Mainsheet Twist

[DHV90]

My 6:1 mainsheet is on a dyneema strop to the boom to make the overall length as short as possible so as soon as the booms over the traveller a bit of tension pulls any twist out of the purchase quite quickly, yours going down to the floor looks really long and any tendency to twist in the rope might be magnified by that. Might be worth trying to shorten it a bit if you can? My blocks are not locked off so I can take the sheet with me as I move around the cockpit and work the main from any position, so both swivels are free to turn.

 

[ProMariner]

As already identified, the blocks twist because the rope has been twisted. Take the twists out of the rope, easiest way for me is take it out the tackle, tie off one end and stretch rope out full length, you can also rebalance the rope cover, and end for end the rope, while you're there.

Then, never do the rope twisty 3 strand coiling thing on balanced braids again, instead either half hitch coiling (gasket coiling), or figure of 8 coiling (takes practice to overcome muscle memory), so as to not introduce twists.

 

[yerffoeg]

I had the same problem. Fit a swivel at the top or bottom. eg

https://www.marinesuperstore.com/de...N-Ouk84-TUDUhGKpLJcz4HzkGNLIhHG4aAt1vEALw_wcB

It solved the problem I was having.

 

[lw395]

I had the same problem. Fit a swivel at the top or bottom. eg

https://www.marinesuperstore.com/de...N-Ouk84-TUDUhGKpLJcz4HzkGNLIhHG4aAt1vEALw_wcB

It solved the problem I was having.

Conversely I have solved problems by removing such swivels, or locking them.
First time was on a dinghy when I was about 12.
Rope has a mind of its own sometimes

 

[Daydream believer]

Conversely I have solved problems by removing such swivels, or locking them.

if one locks the bottom block how does one operate the cleat when sitting up to windward on one side or the other when helming, or if the crew sometimes does it for the helm, how can the block be quickly rotated to allow this?

 

[Daydream believer]

My 6:1 mainsheet is on a dyneema strop to the boom to make the overall length as short as possible so as soon as the booms over the traveller a bit of tension pulls any twist out of the purchase quite quickly, yours going down to the floor looks really long and any tendency to twist in the rope might be magnified by that. Might be worth trying to shorten it a bit if you can? My blocks are not locked off so I can take the sheet with me as I move around the cockpit and work the main from any position, so both swivels are free to turn.

If one tries to shorten it by putting a strop at the top then when the boom is tacked there is a flailing block swinging about which can be dangerous. Conversely if one puts a strop at the bottom the block will want to fall over at a variety of angles making cleating it difficult unless it is under tension.. Perhaps on your boat the presence of a traveler keeps the crew out of the swing line of the block but the Op does not have a traveler so may well be liable to a clout from the block. This could be extremely dangerous if he gybes & cannot get all the falls of the mainsheet in fast enough so that the block is not under control