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Old 24-07-2023, 06:43   #46
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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Originally Posted by rslifkin View Post
For extras like the baby stay, I'd skip it to start. Stick with just the basic rig and the running backstays (which I expect you'll need to use with the inline spreaders and no fixed backstay). Watch how the rig behaves, and if you see any points where it's too easy to get the mast to pump or anything, then it's time to add additional support.

I feel like the babystay is more important than the running backstays actually. I could be wrong.

The unsupported little top section is the only place the Mast can move forward or aft, assuming it doesn’t bend to do so.

There are no sails flown from that top area other than the triangle top main I have right now.

The jib goes up to the top of the forestay.

The spinnaker goes up to the top of the forestay also. That’s all I have right now.

I agree to keep things basic and observe to see what’s needed and what isn’t. But I think the running backstays are part of that “see if it’s needed” group.

Right?
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Old 24-07-2023, 06:53   #47
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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Originally Posted by The Yacht Rigger View Post
That's plenty in terms of radius. Remember, you are making a loop, with multiple passes. The most important thing here is to make sure that no single part of the loop (single pass) is taking more load than the others. And put some cover on it to protect it. You really should pre-stretch (pre-load) the loop to get as much stretch/creep out of it as initially possible. A lot of places that have load cells will do this for between $50 and $200 per pull depending on their setup.
You don't want to spend a bunch of time and effort making some nice loops, and then having them elongate so much that your turnbuckles bottom out in 3 months. Try and set them up so they never see more than 10% of their SWL. I would shoot for 5 % for the application you are using them in.


Ok. Cool! I’m glad the radius is enough.

I do know about trying to get the loops to have the same load. I will have to review how to best accomplish that, but I know that’s the goal. I do remember. Thank you.

I’m using the following cordage:

DynaTechģ is pre-stretched, heat set 12 strand UHMWPE rope with exceptional strength and extremely low stretch. In fact, size for size, DynaTechģ is stronger than steel cable of the same size, yet only 1/8th the weight. It's so light it even floats.

I don’t think I have to go get it stretched. it’s made like that. Right?

And when you say 5% or 10% of SWL, you mean for each loop right?
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Old 24-07-2023, 06:54   #48
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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Too late. The plans show a self tacking jib. I already have a self tacking jib. That hardware has already been purchased and is shown in the pictures. I already have the track. Iím not changing that and throwing away a ton of money.

The only thing I could really do is a removable one. Even that is a lot of extra effort thatís not in the plans.

Itís a used mast so it must have worked the way it is rigged before. Weird though, because if there is no pre-bend in the mast (according to your rigging plan) then what stops it from inverting? Think of a double reefed mainsail where the head and leech load are well below the forestay and pull aft on the middle of the mast! Add in some pumping in the seas generated by that wind and your mast is at risk of inverting.

Usually with diamond stays the spreaders are aft-swept with an additional prod and stay to the front, so the mast column is locked in place both side to side and fore and aft. Instead, your mast has inline spreaders and lowers to prevent over-bending, so perhaps the mast is meant to have pre-bend? Is the mainsail cut for a straight luff or for a pre-bent luff?
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Old 24-07-2023, 07:04   #49
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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It’s a used mast so it must have worked the way it is rigged before. Weird though, because if there is no pre-bend in the mast (according to your rigging plan) then what stops it from inverting? Think of a double reefed mainsail where the head and leech load are well below the forestay and pull aft on the middle of the mast! Add in some pumping in the seas generated by that wind and your mast is at risk of inverting.

Usually with diamond stays the spreaders are aft-swept with an additional prod and stay to the front, so the mast column is locked in place both side to side and fore and aft. Instead, your mast has inline spreaders and lowers to prevent over-bending, so perhaps the mast is meant to have pre-bend? Is the mainsail cut for a straight luff or for a pre-bent luff?


Pretty good point.

I forgot about the reefed situation.

The Mast has a place for a baby stay. I could put one in. But then I couldn’t have my self tacking jib that I already bought all of the hardware for.

Unless it was a removable baby stay only used when reefing. Which defeats the point of running all control lines inside.

Although there is no reason it couldn’t be synthetic line turned around a block, run inside and winched into action when needed I guess.
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Old 24-07-2023, 07:23   #50
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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Pretty good point.

I forgot about the reefed situation.

The Mast has a place for a baby stay. I could put one in. But then I couldnít have my self tacking jib that I already bought all of the hardware for.

Unless it was a removable baby stay only used when reefing. Which defeats the point of running all control lines inside.

Although there is no reason it couldnít be synthetic line turned around a block, run inside and winched into action when needed I guess.
Yeah, I don't see why you couldn't make a running baby stay. In theory you could also put an inhaul on it so when you slack it off, you can pull in on the inhaul to pull the baby stay against the mast, keeping it out of the way.

As far as the running backstays, the time I'd expect them to be needed most is downwind (with or without spinnaker) as you're either going to have the main out to one side or dropped, so the mainsail will no longer be keeping the mast from falling forward. And the inline spreaders don't exactly give the shrouds a lot of leverage to keep the mast from going forward either. It might work ok without the running backs, but having them there will certainly make the rig more sturdy in that situation.
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Old 24-07-2023, 08:04   #51
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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Originally Posted by rslifkin View Post
Yeah, I don't see why you couldn't make a running baby stay. In theory you could also put an inhaul on it so when you slack it off, you can pull in on the inhaul to pull the baby stay against the mast, keeping it out of the way.

As far as the running backstays, the time I'd expect them to be needed most is downwind (with or without spinnaker) as you're either going to have the main out to one side or dropped, so the mainsail will no longer be keeping the mast from falling forward. And the inline spreaders don't exactly give the shrouds a lot of leverage to keep the mast from going forward either. It might work ok without the running backs, but having them there will certainly make the rig more sturdy in that situation.

So this is the reefed situation again?

When I have a deep reef in and I’m running deep?

Trying to understand the use case.

At first without some other kind of downwind furling sail, I’m imagining I’m going to use the spinnaker when I am running downwind that deep. With no mainsail. I’m lazy. I like “set it and forget it” sailing.

So in this case there is no force on the mast except for at the shrouds. So it would not be able to bend forward.

It would only be able to do that when reefed with the mainsail way out in serious wind.

I guess that’s the situation in really heavy weather or something. But in that case I would probably just roll that blade jib out and run with that. Easier.

But you also have to remember this kind of boat has apparent wind like crazy. In fact, most of the sailing will be on a reach or tighter I think. Those with fast boats can correct me. But I’m pretty sure that’s how it works. All theory of course.

Then deep downwind you just kind of give up on reaching and use the spinnaker I think. I think that’s why a lot of them have an asymmetrical.

Also people who are trying to go really fast with these boats tack downwind. So they are always on a reach (or broad reach) but make better VMG. I guess. Again this is all theory. Lol I won’t be doing that I’m too lazy. That’s why I have a spinnaker.

Where is Thomm actually??

With all his Hobie cat experience racing, this is exactly the thing that he should be posting here about. I wonder what he thinks about this post I just made. And it also what other people with pretty fast boats think.
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Old 24-07-2023, 08:10   #52
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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So this is the reefed situation again?

When I have a deep reef in and Iím running deep?

Trying to understand the use case.

At first without some other kind of downwind furling sail, Iím imagining Iím going to use the spinnaker when I am running downwind that deep. With no mainsail. Iím lazy. I like ďset it and forget itĒ sailing.

So in this case there is no force on the mast except for at the shrouds. So it would not be able to bend forward.

It would only be able to do that when reefed with the mainsail way out in serious wind.

I guess thatís the situation in really heavy weather or something. But in that case I would probably just roll that blade jib out and run with that. Easier.

But you also have to remember this kind of boat has apparent wind like crazy. In fact, most of the sailing will be on a reach or tighter I think. Those with fast boats can correct me. But Iím pretty sure thatís how it works. All theory of course.

Then deep downwind you just kind of give up on reaching and use the spinnaker I think. I think thatís why a lot of them have an asymmetrical.

Also people who are trying to go really fast with these boats they tack downwind. So they are always on a reach but make better VMG. I guess. Again this is all theory. Lol I wonít be doing that Iím too lazy. Thatís why I have a spinnaker.
With just a spinnaker going downwind (no main), the spinnaker should be pulling forward on the mast. With inline spreaders, nothing is attached aft of the mast, so I'd be concerned about having enough strength to avoid pulling the mast forward if the wind picks up unexpectedly. The running backstays would give you more margin in that situation by providing a counteracting aft pull on the mast. It's not a matter of the mast bending wrong in that situation, it's a matter of whether the whole thing may fall forward.
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Old 24-07-2023, 08:14   #53
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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Originally Posted by rslifkin View Post
With just a spinnaker going downwind (no main), the spinnaker should be pulling forward on the mast. With inline spreaders, nothing is attached aft of the mast, so I'd be concerned about having enough strength to avoid pulling the mast forward if the wind picks up unexpectedly. The running backstays would give you more margin in that situation by providing a counteracting aft pull on the mast. It's not a matter of the mast bending wrong in that situation, it's a matter of whether the whole thing may fall forward.

You are definitely not understanding the geometry of the rig. Please take another look at the drawings I made.

The only thing the running back stays can possibly do is prevent bending of the mast in a foreword direction.

They could either be located all the way up at the top which is not shown in this particular diagram and is completely unsupported, or they could be located somewhere in the middle below the upper and lower shrouds. In either case all they could do is prevent bending.

The spreaders don’t touch the shrouds. That’s where you are confused.

They exist only to support the double diamond configuration which supports the Mast from bending athwartships. Take a look at the diagram at the top of this page also. You can see it more clearly there too
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Old 24-07-2023, 08:17   #54
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

Ok, it looks like you have shrouds running aft to provide support. That's good. It's a bit odd with non-swept spreaders, but if it was set up that way on the original boat the rig came from, then clearly it must work.
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Old 24-07-2023, 08:23   #55
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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Ok, it looks like you have shrouds running aft to provide support. That's good. It's a bit odd with non-swept spreaders, but if it was set up that way on the original boat the rig came from, then clearly it must work.


No no.

The spreaders have nothing to do with the shrouds on this type of boat.


The spreaders only exist in order to support the wires for the double diamond configuration.

The double diamond configuration supports the mast athwartship.

The spreaders do not touch the shrouds, so they have no effect on the shrouds at all.

That’s how these work.

Not a monohull.
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Old 24-07-2023, 08:25   #56
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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No no.

The spreaders have nothing to do with the shrouds on this type of boat.


The spreaders only exist in order to support the wires for the double diamond configuration.

The spreaders do not touch the shrouds.


Thatís how these work.

Not a monohull.
Ah, so you don't have cap shrouds going through the spreaders and down to the deck? Just lowers and intermediates attached below the lower and upper spreaders, then the diamonds going through the spreaders?

In that case, you should be fine in terms of forward pull on the mast unless you want to fly a masthead spinnaker, in which case the running backs from the masthead would be a good idea to counter that pull.
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Old 24-07-2023, 08:29   #57
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

One more thing:

I completely forgot that I have to do my seagull striker!


That’s my first order of business. I have the wire. I have to get some connectors for it.

Sta-lock is the way to go?

This is beefy stuff. It’s 1/2” wire.

Any advice on what to do with that?
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Old 24-07-2023, 08:30   #58
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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Ah, so you don't have cap shrouds going through the spreaders and down to the deck? Just lowers and intermediates attached below the lower and upper spreaders, then the diamonds going through the spreaders?

In that case, you should be fine in terms of forward pull on the mast unless you want to fly a masthead spinnaker, in which case the running backs from the masthead would be a good idea to counter that pull.
Exactly!

And there is no provision for running a masthead spinnaker so it’s not a case. It runs from the top of the forestay (fractional rig) Probably for this very reason.

I am a little bit lost on what you mean by intermediate. There are no intermediates. Just upper and lower shrouds. Both swept back. Neither touch the spreaders.

The spreaders only support the diamond configuration in the drawing. They do nothing else.

There are no other stays whatsoever. 5 stays.

Forestay, upper and lower shrouds(swept back) on each side.

That’s it. Nothing else.

Completely standard issue rig for a Catamaran. Very basic stuff for a Catamaran. Newer ones don’t have all of this complexity. They have even less. They don’t have the double diamond.

This is kind of the old way. Good enough.
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Old 24-07-2023, 08:36   #59
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

But before it gets lost in the sauce here,

what should I use to connect my stainless wire to do the seagull striker?

The boat my crossbeam came off was connected in a very unique way. It was a Chris White Atlantic 55.

I’m just using a standard connection like people use on chainplates.

So is Sta-loc the way to go for that?
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Old 24-07-2023, 08:52   #60
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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Exactly!

And there is no provision for running a masthead spinnaker so itís not a case. It runs from the top of the forestay (fractional rig) Probably for this very reason.

I am a little bit lost on what you mean by intermediate. There are no intermediates. Just upper and lower shrouds. Both swept back. Neither touch the spreaders.

The spreaders only support the diamond configuration in the drawing. They do nothing else.

There are no other stays whatsoever. 5 stays.

Forestay, upper and lower shrouds(swept back) on each side.

Thatís it. Nothing else.

Completely standard issue rig for a Catamaran. Very basic stuff for a Catamaran. Newer ones donít have all of this complexity. They have even less. They donít have the double diamond.

This is kind of the old way. Good enough.
I'm considering those uppers as intermediates because they appear to start just below the upper spreaders, rather than at the level where the top of the diamonds attach (above the spreaders) where a cap shroud would typically go.
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