Headsail Furling

[Cynara]

Do you ever plan on heaving-to. How would you do that with just head sails.

Obviously I know nothing about catamarans.

How experienced is your designer

Has this been done before or are you breaking new ground.

If it dosen't work as planned you will have a boat you couldn't sell

Looking forward to hearing how it works out

[Elleroo]

Originally Posted by markiobe

We are having a light, performance orientated, semi-custom, cruising catamaran built with a very innovative design.


We will obviously be discussion in detail with the sailmaker however before that, does anybody have any thoughts, particularly those with experience on large yachts with big furling headsails?

Yes.
The furlers are great for 99% of the time, and jam up that one time you really need to get that sail down and reduced. Sods Law an Murphy's.


Let someone else do the R&D on your designers dream.


Me, I'd put hanks on any headsail, and slides on a mainsail, and a sock for spinnakers.


But I'm a dinosaur that's done a lot of long ocean miles on big raceboats.

[Wireless1]

Originally Posted by catsketcher

I talked to John about X it. He liked it and it worked well for deep downwind sailing. But I wouldn't want one. It was fast, but it was very big and incredibly thin hulled - you can't point to the rig as the reason it sped along.

After spending over 15 years getting patents and making very innovative catamarans (my hands have paint on them right now because of working on the small cat) I would warn anyone from doing large innovations without huge experience. There is a reason most people don't do something brand new - it is because it probably doesn't work. Small progressions are fine, but massive changes are fraught with bad potential.

The OP mentions that headsails are more efficient - but they are not. If fact large genoas are very inefficient - which is why they are rarely seen on racing boats, and never on fast multis - reachers and screechers for downwind, but when the wind blows up, short overlap headsails and mains are all you see.

The plan form for a genoa is a triangle which is about the worst shape in aerodynamics. Then you have headstay sag, which on this rig will be increased. And with no main to increase foreasty tension the sag will be even greater. Also both rigs require a mast, but the effects on the main are small and the main saiplan can be elliptical or even square top increasing main efficiency and reducing parasitic drag. The mast will not sag to leeward in gusts, like a forestay and the main can even depower itself in gusts, whereas a genoa, especially a large one just gets fuller when you don't want it to.

Mast aft rigs were introduced by Prout decades ago and slowly they morphed into more normal rigs. Problems with reefing mains downwind can be overcome by getting rid of spreaders (use a 3 stay a side rig) and putting nice slides on. Going upwind without a main is pretty hard to do, getting sufficient forestay tension on mast aft rig is hard because of the larger J measurement compared to the aft sweep of the shrouds. So by going large with the genoa you reduce the effectiveness of the genoa itself. I was on board a 40ft cat with an aftish mast rig the other day (it had a main). The forestay was pretty loose but the shrouds were very tight. It is impossible to get high tension on the forestay (without overloading the shrouds) because of simple trigonometry unless you over engineer the mast and shrouds.

Also our boats are not fast enough to do without the beneficial interaction of main and jib upwind or reaching.

As for problems with chafe - I still have my original 21 year old main and altough it needs replacing sometime soon, it is in nice shape and free from chafe. Chafe is not a reason to totally change the rig.

I guess that my words of warning will not be heeded. When I came up with my new cat design 20 years ago, no one could have talked me out of it. I had been around multis for 18 years and had sailed lots of different boats. Same with all the innovations in my larger cat. Most of the major innovations have been removed from the large cat, and if I could go back in time and slap myself in the head and say "Don't build crazy new things, just refine a little" I would jump at the chance. There is so much work in getting something custom built, getting it wrong and redoing it, over and over again.

I had so much eagerness to try something new. It cost me huge amounts of time and lots of money. My advice for the OP is to drop the rig innovation. Or at least try it on a small cat, or talk to John Hitch, he is very approachable, or do lots of sailing on a range of cats. Most new innovations are silly, and waste money. Most working innovations have been done before - my wishbone is old tech, as is the three stay a side rig and the pivoting engine pods. I just refined them slightly to make them work better.

John Hitch drew an amazing new structure for his boat Wired in the 80s. He got an old beach cat and tried it out on this test bed (Flight of Fancy) first. Adrian Rogers wanted to make a fast cat schooner - he made a small version first to prove it (He then built Shotover 2 and it was super fast). These guys really knew their stuff, had built many boats before, were already legends in Oz multis and still they built small test versions before they went full size. To do otherwise is to risk huge amounts of timer and money.

Brilliant post. As you say most likely will not be taken seriously. Enthusiasm tends to cause blindness to reality.

[markiobe]

Originally Posted by Cynara

Do you ever plan on heaving-to. How would you do that with just head sails.

Obviously I know nothing about catamarans.

Don't know! guess we'd have to figure out the boat behaves and design methods to cope with big conditions.

Originally Posted by Cynara

How experienced is your designer

Very. He is also the builder. The yard has tons of experience and in addition a prototype boat is being built as we speak for testing.

Originally Posted by Cynara

Has this been done before or are you breaking new ground.

If it dosen't work as planned you will have a boat you couldn't sell

It turns out that yes it has been done before (I wasn't aware) and it apparently works really well...

Regardless, the boat wouldn't sell to the mainstream as the hull design is also very different, even if we go with a more conventional rig. However an experienced sailing couple that wants to live aboard and has gone through the same exercise we have (and decided that the vast majority of the mainstream boats are dross) would understand what it is and why.

Originally Posted by Cynara

Looking forward to hearing how it works out

We may not do it, we'll sail the prototype and decide what we want to do, will post here if it goes ahead!

[markiobe]

Originally Posted by Elleroo

Yes.
The furlers are great for 99% of the time, and jam up that one time you really need to get that sail down and reduced. Sods Law an Murphy's.


Let someone else do the R&D on your designers dream.

We are! see reply above

Originally Posted by Elleroo

Me, I'd put hanks on any headsail, and slides on a mainsail, and a sock for spinnakers.


But I'm a dinosaur that's done a lot of long ocean miles on big raceboats.

And I totally understand. However someone needs to do something innovative, even if most innovations never reach the mainstream, otherwise nothing ever changes and we'd still be using hemp lines!

[Tupaia]

Originally Posted by Elleroo

long ocean miles on big raceboats.

With a keen and able crew probably?

[catsketcher]

We gotta see some pics.

Like you Mark, I was/am a racer. I sailed Lasers and represented Australia at the worlds, raced skiffs, 420s, sailboards and Tornados. I am a racer who loves to cruise.

If you are like me you will be EXACTLY the right type of person to get a Schionning or Pescott or Chamberlin or similar and cruise it and have a blast sailing it. You don't need to invent anything new.

As for not tacking - well that aint true. Just two days ago I came back from work, rowed out to the boat and took her out for a gentle sail around the bay. . I sailed her off the mooring (using skills from racing starts) and tack on the shifts, not for any real reason but for the fact that the boat speaks to me - like a nice 16 when you are at the top range of the big rig, or when you are railing a sailboard upwind.

If you are a racing sailor then it is even more reason not to throw away all the wonderful things that we have learnt - driven by racers like you. Crowthers, Pescotts, Schionning and Graingers were designed over decades, with racing being a major part of the evolution of the boats.

If you look at production cats, they are a different species. They do not have the background we can trace back to AMOC series and about 50 Brisbane to Gladstone races, events replicated around the world.

If you think you cannot have a fabulous cruising cat, that makes you want to sail it, and will satisfy the most experienced racer, you have not looked over the portfolios of the designers above. Getting rid of the main, will kill the boats playfulness and speed. Playing with the main to get the right helm feel and the right slot effect and the proper upper leech trim makes my boat get up and go. You will not get that with just a large genny. You will get sag and drag.

I would hate to cruise a boat that doesn't speak to me. I love the hundreds of times I can look back to and remember how I got my main and jib breathing and then when we got the screecher or kite up and the boat just flew, with a happy family on board. Main up almost all of the time because we know how to sail a performance boat that can generate apparent when the others are motoring, or can do windspeed if we sail 10 degrees high in the light morning air, coming down deep when the seabreeze kicks in. To not be able to do this would kill cruising for me.

Not investigating the race derived Aussie cats is a major mistake if you are a racer who wants to cruise. After 21 years, my cat still calls me out to sail it. Major cat manufacturers now make up the largest share of new cats - but it does not mean those boats are best for all.

Just go for a sail on a performance cat. At least make your decision after you have felt how they sail and how much space the good ones have.

[merrydolphin]

If you look at a very successful sailing cat, the Prouts ,you will see that the mast is very far aft and the main is very small. Many have sailed the world for decades.

[catsketcher]

Prouts are great boats, but they have never been called fast boats. The only one I know that has raced in Australia (Maripi - a 35ft Snowgoose) was usually last in Gladstone races. The OP says he wants a performance cat and that it will have a large genoa as well. Fast boats bring the apparent forward and this type of rig usually favours a smaller jib and large main. The two concepts, large heady and high speed, are pretty much mutually exclusive.

Look at any unrestricted class performance boat, like 18 footers or box rule monos, or offshore monos and multis, and you will see small headsails and large mains, combined with large kites/screechers at times. The experiments have been done hundreds of times in different designs and going with large genoas is not consistent with high performance. There are no boats that have large genoas that can do what a large main/small headsail rig type can.

In Australia we have a design called the NS 14, a reasonably high performance dinghy that has an overall sail area of about 100 square ft. It requires a highly efficient rig. You can apportion the sail area however you want. After much evolution the rig looks very similar to a typical fast mono/multi rig - large fully battened main and small jib. People have gone large jib and no jib but for the last 30 years the jibs are about 1/3 to 1/4 the area of the main.

It takes wilful blindness on the part of a designer to not see the obvious progress that has been made in high performance rigs. Large genoas can be great but they are not consistent with boats that operate at low apparent wind angles and which require different sailing modes. Large genoa boats suit sailors who don't sail different modes and who want boats that don't generate apparent. For a 49er sailor to want this type of boat seems strange to me.

One should also be careful of using experience derived from non-apparent wind boats on high performance multis. Whilst knowledge gained in heavier monos is useful, one really has to experience the ability of a typical performance cat to be able to change course slightly, sometimes only 10 degrees, and double its speed - with main and screecher/kite up. It is very different from heavy displacement sailing, and the reason fast boats tack downwind whilst slower boats don't.

As long as the OP knows that the boat will probably be disappointing and that he is taking on a huge gamble, I guess I have said all I need to. I have met a few designers though, who are happy to use other people's money to try new ideas. You need to be careful with the promises made by designers suggesting unproven new ideas.

[markiobe]

Originally Posted by catsketcher

We gotta see some pics.

Like you Mark, I was/am a racer. I sailed Lasers and represented Australia at the worlds, raced skiffs, 420s, sailboards and Tornados. I am a racer who loves to cruise.

If you are like me you will be EXACTLY the right type of person to get a Schionning or Pescott or Chamberlin or similar and cruise it and have a blast sailing it. You don't need to invent anything new.

As for not tacking - well that aint true. Just two days ago I came back from work, rowed out to the boat and took her out for a gentle sail around the bay. . I sailed her off the mooring (using skills from racing starts) and tack on the shifts, not for any real reason but for the fact that the boat speaks to me - like a nice 16 when you are at the top range of the big rig, or when you are railing a sailboard upwind.

If you are a racing sailor then it is even more reason not to throw away all the wonderful things that we have learnt - driven by racers like you. Crowthers, Pescotts, Schionning and Graingers were designed over decades, with racing being a major part of the evolution of the boats.

If you look at production cats, they are a different species. They do not have the background we can trace back to AMOC series and about 50 Brisbane to Gladstone races, events replicated around the world.

If you think you cannot have a fabulous cruising cat, that makes you want to sail it, and will satisfy the most experienced racer, you have not looked over the portfolios of the designers above. Getting rid of the main, will kill the boats playfulness and speed. Playing with the main to get the right helm feel and the right slot effect and the proper upper leech trim makes my boat get up and go. You will not get that with just a large genny. You will get sag and drag.

I would hate to cruise a boat that doesn't speak to me. I love the hundreds of times I can look back to and remember how I got my main and jib breathing and then when we got the screecher or kite up and the boat just flew, with a happy family on board. Main up almost all of the time because we know how to sail a performance boat that can generate apparent when the others are motoring, or can do windspeed if we sail 10 degrees high in the light morning air, coming down deep when the seabreeze kicks in. To not be able to do this would kill cruising for me.

Not investigating the race derived Aussie cats is a major mistake if you are a racer who wants to cruise. After 21 years, my cat still calls me out to sail it. Major cat manufacturers now make up the largest share of new cats - but it does not mean those boats are best for all.

Just go for a sail on a performance cat. At least make your decision after you have felt how they sail and how much space the good ones have.

Thanks for your comments, you are absolutely spot on with a big part of the decision making process, we absolutely want a performance cruiser We've actually spent a lot of time looking at the boats you mentioned and had narrowed the choice down to an Arrow 1360 or Raku 44. However we also have some other constraints which led us away from those designs and to a different designer/builder.

This design has been considered from first principles i.e. what do WE want in our boat and when you do that it's almost impossible to find something that fits our requirements, the Raku came the closest. This includes both hull and rig and the rig is the most contentious part of it and you've highlighted some of the reasons why, again .

We may well go with a more conventional rig but it would have a saloon stepped mast (like the FreeFlow) for various reasons. This would satisfy the racer in me (and you it sounds like). We're exploring the headsail only rig as it also ticks some other boxes, however we haven't made any decisions yet and the designer is leaning towards the conventional, that's what he's putting on the prototype.

This exploration was why I posted, to see if anyone had experience of this type of rig, and it turns out that a similar rig and hull design has been done before and I'm contact with one of the people that owned the boat (X-IT). Let's see, the process is fascinating.

Whatever we end up doing it will be considered by a very capable experienced designer, it's not some radical whim from a design neophyte (me ). But it will also, hopefully, fit our particular requirements and will be a fab tropics liveabord for a couple of decades at least

[markiobe]

Originally Posted by catsketcher

Look at any unrestricted class performance boat, like 18 footers or box rule monos, or offshore monos and multis, and you will see small headsails and large mains, combined with large kites/screechers at times. The experiments have been done hundreds of times in different designs and going with large genoas is not consistent with high performance. There are no boats that have large genoas that can do what a large main/small headsail rig type can.

In Australia we have a design called the NS 14, a reasonably high performance dinghy that has an overall sail area of about 100 square ft. It requires a highly efficient rig. You can apportion the sail area however you want. After much evolution the rig looks very similar to a typical fast mono/multi rig - large fully battened main and small jib. People have gone large jib and no jib but for the last 30 years the jibs are about 1/3 to 1/4 the area of the main.

What you say is obviously true, for high performance racing boats. However a 'fast' cruising catamaran is not 'high' performance in the same sense, for the vast majority of time. The reason to have a performance based cruiser is not that you blat around at 20kn all the time, it's so you have a big performance envelope - you can sail in light winds when everyone else is motoring, at the other end you can sail fast, safely, when required.

Also, a rig optimised for racing has an obviously different set of requirements. Arguably the main one is that, certainly in round the cans racing, you spend more than 50% of the time going upwind. This also talks to your point about apparent wind sailing. If you are going so fast that you're effectively sailing upwind all the time the rig design is completely different. However literally nobody does that when cruising, regardless of how fast the boat is in theory.

The imperatives for a cruising rig are utterly different and there is no aerodynamic reason why a headsail only rig is, a priori, a bad idea. Especially when the hulls are very light and easily driven thus not requiring much sail area. On the other had there are lots of practical advantages which are pretty obvious.

Ketches/Yawls are no longer built because we can now build masts/stays strong enough to support enough sail area on one mast. In the same way you can now use modern cloths to build extremely efficient headsails that don't need as much help to maintain their shape. And, regardless of what an earlier poster said, the absence of a mast makes a reasonably sized headsail, whose aspect ratio doesn't need to be too low, more efficient than an equivalent sized main when set on a round section mast. One practical application of this was X-IT which could sail windspeed at 13kn upwind with a headsail only rig.

Originally Posted by catsketcher

For a 49er sailor to want this type of boat seems strange to me.

If I wanted a racing catamaran it would obviously be a very different design. I don't get why you think it strange to have different boats for different uses...

Originally Posted by catsketcher

It is very different from heavy displacement sailing, and the reason fast boats tack downwind whilst slower boats don't.

No, they gybe downwind

Originally Posted by catsketcher

As long as the OP knows that the boat will probably be disappointing and that he is taking on a huge gamble, I guess I have said all I need to. I have met a few designers though, who are happy to use other people's money to try new ideas.

Comes back to point above. Disappointment is based on expectations. This will be a live aboard, very light, slim hulled performance cruiser. I don't think I'll be disappointed at all as the design hits that spot perfectly. There is still a question over the rig design, hence me starting this thread.

Originally Posted by catsketcher

You need to be careful with the promises made by designers suggesting unproven new ideas.

How about very experienced designer/builder that listens very carefully to their not-uninformed customers...? And ends up with a design that does nothing that hasn't been done before, but is not mainstream...? And is also building one himself as a prototype that we will sail before deciding...?

[Tupaia]

Originally Posted by markiobe

However a 'fast' cruising catamaran is not 'high' performance in the same sense, for the vast majority of time. The reason to have a performance based cruiser is not that you blat around at 20kn all the time, it's so you have a big performance envelope - you can sail in light winds when everyone else is motoring, at the other end you can sail fast, safely, when required.

Most "cruising" is off the wind and Prouts expertly exploited this with their mini-mainsail, big genoa sail plan. There have been many passages where I myself would have preferred this set up. But as someone pointed out earlier Prouts are not quick (performance) boats.



You envisage being able to sail in light winds when others are motoring in most cases this requires an "upwind" sail plan and good underwater appendages. The problem is the lighter the wind and the faster you go the further the apparent wind is drawn forward so light wind performance is limited by the boats ability to point high, more akin to "racing".


In calm conditions in 10 knots TWS we can make 9 knots boat speed at between 60-70 degrees TWA. This requires us to pull 35 degrees AWA and about 15 knots AWS which is about the about the limit for our screecher and full main. In very light conditions 6 knots TWS depending on the direction we want to go we often perform better under fractional jib and main as we can pull the apparent wind down to 29 degrees. I cannot see a headsail only sail-plan being able to achieve this.



There have been a few examples of what you are planning, the Bamba 50 and the HK40 but both are essentially sail assisted motorsailers being unable to sail "upwind".


Good luck with your project.

[markiobe]

Originally Posted by Tupaia

Most "cruising" is off the wind and Prouts expertly exploited this with their mini-mainsail, big genoa sail plan. There have been many passages where I myself would have preferred this set up. But as someone pointed out earlier Prouts are not quick (performance) boats.



You envisage being able to sail in light winds when others are motoring in most cases this requires an "upwind" sail plan and good underwater appendages. The problem is the lighter the wind and the faster you go the further the apparent wind is drawn forward so light wind performance is limited by the boats ability to point high, more akin to "racing".


In calm conditions in 10 knots TWS we can make 9 knots boat speed at between 60-70 degrees TWA. This requires us to pull 35 degrees AWA and about 15 knots AWS which is about the about the limit for our screecher and full main. In very light conditions 6 knots TWS depending on the direction we want to go we often perform better under fractional jib and main as we can pull the apparent wind down to 29 degrees. I cannot see a headsail only sail-plan being able to achieve this.



There have been a few examples of what you are planning, the Bamba 50 and the HK40 but both are essentially sail assisted motorsailers being unable to sail "upwind".


Good luck with your project.

The ability to go upwind has nothing to do with any particular sail-plan, it's to do with the relative positions of the CoE of the sails and the CoLR of the hull (plus obviously sail size/power, boat weight, length, how easily it's driven etc). In exactly the same way that the mass of an object can be resolved down to it's CoM so a sail-plan can be resolved down to a CoE. You could have a 5 sail-plan or a 1 sail-plan, if the CoE of both sail-plans is the same in terms of size and position, the effect on the hull is identical.

It makes complete sense why a boat designed around a main/headsail sailplan can't go upwind with only the headsail, the CoE is too far in front of the CoLR. You have constant lee helm and it would be very inefficient. Many cruisers won't be aware of this as the autopilot is on most of the time and you'd be unaware of the constant fight the autopilot would be having against the boat, plus the stress on rudder fittings etc. You'd just see it in terms of slow speed and poor angles upwind.

The rig that we are looking at would be designed in concert with the hulls so the CoE and CoLR would be balanced. In this case there is absolutely no reason why it couldn't go upwind efficiently.

Interestingly this is actually one area where this sail-plan would be more difficult to manage than a main/headsail one. With a traditional rig you can more easily balance the boat (CoE and CoLR) by changing the size of both sails, (reefing etc.) With this proposed headsail only rig, in theory you'd need to have 1 maybe even 2 inner forestays (this would depend on sail size and boat size) as simply furling the main headsail would reduce sail but automatically unbalance the boat. There'd be a threshold past which furling the sail any more would unbalance the boat too much.

This, as far as I can see, is the major drawback from a ease-of-use point of view with this idea as you'd be changing sails more often. I'm guessing that you'd need to sail as a matter of course with 2 headsails hoisted and furled on the main and inner forestays so you can switch between them as conditions changed.

Anyway, lots of pondering to do with designer and sailmaker before any decisions are made, thanks for your good wishes