From Michael Moroney@21:1/5 to All on Sun Sep 26 00:28:03 2021
I'm not sure how many follow this group but I'll try...
A rail line out of Boston (Fitchburg line) is being upgraded with PTC at
this time. Commuter rail is 'bustituted' around this segment during the
work but freight still runs (why?). There is a signal at the entrance
to a rail yard in Fitchburg, there are three lights each on two columns
for the two tracks there. I've noticed they've attached a fourth light
head on each side. It is not above or below the others but off to the
side. Right now, as it's not in service yet, it's pointing away and
covered with black plastic so it's hard to tell the final configuration.
What will this new signal head display, what meanings will it have? I
have the meanings of the colors of the other lights written down
somewhere, will their meanings change?