A Bridge Too Far
The 1929 Lake Champlain Bridge Must Be Demolished.
By Elizabeth McNamara | Online Only | Dec. 21, 2009
Last month, it took Carole St. Pierre more than two hours to commute from her home in Crown Point, N.Y. to her office in Vergennes, Vt. As the crow flies, the two towns are about 30 miles apart, and for 25 years St. Pierre's commute by way of the Lake Champlain Bridge took fewer than 30 minutes.
But on Oct. 16, following inspection tests, including a core-boring assessment that ruled the piers of the steel-and-concrete bridge unstable, New York State's Department of Transportation (NYSDOT) and the Vermont Agency of Transportation closed the 80-year-old structure that more than 3,500 cars cross daily. As a result, commuters such as St. Pierre are forced to take a 100-mile detour.
"I've lived here my entire life … and [the bridge] was something we always took for granted," St. Pierre says. "Especially because it only took two minutes to cross."
Now, to get to the office by 7 a.m., St. Pierre must travel about 90 minutes to catch the first Essex Ferry, which departs at 5:30. "It's sort of a bastardized version of Planes, Trains and Automobiles," she says. "Except there's no polka band."
HNTB, the New York-based structural engineering firm that performed the underwater inspection of the Lake Champlain Bridge, found cracks in the piers larger than three-eighths of an inch. The firm said the piers were constructed with unreinforced concrete, and the cost to temporarily rehabilitate them would exceed $20 million. HNTB, whose design agreement with NYSDOT can be extended to include the preliminary and final designs of a new bridge, suggested the bridge's immediate demolition to eliminate the risk of a "sudden, potentially catastrophic, bridge failure." After hearing the news, Governors David Paterson and Jim Douglas of New York and Vermont, respectively, declared a state of emergency and established free ferry service between the states.
Built to Last?
The 2,186-foot-long bridge was designed by New England engineering firm Fay, Spofford and Thondike, and is distinguished by its elegant channel approaches and crossing. It was the third case in which continuous-truss technology was adapted to a highway bridge, and Vermont preservationists such as Ann Cousins say it's still significant. "The bridge is Vermont's most important bridge of any type," says Cousins, special gifts officer at the Preservation Trust of Vermont. "It's the poster child."
Bob McCullough, a professor at the University of Vermont's graduate program in historic preservation, says the HNTB's claim that the piers are unreinforced is incomplete and is therefore inaccurate.
"When Fay, Spofford and Thorndike prepared and submitted their plans for the bridge, they left the pier design unfinished," says McCullough, who submitted the bridge's 43-page National Historic Landmark nomination one day prior to the bridge's closure. The reason for that, he says, was to allow a subcontractor to help design the substructure. Once selected, the subcontractor and engineer jointly developed final plans for the piers. They used the open coffer-dam method, which includes steel cages that ultimately reinforce the concrete (as reported in Foundations of Bridges and Buildings, by Henry Jacoby and Roland Davis).
"To say that the piers are unreinforced concrete is ridiculous," McCullough says. "It wouldn't be around after 80 years; it would have failed along time ago."
NYSDOT stands by the engineering firm's assessment. "There's a lot of [rumors] going around," says Geoff Wood, the NYSDOT design supervisor for the project. "And it's easier to listen to what your neighbor says than to look up the information yourself."
Wood says that if the bridge could be rehabilitated, the biggest concern would be for the safety of the workers. The piers are so unstable, he says, that it is even unfeasible to use them to support a new bridge. The existing underwater foundations are too large to remove, and the design of new bridge will have to work around the old foundations.
"Everyone in DOT recognizes and appreciates its significance as a landmark," Wood says. "But this 80-year-old bridge was designed to last for 50, maybe 75 years. I'd say we've gotten our money's worth. Bridges are not meant to last forever."
The New Bridge
Cousins, who also sits on the local public advisory committee, acknowledges that there is no way to save the Lake Champlain Bridge. Her group, along with the National Trust for Historic Preservation's Northeast Office, is now working with the engineering firm, HNTB, to try to come up with a design that is reminiscent of the old bridge, with a segmented arch.
"[The bridge has] a really incredible design and is incredibly beloved. But as much as we really hate to see it demolished, we're trying to advocate that the design of the new bridge is in some way above and beyond your standard concrete [structure]," says Roberta Lane, senior program officer at the National Trust's Boston-based Northeast Office. "But they need to do something quick, because it's a pretty dramatic story for local people in the communities on either side of the bridge."
NYSDOT held three meetings on Dec. 12 to present concepts and options to the public. "The meetings [were] not just to get input about the type of bridge that will replace it, but also think of ways to commemorate the existing bridge," Wood says.
Until the new bridge is completed, locals such as Carole St. Pierre will have to endure their grueling commute.
"I used to work 10- or 12-hour days, but I can no longer do that," St. Pierre says. "By Thursday I am completely whipped."
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