rlaxton wrote:Hi,
IIt seems that the construction of UHMWPE (Ultra High Molecular Weight Polyethylene) rope varies between that used for mooring boats and that used for winching.
Richard.
I've never seen UHMWPE used for mooring boats. It is absolutely unsuitable for this task due to the lack of stretch, mooring lines are much better when they have some "give" as it helps to avoid damage to the vessle from shock loading.
UHMPE is used on boats (mainly racing yachts) for both running and standing rigging, where it is preferable to have no stretch at all. The loads applied to these lines is often greater than what a 4x4 winch could dream of. Running rigging on a yacht is the ropes used to hoist and hold up sails, and the control lines that are used in positioning the sails. Standing rigging is the ropes that are used to hold up the mast(s), and theonly movement they gain is when a mast is "tuned". Traditionally wire rope was used for standing rigging, and for the halyards, or the hoisting ropes for sails, but on modern racing yachts, wire rope has given way to the likes of dyneema and spectra, due to a massive weight saving. When a sail is hoisted, it is winched into place and then tensioned with a winch (either electric or hand) that puts immense tension on the rope, but even more is applied once the sail starts to fill with wind.
Those applications sound rather similar to the stresses faced by a 4x4 winch ehhhh? I would certainly use the cheaper (because it's not marketed for 4x4's) marine ropes as in all likelyhood they have come off the same spool at the factory. Due to the chemical compositions of these ropes being patented (mainly by DuPont), their are very few manufacturers of high tech ropes in the world. MSDS and load bearing specifications are available at all good marine chandleries, and a marine rigger who works with synthetics would be able to splice (that is his job after all!!) a hook/eye onto the rope for a modest sum.
Cheers, Dean
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