Colrain bridge replacement in the works
COLRAIN — Calling the current Jacksonville Road bridge “structurally deficient” by Federal Highway Administration standards, engineer Stephen Descoteaux and MassDOT Project Manager William F. Brown spelled out details for the state’s plan to replace the 1933-built bridge at a “25 percent design stage” public hearing at Colrain Central School Tuesday night.
The $7.8 million replacement of the bridge, which connects the elementary school to the town center, will have sidewalks, wider shoulders for bicycle travel, and about a 1-foot higher elevation, enabling the bridge to withstand the equivalent of a 50-year flood of the North River’s East Branch.
After meeting with town officials, Brown said plans will also include supports beneath the proposed 300-foot span for future water and sewer pipes, should the town develop those systems. Also, at the Fire Department’s request, a dry-hydrant will be installed, allowing firefighters to pump water from the river during a fire.
According to Brown, the FHA will pay 80 percent of the cost, while the Massachusetts Department of Transportation will pay 20 percent. He said MassDOT wants to work with the town, which is planning to reconfigure the Jacksonville-Greenfield-Main Road T-bone-shaped intersection, just south of the bridge.
Brown said he hopes to start building the bridge during the 2015 construction season. Because there is no reasonable detour for traffic, the work will be done in two phases, with one lane open to traffic on an alternating basis, with the use of traffic signals.
During the first phase, a temporary pedestrian bridge will be put up primarily so that schoolchildren are not walking within the one lane or in the construction area. During the second phase, both cars and pedestrians will be able to travel on the new “half,” where there will be sidewalks. The work is likely to take two construction seasons.
Descoteaux, of Mistry Associates Inc. in Reading, explained that the concrete on the existing, five-span bridge has deteriorated to a point beyond repair, which has reduced weight limits posted for the bridge. Currently, the weight limit ranges from 16 tons for two-axle trucks up to 32 tons for five-axle trucks. When the bridge is completed, the weight limit will be 20 tons for two-axle trucks and 36 tons for the largest trucks.
He said the bridge was originally a three-span bridge, but after the 1938 hurricane, two additional spans were added, extending the span to 227 feet.
When finished, the bridge will have 11-foot-wide traffic lanes with two 5-foot shoulders and at least one 6.5-foot sidewalk on the west side. If possible, a sidewalk may be added to the other side as well.
The new bridge will have four spans, and the components will be precast and prefabricated, as much as possible. The steel components will be made of an oxidized steel, in which rust doesn’t penetrate, once the component’s in place. The bridge will have metal railings.
While working in the riverbed to lay abutments, the water will be diverted. This is another reason for precasting concrete and other components.
During the hearing, which drew about two dozen residents, Deputy Fire Chief Kevin Worden raised concerns about emergency access on the one-lane bridge, and asked that the fire department be informed throughout that process. Highway Superintendent Scott Sullivan asked about the width of the temporary travel lane, to make sure it was wide enough for the town’s snow plows.
Some were concerned that the increased bridge elevation would obscure the sight of stopped school buses or of traffic turning onto River Street, just south of the bridge. The engineers didn’t feel the elevation would change motorists’ views, provided they are traveling at reasonable speeds.
You can reach Diane Broncaccio at: firstname.lastname@example.org or 413-772-0261, ext. 277