I was in my senior year of high school (1971) when EL put a eastbound hot piggyback all over the ground in Mahwah. I remember it well, as some of the trailers split open and there were beef carcasses all over the right of way. I was able to get a ride to the scene in early afternoon to see it. I just missed the following eastbound that was sent east on the Piermont Branch to Spring Valley, then down the NJ&NY. It had a pair of SD-45's as the power with about 100 cars. The RR had to call out managers to flag the crossings in Hackensack, as the manual gate tenders were not on duty during the middle of the day.