Wednesday, 20 April 2011

Sailboat Running Rigging Lines and Ropes for Cruising Sailors

Replacing the running rigging on your boat seems like it should be fairly simple, and a decade or two ago, it was. As with electronics, safety gear, and even sails, technology has significantly improved cordage. The downside to all these improvements is that not only are there more options then ever, but you may feel like you need a materials-science degree in order to choose the right line for your new jib halyard. Here, we’ll take a look at what the newer, high-tech materials can do for your boat.

When it comes time to choose new rope for the lines aboard your boat, you’ll need to consider the type of sailing that you’ll be doing (a year in the tropics? racing to Bermuda?), the hardware that you currently have (clutches, sheaves), what qualities you feel are important (soft hand, ease in splicing, weight, durability), and your budget. The type of sails you have is another consideration. “If you’ve already made the investment in laminate sails, then you should really consider upgrading your running rigging to a low-stretch material,” says Brian Fisher of Rig Pro, in Portsmouth, Rhode Island. “But even if you have Dacron sails, you can benefit from a cordage upgrade.”

Halyards
Starting at the top, you should check over your sheaves before replacing your halyards, and if you’re going from wire to rope halyards, you’ll need to change to rope sheaves. (Wire halyards use a V-shaped sheave; rope sheaves are U-shaped.) While you’re aloft, look for any sharp edges that could chafe through your new line, especially if you’re going from wire to rope halyards.

There are plenty of choices for new halyards, from basic polyester double-braid to all the high-tech materials. Whatever you choose will probably be a compromise between such factors as amount of stretch, cost, weight, and ease of handling.

Long the workhorse on many a cruising boat, polyester (Dacron) double-braid is still a good choice for many onboard applications. Polyester is long lasting, resistant to ultraviolet radiation, and costs a fraction of high-tech rope; however, it’s somewhat stretchy and heavier than more modern materials, and if there’s one area on board that could benefit from an upgrade to lightweight low-stretch line, it’s the halyards.

Most cruising boats have a roller-furling headsail, and many have in-mast furling mainsails as well. Since these remain hoisted for possibly months at a time, a lightweight low-stretch line will offer better halyard tension and sail shape over the long run. This is true for non-roller-furling sails as well, especially if you’re heading out on a long passage where the sails will be set for a while. Here Fisher recommends using a Spectra/Dyneema-cored line, since it’s extremely strong, lightweight, and doesn’t absorb water. An alternative would be a Vectran-cored line, which stretches even less and doesn’t creep; however, it’s heavier than Spectra/Dyneema and absorbs water. When switching from polyester to a high-tech line, it’s usually possible to downsize the line by a few millimeters since these fibers are so strong. This is a definite advantage for bigger cruising boats, since polyester line can be quite bulky at larger diameters.

If the price tag of Spectra/Dyneema-cored or Vectran-cored line is a little steep, all the major rope manufacturers currently make “mid-level” blended-core ropes that would be well suited to the cruising environment (and easier on the wallet). A few examples are New England Ropes’ VPC, with a Vectran and polyolefin core, and T-900, with a Dyneema and Technora core; Samson’s MLX, featuring an Innegra-S and Dyneema core; and Yale’s Aratech, with a Technora and Spectra core. Both high-tech lines and the mid-level blends typically have polyester covers, which provides extra U.V. protection and a nice hand, although there are also covers available that blend the polyester with materials such as Technora, for its abrasion-resistant and heat-dissipating qualities. If weight saving is a major issue aboard your boat, note that many of the high-tech ropes available are core dependant, and the cover can be stripped off. On the majority of cruising boats, however, the effect would be negligible.

Sheets
Like halyards, sheets are an area where Spectra/Dyneema-cored lines can improve performance and even your sailing experience. “Since you can downsize your line when you switch from polyester, you end up with smaller, lighter piles in your cockpit and less weight pulling at your sail,” says Fisher. He offers an example of genoa halyards on an Oyster 46, which are 69 feet long. In this application, polyester double-braid lines would measure 3/4-inch in diameter, with a breaking strength of 16,000 pounds and a weight of 11 pounds. A Spectra/Dyneema-cored line would have a 1/2-inch diameter, a breaking strength of 20,000 pounds, and a weight of only 4.6 pounds. And only the polyester cover would absorb water, offering additional weight savings as well as more pleasant tacking.

It’s worth noting that if you’re replacing your running rigging, the time’s right to inspect your deck hardware, too. Since polyester line has more give, it absorbs more of the load from the sails. If you make the switch to high-tech line, be sure that your deck hardware is appropriately sized and reinforced.

Spinnaker sheets are well suited for a high-tech upgrade as well, since a lightweight, small-diameter line that’s also very strong will offer better performance. Examples of good choices for this application are Samson’s WarpSpeed, featuring a Dyneema core and a polyester cover, and New England Ropes’ Flight Line, which has a Dyneema core and a polypropylene cover.
Rope construction for the mainsheet is much a matter of personal preference. Single-braid is usually softer, has a nice hand, and doesn’t kink, but it could snag more than a double-braid line and doesn’t have the additional abrasion resistance of a cover. Yale Cordage’s new Ph.D. rope, introduced in 2010, is a single-braid construction made from polyester-coated Spectra. According to Yale, the polyester coating gives the rope a nice feel and good grip on winches, while the Spectra core gives it strength and weight savings.

All the Rest
While halyards and sheets have been the focus here, there are plenty of other places aboard that could benefit from a high-tech makeover: runners, the outhaul, the traveler, the boom vang, even lifelines. If a major high-tech cordage upgrade is in your future, it may be wise to consult with a rigger to ensure that the chosen material is suitable to the application on your particular boat and that your lines are appropriately sized. “I’ve seen several situations in which customers have forgotten to take into account proper line size with regard to the winches and rope clutches on their boats,” notes Andrew Spiro of The Ship’s Store and Rigging, in Portsmouth, Rhode Island. “It’s simple, but just because you can use a smaller-diameter line with the same strength, they forget that the winches and clutches are limited to certain sizes. The result is often slipping.”

Always on the forefront of technology, raceboats have been using high-tech fibers for years in many applications on board, even standing rigging, and as these fibers have improved and their acceptance has grown, more and more wire is being traded out in favor of these lightweight alternatives. Cruisers can also reap benefit from these advances.

The Right Stuff for ropes
Aramids (Twaron, Technora, Kevlar): Like other high-tech fibers, aramids are strong and stretch little, but they also have the benefit of being resistant to heat. You’ll find aramids in both double-braid cores as well as blended with other fibers in the covers.

Dynex Dux: A relative newcomer to sailboat rigging, Dynex Dux is pre-stretched and heat-treated Dyneema. This process, however, produces an extremely strong rope with virtually no creep that is suitable for service in standing rigging.

H.M.P.E. (Dyneema, Spectra, Amsteel): High-modulus polyethylene has many benefits for running-rigging applications: It’s very strong, lightweight, doesn’t absorb water, has decent resistance to ultraviolet radiation, and it can float. On the downside, it has more creep (see “Rope Speak,” page 80) than other high-tech fibers.

L.C.P. (Vectran): Liquid-crystal polymer fiber possesses high-strength and low-stretch qualities and suffers virtually no creep. L.C.P. is one of the strongest core materials, although it doesn’t have the U.V. resistance of H.M.P.E., and it’s a little bit heavier.

Nylon: Strong yet stretchy nylon is commonly used in applications for which shock absorption is important, such as in dock lines and anchor lines.

P.B.O. (Zylon): Polybenzoxazole is extremely low stretch and high strength. It’s also ungodly expensive and lacks the durability that most cruisers desire. As such, P.B.O. is usually only found on high-end raceboats.

Polyester (Dacron): For decades, polyester has been the go-to rope for cruising-boat halyards and sheets. It’s cost efficient, strong, and resists ultraviolet radiation.

Polypropylene: Usually used in applications like ski and dinghy tow ropes, polypropylene is lightweight and can float. Alone, polypropylene isn’t usually seen in cruising-boat lines since it’s very susceptible to U.V. degradation, but it’s sometimes combined with other fibers that benefit from its lightweight, low-cost qualities.

Extract courtesy Jen Brett and Cruising World.com 

You can read more about running rigging and repairing whilst on passage in my ebook 'Sailing Adventures in Paradise' downloadable from my website http//:www.sailboat2adventure.com                     

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