Lift bridge in Placentia has to be durable

Placentia, the historic French capital of Newfoundland, is about to have a new lift bridge to replace the existing Sir Ambrose Shea Lift Bridge that has been a prominent site since 1961.

The small town of approximately 4,000 people is 100 kilometres southwest of St. John’s, on the Avalon peninsular, which was one of the first places in North America to be settled by Europeans. Its history goes back to the early 1700s.

Delcan are the engineers for the new bridge, which has just started construction adjacent to the existing bridge on Route 100. It crosses a narrow water channel referred to locally as the “gut,” and forms an essential link between the communities of Placentia and Jerseyside. It is the only movable bridge in the province.

Joanne McCall, project manager with Delcan, explains that the replacement looks similar to the existing bridge. It is a three-span structure, with a centre movable span (vertical lift span) flanked by two simple fixed girder spans.

“The new bridge is designed to provide a durable, efficient and reliable bridge,” McCall says, “but also to celebrate the local heritage of the community by providing an aesthetically pleasing structure with architecture to reflect the local culture and the tourism potential of the region.”

The new bridge is being constructed adjacent to the existing bridge in order to minimize disruption to the local fishing boats and road traffic.

Because it is in a harsh marine environment, the structure has to be durable and reliable. The elements consist of structural steel closed sections (HSS) in order to avoid flange surfaces susceptible to salt spray, a key downfall of the existing bridge.

All the machinery for the tower-drive lift span is located at the tops of the towers in an enclosed machinery room designed for maximum protection and ease of access for maintenance.

The new bridge will be wider than the original, in order to accommodate two proper traffic lanes and two sidewalks in accordance with TAC standards. There will also be a new control house with improved sight lines and increased functionality for the operators.

The team leaders with Delcan are Joanne McCall (project manager), and Jack Ajrab (structural design lead). Architecture is by Barry Padolsky Architects; utilities coordination is by Meridian; mechanical-electrical is by Stafford Bandlow Engineering; geotechnical is by Fracflow and Golder Associates, and HVAC is by GPY. H.J. O’Connell Construction was awarded the $40.6 million contract to construct the bridge by the Newfoundland and Labrador Department of Transportation and Works. Structal-Bridges, Canam Group are fabricating the steel structures.

To read more about the history of the existing bridge, click here.