Docking lines, 3-strand vs braided

[SV_Harbinger]

I use the ubiquitous 3 strand nylon in all my dock lines. I like to have an eye splice in one end, but not all of them have one. As far as them getting stiff, I just give em a misting with some fabric softener when they start to harden.

[zboss]

Originally Posted by Capt Dave H

I once had a slip where occasional surge was possible, could be interesting at times.

The braid would not stretch, as a result I've seen cleats ripped out.
I used 3 strand for the stretch and did not damage the boat.

Agreed. We switched from 3 strand to braided two years ago because its easier to handle and store on the boat. In slips where there is surge or wakes from boats the braided line jerks the boat. There have been quite a few times where I was thinking a cleat was going to be ripped out.

We are going back to three strand nylon.

[rslifkin]

In a given size, double braid is a bit stronger than 3 strand and at a given percentage of load, it stretches about half as much. So figure about 40% as stretchy as 3 strand for a given force.

Personally, I use double braid (handles better, looks better, better chafe resistance), but I try to lay out my lines so that they're all fairly long to ensure enough stretch. I typically use 5/8", but 1/2" is strong enough for the size of the boat, so I will sometimes use a 1/2" line if I have to make a somewhat shorter run and find it not stretchy enough.

[BlackHeron]

We buy black 1/2" 3-strand nylon in bulk and make our own lines for our 35' HR Rasmus.

Black lasts a bit longer as it doesn't get UV damaged as quickly as white, contrary to what someone earlier stated. But it unfortunately doesn't show filth or tar-pitch which may become a mess on your hull or deck if you pick some up from a treated piling and don't realize it until it is too late.

I don't like eyes as we don't have a home port and are always staying in different places and not often at marinas. Usually we only dock for fuel/pumpout and are off again, or at a free wall or dock since we are cheapskates. Currently nwe are in a marina slip but that is a COVID-19 thing.

I prefer to make my own loop with a bowline when necessary, a bowline is not as strong as a spliced eye but breaking strength is really not an issue most of the time. Oftentimes a loop is pulled through the bowline to make a slip loop and the force on the bowline is but a small fraction of what the line sees due to purchase around the pile. I like not having an eye to catch on a cleat when pulling the line back from on deck. It happens on smaller cleats where it can jam as it comes around that last bend.

I can tie a bowline as fast or faster than it takes for you to read this sentence out loud. No big deal.

We leave our docking lines out all of the time, cow-hitched to the rail for quick access and cleated ready to go. UV damage is a thing so we replace them every couple of years since they are cheap since this stuff is only around $.50/foot or less in bulk. I like to have about 40' of line so there is enough to go around a piling or cleat and come back to the boat again if necessary which allows adjusting from on deck and casting off without going to shore.

On many older bulkheads and free walls they have massive cleats, dols, or sampson posts that were there for huge ships and barges. Going around and back to your boat works best for us on those if we have enough line. These are very common in canal-systems such as in New York.

If using fire hose for chafe protection get the stuff used for fighting wildfires. It isn't lined so the hose gets wet when in use, and doesn't burn when dragged over hot coals or still-burning ground. As others have said the lining inside regular fire hose will not let cooling moisture into the inside to lubricate the line and reduce heat build-up in extreme events.

With stretchy line like nylon it is best that fairleads/chocks and hawseholes be as close to the cleats on deck as practicable. The shorter this distance the least movement there will be at the chafe point. We have about 10 inches between the bow chocks and the far side of the bow cleat. That is only a tiny fraction of an inch of movement even at maximum stretch since there is less than a foot of line to do the stretching between those two points. Our stern cleats are similarly closely located to their matching chocks.

[slug]

Originally Posted by rslifkin

In a given size, double braid is a bit stronger than 3 strand and at a given percentage of load, it stretches about half as much. So figure about 40% as stretchy as 3 strand for a given force.

Personally, I use double braid (handles better, looks better, better chafe resistance), but I try to lay out my lines so that they're all fairly long to ensure enough stretch. I typically use 5/8", but 1/2" is strong enough for the size of the boat, so I will sometimes use a 1/2" line if I have to make a somewhat shorter run and find it not stretchy enough.

Yah ..,plus double braid handles better in winch self tailors

I never buy docklines , I recycle sailing sheets

[BlackHeron]

Sheets are supposed to be low-stretch -not exactly what is wanted in dock lines. Low-stretch is more subject to shock loads and more likely to snap. If it is too burned to be servicable as a sheet that's just perfect to trust for a dockline then...

I guess breakaway docklines are a thing now?

[LEOCAT66]

In our home slip, we use 1” 3 strand, with tide minder roller balls, on dedicated pilings, as we are usually dealing with hurricane issues each year, on the Gulf Coast. Don’t even need spring lines as boat stays well centered without them. We may use them if expecting a major hurricane.

When we cruise we use 3/4” three strand lines.

[wilson eavis]

After buying expensive dock lines and seeing them fade, chafe, etc. I've come to the opinion that 3 strand polyproline line is as good or better than anything. That's what most of the fishermen up here in eastern Canada use and if it's good enough for them, it's good enough for me.
Sure the sun is hard on them but they're super cheap, so if you get 5+ years out of them, what's the big deal. Besides being easy to splice, have more stretch and are a lot cheaper than fancy lines, "they float"... something very important for less experienced, or short handed sailors like myself.
If you use conventional lines that do not float, I'd suggest a bow line that's not long enough to reach the prop. Yes, I've learned the hard way, lol.
Just saying...

[CarinaPDX]

Many of these posts imply that all that is available is either double-braid or 3-strand, which was always the choice in the US (but no longer). I use 8-plait for dock lines; it has stretch between the other two and has the advantage of staying very flexible and not hockling like 3-strand. For 5/8" and up a 12-plait line is available from New England Ropes and should also work well for larger boats. The plaited lines have a beautiful eye-splice that produces a square (8-plait) or hexagonal (12-plait) cross-section.

Greg

[Oceanconcepts]

What Greg says.
I have a slip that is incredibly exposed in winter, and have broken more lines and snubbers than I can recall. Braid was the worst for durability, both chafe and breaking. Three strand holds up better, but does tend to get hard and kink. The 8 plait I got from Defender several years ago (5/8" for a 39' 18,000 lb sailboat) is by far the most durable, easy to splice, and remains soft and flexible even after years of use. Definitely my go-to for dock lines.