For a "cab ride" view of the Dorchester freight branch ("Fairmount Line") check out Railroad Video Productions Tape #9B, "NY., NH. & H. Shoreline, Providence to Boston." It was shot in 1985 with Herbie Clark as the Amtrak's "Yankee Clipper" engineer. Because if the construction on the main line, Amtrak's trains used the old freight line into Boston, turning off at Readville.
It was recorded in the summertime and the trees are in full foliage. However, you can still see a lot of railroad scenery, i.e. sidings, buildings, factories, and old station platforms (Morton Street, Upham's Corner & Fairmount) in their deterioated condition.
It is amazing to see the good condition of the branch as a result of being used for all of the years the old main line was being rebuilt.
It was at this time the tracks in Providence RI were being moved to the current Amtrak Station. At one point (between Pawtucket and Attleboro, the train's speed was announced as 95mph!
Paul