Dock Lines

[Island Mike]

I am getting close to launching my sailboat and because I have to totally refit here I am in need of some advice on some of the refit items. She is 40 feet long and weighs 27,000 lbs, what type and what size dock lines should I use? I know this questions is a little novice, but what the hey, I just want to be sure.

Thanks in advance for your suggestions.

[GordMay]

A forty footer will usually use 5/8" to 3/4" dia. dock lines.
Bow & stern lines are usually about 2/3 LOA (about 25' - 30' in your case), with spring lines about equal to LOA (50' in your case). These are minimum lengths.
Permanently attached dock lines can be custom sized to the application (allowing some extra line for easing).
When doubling lines, for storm security, I like using a tauter smaller line (1/2" in your case), backed by a slightly looser larger line (3/4"). The looser/larger line will be set to take up a load as the tighter/smaller line stretches.
Don’t forget chafe protection.

[Island Mike]

Thanks for the input Gord, one more question, I am confused about the type of line? Poly-Dacron, Nylon, Twisted, Braided - Any insite in this area would be so helpful.

[Jeff H]

I strongly prefer three strand nylon for docklines. Nylon's natural stretch provides some cushion from shock, and three strand builds up less internal heat and is more abrasion resistant that braid. I would only add a couple notes to Gordon's notes. There is nothing worse than too short a dockline. I would suggest that the length of Bow & stern lines should be about 2/3 LOA plus the length of the knots at either end (in my case I typically add 10 to 12 feet for knots since I use clove hitches at the piling end of the line), with spring lines about equal to LOA again plus the knots at either end. I use clove hitches with an extra wrap and double half hitch at the pilings to minimalize chafe.

Jeff

[GordMay]

As Jeff H indicates, longer lines are generally better - and minimum effective lengths should be considered to include any special requirements (clove hitches on dolphin pilings may require 10'-15' extra rope).
Nylon is the appropriate dockline material, which I also prefer in three-strand twist construction.

Chafe occurs when a line “saws” across a fairlead, or otherwise abrades due to motion or stretch. The greater the distance between a cleat and the fairlead serving it, the greater the chafe. Fairleads should be as close to the cleat as possible to reduce chafe. Fairleads should also “lead fairly” between the shore & boat side strongbacks.
The failure of many manufacturers to provide adequately sized, properly oriented, and “fair” cleats & fairleads, also rates high on my “pet peeve” deficiency list.

[CSY Man]

I bought new docklines the other day:

200' 3/4" 3 strand New England nylon.

(Got a Port Supply price @ west, $187.00 including tax..Bargain)

Cut the 200' into 5 lenghts of 40' each, whipped the ends the old-fashioned way, then dipped 'em in "Liquid Rope Whipping", (pg. 210 in the West catalog)

See way too many people around here using old sheets for dock lines. They are already worn out and chafed, then used to tie up a boat before the owners leaves town for the hurricane season...Idiots...

[markpj23]

I prefer double-braid just because it stows much easier and does not kink. In the larger sizes 3-strand is too unwieldy for me, hard to turn around the cleats, yadda yadda.

I found a manufacturer in Tucson AZ - good quality double-braid at prices that beat anything I've been able to find. Tubbs Cordage is the brand, sold through distributors such as Winney & Sons in CA (949) 756-1335.

5/8" double-braid nylon, 9000lb minimum tensile, $255 per 600ft roll = $0.43 / foot
3/4" double-braid nylon, 12,825 minimum tensile, $379 per 600ft roll = $0.63 / foot
They will splice eyes on both ends of the roll for $6 each. Pricing was as of May 06.

You can't choose color, line is white with a green tracer. Has a braided core (of course) - some lines advertised as dbl-braid have a solid core I've found...
This line will not have any special coatings or fancy features you may find with the pricey brands - up to each of us to decide if those are necessary I guess. Some chafe gear and good basic line are OK by me.

I have no affiliation with the manufacturer or any distributor. These guys were local - I saw the sign as I drove by their factory a few months back. Upon investigation I believe this is a good quality line at a great price.

Your perceptions may vary

[GMac]

Nylon 8 Braid (Octiplait, Square Braid, 8 Prait or whatever it is called in your corner of the world) with chafe protection. A Type66 nylon is better than a Type6, given a choice.

The best of both worlds. No rotating issues the 3 strand has, also better shock absorbsion and a s**t load better lasting , as dock lines, than a double briad.

You can get it in some pretty colours now as well

[CSY Man]

Yeah, I like Octiplait as well, just too pricey...

[SeaKing]

Originally Posted by Jeff H

I use clove hitches at the piling end of the line), with spring lines about equal to LOA again plus the knots at either end. I use clove hitches with an extra wrap and double half hitch at the pilings to minimalize chafe.

Jeff

I too use that same described clove hitch w/ extra wrap and hitchs. I have always used clove hitchs in my knot tying, since I was a boy scout. My dad taught me to splice three strand rope as a young boy, I was actually splicing rope before becoming a boy scout. I remember showing the scout master how to put eyes in 3 strand! My problem is my CEO (wife, chief everything officer) only likes the braided stuff and I don't like splicing that line. Had to change the fender lines to braided.$$$$$$ I like the cost of the 3 strand too!

[hellosailor]

AFAIK nylon 3-strand twisted is all you need. Plus, it is intentionally built to be "stretchy" and when it stretches it absorbs shocks that otherwise could tear out cleats. A dock line should be able to do this--halyards and braided line usually are built not to stretch, and AFAIK none of the "stretchy" braided lines will stretch as much as 3-strand.

That shock absorbing may not mean much on a calm day, but with 60+ knots and a storm surge...that's when it shows.

[GMac]

Hellosailor I think you mean Nylon or Polyesters fibres are stretchy. A 3 strand of vectran or manila for example won't stretch at all no matter what construction it is.

Think fibre types not so much construction. Fibre types mostly decide any stretch factors.

You are right about the double braids being less stretchy than 3 strands or most multiplaits though. Octiplait and 3 strands stretch pretty much the same, if made of the same fibre, just the octiplait will start to do it sooner and softer.

[hellosailor]

GMac-
Both the material and the construction, AFAIK. Manila is a traditional natural fiber rope, I wouldn't use it in the same sentence as vectran, since Vectran is AFAIK the much newer "artificial spider silk" high tech extreme low stretch fiber. Nylon would fall in between.

[Jeff H]

Manila is a bad choice for docklines. Manila will stetch but unlike the synthetics Manilla does not have a 'memory' and so will continue to stretch over time. Manila loses more strength when wet than the synthetics. Manila will rot if left wet for long periods of time. Not a good choice.

Brittle/low stretch materials like vectran are not suitable for docklines either.

Jeff

[hellosailor]

Jeff-
One good use for manila lines: If you have to tie off to a creosoted pier and want to throw them away afterwards!<G> Or, if you need to keelhaul someone and don't want to chafe up the GOOD lines in the process.<G>