There are three shut-down systems.
(1.) All track power runs through (2) TPC's, Track Power Controllers, silver boxes pictured. The halt button, on the Cab-1 remote, cuts power to the TPC's. The emergency shut-down is in your hand.
(2.) All electric for the layout is via one receptacle near the power control center, left bottom of first picture. The receptacle is switched by the door to the main room of the layout.
(3.) There is also an E-stop button on the DCS remote.