Dear Mr. Sidecar

Sidecar

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3,264
1,653
Tasmania
As a point of comparison, the mast on Jester 2 (same Displ and LWL) is 1.5 metres taller for 1m2 less mainsail and its CE is a little higher and ~ 880mm further aft than Sidecar. Refer to diagrams and tables upthread.
Ditto:
 

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SeaGul

Super Anarchist
1,375
120
Oslo Norway
This about 60% more sail to get to 88% of basespeed ref SeaCart30; how important is "basespeed" to a multihull that really has no resistance to overcome at basespeed? The total square sails are they possible to trim - can you control the top? In light the trimarans can be trimmed in many different ways - to get less wetted surface - only mainhull in water - stern out etc. And with big sails it will be very fast.
 

Sidecar

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Tasmania
Not entirely sure what you are trying to say.

OMR, Texel, and MOCRA are all Base Speed related, with varying formulas and emphasis in order that multihulls can be compared to and raced against each other. FWIW, adjusted for white sails only, singlehanded, same Displ, Seacart 30 (Morticia) OMR 1.001, Sidecar OMR 0.863. I use Base Speed, because there is little and easy input. OMR takes account of a lot of other things and requires much more detailed input, especially on the rig and sails yet still comes up with more or less the same relativity/answer in a less relatable form.

As you can see from the videos etc, Sidecar is a pretty basic machine, with very basic sails and setups. Plenty of room for improvement and absolutely nothing to race/tune up against. No handicap system mentioned above or Base Speed rates the quality of the sails and their set up, the quality of finish on hull and foils, nor the skill and technique of the crew.
 
As promised, I've been messing around with the biplane rig and have a demonstration model. Proportions are off, especially on the main because I'm trying to get a lot of sail on a shorter mast than anything else of this size and because it's not as intuitive to design as I thought, but then I'm not an architect... The jib foot is shorter because it needs to clear the cockpit and it's as long as it could possibly be. I've made it balanced as well to get as much area as possible, but I believe that it's still too small to properly balance the big main upwind. However, in 3 months on an equivalently sized cat, I sailed exactly 0 miles upwind so there's that. The vang strut is still missing, and the mast base should also be about another foot to leeward to sit on top of the ring frame properly...

CP55WithRigCloseWWPerspective.png
CP55WithRigWWElevation.PNG

CP55WithRigBowElevation.PNG
 
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Sidecar

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FWIW, on Sidecar, the windward staysail is ~ 39% of the mainsail. XFoil says that performance will improve with a bigger staysail, so increasing area by balancing it as well as endplating at least the front third onto the wing deck Is something I am looking at. Should improve balance as well. Aim is to get it up to 50%. There are still issues with rig stability and leech control to deal with.

The proportion of your staysail looks on the tall side, which may exacerbate these issues. Moving the wheels inboard will help to get more foot. You can always sit to windward of the wheels again after the staysail has swung through?

I touched on it earlier upthread, but maybe the best all round compromise situation is that the windward staysail is used as the working jib, for frequent tacking and heavier weather. Use a larger jib/genoa/screecher off the bow for long legs and reaching/off wind (as well as the staysail if you want). At least that way you avoid the duplication of sails, furlers and sheets.
 

Sidecar

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Tasmania
^^^^ The windward staysail only lifts the ama when the proa is caught aback, which is a good thing? Otherwise, it always has a downward force component, except for dead down wind, when it is all horizontal.

The “loss” of RM due to mast location is peanuts in the scheme of things and offers other advantages.

Pay your money and make your choice.
 
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ProaSailor

dreaming my life away...
6,124
810
Oregon
^^^^ The windward staysail only lifts the ama when the proa is caught aback, which is a good thing? Otherwise, it always has a downward force component, except for dead down wind, when it is all horizontal.
Granted about the windward "staysail". I was wrong, confused, not fully awake.

Pay your money and make your choice.
This phrase has grown stale. I don't have to pay any money to express opinions.
 
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munt

Super Anarchist
1,328
331
The belt
I saw a pic of a proa (maybe Hell-Bent's?) with a nice crab claw rig. Makes so much sense for the proa. Any particular reason it's not the rig of choice?
 
I saw a pic of a proa (maybe Hell-Bent's?) with a nice crab claw rig. Makes so much sense for the proa. Any particular reason it's not the rig of choice?
I've done a crab-claw before. There are some challenges there that become more pronounced the larger the boat becomes. If you want to be able to shunt without a ton of manual work, you need some way to move the yard from one end to the other. On smaller boats this can be done purely with lines or a simple guide rail. On larger boats, even around 30 feet, you need a track that won't bind up under high loads. There's also the issue of how to properly reef the sail on bigger offshore boats. Yes you can use spilling lines and the like but while that might be good for short periods, how well is that going to work for days on end when it's blowing 40 knots a thousand miles offshore. You also need to either tilt the mast during the shunt or use some kind of bridle or track on the yard (which is what I did) to allow the sail to actually move from one end to the other.
High Quality 3-Way Comparison.jpg
 

Sidecar

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Tasmania
Little rigs rule!
Totally agree.

As it happens, The LWL’s and Displ’s of our boats are pretty similar, and fag packet, despite a slightly larger and taller rig, the (singlehanded) Sail Carrying Power ratios are: Incognito: 19.4%, Sidecar: 21.1%.

Would love to know at what boat speed and wind speed you fly a hull upwind?
 
Michelin partnered with a company that has developed an inflatable wingsail that actually works. The test-bed is a Beneteau Sense-something that was previously used to test a wingsail similar to that one. It was developed to be another one of those adaptations that are easy to fit to cargo ships to reduce emissions, but they said that smaller sailing yachts were a niche they were exploring at least.

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Sidecar

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3,264
1,653
Tasmania



Love a lot of the ideas, but always get put off by their inherent double weight and cost……and a lot of them are on free standing masts which are also heavier and more expensive.
 

MultiThom

Super Anarchist
1,802
430
Benicia, CA
Love a lot of the ideas, but always get put off by their inherent double weight and cost……and a lot of them are on free standing masts which are also heavier and more expensive.

And while there is some "cool" about them, you have to wonder how they work in a pitching deck with forty knots. You can sail anything on a lake with 5 kt breeze, but we sail in places where it is just "worth your life" to be too innovative.
 
^^^^^ Their apparent complexity and fragility is also a bit of a turnoff for me.
^^^ This. I'm not sure how much I trust that telescopic mast and inflated sail to stand up in adverse conditions. There's also the issue that if you get a puncture or crack in the sail it's undoubtedly an expensive proposition to repair and I could see a new sail or rig being prohibitively expensive. If your electronics go out and you don't have power to inflate the sails, you've got a problem.
 


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