By Michael Argyelan
Strings, lines, ropes, running rigging, cordage, whatever you want to call it, understanding the basics of cordage is an important aspect of being a good sailor. If you don’t know the breaking strength of your halyards you might be putting yourself and your crew at risk. Do you know what stretch and creep are? How about core dependant versus cover-core dependent? No? Well you will after reading this article. First, let’s explore the fibers and materials used in the covers and cores of lines.
Polyester: A general grade line for applications not too concerned with stretch. Most covers of lines are constructed of polyester. There are different grades available to the line manufacturer, which affect color retention, sheen, wear and UV degradation. Polyester stretches less than nylon and is durable and economical.
Spectra: Very strong and durable. It has super low stretch, and is light enough to float. Spectra has the best fatigue life of most any fiber. One issue with Spectra is “creep”. Under high static loads (think main halyard), Spectra will elongate very slowly. After a period of time you might notice that your main halyard now seems an inch looser. Using one size larger will greatly reduce creep, but it may still be noticeable. Spectra is the ultimate material for high fatigue and lightweight spinnaker halyards, guys and sheets. Spectra does not absorb moisture, which keeps it lighter on the boat. Read More