Rehabilitation of a 368-ft-long,70-year-old Warren through-truss bridge in Westfield, Mass., is now a major urban revitalization project that includes three bridges and a half-acre of parkland, as crews deal with live trains, endangered mussels and sub-zero temperatures. “Originally, in 1994, we were just studying the old bridge,” says Mark Ennis, project manager for STV Inc., New York City, the principal architectural and engineering firm for the $70-million project. “We found it could be rehabbed. The work would involve replacing the deck system and some strengthening of truss members, repainting and updating of the bearing systems.”

Graphic: STV Inc.

Warren truss bridge will get a partner.

But STV also noticed the three-lane bridge was a choke point for Westfield, 100 miles west of Boston, with the Massachusetts Turnpike only a mile away. Through discussions with the city and the state Highway Dept., “a larger project blossomed,” says Ennis.

The scope of work expanded to include a new sister bridge 150 ft downstream to ultimately carry three lanes of northbound traffic, plus a new railroad viaduct north of the existing bridge and an 80-ft clock tower. Work is expected to wrap up in 2012.

J.F. White Contracting Co., Framingham, Mass., holds an approximately $60-million contract. It began work in spring 2007 with demolition of one half of the existing two-track viaduct and relocation of the endangered mussels, says Bob Murphy, the contractor’s vice president. The new railroad bridge will increase the original clearance by 5 ft, adds Ennis, saying, “There is a mile of trackwork on either side to accommodate the new elevation.” Crews have just completed the first half and are beginning work on the second, working around the passage of up to 30 trains a day.

The contractor is using a temporary timber bridge supported on steel-pipe piles for river access as it builds the new twin bridge, which requires one million lb of steel and is just about completed. Winter work was required to avoid thermal expansion of the steel bolts,.

Once the new Warren through-truss bridge is finished this summer, traffic will be switched over and the old bridge can be demolished. “It is not a typical demolition,” says Murphy. The contractor has to de-lead the bridge and take it apart two floorbeams at a time. The 28-ft-tall pier’s rocker bearings will be replaced with neoprene bearings. The two trusses will stay in place, though their concrete deck and steel stringers will be replaced.