Ask Sail: Twist and Shout
Don Glynn of Westlake Village, California, asks:
"My ground tackle consists of 30ft of 5/16in galvanized chain, 270ft of 5/8 in three-strand nylon and a 22-pound Danforth anchor. Recently I discovered a 20ft hockle in the middle of the 10-year-old nylon rode and assumed that the kinks occurred after being coiled many times, and the boat circling around the anchor. I am going to replace the line, and I'm curious whether putting a swivel between the chain and the rope might prevent future hockles. This looks good on paper, but I worry that I might be creating a vulnerable link in my ground tackle.
Everyone seems to have an opinion, with one sailor telling me that introducing a swivel could cause hockling, and another saying that three-strand line should always be coiled in a clockwise direction. But since that's what I always have done, I'd like to know what does cause hockling and what's the best way to keep it from occurring?"
Don Casey replies:
You can create a hockle when you rotate a twisted rope in the opposite direction of its lay, but the most common cause of a hockle in an anchor rode is when it is used with an anchor windlass. When line is hauled around the windlass in a counterclockwise motion, the windlass will tend to unlay the rope even as the individual strands in it are being twisted more tightly. Very often the end result is a kink, or hockle, in the rode - which is why rope manufacturers recommend that whenever you have new rope, you make clockwise turns around the windlass drum. Unfortunately, while doing so will tighten the lay, it will loosen the strands, which makes the rope stiff and, once again, subject to kinking. For this reason, if the windlass will accept it, the ideal solution is to alternate between clockwise and counter clockwise rotations when hauling.
If you haul your rode in by hand, do not coil it in a counterclockwise direction. Coiling clockwise is better even though it will tighten the lay. Pulling rope from a clockwise coil will tend to reverse the twist, but since this loosening is concentrated at the top of the loop as it closes, this can sometimes result in a hockle. The best method of stowing twisted line is to flake it in a figure 8 because that maintains the original balance of the rope's twist.
Installing a swivel is not a good idea, because twisted rope, when it is put under pressure, will want to untwist, and over time this tension will unlay the rope. Although the rope will try to return to its original balance when the load is released, if that happens suddenly, a hockle could easily appear.
Finally, unless your boat is anchored in a tidal area for long periods of time, I don't think circling the anchor will cause the rode to develop a hockle; how you coil and uncoil it is the most likely cause. Incidentally, soft-lay rope, even though it might be soft on one's hands, is far more likely to hockle than a rope that has a medium or hard lay. That's why your new rode must be made by a first-rate rope manufacturer, and be specifically recommended for use as an anchor rode. To avoid any risk of getting a hockle, select a braided rope for your anchor rode.