I would think extended loss of power would get sensed and result in shutting down. I'll see what my local dealer can demonstrate to me in his store.A little MY2 or LY2 relay (search ebay., etc.), available in several different coil voltages, would be appropriate. Before I bet the farm, I would make sure that your DCC controller will not try to stop the train if it senses extended loss of track continuity. That stuff about Digitrax confirming power up, with no restart, contradicts their DCS52 operations manual, just saying. And yes, I vote to interrupt both sides. 😊 Your Tyco relay probably has two contacts and would be fine.