Complex sentence: The Hudson, Harlem and New Haven lines and the New Canaan branch and all passenger rolling stock is equipped with cab signalling, which displays the appropriate block signal in the engineer's cab.
Split into simpler sentences: The Hudson, Harlem and New Haven lines and the New Canaan branch are equipped for cab signaling, and all passenger rolling stock is equipped to receive the cab signal. Cab signaling displays the appropriate block signal in the engineer's cab.