Jack Line Knot: best Type?

[roxbury]

What is the best of knot to use for securing a tape-type jack line to a pad-eye?

[sailingdog]

One side should have an eye splice and that should be run through the center of the cleat and over it... the other can be secured using a normal cleat hitch and then have the tail seized or sewn to the standing part to prevent it from coming loose.

Originally Posted by roxbury

What is the best of knot to use for securing a tape-type jack line to a pad-eye?

[GeorgeB]

I am not sure of what is the “best way”, but here is “my way”. If you have a sewn loop, do a “Lark’s Head” on the pad eye. I tie a “Waterman’s Knot” on the other end. Which is merely an overhand knot that the tail is re-roved through the original knot. The picture really doesn’t do it justice, look it up on one of the knot tying websites.

Not to hijack the thread, but have you seen this month’s Sail Magazine? They have a short “how-to” article on jacklines where they advocate twisting the webbing multiple times (like ribbon candy) before securing it. The theory is the line will “stand up” better and be easier to grab. I thought that one of the purposes of webbing was to lie flat and not pose a tripping hazard. Kind of defeats the purpose IMHO. Comments?

[QuickMick]

lol, i love the warning sticker... it just cracks me up every time

[sailingdog]

I wouldn't use a waterman's knot. The overhand knot it is based on has a pretty low strength compared to many others.

For a padeye without an eye splice or loop, you might want to use a pedigree cow hitch, which is a cow hitch with the terminal end passed through the two loops and then seize the tail to the standing part of the line.

Originally Posted by GeorgeB

I am not sure of what is the “best way”, but here is “my way”. If you have a sewn loop, do a “Lark’s Head” on the pad eye. I tie a “Waterman’s Knot” on the other end. Which is merely an overhand knot that the tail is re-roved through the original knot. The picture really doesn’t do it justice, look it up on one of the knot tying websites.

One real good reason for adding multiple twists to a jackline is to prevent them from humming. Pete Goss cut his jacklines on his boat in one race because he couldn't stand the humming caused by taut jacklines—it was driving him crazy. Another sailor showed him the trick of adding a few twists as that prevents them from humming.

Not to hijack the thread, but have you seen this month’s Sail Magazine? They have a short “how-to” article on jacklines where they advocate twisting the webbing multiple times (like ribbon candy) before securing it. The theory is the line will “stand up” better and be easier to grab. I thought that one of the purposes of webbing was to lie flat and not pose a tripping hazard. Kind of defeats the purpose IMHO. Comments?

[Plumbean]

A water knot is the knot of choice in the climbing community for securing webbing like this. It won't slip and in this configuration has a great deal of strength. I would think it would be fine for a jack line.

[RichH]

Originally Posted by roxbury

What is the best of knot to use for securing a tape-type jack linet to a pad-eye?

'Water Knot' tied to an 'alpine butterfly' is best to terminate webbing - this will result in a 'gun-tackle' 2:1 termination. Both are 'standard' mountain climbers knots.

[pdqaltair]

Originally Posted by sailingdog

I wouldn't use a waterman's knot. The overhand knot it is based on has a pretty low strength compared to many others.

For a padeye without an eye splice or loop, you might want to use a pedigree cow hitch, which is a cow hitch with the terminal end passed through the two loops and then seize the tail to the standing part of the line.



One real good reason for adding multiple twists to a jackline is to prevent them from humming. Pete Goss cut his jacklines on his boat in one race because he couldn't stand the humming caused by taut jacklines—it was driving him crazy. Another sailor showed him the trick of adding a few twists as that prevents them from humming.

Actually a water knot (trace overhand) is the prefered knot in webbing. I have conducted laboratory climbing gear distruction, and it scores very well; 85% strength. The reason is the same reason a chain to rope splice works; webbing is thin and the bend radius and forc distribution factors do not apply in the same way. That said, the knot must be tied flat and well formed.

You are correct in for rope, where it is not a very good knot.

I will add that 1-inch climbing webbing is not quite strong enough and is a bit too stretchy for jacklines unless the boat is under ~ 32 feet. You really need 6000-pound test if you will ever have 2 people on the line.

Sail Delmarva: Sample Calculations for Jackline Stress and Energy Absorption

[sailingdog]

Good to know.

Originally Posted by pdqaltair

Actually a water knot (trace overhand) is the prefered knot in webbing. I have conducted laboratory climbing gear distruction, and it scores very well; 85% strength. The reason is the same reason a chain to rope splice works; webbing is thin and the bend radius and forc distribution factors do not apply in the same way. That said, the knot must be tied flat and well formed.

You are correct in for rope, where it is not a very good knot.

I will add that 1-inch climbing webbing is not quite strong enough and is a bit too stretchy for jacklines unless the boat is under ~ 32 feet. You really need 6000-pound test if you will ever have 2 people on the line.

Sail Delmarva: Sample Calculations for Jackline Stress and Energy Absorption

[GeorgeB]

I currently use the Water knot based on advice I received from my rock climbing friends. The fenders we tie on with hitches occasionally come loose, but this knot never has (yet!). Alpine Butterfly? Gun Tackle? What are these things and how would I used them on my boat? My webbing is tubular and is either 6,000 or 8,000 pounds breaking strength (Can’t recall which off of top of my head) and were made by one of my local sailmakers.

Did the Sail article mention harmonics? I lost interest at the point where they thought that ease of grabbing trumped the tripping hazard. I can’t recall getting a bad harmonic off of a jackline. Usually, on the boat’s I’ve sailed, when it is that windy, the decks are wet and the jacklines have begun to stretch. We start out at the dock with them banjo string taught, but bythe Golden Gate, they have already stretched due to wetness. The biggest noise problem for me is somebody dragging their tether shackle across the non skid while I’m trying to sleep. Note to newbe’s and tyros – Pick up your tether when you go forward, don’t go clumping around like a Neanderthal!

Yes, that warning sticker cracks me up. MrsB wanted me to remove it years ago, but it is too funny not to keep. Sort of like the molded in warning on the business end of a Claymore – “This side towards enemy”.