A
Few Lines on Rope
By
Chuck Rose
21st century sailors are faced with a
bewildering array of choices when it comes to rope. You will have to decide between laid or
braided, double or single braid, nylon, Perlon, polyester, Dacron, Terylene, polypropylene
HMPE, Dyneema, Spectra; aramid, Kevlar, Technora, Twaron, LCP, Vectran and, in
the interest of inclusiveness, hemp, manila and cotton.
Modern
synthetic materials have long since replaced the hemp and manila that for
hundreds of years were the only choices.
Hemp for standing rigging, manila for running rigging; from the days of
Lord Nelson until after World War II these were the only materials considered
suitable. Cotton was, and is still, used
aboard yachts in decorative applications such as bell ropes and lanyards but
has no practical application in rigging.
Hemp and manila rope are almost impossible to find these days and their
use on modern yachts is not practical for a number of reasons. They are inferior to modern synthetics by a
large margin so I mention them only in historical context. The 21st century sailor will be
choosing from among the wide selection of synthetics. Let’s see if we can simplify the choice a
bit.
Perlon is a trade name for nylon. Dacron and Terylene are polyester. Kevlar and Twaron are aramid. HMPE, or High Modulus Polyester, is also
known as Dyneema and Spectra. Vectran is
a liquid crystal aromatic polyester fiber or LCP. Hybrids and mixed fiber trade names could extend
the list to several pages but such exotics are beyond the scope of this
article. Sailors with unlimited racing
budgets can do their own research.
The first
widely available synthetic rope to come out of World War II in the mid 20th
century was Nylon. Vastly superior to
any natural fiber for any application aboard a yacht it is much stronger, impervious
to rot, easier on the hands, has good UV resistance, and is stretchy and
elastic. Nylon is the ideal choice for
mooring lines, dock lines and anchor rodes.
Nylon rope is available in traditional laid, single and double braid
construction as well as in combination with other fibers such as polypropylene
or polyester for specialized applications.
Next came
polyester, also known by the trade names Dacron and Terylene. Polyester is a good choice for running rigging
and is the most practical for the average sailor. Polyester double braid is the most common
rope found on modern yachts for all running rigging applications. Like Nylon, polyester rope is available in
traditional laid, single and double braid construction as well as in
combination with other fibers.
Combinations of a braided polyester cover over a core of HMPE or LCP are
often recommended as halyard material for their extremely low stretch and high
strength.
Polypropylene
is often found on boats. It has low
strength, high stretch but is not elastic, and has poor UV resistance. Polypropylene does have two virtues
however: It is cheap and it floats
making it a good choice for dingy painters, crab pot buoy lines etc. It is also very light weight so it is
sometimes used for spinnaker sheets. I
have one length off polypropylene that I use when towing the dingy because it
will stay out of the prop.
The
dedicated racer with a generous budget may opt for extreme low stretch ropes
for halyards and control lines of HMPE or LCP but these are very expensive and
offer no substantial advantage to the cruiser or recreational sailor. The advent of high tech, high strength, low
stretch fibers may presage a return to rope standing rigging. Size for size it is stronger than stainless
steel wire rope and much lighter. It is
also impervious to corrosion. A friend
of ours recently consulted with rigger Brion Toss on re-rigging his Ranger 33
cruiser and Brion recommended Dyneema for the shrouds and backstay. Expense is still a consideration however and
long term durability has yet to be established.
The use of HMPE for standing rigging is intriguing though and I plan to
carry a length for possible emergency repairs as it is lighter and easier to
coil and use in this application than stainless steel wire rope.
Simple and
economical, in my view, are preferable to complex and expensive unless you are
Roy Disney perhaps. Here are my
solutions:
For my Vega
27, I prefer half inch or five eighths inch three strand nylon for towing,
mooring and anchoring applications. If
replacing all, I’d buy a 600 foot spool to get the best price, make up four
dock lines, each the length of the boat with an eye splice in one end, a
mooring pendant with a snap shackle spliced on and two anchor rodes to which I
would attach fifty feet of chain each.
For running
rigging, because of the size of the masthead sheaves, sheet blocks and cleats
on the Vega, three eighths inch (10mm) double braid polyester is my
choice. You can spend more but I do not
consider the benefits cost effective for a cruiser or recreational sailor. Again, I would buy a 600 foot spool and make
up halyards, sheets, topping lifts, boom vang, preventers and downhauls. You may have a little left over for lashings
etc. but not much.
Steve Birch
of the VAGB (Who ought to know) gives the following specifications for the
Vega:
Main
Halyard 22 meters (10mm Braid on Braid pre-stretched polyester)
Genoa Halyard 24 meters (10mm Braid on Braid pre-stretched polyester)
Mainsheet 18 meters (10mm Braid on Braid pre-stretched polyester)
Genoa Sheets 9 meters (10mm Braid on Braid pre-stretched polyester) x 2
Topping lift 25 meters (6 or 8mm Braid on Braid pre-stretched polyester)
Spinnaker Halyard 25 meters (8mm Braid on Braid pre-stretched polyester)
That is a
total of 132 meters or 433 feet of rope.
Note that Steve does not include rope to reeve a boom vang or to rig
downhauls or preventers. Neither is the
topping lift for the spinnaker pole included.
Also notice that Steve recommends different diameter rope for the
topping lift and spinnaker halyard. In
truth, I prefer larger diameter rope, seven sixteenths or half inch, for sheets
because the larger diameter line is easier to handle than the smaller three
eighths stuff. For simplicity and
economy, however I think it is best to use one size and buy a full spool
whenever possible. The size being
determined by the width of the masthead sheaves, sheet blocks and cleats
fitted. Never use rope too big for the
fittings. It will cause excessive
chafe and premature failure of the line. On a Vega, the mooring cleats are
sized for approximately half inch rope, the sheet and halyard cleats, sheet
blocks and masthead sheaves for 10mm (three eighths inch) rope. If you opt for larger diameter rope in these
applications you should fit larger cleats and blocks. The masthead of the Vega will not accommodate
larger sheaves so, unless you replace the mast or hang blocks, you will be
limited to three eighths inch halyards.
The Vega originally was rigged with wire/rope halyards, the hot setup
forty years ago. If your boat is still
rigged with wire/rope halyards it is time to get rid of them and go with all
rope halyards. If you are all that
concerned about stretch go with HMPE or LCP cored, polyester covered, halyards.
I think that
one 600 foot spool of half or five eighths inch three strand nylon and one of three
eighths inch double braid polyester will take care of all the major cordage
needs of any boat in the thirty foot or under class. That is not to say that you will not need any
other cordage however. In addition to
the twelve hundred feet of rope accounted for above, I keep a one hundred foot
heaving line, a couple of fifty foot lengths of half inch three strand nylon, a
spool of three sixteenths inch single braid polyester rope, a few hanks of one
eighths inch flag halyard stuff and a couple of spools of tarred seine twine
for small lashings and decorative rope work.
Finally,
you will need a ditty bag or box containing, at minimum, a sail makers palm,
several sail needles and a spool of waxed sail twine and a sharp knife; not the
serrated kind as they tear the rope, but plain edged and sharp. Put on permanent whippings before you cut the
rope. Yes, you can use a lighter to melt
the ends of synthetic rope but, in my experience, the traditional twine
whipping is superior. If you want to
make your own eye splices you will also need a marlinespike and fids, but that
is getting beyond the scope of this article.
If you want
to learn more about working with rope, visit the Ship’s Store and check out
Ashley’s Book of Knots, Hervey Garrett Smith’s Art’s of the Sailor and
Marlinspike Seamanship and Roger C. Taylor’s Knowing the Ropes.
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