Waltham Signal Tower. GX1, Leitz Summitar 50mm

Today's Blip is of the last active railway signal tower in Massachusetts, built in 1928.  It stands guard over the eastern entrance to Waltham commuter rail station on the Fitchburg line. Of particular interest are the lower quadrant, three aspect semaphore signals.  Regrettably they are no longer active and the 34 trains that use the line every day are controlled by color light signals.  Wikipedia tells me that the tower is still manned around the clock, although there was no sign of life when I was there today.
Also of interest is the 1890 factory building in the background.  This is one of many that dot the small industrial towns of New England.  A lot stand in ruins, but some, like this one, have been totally restored and repurposed as luxury condominia or sometimes studio space for artists and crafts people.