The Curtain Closes on IRT Signaling (Take 2)

One of my earliest posts for this blog back in 2011, covered the closing of the NYC Subway's E. 180th St interlocking tower.  This was the last instance of an electro-mechanical single interlocking tower on the IRT division and also what I thought at the time was the last bastion of old IRT signaling as well.  You see, in addition to it's on interlocking plant, E. 180th St tower also had CTC control of the (5) Dyre Ave line.  It seemed logical that closing the tower would be followed by a re-signaling of the Dyre.

Well it turns out I was wrong and the old IRT signaling on the Dyre persisted for another 6 years!  Unfortunately, I was just informed that the NYCTA would finally be concluding it's closure of the E. 180th extended enterprise by cutting in a new, bog standard IND style system on the Drye on or after Labour Day 2017.

If you want a full explanation of IRT and IND/BMT signaling, you can find it here, but the short explanation is that the IND/BMT system uses the upper head for block occupancy and the lower head for route.  So a G/Y signal would be Diverging Clear and Y/G would be Approach Straight.  The IRT used a more railroad style system with each head representing a different route.  R/G would be diverging clear, etc.  Basically something that would be familiar to almost any real world railroader.  The NYC Subway marked old IRT signals with a red number plate and outside of the Dyre they were last seen on the (2) and (4) lines in the Bronx up through the turn of the Millennium.

While I guess it was a good thing that these signals survived 6 more years that I had assumed, I'll definitely regret not taking the time to go up and see them beyond my last visit in 2009.