The iconic "salt and pepper" towers along the Longfellow Bridge will soon be dismantled as part of rehabilitation work being done to the century-old structure.
The Massachusetts Department of Transportation said that work will begin Thursday by contractor White-Skanska-Consigli JVin preparation to remove the upstream towers. (An animation of the work can be viewed online.)
A barge-mounted crane will follow an ice breaker to the bridge where, once in place, it will begin to remove the granite stones which will be taken to a staging area for storage, cleaning and repair, according to MassDOT. The removal was expected to take place late this week and is weather permitting.
"The towers will be dismantled to sidewalk level only. All remaining pier granite below the sidewalk will be restored in place," MassDOT said.
Depending on conditions, some of the uppermost stones making up the tower roof may need to be removed by a crane on the bridge deck. That work would be done at night when the MBTA Red Line is not operating.
The towers are expected to be reassembled on the bridge later this year. The towers on the other side of the bridge will go through the same process during the final phase of construction expected in fall 2015.
The Longfellow Bridge, completed in 1908, is currently undergoing a more than three-year rehabilitation project to address structural deficiencies and upgrade capacity. Each day the bridge carries 28,000 motorists, 90,000 transit passenger and pedestrians and bicyclists across the Charles River.
Follow Michael Naughton on Twitter @metrobosmike.