I was in a rush to get to the airport on a good day. Hooked the trailer up at the barn where it lives (up the hill from the airport) and drove off. First bump I hit, I heard the coupler disengage. I had in fact crossed the chains, and they worked as advertised in your link. The trailer tongue was hung up in the "basket", and it swung gently fore and aft with very little side-to-side motion. The automatic brake cable also worked. I was left with a small dent in the mini-van bumper and a slightly elevated heart rate. The guy who taught me to tow trailers was a WW2 truck driver who claimed that crossing the chains was "critical". I don't know that my outcome would have been much worse if the chains hadn't been crossed, but it sure seemed to work well when I inadvertently tested out the theory .