Longtime engineer looks to solve Canso Canal conundrum

Glen Fry knows the Canso Canal inside out.

The engineer spent 30 years working on the structure before he retired in 2006.

It's perhaps no surprise, then, that Fry, 70, has been called on to help solve a mystery: why the canal's walls have moved.

Fry said the problem with the walls was discovered during "cyclical restoration" of the north canal gates, scheduled to take place every five years.

"We were placing our cofferdams last winter and noticed a 50- to 75-millimetre variance at different points from the top to the water level," he said.

A cofferdam is a watertight enclosure pumped dry to permit construction work below the waterline.

While working on the south gates, workers found a similar change in the wall. Fry said the movement would have happened within the last 10 years. 

Even though the movement is small and does not affect the canal's operations, Fry said they want to find out what's wrong and correct it.

The federal government has issued a tender to discover the cause. The work will also help determine the condition of the walls, as well as prioritize and schedule future long-term restoration as required.

"It could be corrosion in the steel structures that are behind the wall," he said. "Perhaps it's every bit as big as it's going to be. We really don't know and we don't want to hypothesize."

Fry's enthusiasm and knowledge of the canal is hard to hide.

"The ability to be able to go down into the bottom and look at the structures, very unique structures," he said. "In fact, the Canso Canal was built as a predecessor to the St. Lawrence Seaway."

The canal's dimensions are based on the Welland Canal in Ontario.

"The Canso Canal represents the smallest lock of the Welland structures," he said, "so any ship that can go through the Canso Canal can go all the way through the Seaway to Thunder Bay."

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Fry said any work has to be planned well ahead "because everything that's in the canal is custom-made, it's unique." In fact, the mechanical motors that operate the gates are original from the 1950s.

Fry won't predict how long it will take to fix the walls, saying workers must uncover the cause of the problem first.