Storrow Tunnel may need replacing
Structure wasn't waterproofed
State officials, who had planned to quickly and inexpensively fix the crumbling Storrow Drive Tunnel, have learned that it was not waterproofed when it was built in 1951 and may need to be replaced, a much costlier and more disruptive project.
Cranston R. Rogers, who was a structural engineer for the Massachusetts Department of Public Works in the 1950s, told officials at the state Department of Conservation and Recreation that the lack of waterproofing has led to such extensive structural damage that it would be impractical to repair the tunnel.
The news potentially spoils state plans to save money on the Storrow Tunnel project as officials confront other costly restorations, including a $200 million reconstruction of the Longfellow Bridge and rebuilding of the BU Bridge.
The Department of Conservation and Recreation just a month ago had eliminated all but three of the options for the tunnel and said it preferred the least expensive one, repairing it at a cost of $52 million over 2 1/2 years. It is now having to give serious consideration to costlier and more time- consuming options, including filling in the tunnel and constructing a surface road, at a cost of $80 million over 3 1/2 years, and building a bigger tunnel at a cost of $130 million over 4 1/2 years. The agency is also considering options that include elements of both plans.
"As it was built, it would make it impossible to rehabilitate," Rogers said yesterday. "It would have to either be rebuilt or demolished."
Department officials, who met with Rogers Friday, said yesterday that they had not been told about the lack of waterproofing by Simpson Gumpertz & Heger Inc, the private firm they hired to develop options for the tunnel. They said they have asked the Waltham-based firm to investigate.
"That's certainly an important piece of information that we've asked our engineers to review," said Jim Baecker, the department's project manager for the Storrow Tunnel. "If [Rogers] is correct, it might be very unwise to consider that particular option," to repair the tunnel.
Rogers, 82, a prolific structural engineer who designed the Harvard Square underpass in the 1970s, did not design the Storrow Tunnel. But he said he studied its design and consulted with its engineers in the mid 1950s when he designed the Dewey Square Tunnel to carry Interstate 93 traffic under downtown Boston.
At the time, he said, "there were all sorts of beliefs and theories," that suggested concrete tunnels could withstand water.
But he said he was convinced otherwise and designed the Dewey Square tunnel to include walls protected by layers of a gooey, tarlike substance that repels water.
Rogers said he had recently made a mental note to study the Storrow Tunnel plans but didn't look at them in detail until this summer, when they "fell in my lap" at a meeting of regional planning officials.
Rogers aired his concerns at a community meeting Wednesday.
"As a generality, it could create unsafe conditions and demand attention and funding, if it continues to be left open for traffic," he said. "So the safety of the tunnel should be of prime concern to the Department of Conservation and Recreation. I'm not alleging that there's any fault here, I'm just staying they're playing with matches -- they could cause a problem."
Baecker said the tunnel is inspected monthly and is safe. Over the last several months, he said, workers have repaired a beam on the entrance near Clarendon Street that had been hit by trucks, another that developed a stress fracture, and patches of ceiling where steel reinforcements had become exposed.
Every day, 103,000 cars use the tunnel, which carries traffic in one direction, eastbound along the Esplanade, while westbound traffic travels on the surface on the roof of the tunnel. Over the years, the tunnel has been plagued by leaks, deteriorating concrete and corroding beams.
Members of neighborhood groups who heard Rogers speak Wednesday said they were stunned. Some of the groups -- including the Back Bay Association, which represents 300 neighborhood businesses -- had been pushing to repair the tunnel and avoid a more costly and disruptive construction project.
"A lot of time and effort has gone into considering the options presented by Department of Conservation and Recreation, and it's surprising that one of those options is not feasible," said Meg Mainzer-Cohen, president of the association. 