Mainsheet blocks twisting

BlueChip

BlueChip

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My mainsheet has two triple blocks, the one on the boom has a becket and the lower one a cam cleat
Having removed the sheet this winter for a wash I now cannot seem to get the right order of line through the blocks to stop it jamming, the top block twists and locks the mainseet solid.
Hope this makes sense - a picture would have helped I know. Can anyone offer an explanation of why the top block is twisting - should it be locked? and what is the preferred way of feeding the mainsheet through the blocks
 
Google "handy-billy" or "Reeving block and tackle" ... and you'll get the reeving of blocks ... '' whats happening is the sheet passing through is imparting the twist ... reeving according to naval tradition removes that twist effect.
 
[ QUOTE ]
Google "handy-billy" or "Reeving block and tackle" ... and you'll get the reeving of blocks ... '' whats happening is the sheet passing through is imparting the twist ... reeving according to naval tradition removes that twist effect.

[/ QUOTE ]Thanks! I didn't know that! /forums/images/graemlins/smile.gif
 
Or here, stolen from the Barton site
Triple-line-diagram.gif
 
The barton diagram shows the trick - the blocks are at 90 degrees to each other. Bet OP laid the blocks in line to reeve. It's natural for person to do this unless they know of the "Handy Billy" 90 deg. trick.
 
my mainsheet block on the boom and the traveller are both swivel-mounted and I have to unreeve the sheet twice a season to get the twist out. Do you have a solution? Thanks!
 
nope - all I can say is it sounds like you have either wrong rope form used or not reeved correctly.

I'm lucky - I have double blocks not triple. If I get twists or anything - I can flip the block 360 through the 'loops' to get it fair again.
 
<<<< my mainsheet block on the boom and the traveller are both swivel-mounted and I have to unreeve the sheet twice a season to get the twist out. Do you have a solution? Thanks! >>>>

Are you sure they are reeved exactly as shown? The change of direction on the two outer sheaves should take out the twist. I raced Hobie 16s for many years (with 6:1 mainsheet) and have had a 6:1 mainsheet on the Sadler for the past 13 years. All were reeved as shown and I never had a twist problem in service. The only time I do now is when I remove the lower connection to the traveller car when anchored, and the block passes through the ropes when stored on the coachroof.
 
I have 2 blocks with a becket on each - sheet goes round the smaller pulleys on each block then around the larger ones..
 
no I can't - fixed eye on one end. It's fine after I stream it (carefully!) over the side when motoring, but eventually twists again (bit like the Beatles really!)
 
You may find it helps to remove the swivel from the top block, or lash it, cable tie it, whatever, or at leat limit how far it can turn. Some rope just does not want to behave, and its expensive to keep changing the rope! Even symmetrical plaited rope can give problems sometimes. Unnecessary swivels are a pain! If a rope is happily twist-free at rest, it can develop twists under high load, and allowing the block to turn will add gross amounts of friction.
 
Could be the way you make up the rope.

Some people like to give a rope a bit of a twist when making the hanks... it makes it loop nicely. This does, however, put twists in your rope. if you then let this run into your mainsheet system it can make the system twist up. Various poeple crew with my mum on Eider Duck, I & know when I come on board if someone uses the half twist method of making up the mainsheet.... the traveller is all twisted. I then take the mainsheet off, straighten it & re-reeve.

If you make up the mainsheet without adding the twist (which means the sheet often ends up in a sort of figure of eight whe you lie it down) then you won't get a twisted traveller.

I'd rather have a smooth running sheet than nice neat looking hanks of made up mainsheet.


I may be wrong... but it works for me.
Cheers
SmileyG
 
I vaguely remember some chant about down through the center ofblock A then up through the right of block b etc etc . On second thoughts I think I will print off the diagram.

On standing derricks we used to lash a short spar through the center of the running block with guys attatched. Probably a bit impractical on a yacht... /forums/images/graemlins/wink.gifBob 234s suggestion of locking the swivel would have the same effect.
 
[ QUOTE ]
Could be the way you make up the rope.

Some people like to give a rope a bit of a twist when making the hanks... it makes it loop nicely. This does, however, put twists in your rope. if you then let this run into your mainsheet system it can make the system twist up. Various poeple crew with my mum on Eider Duck, I & know when I come on board if someone uses the half twist method of making up the mainsheet.... the traveller is all twisted. I then take the mainsheet off, straighten it & re-reeve.

If you make up the mainsheet without adding the twist (which means the sheet often ends up in a sort of figure of eight whe you lie it down) then you won't get a twisted traveller.

I'd rather have a smooth running sheet than nice neat looking hanks of made up mainsheet.


I may be wrong... but it works for me.
Cheers
SmileyG

[/ QUOTE ]

If you follow this little rule - there is no need for the twist :

Stream your rope out in the water behind you and pull in to coil ... twists all fall out as you puill in the rope. Or lay it along a dock / deck and then coil. I do this to my ropes at intervals as in use they tend to get odd twists in and they need to be removed. Trying to coil and 'flick' them out doesn't work and leads to the twist the rope to coil compromise. This then makes the twist semi-permanent in the rope.

Another error made by some is to coil back to the standing part - ending up with a twisted mess at the fixed end. You should always coil from the standing fixed end to the free end - that way twists and turns come out as you go along.

(sorry if it sounds like I'm teaching granny etc. - but I see the above error so often ....)
 
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