Self tacking jib sheeting

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Amati

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Mulling over a different self tacking jib setup- track this time- if the jib sheet is run up (and down inside) an aluminum Ballenger mast, does the mast need reinforcement to handle the extra compression?  Thought I’d ask here before I bug Skip again.

I’d like to be able to fly the self tacker (3/4 hoist)along with an upper flying jib at the same time.

 
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slug zitski

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Mulling over a different self tacking jib setup- track this time- if the jib sheet is run up (and down inside) an aluminum Ballenger mast, does the mast need reinforcement to handle the extra compression?  Thought I’d ask here before I bug Skip again.

I’d like to be able to fly the self tacker (3/4 hoist)along with an upper flying jib at the same time.
You are adding compression 

you could remove compression elsewhere with halyard locks or simply  ask the mast builder if your mast can handle the extra compression 

 
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slug zitski

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You might look at the way Wally yachts does their self tacker.

2 to 1 main and Genoa halyards are simple and reduce compression 

C708EDFF-6CDD-4BDF-8C24-0641623BCC98.png

 

DDW

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The weird thing about the setup pictured is it does not reduce compression at all. If fact there is twice the jib sheet load put on the mast in compression. Spreads the load on the track a little is all. 

 

slug zitski

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The weird thing about the setup pictured is it does not reduce compression at all. If fact there is twice the jib sheet load put on the mast in compression. Spreads the load on the track a little is all. 


the two blocks are to spread the high  load onto two  traveler cars… because of the turning angle 

it’s still 1 to 1…a continuous loop 

the third sheet pulls aft flattens the sail

 

slug zitski

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Fleetwood said:
If you have the third sheet pulling aft where is the self-tacking advantage?
The third sheet is because that boat is sailing with a maximum size headsail

its not possible to move the track aft 

a self tacker  is not a very versatile rig .. difficult to shift gears , sail design is limited 

BC0F6B98-F746-41C0-879D-B317C025CEA4.jpeg

 
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slug zitski

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Wally yachts are esthetic , design driven  , cruisers racers 

that boat was designed with a super clean deck .. nothing on deck 

this was the design goal 

everything is a compromise 

you will find that once Wally designs a detail or system ..like anchors that drop through underwater Bombay doors to keep the yachts stem clean  ….other designers follow 

 

PaulK

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the two blocks are to spread the high  load onto two  traveler cars… because of the turning angle 

it’s still 1 to 1…a continuous loop 

the third sheet pulls aft flattens the sail
Instead of adding a third sheet (a twing?) Wouldn't moving the sheet to a lower point on the curved clew board flatten the sail while still allowing it to be self-tending ?  Or is the sail cut with too loose a leech and so needs the sheet pulling down and aft more than it should? The sheets on self-tacking jibs we had on Solings went forward on deck instead of up the mast so there was no mast compression issue. Why is that not being done here?

 

European Bloke

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 The sheets on self-tacking jibs we had on Solings went forward on deck instead of up the mast so there was no mast compression issue. Why is that not being done here?
The line would make the pretty deck of the sailing boat look untidy. Try to keep up.

 

slug zitski

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Instead of adding a third sheet (a twing?) Wouldn't moving the sheet to a lower point on the curved clew board flatten the sail while still allowing it to be self-tending ?  Or is the sail cut with too loose a leech and so needs the sheet pulling down and aft more than it should? The sheets on self-tacking jibs we had on Solings went forward on deck instead of up the mast so there was no mast compression issue. Why is that not being done here?
Not easy to change the clew board position when loaded 

an extra sheet its easy to shift gears 

On some boats the luff in not full length , you ease the tack down haul and hoist the sail higher to change the sheeting angle when close reaching 

 
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PaulK

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Not easy to change the clew board position when loaded 

an extra sheet its easy to shift gears 

On some boats the luff in not full length , you ease the tack down haul and hoist the sail higher to change the sheeting angle when close reaching 
So...  a third sheet is a Micky-Mouse adaptation by a lazy crew. It could also be used to unload the sheet and enable changing the clew board position. Then stow it away.  While an extra sheet may make it easier to shift gears, it makes it more difficult to tack. It also looks untidy! Shifting the whole sail higher to change the sheeting angle seems like the tail wagging the dog. None of this seems helpful for the OP. 

 

slug zitski

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So...  a third sheet is a Micky-Mouse adaptation by a lazy crew. It could also be used to unload the sheet and enable changing the clew board position. Then stow it away.  While an extra sheet may make it easier to shift gears, it makes it more difficult to tack. It also looks untidy! Shifting the whole sail higher to change the sheeting angle seems like the tail wagging the dog. None of this seems helpful for the OP. 
Explain your method of changing the clew board sheet positions while loaded 

Sail luff length is relative to the original poster 

 

European Bloke

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Your question was about compression in the rig.

I'd be very surprised if a jib sheet load would put enough compression into the mast for it to be a factor. The very lightest cutting edge rig possibly, but it wouldn't be my biggest worry 

Make it 2:1 if you're worried.

That said I'm not a rig designer and my advice is worth what you paid for it.

I still think that 99 out of 100 self taking set ups are shit. That wasn't the question either 

 

PaulK

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I still think that 99 out of 100 self taking set ups are shit. That wasn't the question either 
On our Soling we set up a 2" stainless steel pipe that my father had had bent in a curve.  We bolted it to the deck with 3/4" galvanized bolts, held off the deck by chunks of 2x4 in the way of the bolts.  A steel ring with a sheave shackled to it served as the traveler, with a short line led from it to a centerline padeye to regulate the size of the slot.  The sheet went from the clew board to the sheave, up forward to a through-deck sheave, and then to an under-deck tackle whose fall went to a swivel cam at the forward end of the cockpit.  Cheap but effective.  The guys with the Harken ball-bearing travelers all looked very surprised when we beat them.   

 

slug zitski

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Your question was about compression in the rig.

I'd be very surprised if a jib sheet load would put enough compression into the mast for it to be a factor. The very lightest cutting edge rig possibly, but it wouldn't be my biggest worry 

Make it 2:1 if you're worried.

That said I'm not a rig designer and my advice is worth what you paid for it.

I still think that 99 out of 100 self taking set ups are shit. That wasn't the question either 
At 180 degrees turning , The load on the block handling the self tacker sheet  is 2 x the load on the jib sheet 

 
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