Running backstays on a condo cat

[Tornadosailing]

Looking at my rig, I would be shocked if it were more than 20 degrees swept back shrouds. The mast has a significant pre-bend. Just eyeballing it, maybe 10 inches over the 60 feet of mast. It also has a 3 degree aft rake.

It's a heavy boat, and the loads are incredible. So I think I'm going to add them, even if it comes down to no more than making me feel good.

Thank you all for your thoughts. It's always nice to get the input of people way smarter than me.

[LeeV]

Just don’t freak out the first time you get some bigger winds, you’ve snugged down the windward runner, and you glance over and see the leeward side swinging wildly doing the hokey pokey!

[DerekKelsall]

Originally Posted by Falbala60

I am new to catamaran, my Lucia is now on a cargo to Florida. When looking at catamaran rigging, all brands FP, Lagoon, etc., I am surprized that the shrouds are with a so small angle backward from the mast.

What is the reason for not moving them more back to give a better support to the mast ? A brilliant answer is required.

To add to my last - the forestay is pulling the hound position forward. This is resisted by the shrouds (in the three stay rig). The effective angle is the one in the profile, not in line with the stay. Ie the forces can be resolved onto the central plane to assess the forces coming from the forestay tension. That is where the 8-9 degrees comes from. Yes it would reduce the forces to move the fixed shrouds back but that then reduces the angle to which you can let out the boom - increasing the chance of the unintentional gybe when running down wind. I know one cat owner was amazed when I was on board and measured the angle of the boom with the sail against the shroud to find it was only 40 degrees off center line. The runners to me are well worth having the extra control for all the advantages. There is some hang over here, from the days when mono rigs would fall down with a runner failure.
We have twin rigs on some cat designs - like Cool Change - where booms can be let out more than 90 degrees, which gives almost self steering in say trade wind sailing, which is when steering gets difficult with the currently popular three stay, large main etc. Happy boating, Derek.

[Lambretta]

Originally Posted by Tornadosailing

So is this a great idea or a terrible idea?

Flying a big symmetric spinnaker on my boat makes me a little concerned considering a video I saw with a new FP cat flying the spin and had significant headstay sag. I just purchased a used symmetric spin (52' luff, 29' foot) Makes me concerned about what happens if I get a sudden gust. Could I be in danger of losing the rig? So it got me thinking about running backstays. Dyneema is cheap, and I could get a pair of chainplates made for pretty cheap, and the blocks to make it happen would be reasonable. Plus, if I could pull some of the sag out of the headstay on a beat, could I improve my (pathetic) pointing by a few degrees?

My thought was that I could stow them by securing at the mid ship chainplate along side the existing shrouds, then deploy them to a new set of chainplates bolted on near the aft bulkhead. I bet I could get the whole thing done for about a grand.

Thoughts?

I would suggest changing your main sheet and topping lift to a dyneema core , dont fly the main ,just the kite and then center the boom and sheet it in tight and also center the traveller. Then tension the topping lift, this will act like a back stay tensioner.

That said, I am not familar with the FP Salina mainsheet system and whether it is even on a traveller or if it has a triangle block system like the Leopards. Also need to note whether your vang is fixed or adjustable as this adds another variable
My two cents

[LeeV]

Originally Posted by Lambretta

I would suggest changing your main sheet and topping lift to a dyneema core , dont fly the main ,just the kite and then center the boom and sheet it in tight and also center the traveller. Then tension the topping lift, this will act like a back stay tensioner.

That said, I am not familar with the FP Salina mainsheet system and whether it is even on a traveller or if it has a triangle block system like the Leopards. Also need to note whether your vang is fixed or adjustable as this adds another variable
My two cents

Yeppers; what he said!

[Tornadosailing]

I have a traveler, but no vang of any kind. I can actually install dyneema runners for not much more money as replacing topping lift and mainsheet with dyneema core line. Then I'll have the option of pulling on one of the runners if I'm also flying the main.

A 12mm dyneema core topping lift will run me about $500. A 14mm dyneema mainsheet will cost about the same. I realize that I could reduce the diameter with dyneema core, but then I may have to be concerned about how well it fits in clutches.

[Lambretta]

Originally Posted by Tornadosailing

I have a traveler, but no vang of any kind. I can actually install dyneema runners for not much more money as replacing topping lift and mainsheet with dyneema core line. Then I'll have the option of pulling on one of the runners if I'm also flying the main.

A 12mm dyneema core topping lift will run me about $500. A 14mm dyneema mainsheet will cost about the same. I realize that I could reduce the diameter with dyneema core, but then I may have to be concerned about how well it fits in clutches.

Sounds good ......... I would stay with the same diameter rope that you are currently using as you know it works in the clutches you have and with dyneema you are most definitely going up the strength curve

Or it could be an option to go down 2mm on each line with dyneema ..... (check out the specs of your clutches on the manufacturer website) this will save some good beer money

[Tornadosailing]

Originally Posted by Lambretta

Sounds good ......... I would stay with the same diameter rope that you are currently using as you know it works in the clutches you have and with dyneema you are most definitely going up the strength curve

Or it could be an option to go down 2mm on each line with dyneema ..... (check out the specs of your clutches on the manufacturer website) this will save some good beer money

I've been down that road with the main halyard. Previous owner replaced it with a lower strength but larger diameter line. It wouldn't run freely through the clutch, so I replaced it with New England VPC 12mm (the correct diameter). But then the clutch wouldn't hold the slippery cover they use on VPC. It was cheaper to replace the clutch with a truly awesome Lewmar Domino clutch than replace the halyard again.

[jmh2002]

Originally Posted by Tornadosailing

I realize that I could reduce the diameter with dyneema core, but then I may have to be concerned about how well it fits in clutches.

In the old days when 'hi-tech' rope products were coming out one of the solutions to this was to add (or just keep, since we used to strip off the outer covers to save weight) an exterior sleeve just where the line sat in the clutch, or on the winch, or where handled, etc.

Could be half of the line in some cases, in others just a foot or half a metre.

Food for thought too maybe.

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