before the Big Lift.
Over it’s duration, the Big Lift would see the complete replacement of the road deck, floor beams, stiffening trusses and suspender ropes on the suspended spans (2,500 ft of the overall 4,418 ft length) of the Macdonald Bridge. Now complete, much of the bridge infrastructure is new, leaving only the towers, main cables and anchorages on the suspended spans as original.
How It Was Accomplished
Starting near the Dartmouth shore, the bridge deck panels (in either 20- or 10-metre lengths) were replaced overnight.
A lifting gantry was positioned on the suspender ropes, which worked to lower the old bridge deck panels to a barge on the harbour, and then lift the new panel into position, also from a barge in the harbour. existing panel lowered to a barge in the harbour.
Workers replaced one deck panel every three to four working nights.
Crews faced many challenges as the work carried on throughout the year. Weather — particularly wind — was a major concern for lowering and raising panels, but was managed successfully.
On the Halifax side, the bridge deck panels were replaced in 10-mere lengths over land, because they could be brought in by truck rather than on a barge.
This is the second time in history, a project like this has ever been done. Halifax, Nova Scotia is re-decking the Macdonald Bridge to extend its life. This time-lapse chronicles the first deck segment replacement on October 16-19, 2015.