Jackline keeps spinning round and round

[mark0978]

When I lower the jackline to work on something, pulling it back up is almost impossible. because it starts twisting, the causes the first line split (where the first ring is joined to the line that goes up the mast spins. This causes the line passing thru that ring to twist around each other and lock things into place so that I just can't haul the line up anymore.

This is a new trick, and it seems to vary depending on things I try to do, pre-twist it the other direction has been the most fruitful thing I've tried, putting a swivel on the rope so it could spin in place (it won't spin before the rope is twisted :-(

What is causing this and how do I stop it?

[Discovery 15797]

I suspect you are referring to lazy jacks.

Are these Harkin lazy jacks, or some other company, or are they homemade?

Do you have a diagram?

What type of line are you using?

[psk125]

Are you using twisted nylon line? I had major problems with twisted nylon line doing this in a hoisting setup for lifting kayaks in the garage. Swivels helped but did not solve the problem. Braided line might be less prone to twisting.

[zboss]

Our first set of jacklines were made of dyneema - no twisting whatsoever.

[JPA Cate]

Ours are double braid, no twisting with it, either. If you're using 3 strand, consider replacing with lifeline lacing, or maybe 1/4" venetian blind cord.

[roverhi]

Remove one end, undo the twist and put it back together. Repeat till it doesn't twist anymore. Used dacron double braid for mine and had minor twist that went away when i did the above.

[RogerLloyd]

I prefer tape. It does not roll you into the drink when you step on it. But bring it below if you are not sailing the boat for a while because the UV does not improve it.

[philcun50]

I feel sure you must be using twisted line. I had this problem at our yacht club when I was the flag officer. Someone previously had used twisted line for the halyards on the flag poles. I found they would twist if I put any reverse tension on to control the flag/pennant as I hoisted. Solution double braid. The swivels would not stop the twist as they wouldn’t rotate when loaded.
Like others I’m not familiar with the term “jack line”. I know of jack stays or lazy jacks.

[RogerLloyd]

American "jackline" = British "jackstay".
Lazy jacks are something else.

[mitiempo]

I don't think the confusion above will end until the op states exactly what he is referring to -

Lazyjacks which are attacked to mast and boom to tame the mainsail when raising and lowering it.

or

Jacklines which are attached to fore and aft sections of deck to clip a harness to so you do not go overboard when traversing the deck.

[Discovery 15797]

I've never seen a jackline (or jackstay) that "goes up the mast."

Why don't we wait for the OP to clarify?