a round up of work in progress at the port
Viau and Maisonneuve sectors
The first phase of redevelopment projects in the Viau and Maisonneuve sectors is complete. Together, these two sites can now accommodate 200,000 more containers for a total of 1.7 million TEUs (20-foot equivalent units). Transport Canada participated in this project with a $15.1 million contribution. The total cost of the work is estimated at close to $40 million.
Berth improvements in Sections 101 and 102
The Port of Montreal is retrofitting certain sectors in the east part of the Port. We are increasing berth depth at Sections 101, 102, 105 and 106. We are also extending the length of the berth at Section 102 so that it can accommodate larger vessels.
At Section 102, to restore the berth we solidified the retention structure and redid the concrete both above and below the water. Divers were needed for this phase. Since it took place last winter, the divers wore heavy heated diving suits to dive into the icy water, and spent no more than 45 minutes underwater, not a second longer.
To accommodate larger vessels, the length of the berth had to be extended by 40 metres. To do so, we opted for two dolphins. A dolphin is a group of piles not connected to the shore, but drilled or driven into the riverbed and bound above the water level into a single structure with wire, concrete capping or a steel frame, depending on how the dolphin will be used, e.g., mooring, docking or as a fender.
Dolphins were traditionally made of wood, but especially those intended as mooring posts for large merchant ships are now made of steel and concrete.
During the construction period, the Port of Montreal monitored the noise levels from the construction site. However, since we had chosen to drill the piles into place instead of driving them down, there was no disturbing noise either for local residents or for aquatic life.
The yellow barge is used by the divers. The blue barge is used to excavate the riverbed floor.
December 9, 2013. Work continues, snow or shine.
Braces are installed to make the dock more structurally sound. They consist of metal rods attached to concrete blocks that go from the ground to the end of the dock and pull it toward land. These braces counterbalance the weight of the moored vessels, which pull the dock towards the water.
Divers’ vision is reduced along the docks. New 3D imaging technology is a great help to inspect underwater structures. It provides an extremely accurate picture of the submerged portion of the dock. For example, here we can see that the third pillar from the right is damaged and needs repair. This technology is constantly evolving at the Port of Montreal, and the Port is a leader in this area.
Here we see a major repair of a gravity wall, which is the retaining wall on the side of the dock.
We begin installing the mooring dolphins. First we sink the piles to the riverbed, using a drilling technique instead of the alternative technique that drives in the piles with a heavy weight, like a hammer and nail. We opted for the quieter technique.
A diver welds the metal frame that will guide the piles forming the future dolphin down to the riverbed, properly positioning them to be drilled in place.
All set! The three piles for one of the two mooring dolphins are in place! They are made of steel and are about 25 metres long; 7.5 metres are driven into the rock below the riverbed and 5 metres are above water. A crane was used to manipulate these piles into place. Now they’re ready to support the concrete block on which a ship mooring system will rest.
The concrete block is constructed by building a metal frame…
…then covering it with formwork…
… into which the concrete is poured. Once the concrete is hardened, we release it from the formwork. And that’s how it’s done!
David Dionne, the Port of Montreal engineer in charge of this project, who explained to us how the high-tech bollards behind him work: The traditional bollard is a short, stocky pillar installed on a wharf that the mooring rope is tied around. The modern bollard has claws that hold the rope in place. When casting off, the claws relax and automatically release the cable.
There are many different models of dolphins: