Chotu's Advanced Running Rigging Thread (lots of pics)

[rslifkin]

I can't remember on this one... Is the roof area where the davits mount strong enough to handle the load of a traveler or mainsheet? Or can it be reinforced easily enough if it's not?

[Chotu]

Originally Posted by rslifkin

I can't remember on this one... Is the roof area where the davits mount strong enough to handle the load of a traveler or mainsheet? Or can it be reinforced easily enough if it's not?

that is questionable. I don’t know. I don’t think so.

I think there will be a problem with racking.

those upright columns that hold the roof up also hold it down. As you can see they have pretty immense backing plates and hardware. they are attached to the main structural beam with massive backing plates inside there as well.

However, there is nothing to prevent them from falling port and starboard as the main sheet pulls to port and pulls to starboard. It would exert a pretty strong pull and potentially rip them out of the main structural beam as they tip to port it starboard. Hard to imagine this happening with the level of backing plates I have behind them, which is pretty much what you see on the roof as well, but it seems like less than an ideal geometry

I have to put some diagonal support lines in to keep it from racking. i think.

[Chotu]

Originally Posted by malbert73

Again not a cat person but prior racer- and since the boat/rig/setup is new, wouldn't two fixed jib sheet leads allow you to barber-haul (windward sheet) like we used to do on 420s to go upwind when I raced? Ie on a close reach you just sheet the leeward jib sheet. As you come up to close hauled, you can experiment with windward (prior slack) sheet tension to bring the clew in tighter to allow a closer sheeting angle. This approach would follow the KISS principle until you sail the boat and learn what works/etc.
maybe these come through?
https://www.gbr420.uk/assets/uploads...r%20Hauler.pdf

yes, you know when I was looking at my drawing with the three sheets maybe it is redundant.

it seems like everyone gets away with just using two of them. that’s probably the smart way to do it.

and please by all means bring racing backgrounds into this. You guys know how to control and optimize sails way more than any of us cruiser types. if you see something that seems wrong, please speak up. that kind of input is invaluable.

but I think you are correct here because I don’t see a three line system on any boats. It doesn’t make sense I guess. I suppose it only takes two lines to position it anywhere in the plane doesn’t it?

[s/v Jedi]

You will need to put the main sheet up on the roof so that’s a given.

With those massive pillars you can start with the simplest option and that is two diagonal stays between them. Those pillars are fiberglass aren’t they? Have someone glue some blocks on them that keep Dyneema loops from sliding towards the middle and cow hitch the loops around the pillar bases and tops. Now you have attachments for Dyneema stays. I would splice them with an eye on each end, cow-hitch one side and use a lashing on the other side.

Of course this ruins your access to the dinghy so you need to remove them when not in use and wrap them around something so you can’t forget to put them back to go sailing.

This gets you moving while figuring out better ways. A better way is how Chris White does the dinghy: chocks to put it on and a massive hoisting swing. Alternatively without the swing, you can use a pole extending from the boom to lift the dinghy into position but it will be a pain.

[rslifkin]

Originally Posted by Chotu

that is questionable. I don’t know. I don’t think so.

I think there will be a problem with racking.

those upright columns that hold the roof up also hold it down. As you can see they have pretty immense backing plates and hardware. they are attached to the main structural beam with massive backing plates inside there as well.

However, there is nothing to prevent them from falling port and starboard as the main sheet pulls to port and pulls to starboard. It would exert a pretty strong pull and potentially rip them out of the main structural beam as they tip to port it starboard. Hard to imagine this happening with the level of backing plates I have behind them, which is pretty much what you see on the roof as well, but it seems like less than an ideal geometry

I have to put some diagonal support lines in to keep it from racking. i think.

If adding diagonal supports will make the structure adequate for the load, then I'd plan to do that. If it's not in the way of anything usable, maybe a beefy X brace that mounts between the existing uprights (which would also give something additional to use for dinghy strapping to avoid movement). Fortunately, it looks like you'll be sheeting to the end of the boom, so that will help keep the loads down compared to a mid-boom sheet setup.

And then if everyone else agrees that the track you have is adequate for the main, use it for a traveler. The only question will be with structural constraints and working around the davits whether you can get a long enough traveler to avoid the need for a vang (sticking with the idea that cats typically have long travelers and no vang).

[Chotu]

Originally Posted by s/v Jedi

You will need to put the main sheet up on the roof so that’s a given.

With those massive pillars you can start with the simplest option and that is two diagonal stays between them. Those pillars are fiberglass aren’t they? Have someone glue some blocks on them that keep Dyneema loops from sliding towards the middle and cow hitch the loops around the pillar bases and tops. Now you have attachments for Dyneema stays. I would splice them with an eye on each end, cow-hitch one side and use a lashing on the other side.

Of course this ruins your access to the dinghy so you need to remove them when not in use and wrap them around something so you can’t forget to put them back to go sailing.

This gets you moving while figuring out better ways. A better way is how Chris White does the dinghy: chocks to put it on and a massive hoisting swing. Alternatively without the swing, you can use a pole extending from the boom to lift the dinghy into position but it will be a pain.

i’m not sure if we have ever so quickly arrived at the same conclusions with things. ha ha. i like it!

The bases are fiberglass and the columns themselves are aluminum.

but yes this is exactly what I was thinking of doing. Some dyneema stays.

there is a way to do it where I don’t need to destroy the dinghy access however. Check this picture out.

there is plenty of room to do it on the outside of the columns. That way I don’t have to worry about the dinghy access problem. And no one passes where the red line in the picture is. So it’s a perfect place. It’s out-of-the-way.


note: I blacked out some areas that had a bunch of junk that looked unsightly.

[s/v Jedi]

Is there room for a vang? Do the mast and boom have reinforced attachment points for a vang?

For main sheet you could possibly put two pad eyes with blocks on top of the pillars using either two sheets or a single A-frame like one. I have that on my mizzen and don’t like it but I also don’t like theHarken traveler on my main

[Chotu]

Originally Posted by rslifkin

If adding diagonal supports will make the structure adequate for the load, then I'd plan to do that. If it's not in the way of anything usable, maybe a beefy X brace that mounts between the existing uprights (which would also give something additional to use for dinghy strapping to avoid movement). Fortunately, it looks like you'll be sheeting to the end of the boom, so that will help keep the loads down compared to a mid-boom sheet setup.

And then if everyone else agrees that the track you have is adequate for the main, use it for a traveler. The only question will be with structural constraints and working around the davits whether you can get a long enough traveler to avoid the need for a vang (sticking with the idea that cats typically have long travelers and no vang).

definitely absolutely sheeting to the end of the boom. In my mind, I can’t see doing it any other way because why increase loads when you don’t have to? It feels like it’s against my religion or something ha ha.

The thing about the track I have is it is two sections of 6 foot length. That’s not much of a traveler. so it kind of stinks. probably selling the track and going with another 2 sheet system like the jib would be more ideal for sail shape.i guess . But I don’t really know. That’s definitely the point of the thread. Trying to get the basics here so I can start figuring out where all the lives will run.

[rslifkin]

I'd think a traveler is easier to deal with structurally, as the track spreads the load somewhat more across the width of the assembly than the attachment points for a 2 sheet system.



For a traveler, I'd think you want to build it up on blocks so it can extend across the davits with a longer track. Or if you have attachments and clearance to install a vang, use what you have for a shorter traveler between the davits.

[s/v Jedi]

Originally Posted by Chotu

i’m not sure if we have ever so quickly arrived at the same conclusions with things. ha ha. i like it!

The bases are fiberglass and the columns themselves are aluminum.

but yes this is exactly what I was thinking of doing. Some dyneema stays.

there is a way to do it where I don’t need to destroy the dinghy access however. Check this picture out.

there is plenty of room to do it on the outside of the columns. That way I don’t have to worry about the dinghy access problem. And no one passes where the red line in the picture is. So it’s a perfect place. It’s out-of-the-way.

note: I blacked out some areas that had a bunch of junk that looked unsightly.

Ah yes, that’s a no-brainer then. You may need some reinforcement on top of the roof between the posts or alternatively, use pipe for those diagonals so they support both push and pull. I did that for the struts on my solar array.

[Chotu]

Originally Posted by s/v Jedi

Is there room for a vang? Do the mast and boom have reinforced attachment points for a vang?

For main sheet you could possibly put two pad eyes with blocks on top of the pillars using either two sheets or a single A-frame like one. I have that on my mizzen and don’t like it but I also don’t like theHarken traveler on my main

yes I am trying to get away from having a track. I don’t like them very much either.

and I really want simplicity.

here is a picture of the entire boom. No spot for a vang, although a wide, high friction strap could probably do the trick.

[Chotu]

Originally Posted by rslifkin

I'd think a traveler is easier to deal with structurally, as the track spreads the load somewhat more across the width of the assembly than the attachment points for a 2 sheet system.



For a traveler, I'd think you want to build it up on blocks so it can extend across the davits with a longer track. Or if you have attachments and clearance to install a vang, use what you have for a shorter traveler between the davits.

Do you know what really sucks? Regarding the last paragraph that you wrote? I was on here a couple years back talking about the traveler I had for this boat. It was the main sheet traveler from the boat the rig came off of.

it was something like 16 feet long. And everyone said no way. That’s junk. Get rid of it. Too short. And I did.

now, it wasn’t anyone participating in this thread right now. But a big portion of the multihull people said to get rid of it because it wasn’t big enough.

if I put the 12 feet of Harken track up there, it’s even shorter than the one they told me to get rid of. So it gets a little tricky.

I agree with you structurally that the traveler makes it easier to spread the load. But, putting the loads right at the top of the columns might work as well. But they are kind of close together. Ideally they would have been much farther apart for that.

All in all it’s like I’m trying to trade off and come up with something that is the least bad solution. Not the best solution. It’s kind of unfortunate. And this is what I meant by I painted myself into a corner.

[Chotu]

also, regarding the boom, what are those three attachment points at the bottom? The ones toward the end? They are really, really strong. Why are there three of them?

[rslifkin]

I think the only thing stopping you from going with a longer traveler is the cost of buying one. Jedi's idea of using rigid columns for the outer angled supports would help with supporting a longer track as well.

But at the same time, I remember that discussion being predicated on the idea that "cats don't have vangs", but in reality, they don't because a really long traveler makes a vang mostly unnecessary. If you can put together a structurally adequate vang setup and there's enough clearance for it without hitting the front of the cabin, then a shorter traveler isn't nearly as much of an issue (and a closer spaced double mainsheet wouldn't be either).

In your case, you don't have swept spreaders so you can let the main out pretty far compared to a lot of cats. In my mind that makes a vang somewhat more desirable, as especially without a seriously curved track, you'll always be able to go well past the end of traveler range (no matter how long you make the traveler).


Basically, the goal is to have the ability to let the boom out far enough while still having the ability to pull the boom down when desired to control sail shape. So that can be done with either a really long traveler (allowing the traveler to position the boom and the sheet to control mainsail twist) or with a vang (sheet and/or traveler control boom position, vang controls twist when the sheet needs to be eased for positioning).

[s/v Jedi]

Originally Posted by Chotu

yes I am trying to get away from having a track. I don’t like them very much either.

and I really want simplicity.

here is a picture of the entire boom. No spot for a vang, although a wide, high friction strap could probably do the trick.

In that case I wouldn’t use a vang. Use a topping lift to hold it up and two sheets to hold it down. For starters, I would mount the two blocks right where you have the big bolts from the pillars and the booms that lift the dinghy. There’s a bolt through the center that ruins the possibility to put a pad eye on top of that plate. You can use another plate on top of it with a hole for the head of that center bolt but I don’t know if the big bolts are long enough.

But here’s another idea: buy soft attachment blocks like Antal Looper and simply attach those somehow to that strong point. You can buy “stand up springs” to prevent them from smashing down.