Thursday, August 18, 2016

The Bridge on the River Assabet

Preparing the bridge for removal, August 11, 2016. Notice
orange lifesaver ring in this and last photo. OSHA
regulations require this when working near water, even though
in this instance the river is less than one foot deep.
Click on any photo to enlarge.
Spoiler alert: The climax of the 1957 movie "The Bridge on the River Kwai" occurs when the British officer in charge of the prisoners who built the bridge for the Japanese Army, deeply conflicted, also mortally wounded, falls on the detonator wired to the explosives that destroy the bridge. What happened in Maynard August 11th was not nearly so dire - no World War II, no explosives - but a bridge did end its life. A large crane brought in by D'Allessandro Corporation lifted the bridge from its stone foundation and gently lowered it onto a truck. Once the cables were in place the entire operation took less than ten minutes.

The wooden bridge, forty feet long, six feet wide, had been installed in 1989 as part of the creation of John J. Tobin Riverfront Park. The site was where the railroad bridge had been removed in 1980. Many residents of Maynard remember walking that bridge over the river - no railings and a twenty foot drop.

Cables in place to lift bridge.
Tobin was a long-time resident of Maynard. He was a Board of Public Works member for over 30 years, and also active at times on the town's Finance Committee, School Building Committee and the Board of Appeals. He was so active in town that people referred to him as "Mr. Maynard."

His death in 1986 was a catalyst for the town's government to choose some means of remembering his contributions. Tobin Park encompasses greenspace on either side of the bridge site. This is one of the few places in town where it is possible to walk right down to the riverbank. Barefoot wading is not recommended, however, as while literally hundreds of pounds of broken glass, pottery shards and rusted metal have been removed, much remains.

Up, up and away! If you weren't there at 8:45 AM, you missed it.
The bridge removal and replacement process had originally been scheduled to begin in October and finish by March 2017. D'Allessandro Corporation, the construction company with the contract for the entire project, decided to accelerate the process in order to take advantage of summer's low water level in the Assabet River. The intent now is to have the replacement bridge in place by January. In the interim, people have to detour fifty yards south to Main Street, cross the river on the Main Street Bridge, then return fifty yards north to the original route. No big deal.

The current view from Main Street bridge includes what looks like very large white bags. These create a cofferdam, which provides for a dry workspace in an area that would otherwise be under water. Each bag holds approximately one ton of sand or gravel, and is lowered into place by a crane. Once the new abutments are in place, a prefabricated new bridge, 62 long and 16 feet wide, will be installed and the cofferdam removed. Why so wide? The intent is to provide for six foot lanes in both directions (standard for new rail trail construction), plus allow two more feet to the railings, space for people to pause to look at the river.

Bridge loaded onto D'Allessandro truck.
The bridge is not the only part of the construction project being accelerated. Through August and September the remaining stumps will be cleared and railroad ties removed, followed by trucking in hundreds upon hundreds  of tons of stone to create a base for the asphalt. The center of town will see more curb, sidewalk and path construction. Parking lots will be reconfigured and telephone poles moved. The intention is to complete as much as possible before winter puts a halt to construction.

Cofferdams on both sides of the Assabet River are in place
to keep the base of the walls dry while work is going on.
Work has also been sped up in Acton. Under the original plan all paving, end to end, was to be completed by late 2017, with fence, bench and extensive landscaping (new trees!) scheduled for early 2018.  Although no formal change has been announced for completion date, this could all be done in 2017.

A revised Construction Schedule was shared after this column was submitted to the newspaper. Although much is sped up, completion of the Maynard footbridge is still shown as occurring in spring 2017. We will see. 

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