Genoa Halyard Block query

[Abestea]

Hi all,

Hope you are all having a good new year and everything is going to plan in the boat maintenance front.

Now that i have buttered you all up here is my question /forums/images/graemlins/smile.gif
My boat has wire and rope genoa halyards and as there was no parrel balls on them when i got it the metal collar got jammed in the double genoa halyard block on the mast. Now since i had to take the mast down to fix the problem i decided to replace the halyards with all rope. Now i have been told that i cant do it as it is not a standard double block. Any advice? There is no way 10mm rope would go through one of the openings. Now are the double blocks usually positioned side by side or one above the other?
It just seems that boat are a little quirky. Sometimes

Thanks,
Abestea.

 

[roly_voya]

Several pionts.
If you replace wire hallyards with rope you need to use dyname or similar very low stretch stuff or go to a very heavy rope otherwise yu will find the halyards stretch to much and wont give correct tension.
You will have to change the block as rope blocks are compleatly different sizes and profiles. Also it is normal to have plastic sheavs for rope and alloy ones for wire. Wire will damage plastic sheves and alloy sheaves can damage rope particularly if it doesn't fit the rope profile.
If you have a double block with side by side sheaves both should always be evenly loaded, otherwise you need two seperate blocks. Loading one sheave on a double will substantially weeken it and cause the rope/wire to go out of line and chafe against the side if the block. Normally double with sheaves in line are used for takles but could be used for two lines for example with and inner and outer headsail. The loads don't need to be even but they do need to be in exactly the same direction.
By far the simplest solution is te keep the wire halyard and arrange it so it can't jam in future by adding some form of stopper. Wire halyards are very low stretch, dont chafe, run well on blocks and last for ever. Only disadvantages are that they are damaged if kinked and a bit heavy.

 

[john_morris_uk]

[ QUOTE ]
If you have a double block with side by side sheaves both should always be evenly loaded, otherwise you need two seperate blocks. Loading one sheave on a double will substantially weeken it and cause the rope/wire to go out of line and chafe against the side if the block. Normally double with sheaves in line are used for takles but could be used for two lines for example with and inner and outer headsail. The loads don't need to be even but they do need to be in exactly the same direction.


[/ QUOTE ] I wondered if he really meant 'block on the mast'. Does he mean that they are external halyards? If he does then your comments are correct but external halyards are relatively rare on modern boats, If his sheaves are in the mast with internal halyards, then it doesn't matter half so much about loading them with similar tensions. However, the sheaves still need to be correct for either rope or wire. By the way, why do you say wire MUST be replaced by Dyneema or similar high tech line? Lots of cruising boats managed for years on good quality pre-stretched terylene lines. His profile doesn't say if he's a racing boat, and I suspect that if he was a racing sailor he wouldn't be asking the question...

 

[Aja]

To all intents and purposes, this looks like a Sigma 33 that has retired - note the roller reefing.

I don't know much about the 33, but if you take a walk around any of the boatyards on the Clyde (especially Rhu) you will see what other 33 owners have done.

Donald

 

[john_morris_uk]

If it is a Sigma 33 then the sheaves are definitely in the mast and you can load one up and not the other without any problems.

 

[William_H]

I am confused by "No parrell balls" and the metal "collar jambed ".

If the wire slipped between the sheave (wheel) and the side plates of the block then it sounds like the block has been damaged or the sheave is too narrow.
I would also suggest reusing the wire halyard if it is in good condition. No they don't last forever as the rope tail can degrade in the sun and with wear and the wire strands will start to fail. However the dynema high tech rope is expensive but cheaper than getting someone to do the wire to rope splice and buying new wire and rope.

Just another thought that the wire end of the existing halyard should bbe so long that it is unlikely to be pulled until the rope tries to go through the top sheave. That could jamb it all. On the other hand the wire needs to be so short that it does not reach the halyard winch when the largest jib is right up. good luck olewill

 

[john_morris_uk]

I think he means that there was no plastic ball stopper on the halyard although it isn't normal to put one on a Genoa Halyard anyway. The metal furrule could easily have jambed in the sheave in the mast if he has a genoa with a luff that's too long, or if he put the wrong tack-strop in place. (On our Sigma 33, you needed to change the tack strop according to which sail you were hoisting) A parrell ball is one of those balls that go on the strops round a mast from the gaff of with a traditional or gaff rig etc.

I think his parts naming is all a bit squiffy. I am not sure about calling it a 'block' when it is almost certainly in the mast. Blocks are free floating things in my understanding of things. I think he should have described his problem as the wire halyard getting jambed in the halyard sheaves in his mast (actually 7/8 the way up for these sheaves!!) or similar...

Your suggestions reference wear and using wire halyards etc are spot on but I would be interested to compare the prices of a new wire to rope halyard with new splice and a high tech line. I still stand buy the possibility of using a good pre-stretched braid on braid if its not a racing boat anymore.