Officials said renovations to the bridges are needed to upgrade train safety and operations. The main sections of bridge were built in 1919, but some of the existing foundations date back to 1839. Design for the rehabilitation is being done by HDR, an engineering firm hired by the MBTA. The work will include repairing or strengthening deteriorated bridge members, reinforcing piers, and cleaning and painting the bridges.
According to a June 2009 summary of HDR Engineering’s inspection, the bridge over the river is safe for freight trains as long as only one crosses at a time and it travels no faster than 5 mph. The report said it is safe for two commuter trains to cross the bridge at the same time and as long as they do not exceed 15 mph. Those restrictions are still in place, officials said. The speed restrictions closely followed the Minneapolis bridge collapse that left 13 people dead and dozens injured.
In 2008, the MBTA inspected the double-track span and rebuilt its deck. The job included replacing about 1,600 bridge timbers, installing walkways and railings across the full length, and laying about 8,000 feet of rail.
City Councilor William Macek, who in the past expressed concerns for the structural integrity of the bridge and a possible failure that would halt train travel over the river, said he is pleased the MBTA plans to begin repairs this year.
“The fact that the state is making this project a priority this year underscores the need to assure safety and long-term viability of the rail bridge,” Macek said. “If the integrity of the bridge is secure, it will mean people and businesses on both sides of the Merrimack will be able to count on using rail transportation without question or concern. I know people who will not use the Haverhill (train) station and instead will drive to Bradford to catch the train to Boston .... They are unwilling to be on a train that crosses the river.