One way to keep the chain from flying if it did break would be to thread a wire or rope line through the chain with the line passing through links about every foot. A 35' line on a 20' chain would leave enough slack to tie off to the towing vehicle on one end and the towed vehicle on the other. There is no tension on the line, but with slack in the line so if the chain did break, the line would hold both broken ends in check with only a few inches of the lose broken ends to move around, and provide enough time to stop the tow. If the line broke, the energy would be gone from the chain and the chain would keep the line from flying very far. Cheap Insurance.
Using steel cables can be a fright. In 1970, while on active dury as a Naval Officer, it was 1:30 in the morning, I was the Officer of the Deck on a replenishment ship and we were resupplying a 2,200 ton Destroyer with fuel oil. Our ship was a 56,000 ton AOE (fuel, ammo and food supply ship) We were moving at 12 knots about 100' apart. The fuel line was suspended between the two moving ships on a wire rope 1 1/8" in diameter. Without warning, and in a matter of seconds, the Destroyer took off at a 30 degree angle at 12 knots away from us. My ship rolled about 5 degrees until the span wire parted and we rolled back upright. Fortunately, that wire did not hit anyone, or it would have been fatal. It sounded like a gun going off when it let go. The fuel hose pulled out before it could be released, and we gave the Destroyer a black oil bath from a 3" hose at 40 psi.
I'd rather use an oversized chain with a safety rope or wire through it.
Just my thoughts on this matter. If someone sees a problem in that theory please say so.
