Hearing through the grapevine that the 1600s are cycling through PTC work which is being done on the South Side, tying up somewhere between 3-6 cars. Hence the need to move other control cars north. Might we start seeing 1600s as actual control cars south?
1631 is currently leading a 7 car set Northside. There also seems to be an all-MBB set roaming around? I saw one rolling by a week or two ago while waiting for the orange line at Sullivan. And yesterday, 1512 was leading a Fitchburg line train.