Nylon vs polyester cordage
 

I know conventional wisdom decrees that running rigging use polyester
cordage and anchor line use nylon. The nylon is said to stretch more, and
thus take up shock loads more readily. Polyester, on the other hand,
stretches less and is said to make setting the sails easier. I can
understand this for racing purposes, but wouldn't the same tolerance to
shock load be a blessing in a cruising boat where resilience of the rig is
of ultimate importance?

Bob Swarts

Hi Bob,

Nylon line would be a very bad idea for running rigging on any boat, cruiser
or otherwise. The excessive stretch and spring that nylon line has would
make trimming sails impossible, and could be very dangerous. Likewise, 3
strand twisted dacron line makes a very poor running rigging for the same
reasons. For halyards and sheets, use double braided dacron or better.
You'll be glad you did.

Likewise, using polyester (Dacron) line for anchor or mooring lines is a
very bad idea. We med-moored a disabled yacht to a concrete wall during a
storm. I ran out of sufficient nylon mooring line to move further from the
wall, so we used dacron. Big mistake. The shock loads this caused as the
yacht surged were scarey. I'll never do that again!

--
Paul

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On Sun, 30 Jan 2005 09:54:13 -0800, "Robert or Karen Swarts"
wrote:

I know conventional wisdom decrees that running rigging use polyester
cordage and anchor line use nylon. The nylon is said to stretch more, and
thus take up shock loads more readily. Polyester, on the other hand,
stretches less and is said to make setting the sails easier. I can
understand this for racing purposes, but wouldn't the same tolerance to
shock load be a blessing in a cruising boat where resilience of the rig is
of ultimate importance?

No way. Stretchy halyards are a plague. Your sail will bag out in a
gust, just as you want it flatter.


Indeed, polyester is too stretchy for halyards. I used spectra core
for the main halyard, when I replaced the wire one. It needs
tightening once after a few minutes.

The jib halyard and the port-side spinnaker halyard now have ( IIRC)
twaron and technora cores, which don't creep as much. On a cruising
boat, I keep the polyester cover over the whole length. I suppose if I
were racing I would strip it except where I handle it and put it
through clutches.



Bob Swarts



Rodney Myrvaagnes NYC J36 Gjo/a


"Nuke the gay whales for Jesus" -- anon T-shirt

Robert or Karen Swarts wrote:
I know conventional wisdom decrees that running rigging use polyester
cordage and anchor line use nylon. The nylon is said to stretch more, and
thus take up shock loads more readily. Polyester, on the other hand,
stretches less and is said to make setting the sails easier. I can
understand this for racing purposes, but wouldn't the same tolerance to
shock load be a blessing in a cruising boat where resilience of the rig is
of ultimate importance?

Bob Swarts


You certainly wouldn't want stretchy halyards or jib sheets. But there
are some case where you might want shock absorbing on the main sheet.
When I bought my previous boat, a Nonsuch 30, the mainsheet came rigged
with a rubber snubber, the kind you normally put on a dock line. The
previous owner felt it was worth a little give in the line to have shock
absorbing in the case of a jibe. If you've ever sailed a Nonsuch (or
other large cat boat), you'd understand that jibes can be rather
thunderous. The only other noticeable affect was that the main eased a
little in puffs, not necessarily a bad thing.

On Sun, 30 Jan 2005 09:54:13 -0800, "Robert or Karen Swarts"
wrote:

I know conventional wisdom decrees that running rigging use polyester
cordage and anchor line use nylon. The nylon is said to stretch more, and
thus take up shock loads more readily. Polyester, on the other hand,
stretches less and is said to make setting the sails easier. I can
understand this for racing purposes, but wouldn't the same tolerance to
shock load be a blessing in a cruising boat where resilience of the rig is
of ultimate importance?

Bob Swarts


No. The shock loading is so low as to be immaterial.

Brian W

actually, not true brian w. rod rigging, for instance, puts major shock loads
on a boat. One of the reasons it is seldom used on non-racing boats, except
those non-racing boat pretending to be racing boats.

From: Brian Whatcott
Date: 1/30/2005 7:18 P.M. Eastern Standard Time
Message-id:

On Sun, 30 Jan 2005 09:54:13 -0800, "Robert or Karen Swarts"
wrote:

I know conventional wisdom decrees that running rigging use polyester
cordage and anchor line use nylon. The nylon is said to stretch more, and
thus take up shock loads more readily. Polyester, on the other hand,
stretches less and is said to make setting the sails easier. I can
understand this for racing purposes, but wouldn't the same tolerance to
shock load be a blessing in a cruising boat where resilience of the rig is
of ultimate importance?

Bob Swarts


No. The shock loading is so low as to be immaterial.

Brian W

So what does rod rigging have to do with running rigging?

Actually Jax, as long as the shrouds are tensioned correctly, the
difference in shock loading between wire and rod is minimal.
Load up the wire to 10-15% working load and you eliminate
most of the "settling" of the wire, and the spring constants
or shock response of the two run pretty close to the same.

"JAXAshby" wrote in message
...
actually, not true brian w. rod rigging, for instance, puts major shock
loads
on a boat. One of the reasons it is seldom used on non-racing boats,
except
those non-racing boat pretending to be racing boats.

From: Brian Whatcott
Date: 1/30/2005 7:18 P.M. Eastern Standard Time
Message-id:

On Sun, 30 Jan 2005 09:54:13 -0800, "Robert or Karen Swarts"
wrote:

I know conventional wisdom decrees that running rigging use polyester
cordage and anchor line use nylon. The nylon is said to stretch more, and
thus take up shock loads more readily. Polyester, on the other hand,
stretches less and is said to make setting the sails easier. I can
understand this for racing purposes, but wouldn't the same tolerance to
shock load be a blessing in a cruising boat where resilience of the rig
is
of ultimate importance?

Bob Swarts


No. The shock loading is so low as to be immaterial.

Brian W