Mainsheet advice needed please!

[James W]

I've got what I think is a totally over complicated mainsheet set up on my boat (pictured) and there's too much friction for my liking and nothing runs smoothly.

The boat is a 42 foot, 9 tonne production cruising boat and any ideas would be much appreciated!

Thanks loads, James

 

[pyrojames]

The forward double block is probably the the one causing the most trouble, because if the twist induced by the line going forward.

A better set up would be with triple block at the aft point on the boom and a single block forward. You would Al's do better with the aft boom block directly over the one on the track.

 

[rogerthebodger]

The forward double block is probably the the one causing the most trouble, because if the twist induced by the line going forward.

A better set up would be with triple block at the aft point on the boom and a single block forward. You would Al's do better with the aft boom block directly over the one on the track.

I agree a triple block on the boom with the track triple block set at 90 degrees to the upper block on the line going forward coming from the center sheave of the upper block .

 

[pvb]

It does look rather complex. And I suspect those blocks are all plain axle designs. Had you thought of using new ball bearing blocks?

 

[Ningaloo]

I found my 14mm sheet with a rather "fluffy" casing had lots of friction. I changed to 10mm dyneema with a slippery outer casing which totally transformed things.
As most of the time my sheets are used in a winch this worked well for me.

 

[James W]

The forward double block is probably the the one causing the most trouble, because if the twist induced by the line going forward.

A better set up would be with triple block at the aft point on the boom and a single block forward. You would Al's do better with the aft boom block directly over the one on the track.

Thanks James, so one triple block on the boom, one on the traveller, but keep the two other single blocks?

 

[James W]

I found my 14mm sheet with a rather "fluffy" casing had lots of friction. I changed to 10mm dyneema with a slippery outer casing which totally transformed things.
As most of the time my sheets are used in a winch this worked well for me.

I'm definitely swopping to dyneema, anything for a friction free life!

 

[James W]

It does look rather complex. And I suspect those blocks are all plain axle designs. Had you thought of using new ball bearing blocks?

I was going to go for them, but wondered if they might be too "tech" for cruising? Happy to be proved wrong though if you have experience.

 

[James W]

I agree a triple block on the boom with the track triple block set at 90 degrees to the upper block on the line going forward coming from the center sheave of the upper block .

Now that sounds like simplicity itself! Thanks Roger.

 

[rogerthebodger]

Now that sounds like simplicity itself! Thanks Roger.

Reeving a 6:1 Purchase

 

[dunedin]

Before investing in new dyneema mainsheet rope, perhaps wash existing mainsheet in fabric conditioner, which makes more flexible. Also wash blocks in hot water to remove salt build-up

 

[pvb]

I was going to go for them, but wondered if they might be too "tech" for cruising? Happy to be proved wrong though if you have experience.

If you're concerned about friction in the system, ball bearing blocks should certainly help reduce it. I've got them on my boat.

 

[rogerthebodger]

If you're concerned about friction in the system, ball bearing blocks should certainly help reduce it. I've got them on my boat.

Yes I have looked at you post again just to point out that ball bearings of any kink are not good for a static loaded bearing as the balls tend to dig into the ball races.

PTFE lined or Oilite bushes are much better as it gibes low friction of PTFE whit the load carrying capacity of a plain bush.

The are various different types of plastic that could be used I tend to use vesconite in most of my designs

 

[pvb]

Yes I have looked at you post again just to point out that ball bearings of any kink are not good for a static loaded bearing as the balls tend to dig into the ball races.

PTFE lined or Oilite bushes are much better as it gibes low friction of PTFE whit the load carrying capacity of a plain bush.

The are various different types of plastic that could be used I tend to use vesconite in most of my designs

Perhaps you should offer your advice to the technical people at Harken, Lewmar, Ronstan and other manufacturers who offer low-friction ball-bearing blocks for high load applications. I'm sure they'd value your thoughts.

Ball Bearing Blocks Series 75 | Ronstan Sailboat Hardware World

 

[rogerthebodger]

Perhaps you should offer your advice to the technical people at Harken, Lewmar, Ronstan and other manufacturers who offer low-friction ball-bearing blocks for high load applications. I'm sure they'd value your thoughts.

Any half decent qualified Design Engineer would know that.

What they are doing is supplying goods to the cheque book sailors who don't know better.

They also supply plain bush blocks for those who know better.

In fact I have started to make my own plain bearing blocks based on a plain bearing block supplied by Ronstan. years ago.

I could fit stainless steel ball bearings in them if the application needs then.

 

[pvb]

What they are doing is supplying goods to the cheque book sailors who don't know better.

So some of the most respected names in sailing hardware are just prostituting themselves by selling inferior products? Are you really saying that?

 

[Stork_III]

The block at the mast foot doesn't look too happy, rope rubbing on side cheek. Does it have a swivel base?

 

[pvb]

The block at the mast foot doesn't look too happy, rope rubbing on side cheek. Does it have a swivel base?

Yes, there are a few question marks over the installation. Having two double blocks on the boom is odd, and the triple on the traveller has a cleat, so it wasn't presumably originally specified for that position.

 

[dunedin]

The block at the mast foot doesn't look too happy, rope rubbing on side cheek. Does it have a swivel base?

Yes, good spot. That might be best with a dyneema rope lashing- allow flex to align, but not to over rotate when loose

 

[rogerthebodger]

Yes, good spot. That might be best with a dyneema rope lashing- allow flex to align, but not to over rotate when loose

An extra shackle is all that is needed to lift the block from catching on the deck