It's been eight years since the Annisquam River rail bridge was named the most dangerous within the MBTA system, six years since officials ordered trains to slow to 10 mph while crossing it, and 16 months since the MBTA's fiscal Management Control Board agreed to pay for the work that was recognized as "urgent."

Monday, after months of low-profile work along the tracks, visible signs of the bridge replacement finally zoomed into focus. The project's general contractor began moving heavy equipment into the work zone off Riverside Avenue and launched construction on a giant crane that will be a key part of the project.

The crane construction and other aspects of prep work for replacing the 107-year-old rail bridge drawbridge is being carried out by J.F. White Contracting Co., based in Framingham-based. J.F. White won the bid for the projected $57 million base project in October 2017, when the Massachusetts Bay Transportation Authority's control board approved allocating the money for the work. J.F. White has been leasing a field office since last April in Blackburn Industrial Park in preparation for the project.

The MBTA plans to build two, side-by-side bascule movable bridges — one for each of the two tracks to cross the span — as well as a new control tower and equipment to integrate the new structures with the existing signal system.

The project is expected to be nearly four years in the works, J.F. White project superintendent Jimmy Jones said Monday. It entails securing property easements along the river and other peripheral steps, MBTA officials have said. The total cost is expected to approach $80 million, MBTA officials have indicated.

The presence of the giant crane under construction and other heavy equipment on the chief work site above the river's edge and at the edge of the tracks off the extension of Riverside shouldn't have residents expecting a new bridge soon, Jones said Monday. But, construction "in earnest" is set to begin this spring, he said.

He said removal of the current bridge is "still well into the future." He said the work to date has included grading a small hill to create "a pad" of flat ground to anchor the crane during the main work. 

"Right now, we're still in the phase of setting up to do the work," Jones said. "We're mobilizing for the construction work, as we put it." 

Lisa Battiston, spokesperson for the MBTA, said the preliminary construction activity being conducted prior to demolition work will include strengthening and stabilizing the current bridge to facilitate the contract work as well as the building of temporary facilities.

"This preliminary construction activity will be accomplished during this winter season prior to any demolition work," Battiston indicated. "The work this winter will include the installation of bracing systems and work platforms over the water as well as bringing necessary materials to the site via local roadways."

The side-by-side construction of the twin bridges and tracks means that J.F. White will be able to carry out the work one side at a time. That will, in turn, will allow the MBTA to maintain service using one of the tracks at all times during the construction period.

The work will require 10 service shutdowns over the nearly four-year construction, according to a prior MBTA announcement. Those are likely to come in March and April of 2020 and 2021, toward the final stages of the construction time frame.
 The existing bridge, supported by wooden trestles, was built in 1911, then significantly renovated in 1932. Design plans carried out by Boston-based Fay, Spofford & Thorndike for the new bridge show a streamlined-looking, concrete-based bridge. The current bridge was identified as being in the worst condition of all MBTA bridges in an agency safety study carried out in 2010.

J.F. White Contracting was one of five bidders on the project, which was not even put out to bid in August 2017 — three months before an initial MBTA time line indicated the work was to begin. J.F. White has been among the lead contractors on Boston-area projects ranging from the development of Storrow Drive to the Central Artery. 

Ray Lamont can be reached at 978-675-2705, or rlamont@gloucestertimes.com.