Mass Dot F40s

A few weeks ago I was on the Corridor and saw one of the MassDOT F40s working a single level consist all day long. Not being local to Boston is this a normal occurrence or are the use of the blue F40s somewhat rare use of the engines?

And why exactly is this engine different from the other MBTA units?

The MBTA sold some units to MassDOT. Most are in MBTA colors and have a MassDOT sticker on them. I believe only 2 are in the blue paint job, a special touch they did for them after a rebuilt.

They are used for regular MBTA service.

They were rebuilt by Pan Am (I guess they only had blue paint available.....I keed, I keed). 1056 and 1062. I think they were originally going to be used on the Cape Flyer and special Gillette Stadium event trains, but they are mostly used in regular commuter service.