The Massachusetts Bay Transportation Authority's commuter rail lines are experiencing some delays Tuesday amid extremely frigid weather.
Several lines, including the Newburyport, Franklin and Fitchburg lines, are seeing delays of up to 30 minutes due to mechanical and signal issues.
Meanwhile, the Red Line is experiencing minor delays due to a disabled train at Alewife Station in Cambridge.
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The MBTA is advising commuters heading back to work in the New Year to plan ahead and add 20 minutes to their normal travel time because of expected maintenance issues brought on by the cold.
MBTA officials said crews worked continuously to keep equipment operational, but given the frigid temperatures, some slowdowns were anticipated. A number of trains were stored inside overnight or kept running to prevent them from freezing up.
Extra inspectors also worked during the morning commute to deal with any weather-related problems that came up.
The frigid temperatures also forced the MBTA to temporarily suspend Hingham's commuter boat service because of an ice-damaged dock.
A commuter boat bus shuttle from the Hingham Ferry Terminal will be offered. Commuters will be taken to the West Hingham Station on the Greenbush Commuter Rail Line. Monthly boat passes will be accepted at all stations.