Why do mariners often choose to fight the laws of physics when making and breaking tow? Usually it’s because that is the way mariners were taught. Unfortunately, much of what has been taught on this subject is wrong. Perpetuating it generation after generation only makes it harder to make the necessary changes.
Probably the most common method of breaking tow entails flopping around on the barge, pulling the barge’s pennant over the rail, and using what is often referred to as a “stopper.”
The stopper (line) is used to secure the pennant and take the strain off the pennant-to-tow-wire connection so that the shackle between them can be taken apart quickly. The proper use of the all-important stopper is where the trouble begins. There are three closely associated problems: inadequate breaking strength of the line used for the stopper; the danger of synthetic line snap back if the stopper is parted; and/or how the stopper is rigged. This is also where losing the war against physics begins.
Problem No. 1: Some tug crews use stoppers that are barely strong enough, even when brand new, for their intended purpose. If there ever were a time that when safety is paramount, this would be it. All it takes is an unexpected swell or wake from another vessel to overload and part a stopper.
This brings us to problem No. 2: Because of the recoil effect of synthetic lines that are stretched past the breaking point, serious injury may occur. Some of the stoppers people use are way too small, such as a 3-strand about the size of a man’s thumb that holds 1.75″ or 2″-dia. tow wire. This leaves almost no margin for safety. And even when larger lines (but not necessarily large enough) are used, they are often allowed to deteriorate to the point that their breaking strength is compromised. This provides a false sense of security.
Can you do this and get away with it? As with many unsafe practices, the answer is yes. But any deck crew that does this, or captains/mates that allow it, are taking a significant risk. And they’re doing it for no good reason.