MCG: Third rail shoes are designed to break clear in case of a contact problem between the third rail and the
truck assembly. A single car N5 has four third rail shoes - one on each side of the truck. Shoes are designed
to break protecting the shoe beam and power lead cables - and the rest of the truck itself.
This may have been a case of shoes on one side being broken off - for example as the result of an alignment
problem with a third rail approach section. Since third rail shoes make friction contact they wear out and do
need to be replaced on a term basis - worn shoes are more likely to break.
A single N5 car should be operable with one intact shoe on one side - the problem would be that all of the
car's power and amperage would be drawn over through that single shoe. If that intact single shoe breaks
off on a segment of third rail on that side the car will lose power instantly unless it can roll free to a third
rail segment on the other side of the track.
Replacing third rail shoes is an easy fix - during inspection shop work. Good thing the train operator caught
the problem at 69th Street...MACTRAXX
EXPRESS TRAIN TO NEW YORK PENN STATION-NO JAMAICA ON THIS TRAIN-PLEASE STAND CLEAR OF THE CLOSING TRAIN DOORS