Which size dock line?

[Ward H]

I have been going back and forth on this and decided to ask this good group.

OK, I have read the West Marine Advisor and BoatUS articles on choosing dock lines as well as the Samson and New England Rope websites on breaking strengths and recommended line size for boat size.
Most say the same thing, 3/8" up to 25' and 1/2" 26' up to 35'. (One says 3/8" for up to 27')
Since my boat is at the top of the range for 3/8", which should I go for?

Here is why I am asking.
My slip is on the bay and along a channel so it has little protection from wakes and weather.
Last year I used Samson 1/2" double braid. During a NorEaster in the fall, I doubled up with 1/2" 3-strand nylon. The way I set these lines I could see how the 3-strand would stretch a bit before the double braid snapped taught.

A couple of the DB dock lines got chaffed and need replacing. I plan on changing them all to 3-Strand Nylon this year to make it a little easier on the beating the boat cleats take.

I would be glad to go with the 3/8" line and I believe the boat cleats are made for 3/8" as 1/2" does not go through the opening of the cleat.
BUT, considering the pounding the boat takes in foul weather, should I stay with 1/2". The 1/2" 3-Strand should still be an improvement over DB as far as easing the shock on the cleats.

I've attached a photo showing Moon Shadow in it's slip and how exposed it is. On the outside of the last slip there is a plank bulkhead which breaks up some of the action but on this day the boat was rocking to badly to even think about going aboard.

Opinions?

 

[thinwater]

1/2" sounds right. I used 3/8" on my 27, but it was far better protected.

Get some chafe protection. Dock lines should last years.
http://www.rei.com/product/472049/bluewater-2-climb-spec-tubular-webbing

 

[Stu Jackson]

...and I believe the boat cleats are made for 3/8" as 1/2" does not go through the opening of the cleat.

Opinions?

Dock lines should not go through the holes in the cleat.

Look at the second picture: http://www.c34.org/projects/projects-ron-hill.html

If the HORNS on your cleats, and their height, can take 1/2" line, by all means do so.

Or, save some $$ and just buy line, tie horn cleats on the lines onto both your dock and the boat.

 

[capta]

I sincerely hope when you say "Samson 1/2" double braid" you mean nylon double braid. I personally will not use anything but 3 strand nylon for dock lines, but that's a personal preference, and I don't need to color coordinate my dock lines (no admirals aboard this boat).
In keeping with my signature bellow, coined by an old salt with a few Cape Horn poundings (oops, roundings) under commercial sail, I'd suggest you get the largest line that will fit your cleats comfortably. If your docking cleats can't handle even 1/2" then perhaps you need to fairlead to your winches to properly secure your boat.
Nothing less makes sense. For instance, if using 5/8" and 1/4 of it chafes away, you still have 3/8ths. If you start with 1/2 inch and lose 1/4", well you get the idea. Of course chafe gear helps a lot, but still. I recommend used fire hose from your local fire department. Works amazingly well, very long lasting and it should be free.

 

[Charlie Jones s/v Tehani]

I use 1/2 3 strand on my 25 footer.With chafe guards on the chocks on the boat and on where it cleats on the dock.

Curious about one thing- what sort of cleats do you have that the hole is too small for a 1/2 inch line? My Herreshoff style will take a doubled 1/2 inch where the eye is spliced in

 

[SailingHarry]

Two thoughts:

First, smaller lines have more stretch when surging. Bigger lines may last longer/be stronger, but the smallest acceptable line size will reduce impact loading on the cleats. Like everything, it's a compromise.

Second, the very nicest (but not cheapest!) dock lines are the nylon 12-strand. Even more stretch/give than 3-strand, a dream to work with, just a top not pleasure.

Oh, and as a data point, I use 1/2" in on my 34. 3-strand at my home dock (well protected), 12-strand for my travelling lines (often more surge, also they have to get coiled up).

Harry

 

[Ward H]

TW, Thanks for the link. I believe the chaff came from where the working line first touched the dock cleat. I plan on putting chaff protection at that point.

Stu, I thought the open based horn cleat was open for that reason. I currently twist the loop in such a way that the working line locks down the crossover loop. Will try to get a pic this weekend to see if it is appropriate way to do so. To save $$$ I was planning on buying a length of line and cutting custom lengths and splicing in the eyes myself. Your suggestion to use a cleat hitch instead of a spliced eye on the boat cleat sounds easier. At least that is what I think you suggested. I may still do the eye splice so I have a loop to grab with the boat hook and do the cleat hitch beyond the eye.

capta, yes, only nylon for dock lines.

TSBB 2, No chocks on the O'day, just what I believe would be called "open based horn cleat". Uses two fasteners.

 

[Ralph Johnstone]

Consider snubbers on your dock lines to reduce the shock.

These little buggers are expensive and suseptible to UV so be sure to cover them for protection. I use a 2" dia. flat hose which is about $0.50/ft. and have had the same snubbers for about 14 years. The flat hose only lasts about 2 years before giving up as a sticky mess to the UV. Probably be able to get them here on the SBO chandelry.

 

[Hartley]

Hi Ward,

If your cleats are small enough that 3/8" won't go thru the center, you might consider installing larger ones - cleats aren't all that expensive and that way you would know for sure that the backing was substantial and the deck properly sealed. It looks like your slip is pretty exposed and those cleats will be getting a beating. I have 3/4" and 5/8" docklines on our 48-footer - and they go thru the hole in the cleat easily..

The very first boat we owned chewed about half-way through the docklines the first winter (in San Diego) - at the exact same place you encountered, right at the dock end where the nylon hits the galvanized cleat. I concluded that this was because the somewhat rough galvanizing was able to abrade the nylon - something that didn't happen on the smooth SS cleats and chocks on the boat. So I constructed some chain loops out of recycled anchor chain (3/8" BBB) and built up new docklines (see the attached picture). I've built mine with exact lengths, so no adjustment is required, but they could also be built with the boat end free, and therefore adjustable. I also put rubber snubbers on the short ones to increase the shock absorbing qualities. I keep a set of conventional docklines handy in the lazarette for traveling, but for the home slip the chain loop lines are quick and foolproof.

The original loops I built in 1995 are still on our current boat - they have been painted lots of times, and the lines replaced a couple times - but the loops appear to last forever. The second picture (with the yellow painted chain) is where I have both the bow and spring lines attached.

 

[Stu Jackson]

That's anice idea. I would carefull check the quick links though. I'd put the shackles right through the chain links, or use a carabiner. I have metal thimbles at the ends of my dock lines and put large shackles right through the loops of the dock cleats to that thimble. Same concept, different details.

 

[Steve Dion]

Add chafe protection to whatever lines that you purchase if the come in contact with hard/sharp surfaces.

 

[Hartley]

I did attach to a cleat in Ensenada with a big shackle once, as one of the horns was busted off (yike!) - but that means you have to unscrew or unpin a shackle when you dock or un-dock. With my loops, all I have to do is drop the loop over the cleat and I'm done - and it works on almost any cleat. You will note that my loops are painted in colors, with a corresponding patch on the cleat -makes it easy to toss to someone on the dock helping you out - "just drop it over the yellow cleat".

As a (former) mountaineer, I like carabiners a lot - but not for docking - it's too easy, even with locking ones, to have them shake around to a position where they can be opened and/or overstressed.

I agree that the quick-links are the weak point, which is why I went to SS ones (plated ones kept rusting solid in a year, even when painted) - but they do get wrench tightened and checked annually. You could use a shackle, but you would need two, as you can't get an appropriate-size (reasonably priced) shackle thru two links of chain. I used the SS ring on the one with two lines in order to ensure that the quick link didn't get pulled out of shape.

One other advantage of the chain loop is that if the end of the dockline goes in the water, it WON'T be able to get to the prop until you get a LOT of speed on..

 

[Tom]

I really like my boat..

.. So I use 3/4 twisted, with snubbers. (not a great harbor)

Tom
s/v GAIA

 

[Bill1565]

.. So I use 3/4 twisted, with snubbers. (not a great harbor) Tom s/v GAIA

Me too with 3/8 BBB chain to ground screws in my Yard.

 

[Ward H]

Found a photo I cropped to show how I loop my lines on my deck cleats. Shown is the 1/2" nylon double braid. Is this acceptable practice?
I like the idea of chain on the dock cleat but I prefer to leave the dock side lines adjustable in case they need tending.
3/8" line will fit through the cleat opening, 1/2" won't but does fit the horns well so it sounds like 1/2" it is.

 

[weinie]

Not necessary to loop it through the cleat. Growing up as a powerboater, I always did that. When I switched to sail, the wrench at my marina made me a bet. He told me to just throw a loop around the cleat. He promised me if any one of my lines ever slipped the cleat, he'd buy me a brand new yacht of my choice.
Five years later, I'm still using simple loops and still sailing my old catalina.:cry:

 

[SailingHarry]

Found a photo I cropped to show how I loop my lines on my deck cleats. Shown is the 1/2" nylon double braid. Is this acceptable practice?

Of the three types of nylon, double braid is the least good. 3-strand and 12-plait both have considerably (dramatically?) better stretch, reducing surge stresses. Double braid is best reserved for high performance (high-tech low-stretch) running rigging, not dock lines.

 

[Hartley]

I agree with both weenie and SailingHarry - you don't need the loop/girth hitch around the cleat, and 3-strand twisted or 8/12 strand brait are much better choices for docklines. They're both easy to splice (get a hollow fid and a hot knife to make it extra easy) so you can make up exactly what you need.
I would see if you can get your eyeballs on the backing plates for your cleats - with the beating they get, you don't want them working on your fiberglass because they're loose or inadequately backed. Sadly, many boat manufacturers skimp on the cleat installations because a lot of folks don't really stress them.

Good luck!

 

[Stu Jackson]

Found a photo I cropped to show how I loop my lines on my deck cleats. Shown is the 1/2" nylon double braid. Is this acceptable practice?

Two reasons to not do this (besides it's like a "newbie sticker" or a former mobo guy like weinie said)

1. Most suggest leaving your dock lines at the dock so they are the right length all the time, hard to do this way

2. If you have to get out of Dodge quick, quick, quick, it's a PITA to remove them

 

[Ward H]

SailingHarry, I agree. The photo was just to show how I looped the line. In my rather long beginning post I mentioned how I saw first hand how much more stretch 3-strand had than the nylon double braid of the same size. That convinced me to switch to 3-strand this year.

weinie, I've tried just looping them over the deck cleat but the angles appear to be wrong to ensure a slack loop doesn't pop off one of the horns. That close up photo is at a different location than my slip.

I appreciate all the advice and comments.