The NYCT doesnít want to put cars on any line that might involve a situation in which the trains would have to be routed into the Montague St tunnel where R-32s are banned. That pretty much eliminates the Southern Division.
I wonder if they would make an exception for one train for one day? If the R32 was to have an final run on the Southern BMT and the Bridge is blocked due to an service disputation, they could always turn the train at Court Street. If they ran it on either the D or N Pacific street is also an option. They could always have an T/O at each end of the train like the arnines do to keep dwell times at a minimum.
Apparently, when the tunnel was repaired post sandy, certain cables were hung in such a way that they only could clear cars with a certain side curvature which only included R-46, 68s and NTTs. The R-42s donít curve in as much above the window line and the R-32s and older are completely straight sided so they definitely donít clear. More than likely, the cesspool of incompetence that plans for TA panning and engineering used one of the types that I mentioned as a clearance train instead of testing it with a car with the most restrictive dimensions so that proper adjustments could have been made.