The Missisquoi Bay Bridge in northern Vermont has for a number of years been held together “by tape and wire,” according to the manager in charge of the construction of a new bridge replacing the old one.
“The bridge is in terrible shape, horrible shape,” commented Dan Landry, project manager of the Vermont Department of Transportation (VTrans).
The bridge spans the 4,300-ft. (1,304 m) opening of Missisquoi Bay at a critical location in the northeastern corner of Lake Champlain. It links the Vermont mainland with the islands dotting the lake and New York state farther to the west. As much as 14 percent of the state’s truck traffic crosses the bridge.
Lake Champlain covers 490 sq. mi. (1,274 sq km) and stretches along the border of New York state and Vermont and north into Canada. It is no wider than 12 mi. (19.2 km) at any point so it can be crossed at numerous places, whether by bridge or ferry. Alburg is a peninsula that stretches down from Canada into the United States with lake on both sides.
The Missisquoi Bay Bridge crosses the lake on Alburg’s east side.
Construction on the new $40-million span, according to Landry, should be completed by the summer of 2007.
The old bridge, a seven-span bascule drawbridge, has stood there since 1938, creating an important commercial connection between New York State, Vermont and Quebec. But over the years, the bridge has simply worn out and in 1993, the drawbridge was welded shut and its counterweight removed. Since then, no boats more than 14 ft. (4.2 m) tall have been able to travel underneath it. The only other alternative at the time was to put the bridge through costly repairs, something that was not fiscally prudent at the time.
The United States Coast Guard opposed the idea of closing the passageway to larger boats and threatened to impose fines of $1,100 a day until changes were made. Representatives from both parties worked out an agreement stating that as long as progress was made toward solving the problem, the fines would be waived.
The new bridge will be adjacent to the old one so the route of the highway will be moved only 60 ft. (18.2 m). However, some significant differences will be built into the new span. For one, the new bridge will be much higher. Because it is a fixed span bridge, it will have a much larger arc, rising 35 ft. (10.6 m) above the water, or twice the height of the original.
Second, the proportions between the bridge and the causeways on each end will change. Originally, the steel and concrete bridge was only 580 ft. (176 m) long with the causeways completing the rest of the span. The new bridge will measure 3,600 ft. (1,092 m) and will be attached to two causeways of 300 ft. (91 m) each. From end to end, including the access to the bridge, the project will measure 7,600 ft. (2,305 m).
Finally, to address safety concerns, the new crossing will be much wider. Since Landry started working on the project, four people have died in accidents on the bridge. The most severe may have occurred while a survey crew worked on the bridge. When a truck inexplicably approached too fast, it careened off the causeway and into the water. The driver drowned.
The old bridge has two 10-ft. (3 m) lanes with one shoulder measuring just one-half ft. (.15 m) wide. Lanes on the new bridge will be 12 ft. (3.6 m) wide each with two 10-ft. (3 m) shoulders, so there will be plenty of room for breakdowns to move out of the flow of traffic.
Not all of the old bridge will be dismantled. A short length of the original causeway will remain in place because turtles have been discovered to use it for basking and hibernating. VTrans had to obtain a Threatened and Endangered Species Taking Permit to deal with the population of Eastern spiny soft-shelled turtles. The turtles are threatened in Vermont so they need to be monitored closely.
Researchers from the Vermont Agency of Natural Resources determined that the animals would not be harmed if construction did not continue after Oct. 30 each year of the project. It is just one of the obstacles that VTrans has had to step over.
Despite this, Landry said that the permitting process has gone rather briskly. Work has been progressing for the past five years.
“We did it pretty fast. The project was really pushed very hard. Usually these things work in geologic time,” Landry stated.
It is not certain whether the bridge will be made of concrete or steel girders. That is one of the things that will be determined by the contractor.
“This is one of the more technical projects done by the state,” Landry commented. Work will probably be complicated by the fact that contractors will work with 10-ft. (3 m) diameter drill shafts. Landry explained that most bridges in the state use 2- to 3-ft. (.6 to .9 m) shafts, so VTrans does not have much experience dealing with that. It is also something that makes the project more costly.
Most bridges in Vermont are much shorter than this one, usually no longer than 200 ft. (60.6 m) long. The only exception to that is the new one recently built that crosses from the other side of Alburg west to Rouses Point, NY.