Repair or replace? Province set to weigh options for Seal Island Bridge in Cape Breton

With cracked concrete and corroded metal, the Seal Island Bridge in Cape Breton is starting to show its age. The province is now looking at options to extend its life and plan for its future replacement. 

The Seal Island Bridge, known officially as the Great Bras d'Or Crossing, was completed in 1961. It is now an integral part of the Trans-Canada Highway. It spans the Great Bras d'Or channel and connects Boularderie Island to the west side of Cape Breton Island. It's the route most commonly used to get to Marine Atlantic ferry services to Newfoundland.

Although the bridge has had repairs and maintenance over the years, including deck replacement between 2001 and 2004, recent reports and inspections show the superstructure and concrete piers are deteriorating.

"They didn't have as stringent requirements for the quality of the concrete, for the strength of steel for certain types of analysis. So those are all challenges that we have to deal with on any older infrastructure," said Will Crocker, structures asset management engineer with Nova Scotia Public Works.

"On a bridge of this age, it's common …  to have challenges with the concrete deterioration given the requirements of the day," said Crocker.

It's unclear what it would cost to repair or replace the crossing.

A 2018-19 inspection of the bridge by Harbourside Engineering Consultants gave the various parts of the bridge a rating using the national bridge inventory rating system. It's based on a scale from zero to nine, with zero representing "failure condition" and nine representing "excellent condition."

The superstructure, meaning the metal structure of the bridge, got a rating of three for "serious condition" and the substructure, meaning the cement piers and abutments, got a rating of four for "poor condition."  All of the other parts of the bridge received ratings of six and seven.

Photos from the 2018-19 inspection show corrosion on various parts of the metal superstructure and cracks in concrete abutments and piers.

Despite the issues, Crocker said the bridge is safe.

"I wouldn't hesitate to travel across the bridge," said Crocker.

"As long as those requirements or defects are identified in a timely manner, which they have been and are repaired in a timely manner, which is what we're planning to do for this upcoming season, then there will be no problems."

A recent Freedom of Information Request to Public Works revealed several inspections and reports done on the Seal Island Bridge from the past several years. Boularderie Island resident Parker Donham made the FOI request.

Donham worked as a communications advisor for Public Works during the re-decking project. He said at the time the re-decking was seen as a way to extend the life of the bridge. With that being completed nearly twenty years ago, Donham said he started to wonder what was next for the bridge.

"I live on Boularderie, I use that bridge all the time, my neighbours use it all the time, and I wanted to know, first of all, when we can expect something to happen and when we do, what provisions will be made for people crossing the bridge?"

Donham also wanted to know if a replacement would mean a change in the bridge's placement. According to Dr. Ron Stewart, the bridge's location was controversial, even when it was being built because it spelled the end for several ferry crossings. Stewart is with the Boularderie Island Historical Society and a former provincial health minister. He remembers when the bridge was built.

"There were mixed emotions at the time because we had two or three ferries at one time going across the Great Bras d'Or channel and that was a big deal then," said Stewart.

"There were small communities built around the ferry service in a sense. So, you know, we weren't all that enthusiastic about it because we didn't really see the bigger picture that this was part of the Trans-Canada Highway to Newfoundland."

According to an email from Public Works, there are no plans to change the placement of the bridge.

Public Works is currently awaiting a cost-benefit analysis from engineering firm COWI, the company that designed and planned replacement of the decking on the Angus L. MacDonald Bridge in Halifax, otherwise known as "The Big Lift." The firm did its own inspection and added electronic monitors on the bridge's structure.

COWI's report is expected to offer recommendations on extending the life of the bridge and replacing it. 

According to Don Maillet, executive director of highway design and construction with Public Works, replacing the crossing is definitely in the cards.

"At some point in the future, the bridge will have to be replaced," he said.

"How that's going to be done and how much remedial work will be required is all part of the cost-benefit analysis."

The report from COWI is expected in the coming weeks. In the meantime, Maillet said some work on the bridge is expected this construction season.