by Frank Lanier
From the most odiferous stinkpotter to the rag-baggingest blow-boater, there’s a common thread that binds: dock lines. We all need them and we want them to last as long as possible. Here’s a look at choosing the right rope for your dock lines and some tips on making them last.
What’s Your Line?
The majority of lines found aboard today are made of synthetic fibers such as nylon, polyester and polypropylene, which have numerous advantages over their organic counterparts, not the least of which are increased strength and resistance to rot. The variety of synthetic lines available also allows boat owners to more closey match line characteristics with function.
Basic construction for both synthetic and organic ropes begins with fibers that are twisted into yarns, then twisted or plied into strands, and finally twisted or braided into rope. It’s the last step that determines how the fibers lay or align with the finished line—and thus defines the properties of the line itself. For example, in a twisted or laid rope such as three-strand (the traditional form of manufacture since the early days of natural rope), fibers are not aligned with the line’s axis, so the line will have more stretch than braided or parallel core since the fibers straighten out as the rope comes under tension. Braided rope, on the other hand, has more fiber in the line’s cross section, translating to less stretch and consequently greater strength. While braided rope doesn’t have the stretchiness of traditional laid rope, it’s torque-free, has good abrasion resistance, and is less susceptible to kinking.