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70' Cruising Proa....Big Red Yacht


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Sidecar, Russell,

Thank you very much for an open minded, civil and no-shit-slinging discussion on cassette rudders...

Des Jours Meilleurs, the big schooner proa built by Philippe Guillard had spade rudders like Sidecar. The cassette was oriented such a way that he could raise/lower  the forward rudder while underway. So if you were steering conventionally with the aft rudder, and front rudder raised; for a shunt you would:

  • lower the front rudder first; it is in the flow and you can let it loose
  • shunt the boat
  • both rudders pivots 180° freely while gaining speed on the new tack
  • raise the "new" front rudder (if need be)

Philippe also told me that steering with the front rudder was super effective.

However, his set up did not provide any significant crashbox safety set up. He told me that he hit ground once with a rudder at about 8 knots and the damage was significant; bent shaft, and damage to the hull where the back of the spade hit the hull skin.

 

Russell,

Regarding the skeg rudder, I did not realize that the loads on the shaft and bearing is much smaller, but it makes sense. The moving part is basically like a "super flap" on a wing. And on any non-symetrical wing profile (which a skeg rudder is, once you get the moving flap off centerline), most of the load is in the front half of the profile, therefore, most of it is on the skeg part of the rudder...

But sidecar raises a good point: there is no modern design high performance sailboat built today with a skeg rudder. So why do you think it is so? You say it is not due to lack of efficiency. I trust you on this, but then why no more skeg rudders???

 

Sidecar,

Do you have a spade rudder design that allows for a crashbox and some kind of mechanical fuse, if you hit ground? If yes, can you share some details? If the crashbox make the top of the rudder spade tilt forward after the crash, and the bottom tilt backwards, isn't the top haft of the blade going to damage the hull skin, or even perforate it???

Have you ever hit ground with your current rudder system? if yes, what was the outcome?

 

Both of you, thank you for an enlightening conversation!

 

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This thread has gone the way I thought it would. Rob is going to bash it over the head with his vindictive form of logic, but for what purpose? He's quoting things that I didn't write, some that were

It's happened one time in 10K miles of sailing Jzerro and this was due to an abrupt wind shift under a rain shower in the Gulf while sailing to Cuba.  I dropped the jib, lowered both rudders and put t

I'd rather you went away. I don't see the benefit to you of an ongoing public, lie-strewn war and it's embarrassing to me. Without you, Rob I wouldn't get the hairy eyeball on these forums. I'm not se

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1 hour ago, Laurent said:

Do you have a spade rudder design that allows for a crashbox and some kind of mechanical fuse, if you hit ground? If yes, can you share some details? If the crashbox make the rudder spade tilt forward after the crash, isn't the top haft of the blade going to damage the hull skin, or even perforate it???

Have you ever hit ground with your current rudder system? if yes, what was the outcome?

I have a 12mm thick rubber strip on the back side of the cassette to act as a space/shock absorber. The front and rear faces of the cassette have full length 20 mm teflon strips and the weight of the entire assembly is such that it won’t float up, therefore doesn’t need to be held down, so as long as the downhaul is off, no need for a fuse, the whole assembly can rise with minimum friction. There is a wooden spacer block at the top of the case which could be foam to help protect the front rudder, which is vertical when deployed. Both rudders have a heavily rounded forefoot, which helps to soften the blow and help the assembly to rise. The shafts in both rudders don’t go all the way to the bottom, so as long as the hit was far enough down, the bottom of the rudders should break off before anything else is seriously damaged. The aft rudder is raked, which again helps to glance off/minimise impact. Sidecar is so light, accelerates/decelerates remarkably easily and easy to change trim, that in itself should help to soften an impact, by rising up/glancing off.

I have touched bottom with the front rudder, but it was sand and speed was very slow, I was half expecting it. I also managed to hit an old (historic) jetty pile last Monday. It is barely 100 metres from the mooring, right in front of the house. We see it exposed at very low tides and I know the safe transit markers/bearings. Was doing ~ 3 knots, a gentle bump, but nothing else. No apparent damage in either case.

Regarding “Des Jours” steering wise, the front rudder does seem to be more effective, but I have found that at speed, bearing away, it can dig the nose in and slow you down, which is why I tend to sail with the aft one above 7-8 knots boat speed. It could be just a Sidecar thing....

CASSETTE DETAILS.pdf

Edit:

I can see how you could reduce the bottom front leg, shorten the front top (crush) spacer and put in crush spacers aft top and bottom, which would further reduce the impact of a grounding. Easy to do retrospectively.

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Sidecar, thank you so much for sharing your design; the drawings with your explanation makes sense.

I have to admit though that I am suspicious about the idea that a hit on the rudder will make it raise. I agree with you if you hit at the tip of the rudder blade, at the rounded off leading edge. But if unfortunately you hit a floating but heavy object, the rubber 12mm shock absorber might not be enough.

But nevertheless, it is a very clever design with a lot of interesting and useful features.

Once again, thank you for sharing!

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34 minutes ago, Laurent said:

But if unfortunately you hit a floating but heavy object, the rubber 12mm shock absorber might not be enough.

You probably are right. And I can see how to “upgrade” almost painlessly.  But how big an object, at what speed and what would be “enough”?

At least Sidecar doesn’t have a centreboard any more, much bigger leverage, so that is another risk avoided. And I have hit bottom with that too, as has John Harris of CLC.Boats.

Sidecar’s current centreboard, recommended for the risk averse below:

PS found a cropped photo showing how the rudders are linked back to “conventional” tillers. Apologies for the quality, and the Heath Robinson/MacGyver nature of the link between the tiller and the rudderhead spanner. Left over Carbon bits and pieces which will be upgraded sometime soon. Behind are the now obsolete side hung rudder gantries which will be removed when the boat comes out of the water. Weight saving! Less windage! Twice!

1F8F1BAB-516C-4C8A-88C0-0EFB3E07793E.jpeg

D1EE591D-2E39-4BB5-8F5D-9A9F9A541008.jpeg

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5 hours ago, Laurent said:

But sidecar raises a good point: there is no modern design high performance sailboat built today with a skeg rudder. So why do you think it is so? You say it is not due to lack of efficiency. I trust you on this, but then why no more skeg rudders???

I'm not sure, Laurent. They wouldn't find much appeal for around the buoys racers, but for higher speed long distance boats they seem so much more powerful and robust than spade rudders. Paul Bieker was surprised at the side force generated when designing a skeg rudder, so I'm not imagining the power. I'll dig out some better photos to scan and post.

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2 hours ago, Laurent said:

But if unfortunately you hit a floating but heavy object, the rubber 12mm shock absorber might not be enough.

Not saying it is “enough” but Teflon is pretty soft as well, arguably too soft for bearings, especially on a big proa like Big Red, so there is also a bit of give at  impact at the bearings and cassette edges as well.....

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17 hours ago, Laurent said:

Regarding the skeg rudder, I did not realize that the loads on the shaft and bearing is much smaller, but it makes sense. The moving part is basically like a "super flap" on a wing. And on any non-symetrical wing profile (which a skeg rudder is, once you get the moving flap off centerline), most of the load is in the front half of the profile, therefore, most of it is on the skeg part of the rudder...

But sidecar raises a good point: there is no modern design high performance sailboat built today with a skeg rudder. So why do you think it is so?

Skeg rudders are still quite popular on airplanes, of course.

They have a long history on boats, with distinct advantages, primarily "the skeg also increases the strength of the rudder by allowing a bearing to be placed at the very bottom of the shaft which drastically reduces shaft loading.[source]

P.S.  From Kraken Yachts:

Why our luxury sailing yachts have skeg hung rudders
https://www.krakenyachts.com/skeghungrudders

95f773_6a9c2cb00f6c4563af7f25144b8b82e6_mv2.jpg.3d59db788fe71a441ae3b760c3778472.jpg

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3 hours ago, Ajorn said:

Laurent,

reason's not the power but the balance bit. A balanced rudder requires a lot less steering force.

 

Jörn

You are absolutely correct on the steering load. Or the torque applied to the rudder shaft to make it turn.

But what I was talking about (and I believe Russel as well) was the side load on the rudder. On a balanced spade rudder, the load on the helm can be light, but the shaft of the rudder still has to take 100% of the "lift" (or side force, in the case of a rudder, instead of using aeronautical terms), which can be huge. After all, this is why we turn the rudder in the first place! Create side load aft, to change the course of the boat.

With a skeg, the whole assembly is now a curved profile as soon as you move the tiller from centerline: the aft part of the rudder - the "flap" - is no longer aligned with the front part of the rudder - the skeg. And hydrodynamics show that for a curved profile, the bulk of the pressure exerted on the profile by the fluid passing by (high pressure on the intrados and low pressure on the extrados) in on the front half of the profile. So the brunt of the silde load is exerted on the skeg, not the flap. So the shaft of the flap does not have to take such a big side load; and on top of that, it is held at both ends, at the root of the skeg, but also at the bottom of the skeg.

So the scantling of that shaft, and the size of the associated bearings can be much smaller than on a spade rudder of the same overall plane area

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On 6/4/2021 at 12:53 AM, Russell Brown said:

I guess I disagree with you (which is rare) about skeg rudders. It's high speed control over low speed control and simplicity, although shafts and bearings for large spade rudders are not be simple. I built spade rudders for Cimba The control was very poor (scary) and the bearings would load up and take lots of effort to steer. I had to build a set of skeg rudders to replace them.

If skeg rudders aren't popular, it's not because they aren't way more powerful at speed and structurally better than just a rudder shaft. 

Are both your rudders down all the time? I think I remember that you use the fwd one for lift upwind. I like that in concept, but have no experience with it. Your trunks must be long enough to pull the rudders when they are facing either way.

Would it be possible to put a percentage on how much low speed control I will lose if going to skeg version?? That is not a strong point of Big Red.

I imagine you're not wanting to open pandoras box of build questions but I may ask them anyway and will appreciate the ones you respond to. Jo

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Jo

Quite simply: Do your current spade rudders “reverse” and can be used in either direction?

If the answer is no, then you will gain more control by using reversible spade rudder cassettes.

If the answer is yes, then you are likely to lose some control from what is already apparently poor.

i don’t know the details of Russell’s spade build, but I have sailed on boats with over balanced rudders, (a pain) under balanced rudders (a pain) and ones with inadequate (or too closely spaced) bearings. I can recall once sailing with Jeremy Rogers in the UK on one of his new demo MG34’s where he was squeezing detergent down the shaft from the cockpit to make steering easier. It is a matter of engineering.

The issue is not which cassette system, is in itself best, but by using a skeg cassette you forgo the possibility of using either rudder, both rudders and a reduction in shunt down time.

You money, your call.

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23 hours ago, Sidecar said:

I have a 12mm thick rubber strip on the back side of the cassette to act as a space/shock absorber. The front and rear faces of the cassette have full length 20 mm teflon strips and the weight of the entire assembly is such that it won’t float up, therefore doesn’t need to be held down, so as long as the downhaul is off, no need for a fuse, the whole assembly can rise with minimum friction. There is a wooden spacer block at the top of the case which could be foam to help protect the front rudder, which is vertical when deployed. Both rudders have a heavily rounded forefoot, which helps to soften the blow and help the assembly to rise. The shafts in both rudders don’t go all the way to the bottom, so as long as the hit was far enough down, the bottom of the rudders should break off before anything else is seriously damaged. The aft rudder is raked, which again helps to glance off/minimise impact. Sidecar is so light, accelerates/decelerates remarkably easily and easy to change trim, that in itself should help to soften an impact, by rising up/glancing off.

I have touched bottom with the front rudder, but it was sand and speed was very slow, I was half expecting it. I also managed to hit an old (historic) jetty pile last Monday. It is barely 100 metres from the mooring, right in front of the house. We see it exposed at very low tides and I know the safe transit markers/bearings. Was doing ~ 3 knots, a gentle bump, but nothing else. No apparent damage in either case.

Regarding “Des Jours” steering wise, the front rudder does seem to be more effective, but I have found that at speed, bearing away, it can dig the nose in and slow you down, which is why I tend to sail with the aft one above 7-8 knots boat speed. It could be just a Sidecar thing....

CASSETTE DETAILS.pdf 52.77 kB · 12 downloads

Edit:

I can see how you could reduce the bottom front leg, shorten the front top (crush) spacer and put in crush spacers aft top and bottom, which would further reduce the impact of a grounding. Easy to do retrospectively.

Rob,

I Have grounded Big red at about 5 knots which did no damage except paint, the shafts are massive. but the boards would have come up in the trunk if cassette type, as I could see them trying to when all hull loads came down upon them. Not my finest hour!

With your rear board I think a fuse would be needed as I cant see it going up except if it cuts a new slot, or am I just not seeing it right?

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10 minutes ago, Sidecar said:

Jo

Quite simply: Do your current spade rudders “reverse” and can be used in either direction?

If the answer is no, then you will gain more control by using reversible spade rudder cassettes.

If the answer is yes, then you are likely to lose some control from what is already apparently poor.

i don’t know the details of Russell’s spade build, but I have sailed on boats with over balanced rudders, (a pain) under balanced rudders (a pain) and ones with inadequate (or too closely spaced) bearings. I can recall once sailing with Jeremy Rogers in the UK on one of his new demo MG34’s where he was squeezing detergent down the shaft from the cockpit to make steering easier. It is a matter of engineering.

The issue is not which cassette system, is in itself best, but by using a skeg cassette you forgo the possibility of using either rudder, both rudders and a reduction in shunt down time.

You money, your call.

Rob,

I wouldn't call it poor but as with any large multi windage is not your friend at low speed, the rudders themselves i think do a pretty good job given what's asked of them.

Yes they do reverse and can be used in any direction, they even have the bonus of wheel steering which means no need to reprogram your brain either end, just turn in the direction you want to go, nice.

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1 hour ago, Jo R said:

With your rear board I think a fuse would be needed as I cant see it going up except if it cuts a new slot, or am I just not seeing it right?

The front rudder should hit first…..

And coming back to skeg cassettes, you are likely to lose some of the control and versatility you already have?

Unless I have misunderstood something, linking the rudders to work in unison restricts some of the versatility and manoeuvring options.

But the good news is, either way, if one cassette style doesn’t work for you, it isn’t a deal breaker to try the other, or even have both, one for long distance voyaging and another for coastal sailing. And modifying/adapting cassettes to suit your preference or experiences is no big deal either.

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15 minutes ago, Sidecar said:

The front rudder should hit first…..

And coming back to skeg cassettes, you are likely to lose some of the control and versatility you already have?

But the good news is, either way, if one cassette style doesn’t work for you, it isn’t a deal breaker to try the other, or even have both, one for long distance voyaging and another for coastal sailing. And modifying/adapting cassettes to suit your preference or experiences is no big deal either.

I can see where your coming from, it probably will hit first but when I went aground the front blade kind of lodged while the rear took the dynamic loads as the boat rose and fell in any swell, that can be quite the pounding. pretty hard to engineer for every scenario.

i like the good news aspect, I am currently undecided which way to go, I was set on the skeg version, for me easier to engineer and strong but not really wanting loss of low speed control. But once it is opened up I can do both if need be.:)

Appreciate your input as always,

Jo

 

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Both rudders are independent no linking or restrictions , the reason I can do anything with either and not require mind reset is the quadrant for want of a better name is a full circle with rope linkage so just turn as needed.

20210605_120317.jpg

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I used both rudders at low speeds when maneuvering. The forward rudder wants to turn (obviously), but I would let it turn until it hit the stop and reverse direction when needed. Not much chance of tight quarters maneuvers without the forward rudder on my boats.

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1 hour ago, Russell Brown said:

I used both rudders at low speeds when maneuvering. The forward rudder wants to turn (obviously), but I would let it turn until it hit the stop and reverse direction when needed. Not much chance of tight quarters maneuvers without the forward rudder on my boats.

I am sure that you are right Russell… it is just me. I have experience of carefully using a rudder (on a monohull) in reverse, when it suddenly bit and I was literally thrown across the cockpit into the lifelines with the boat going (too rapidly) the wrong way in crowded quarters.

Sometime I forget to “flip” when reversing out from inside the local jetty, and  there is (still) a big difference in the handling of a rudder facing the wrong way and one facing the right way. But I admit, the difference would be less with a “skegged” rudder….

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2 hours ago, Jo R said:

I can see where your coming from, it probably will hit first but when I went aground the front blade kind of lodged while the rear took the dynamic loads as the boat rose and fell in any swell, that can be quite the pounding. pretty hard to engineer for every scenario.

i like the good news aspect, I am currently undecided which way to go, I was set on the skeg version, for me easier to engineer and strong but not really wanting loss of low speed control. But once it is opened up I can do both if need be.:)

Appreciate your input as always,

Jo

My front rudder remark was flippant. The old jetty pile I hit was aft rudder only. I will review and perhaps modify the cassettes once the boat is out of the water in about a month’s time.

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16 hours ago, Laurent said:

You are absolutely correct on the steering load. Or the torque applied to the rudder shaft to make it turn.

But what I was talking about (and I believe Russel as well) was the side load on the rudder. On a balanced spade rudder, the load on the helm can be light, but the shaft of the rudder still has to take 100% of the "lift" (or side force, in the case of a rudder, instead of using aeronautical terms), which can be huge. After all, this is why we turn the rudder in the first place! Create side load aft, to change the course of the boat.

With a skeg, the whole assembly is now a curved profile as soon as you move the tiller from centerline: the aft part of the rudder - the "flap" - is no longer aligned with the front part of the rudder - the skeg. And hydrodynamics show that for a curved profile, the bulk of the pressure exerted on the profile by the fluid passing by (high pressure on the intrados and low pressure on the extrados) in on the front half of the profile. So the brunt of the silde load is exerted on the skeg, not the flap. So the shaft of the flap does not have to take such a big side load; and on top of that, it is held at both ends, at the root of the skeg, but also at the bottom of the skeg.

So the scantling of that shaft, and the size of the associated bearings can be much smaller than on a spade rudder of the same overall plane area

You need to account for yaw changing the angle of attack of the skeg. If you are requring relatively rapid changes of direction, the skeg portion will have a  negative angle of attack during the rotation and will not create much lift. So you will get high initial side force on the skeg, then less as the yaw velocity increases.

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On 6/1/2021 at 10:48 AM, Sidecar said:

The more you push water under a hull, rather than shove it aside, the more dynamic uplift, not down lift is created. 

Reply to old post I know... But don't Ian Farrier state his main reason for the wide-ish aft sections of his main hull, with lots of rocker aft (as opposed to a flat run like a surfboard), was so that at high speed the stern was sucked down- which was a way of keeping the bows up/avoiding nose diving. That was for the F27 at least...

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14 hours ago, Sidecar said:

The issue is not which cassette system, is in itself best, but by using a skeg cassette you forgo the possibility of using either rudder, both rudders and a reduction in shunt down time.

At 2:42 in this video (Launching Pacific Proa CIMBA on Martha's Vineyard, ~1989), Lou McGregor reaches back to flip the tiller on the forward skeg rudder (starboard tack bow). The effect is instant.

 

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I am reminded that it's possible to have a balanced rudder on a "skeg" with bearings top and bottom - from this old thread that lost all the images I posted thanks to a change in DropBox policy. :(

All original images are here: http://www.islandcad.com/marine/rudder_replacement/

These from near the end:

  • White rudder is pivoting at 15% of area (18% chord on this shape). Blue is pivoting at leading edge and would be shaped accordingly.
    rudder_2017Jan26a.gif.9bad21a5d9768ebc46ecf4528f4f110a.gif
     
  • Here is a balanced rudder based on moving only the bottom pivot point aft ~8 inches, changing only the angle at the top bearing, skipping the middle gudgeon:
    rudder_2017Jan28a.gif.256e5fb4289e11496e32ce8c14060987.gif
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17 hours ago, ProaSailor said:

At 2:42 in this video (Launching Pacific Proa CIMBA on Martha's Vineyard, ~1989), Lou McGregor reaches back to flip the tiller on the forward skeg rudder (starboard tack bow). The effect is instant.

 

The affect is certainly instant but that is the aft rudder for direction of travel, under tow

You can see the linkage move in close up view.

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Sidecar

Rob I think for my first iteration of cassette rudders the spade version looks like it might be the way to go. What you have designed and shared is pretty cool and with a few tweaks I think will be great for Gaias dream/big red. Jo

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Well done Jo.  It's good to see someone prepared to realise Gaia's Dream's potential.  If you are ever in Bris, drop in for a chat and a look at the cargo proa.  If you need any materials,  I buy in bulk from China, am happy to onsell to you at my buying price, which is about half retail.   

On 5/31/2021 at 5:28 AM, Airwick said:

Doesn't the lift come from the fluid flowing on both sides of the asymmetrical foil? So if you throw in a free surface between 2 fluids it changes things a lot no?
There's also a big difference between the outline (silhouette) of a hull and the actual 3D shape so the 3D shape of a rockered hull with a rounded cross section is nothing like a Hobie hull on its side so I don't really see how this is relevant...

If you hold a spoon by the end of the handle and move the back of the bowl section into a stream of tap water, it will be sucked inwards.  Make a model of a rockered hull and the same thing happens.  Make it flat (no rocker) and it doesn't.  Hold the ends of the flat surface and angle it to the water flow and it is pushed away from it.  

Sidecar,

Your examples are mostly planing surfaces.  Any surface that is flat/wide/light/fast enough will plane.    A nominal curve on the tip is insurance against nosediving.   If your hull rises at 4 knots, and is flat/wide/light enough it is planing.  If not, it is some phenomenon other than dynamic lift.  

Do you have any performance data (gps upwind tracks, race results, leeway measurements, etc) for your cross hull leeway resistor? This idea has been tried by Wharram, Kohler, etc but discarded as inefficient.  If it is as efficient as a daggerboard upwind (especially a Seacart 30) and does not add to surface drag downwind, then multihull sailing has become significantly safer and cheaper.

I would be wary about using Sven as a proa authority.  He spent a fortune on the boat, sailed it a couple of times, damaged a beam and put it on the market to build an 'improved' version.  Took years to sell, he has yet to launch (or start?) the new boat.

The discussion about spades vs trim tabs is interesting but ignores the elephant in the room.  ie, what happens when the rudder (or daggerboard) hits a floating object (log, container, whale, etc) at performance  proa speeds?  Either the rudder, case or hull will be damaged unless they are built so strong (and heavy) that they can withstand the impact, in which case the crew will be hurt.  

To give an idea of 'hurt' 'damage' and 'impact', watch a 1.5 ton/tonne car (~ a 35' proa) with crumple zone (a whole lot more effective than a rubber strip, a piece of polystyrene and a bit of teflon) hitting a wall at 25 mph/22 knots.  

 

I have hit a whale at 10 knots (severe damage to the whale, keel and attachments on a 15m/50' mono) a sunfish at ~12 knots (spade rudder smashed) and broken more experimental proa rudders than I can count.  This is why, despite their looks and inefficiency (both of which are improved with each iteration) Harryproas have externally mounted rudders which kick up in either direction.  No antifouling, no holes below the waterline and the ability to steer as long as the boat is floating are added benefits.

 

 

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4 hours ago, Jo R said:

The affect is certainly instant but that is the aft rudder for direction of travel, under tow

You can see the linkage move in close up view.

Oops, I think you're right.  My mistake.  I've been seeing that wrong for decades!

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14 hours ago, Jo R said:

Rob I think for my first iteration of cassette rudders the spade version looks like it might be the way to go. What you have designed and shared is pretty cool and with a few tweaks I think will be great for Gaias dream/big red. Jo

I will still PM you some photos when I get the chance. I can also send you  .dwg or .dxf files as well if you can use them?

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@harryproa

The effect you are referring to is the Coanda effect.

One of the future modifications on Sidecar that I am considering currently is to increase the Coanda effect of my ama. The ama does indeed plane when boat speed gets up to ~ 9 knots upwind in flat water when it is sufficiently unloaded. A lovely sound to hear it skidding over the water.

I don’t have wind instruments, so close windedness and tracking info is moot. It would be on Norfolk Bay anyhow. There is a permanent wind bend in the bay, which varies in location and extent, with all sorts of holes along the way, depending on conditions on the day. The only reliable way to monitor/verify would be to sail closely against a boat of known ability and similar speed. Too far apart and you would be literally sailing in different winds. There isn’t such a boat in the area, and more than 90% of the time, I am the only one out sailing, which is great, but not helpful if you are wanting to compare, learn or improve.

I sometimes short tack Sidecar up the Sound back to the mooring which has even more wildly swinging wind directions strengths and holes. I had an ex national champion NS14 (“Splinter”) and used to sail it in the Sound before I built Sidecar. The average upwind “track” allowing for shunting seemed be similar for both. Plenty of close landmarks and transits on both sides. In fact Sidecar (now) behaves and reacts remarkably similar to a big NS14….. And it even has a similar tiny jib/big mainsail set up.

Can you provide forensic track and wind data evidence of Bucket List’s upwind ability, or indeed any of you condo proas? There are so many, you must be able to provide lots?

If you have succeeded in making rudders 100% safe and “idiot proof” you should share details with everyone. I have shared mine, you show yours, it would be a disservice to the sailing world not to. You could even save lives?

I don’t know what the Wharram cats did regarding chine runners, and FWIW, Berndt Kohler still offers “anti vortex panels” and describes them on his current website. I am much less comfortable with them. Have a look a Matt Layden’s flat bottomed centreboard/keel-less boats, designed for gunkholing.

A sincere piece of advice:

Flat bottomed proas are ideal candidates for chine runners, especially ones which operate in shallow waters, where deep centreboards or oversized rudders could touch bottom inadvertently. And on a Proa, you only need one, the leeward side. The small amount of added frontal and surface area will be more than compensated for by the reduced rudder and centreboard area possibilities. The reduction on Sidecar was massive, with no apparent loss of leeway resistance. And they work better and are more directionally stable at slow speeds, when a highly efficient foil may have insufficient flow.

Peanuts in terms of cost and labour to put them on, even less to take them off.

 

 

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4 hours ago, Sidecar said:

 

The effect you are referring to is the Coanda effect.

Yeah, I know.   You said it didn't happen.  (June 1)

4 hours ago, Sidecar said:

The ama does indeed plane when boat speed gets up to ~ 9 knots upwind in flat water when it is sufficiently unloaded. A lovely sound to hear it skidding over the water.

Any ww hull does this.  You said it started lifting at 4 knots, with no unloading.  And that it was caused by the shape of the hull, which is the opposite of the Coanda effect.  (June 1)

4 hours ago, Sidecar said:

I don’t have wind instruments, so close windedness and tracking info is moot.

It's not.  Half an hour of gps track with shunts upwind and down in the middle of Norfolk Bay (~12 miles x 8 miles) would remove a lot of the "seems to be" from your posts.

4 hours ago, Sidecar said:

Can you provide forensic track and wind data evidence of Bucket List’s upwind ability, or indeed any of you condo proas? There are so many, you must be able to provide lots?

I'm not sure whether an 18m/60' 4.5 tonne/ton proa (lighter than an ORMA 60) counts as a "condoproa",  but as it is ~50% heavier than the next heaviest Harryproa, bar one,  I assume  the Melbourne 60'ter is the boat you mean?  There are a couple of tracks and some expert analysis on www.harryproa.com.  

If you want information from Harryproa owners, join https://groups.io/g/HarryProa/topics, introduce yourself and ask them.  They don't post here because of the sarcasm levels. ;-)

The Bucket List project was cancelled years ago once it became obvious there was no support for the concept of a charter race proa so the boat never got optimised, or recorded.    

4 hours ago, Sidecar said:

If you have succeeded in making rudders 100% safe and “idiot proof” you should share details with everyone. I have shared mine, you show yours, it would be a disservice to the sailing world not to. You could even save lives?

Maybe.  Would certainly save damage bills and weight. And make boats (not just proas) easier to handle and less stressful to sail.   Anyone who is interested is welcome to contact me direct at harryproa@gmail.com.  Check out https://www.boatdesign.net/threads/proa-shunting-in-heavy-weather.65480/ for details of an older version which is worth copying if you worry about rudder impacts and safety.  If you do copy them, maybe contact me first to avoid mistakes leading to you abandoning them as they 'don't work'.

Join https://groups.io/g/HarryProa/topics for details of the latest ones which are a couple of quantum leaps in terms of improvements, looks, drag and cost, albeit in opposite directions.   One idea will be tested on the Norwegian 20m , the other on the cargo proa.  Both extend the envelope from kick up, lifting, bidirectional rudders to include foiling potential.  Fun times.  

Thanks for the "sincere advice".  I am sure it is well meant.  Question is, why bother?  Harryproas are easy to sail and perform well with the rudder size and location, the rigs and the hulls they have.  Adding work, drag, weight, wetted surface and turbulence for no improvement is not productive.

If a HP rudder touches the bottom (or hits a log), it kicks up and is easily kicked back down, then lifted to the appropriate depth.   They still steer and provide leeway resistance if the boat is floating (less than 300mm/12" depth in most cases).   20 odd years ago, I found this to be much less hassle in a slow speed grounding/collision than removing the tiller, pulling the rudder out of the cassette, replacing the foam block and reinstalling the rudders.  And certainly less hassle than building new ones after a high speed collision/grounding.

If swapping the daggerboard for a wooden plank extending a few inches from the side of the keel meant a "massive area reduction and no change in performance" to Sidecar, then elementary physics and accepted boat design principles would suggest maybe there was something fundamentally wrong in the first place? 

Were the "upwind numbers the same as the Seacart 30" achieved with the daggerboard or the plank?  

I'm back building and installing the bottom section (of 3, the other 2 are built) of the cargo proa's first 18m/60' unstayed telescoping carbon wing mast tomorrow, I may not reply for a week or so.  1669874122_Revertingtohandlayuponmasts.thumb.JPG.693f48335fcf80b4e5b0f355804b51fb.JPG

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It is not the first time you have been asked to show (any of) your tracking information. Can you confirm your reply (in part) to Ryan Finn some time ago:

“And you are not doing it "as a learning opportunity" (you will not learn anything from my track), but in the hope that you can score some points against me on apissant forum. “

If you demand such information from others, you should be prepared to supply it yourself, instead of casting aspersions on others in advance.

And if your rudders are now so good, we would love to see the details, rather than just endlessly hear about it.

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On 6/4/2021 at 8:30 AM, Laurent said:

Des Jours Meilleurs, the big schooner proa built by Philippe Guillard had spade rudders like Sidecar. The cassette was oriented such a way that he could raise/lower  the forward rudder while underway. So if you were steering conventionally with the aft rudder, and front rudder raised; for a shunt you would:

  • lower the front rudder first; it is in the flow and you can let it loose
  • shunt the boat
  • both rudders pivots 180° freely while gaining speed on the new tack
  • raise the "new" front rudder (if need be)

Philippe also told me that steering with the front rudder was super effective.

However, his set up did not provide any significant crashbox safety set up.

Laurent, apologies for not addressing Philippe Guilllard’s remarks properly. Pretty much agree with all of it, I don’t even bother to raise the inactive rudder, but I could if I wanted to, on a long leg.

The other thing I forgot was that Sidecar (and Big Red, I believe) are flat bottomed. Sidecar’s rudder shafts are at an angle, so that the endplate effect at the rudder top is preserved as much as possible, a bit like some high performance aircraft:

C16BC1D7-2961-49B5-8983-775A3732EC9E.jpeg

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On 6/7/2021 at 9:14 AM, Sidecar said:

I will still PM you some photos when I get the chance. I can also send you  .dwg or .dxf files as well if you can use them?

Sounds good, I have Rhino now so I think it opens both, got a free viewer if that fails. Thanks Rob.

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4 hours ago, Sidecar said:

Laurent, apologies for not addressing Philippe Guilllard’s remarks properly. Pretty much agree with all of it, I don’t even bother to raise the inactive rudder, but I could if I wanted to, on a long leg.

The other thing I forgot was that Sidecar (and Big Red, I believe) are flat bottomed. Sidecar’s rudder shafts are at an angle, so that the endplate effect at the rudder top is preserved as much as possible, a bit like some high performance aircraft:

C16BC1D7-2961-49B5-8983-775A3732EC9E.jpeg

Yes Gaias Dream has flat bottom Vaka and not much rocker, another reason why it makes sense to go spade.

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14 hours ago, Sidecar said:

Laurent, apologies for not addressing Philippe Guilllard’s remarks properly.

No worries, nothing to apologize about!

14 hours ago, Sidecar said:

The other thing I forgot was that Sidecar (and Big Red, I believe) are flat bottomed. Sidecar’s rudder shafts are at an angle, so that the endplate effect at the rudder top is preserved as much as possible, a bit like some high performance aircraft:

 

I got that from your excellent drawings. The rudeer shaft is slanted in the trunk, but perpendicular to the boat bottom.

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On 6/9/2021 at 3:25 PM, Jo R said:

Yes Gaias Dream has flat bottom Vaka and not much rocker, another reason why it makes sense to go spade.

If you do decide to go “spade”, remember not to overbalance. Several textbooks suggest ~ 17% max. Theoretically, >25% will cause problems. Sidecar has ~ 21% and seems OK. The more balanced you make the rudder, the lighter the tiller loads, the less “feel” you will have and the less likely to cause “problems” in reverse.…..

The rudder that threw me into the lifelines (and almost into the water too many years ago) was on a reversing Farr two tonner, a big unbalanced spade rudder behind a (horizontal) skeg with fairing flaps.

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Nearly finished the bottom section of the 1st mast yesterday.  8m/27' long, weighs 73 kgs, with another 5 or so to add.  Strip planking in carbon is not the fastest or cleanest way to build, but it is the cheapest, materials wise.  $AUS6,000/$US4,000 for a 20m/66' unstayed mast is not bad.  It also produces a higher carbon:resin ratio (70/30) than any other build method and is incredibly consistent in terms of fibre straightness and f/r ratio.

On 6/9/2021 at 9:58 AM, Sidecar said:

It is not the first time you have been asked to show (any of) your tracking information. Can you confirm your reply (in part) to Ryan Finn some time ago:

“And you are not doing it "as a learning opportunity" (you will not learn anything from my track), but in the hope that you can score some points against me on apissant forum. “

I can "confirm" that: 

i) this is a pathetic attempt to divert attention from your claims to have a windward hull which reverses the Coanda effect, achieves Seacart 30 speeds upwind with a piece of 4 x2 timber attached to the side of your hull instead of a daggerboard and that your cassette rudders are dangerous in a high speed collision with a floating object.

ii) the quote is from a private conversation that Ryan expressly asked me to not publicise.   Publishing it is a pissant act, the same as when you published private emails from me to you a year or so ago.

iii) I don't discuss my private conversations in public.  

iv) it is totally out of context as it is not the full quote, nor does it show the background.

v) I don't have any tracking data of my boats, so have nothing to post beyond what is on the web page.  I will not have a boat to record tracking data until the cargo ferry is launched.  Unlike you. 

On 6/9/2021 at 9:58 AM, Sidecar said:

And if your rudders are now so good, we would love to see the details, rather than just endlessly hear about it.

I told you where the information is, said you could copy it and offered free advice if you did.  Next thing you will want me to build them for you as well.  

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For anyone who has any doubt about what is going on here, consider this:

The Melbourne Proa for sale Denney says is 4.5 tonnes, is listed on the sales data as 5.7 tonnes. It does not even have side hung rudders, it has under the hull shaft rudders (with endplates on top). At least three iterations worth.The current shaft diameters being 52mm dia solid high strength stainless steel, designed, so the boat can stand on them.

It also has a centreboard, approx 2 metres x 0.48 metres. Sailing angle without centreboard  is 120 - 130 degrees, ~100 degrees with.

I could tell you a lot more, PM me if you want. We wouldn’t want anything to go public would we? Not withstanding, I have suggested it to a good friend who is on the lookout for a platform to do Pro Bono eye surgery work around Fiji and Vanuatu.

Also, to be clear, all the top speeds on Sidecar are without centreboard and with the lumps of 4x2 bandaged to the side. And I think you are all missing a trick. As I said earlier, fuck all money and effort to put on, even less to take off if not satisfied.

And below are two more examples of high performance multihulls, MOD70 and the Diam24, rescaled for comparative purposes, which exhibit similar “Coanda Catasptrophes” as Sidecar. I could do the same for any number of Farrier designs. From all the examples given, pick the odd one out?

Enough of this.

MOD 9.5 overlay.pdf DIAM 9.5 overlay.pdf

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On 6/14/2021 at 8:53 AM, Zonker said:

What is a strip planked mast? Do you use pultruded planks of carbon? Or a wood core and covered with carbon?

Pultruded planks, 100m rolls of 50 x 1.2mm/350' x 2" x .055".   70% standard modulus carbon, perfectly aligned fibres with reliable properties.  $250 per roll, plus shipping from China.  We used them on the beams and the rudders, where they saved a lot of time and work, but the masts are probably a step too far in terms of labour required.  They are no use for tapered masts, but the telescoping wing masts aren't.  They're also no use for infusion unless the strips are preglued to the required thickness which causes other hassles.  On the bright side, they are about the same price as the carbon tow and epoxy they contain, so cheaper than building our own strips which I did to make a tapered (dia and thickness) 10m/35' mast 20 years ago and way cheaper than uni.
 
Nearly finished the second mast last week, should install them both this week. Once they are in, we can finish the beams and close up the windward hull. Happy days!  Progress pics and information at http://harryproa.com/?p=3788and https://groups.io/g/HarryProa/topics  
 
The 10.5m/35' Harryproa for sale in Maine mentioned earlier in this thread has been sold to a local guy.  He has employed a yard to make the windward hull standard (enclosing the walk through cockpit) and is doing the  cleaning up himself.  Hopes to be sailing this summer.
 

Sidecar,

Thanks for recommending the boat to your surgeon mate.  Maybe suggest he look into making the windward hull the same as the Orbiter 80 which we drew for a doctor with similar ambitions.  Please ask him to contact me if he does proceed.  There is a lot happening around sailing proa finance in Fiji at the moment, some of which will benefit him.  

Thanks also for repeating what is on our web page about the boat.  There are several interesting discussions about the pros and cons of the boards/rudders set up the owner chose, against my advice, on https://groups.io/g/HarryProa/topics  

Which "top speeds on Sidecar" are you referring to?  More importantly given the leeway prevention on the boat, at what wind and leeway angles?  Given your history of unsubstantiated performance claims, how were these measured?     If you avoid answering these questions by referring to my history please quote reference dates and locations.  

None of the boat designers you refer to claim the Coanda effect does not exist or that their hulls rise at 4 knots, contrary to it.  Both of which you did in your post June 1.  Are you saying that the Coanda effect will or will not pull a hull with rocker lower into the water?

No comment on the wisdom/stupidity of dagger rudders in high speed collisions? 

Anyone with any decency would have apologised for posting a private email.  They probably would also have been smart enough not to post it in the first place.  Pissant act.  It's amusing that you resort to using my surname when you are under pressure about your boats or posts. 

Screen Shot 2021-06-19 at 9.05.41 pm.png

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Hopefully this is of interest,

I have added a couple of extra features to Gaias Dream that will help a lot when sailing coastline with flukey winds or anytime the wind is against her direction of travel and one for safety.

I added a removeable stay to leeward wand attachment for sheet inboard which means combined with my big strut I have enough suport to carry headsail backwinded, most useful when motor saiing to windward on both tacks now. Tested to 18knots of breeze so far.

 

The other a heavy dyneema strop on shock cord takeaway that limits boom travel to about 170 degrees, just in case of major stuff up or backwinding. Pretty happy with extra hand that self tends. My boom doesn't come close to the forestays, so was always a concern if it was let loose with probable dismasting the likely outcome. Not anymore:)

Sorry about pic orientation

Jo

20210610_131356.jpg

20210621_122413.jpg

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Jo,

The boat is looking good.  Well done.  Those are smart moves.  Similar gear to stop the mast falling in a crash gybe or when caught aback in a blow should be standard on all stayed rig proas.  

Cargo proa news:

We got the 8m/27' bottom section (78 kgs/175 lbs) of the first telescoping mast (the video is too big for this site) installed this week, then got rained on before the second one could be raised.   

We used the middle section as a gin pole, stayed to sundry boat components.   Bit of overkill, so I have chopped up an old carbon mast to make a deck mounted A frame to replace it.   

Next major job is fitting the beams and closing up the ww hull foredecks.  The rudder mounts, beam struts, winch table and the wing sections for the masts will keep us occupied while epoxy cures.  

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Thanks Rob, yes the additions give some more security.The rig on GD is a very different beast to other stayed proas such as Jzerro. There has been plenty of heated discussion between yourself and others and I'm not wanting to add to to that. 

the backwinding risk is minimal on most stayed proas as you know they do carry a fair amount of leeward support.

Ironically the mast on GD did break about 5yrs ago when the top Windward stay attachment failed on original owner/builder.

Many changes since and feels pretty solid now.

Cheers Jo

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  • 1 month later...
On 10/2/2020 at 8:39 PM, Russell Brown said:

The antagonistic fighting bullshit is what inspired rob's decades long quest to discredit any and all proas that didn't have an H in front of them. I'm partly responsible, but only because I really dislike false advertising and also because it was hard to have my lifetime work in proas discredited. It wasn't smart to fight back, but I say let rob's work speak for itself and please don't fucking fight about this shit. It's stupid.

Ryan Finn is likely the worlds most skilled proa sailer at this point in time, so maybe just appreciate what he has to say.

Russell. I read a lot of the proa posts over the years, if not most of them. I have no stake in this either way. You specifically Russell, and Sidecar and others constantly attack Rob because it appears he's innovating past where you managed to get too. It's childish, lame and very transparent to anyone paying half attention. 

Respond to his actual comments with facts not Ad hominem, or by twisting his posts and private messages. Either respond constructively or don't. if you want a bitch fest do it privately. Or maybe spend your time innovating again rather than reliving your previous fame? Even way back Dick Newick got the benefit of unstayed masts with Cheers. Built for single handing ocean race where he would have to sleep at some point and may be backwinded badly.

I don't agree with all of Robs design ideas and he's made some mistakes along the way (who hasn't) and he's not an Naval architect, but he has some good ideas, and is working hard to break new ground, which is more than we can say for most designers. 

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On 10/6/2020 at 12:24 PM, TwoBirds said:

 

Just curious, those teething troubles, was it that thing that atlantics do where the rig wants to be downwind and when it gets there the boat wants to trip over her foils and capsize?

 

May want to learn a bit about balance before attacking other peoples designs. Figure out where the vector is pointing for the center of effort and where the center of resistance will be, that will give you the lever arm and the distance from it. Do some basic trig to get the force perpendicular to that. Most proa designs are badly balanced (including sidecar), all pacific proas will loose performance to the rudder fighting this imbalance. Atlantics will be better balanced. Newick was smart... it seems he mostly figured it out first go. Probably why cheers (Atlantic proa) placed 3rd in a trans Atlantic single handed race all those years ago. 

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12 hours ago, Ryan.. said:

You specifically Russell, and Sidecar and others constantly attack Rob because it appears he's innovating past where you managed to get too. It's childish, lame and very transparent to anyone paying half attention. 

I don't agree with all of Robs design ideas and he's made some mistakes along the way (who hasn't) and he's not an Naval architect, but he has some good ideas, and is working hard to break new ground, which is more than we can say for most designers. 

I like a lot of Rob Denny’s ideas, and I have supported some of them in the past, but never the way he all too often misrepresents them to the detriment of others.

Try looking up Bucket List details on his website, in the launched boats section or even in the (almost hidden) previous designs section. Why? Was it proven? What lessons to share with the Proa world?

Bucket List’s sail area was touted as being 60 m2, but measured off the website profile image measures 46m2.

Build weights claimed to be light and cheap, say 850kg end up upon completion at nearly double. Not so light and cheap, never mind performance.

His current cargo Proa project (entirely laudable) give hull depths as 200mm empty and 500mm loaded. It is easy with a flat rockered, flat bottomed vaka with vertical sides, to see that a change in depth of 300 caused by 10 tonnes of cargo means that the empty vaka displacement needed to get 200mm draught must be 6.67 tonnes, more than the empty weight of the entire boat? WTF? The unloaded boat and racing version also appear to be deficient in terms of lateral resistance relative to sail area, so it will be interesting to see the eventual upwind VMG’s. Steering and sailing such a large rockerless boat will be interesting as well, especially in shallow water with significantly reduced rudder area.

The Melbourne Proa touted on Denney’s website skims over the fact that it needs a big centreboard and avoids the fact that it has spade rudders, a big HarryProa no no. It also relies on the testimonials of Rick Willoughby, the designer of its current spade rudders. Rick, a long time faithful collaborator, has been thrown under a bus to suit Denney’s arguments on spade rudders elsewhere. ”Irresponsible” spade rudders make up the overwhelming majority of rudders on the water today.

You could say the same about “irresponsible” stayed rigs, and on proas especially, most of the “disadvantages” don’t exist or are minimal. I have no problem with unstayed rigs, they have their place, but to say that they are the lightest, cheapest, fastest and safest is false. All things considered, over a long time, the boating world has already voted on unstayed rigs in all types of boats. The exceptions prove the rule.

Denney claims that his rudders are proven and the best after 20- 30 years of experience. Of failures. Sharing full details, or providing successful examples would be more helpful. Bucket List’s rudders failed doing 6 knots. How many rudder iterations did Blind Date have? Why did the Melbourne Proa always have spade rudders? FWIW, Rick Willoughby considered Sidecar’s cassette spade rudders a “good solution”, long before I eventually did it. I persisted with sidehung rudders way too long. I could have also done leeward sidehung rudders in the same positions as the cassette ones, but they can’t fully “feather” when drifting downwind, are vulnerable alongside and you can’t see them.

What sort of rudders did Cheers have?

A number of proas of all types have sailed across either the Atlantic or Pacific, for all the HarryProas that ”exist” there isn’t one that has to my knowledge. They all seem to be port bound or up for sale.

If you have studied Sidecar at all, you should have recognised that it was an essay in trying to incorporate the best and avoid the worst of the two opposite partisan approaches. I can tell you now, that most of the early problems with Sidecar have come from the HarryProa style closely spaced windward sidehung rudders.

11 hours ago, Ryan.. said:

Most proa designs are badly balanced (including sidecar), all pacific proas will loose performance to the rudder fighting this imbalance. Atlantics will be better balanced.

All proas, regardless of configuration, are fundamentally unbalanced, and having maximum CE lever arm out to windward isn’t necessarily the only answer. 

Having the optimum CE position laterally (or longitudinally) relative to CHR (centre of hull resistance) is.

Traditional examples and foresail rigged proas, can do it longitudinally. Traditional proas can end for end, arguably precariously, foresailed proas can’t without considerable shunting down time or sail duplication.

Do your own geometry, and you can see that Jzerro style proas, with the mainsail  further out to windward and foresails are inherently more balanced than any HarryProa. The exception perhaps is his foiling Proa, (can’t find that one on the website anymore either) and you can see where the rig is, hanging off beams to windward, a big HarryProa (and proa) no no. To get enough LR spread, he had to use a triscaph configuration. Good luck steering it in non foiling conditions, ie, every time you shunt. BTW guess what kind of rudders it had? And how are they spaced?

Sidecar is far from perfect, but it’s overall CE is further to windward than either Jzerro  or HarryProa types. And you can feel the difference when the (well to leeward) mainsail is dominant (upwind) and DDW when the jib can be, due to the lever arm. FWIW, due to the sudden shifting nature of the winds I regularly sail in, Sidecar can get caught and run by the lee easily by 30 degrees without drama. And the best all round balance is achieved with a full jib and 2 reefs in the main, that gives you a clue as to what might happen eventually.

476D7263-8EFA-447B-9313-8D34E9F67C03.webp

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You are deliberately twisting facts sidecar, try keep your little bitchfests to your slumber parties with Russ

Bucket list was a prototype idea, that was never built (except a rough prototype) you already know this. I guess if you don't really innovate you are not used to the concept of a prototypes?

Cargo proa is also a 1st version prototype commissioned specifically for testing, and is under construction so don't be a fool and take a strong position on something you don't understand. 

The Malborne proa was modified by the owner/builder for shallow water... special application requires special mods

Not interested in you sidecar design it's heinously ugly. No one is going to buy that except a few wonks.

You are blinded by you personal rage against Rob and are looking very foolish with your constant personal attacks, because you see his innovation as an affront to your unpopular design. 

8 hours ago, Sidecar said:

overall CE is further to windward

Balance is in all dimensions no just windward leeward. Think about where your pivot point is, your CR, (hint: on a proa that's not in the center athwartships). And were your vector is going from your CE. 

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@Ryan..

Wow Ryan, sounds like you might be struggling personally at the moment.

Now that you are telling others how to think and act I will address the person you appear to be.

You approached me with an offer to help with aspects of GD which I truly appreciated. Then it seems I was deemed unworthy either due to my lack of experience or asking too many questions. You totally ghosted me and stopped communication. I have no problem with your choice to help or not but ghosting people is not cool in anyone's book.

I Have found "sidecar" Rob to be very helpful and take insightful criticism willingly, always responds and acts like a grown up.

One thing I will admit is that my opinion of Rob Denney was impacted by the content of this Forum and that isn't right. I believe all the people you are talking about are passionate creative folks who like most of us do tend to like our own ideas best.

Funnily I do have some more experience in GD after my last trip , we experienced  3m ugly confused seas 30kn+ wind against current, had to shunt in that which was less traumatic than I had imagined but  scarey and not fun with my 3 daughters and partner on board. 

Steering the boat straight downwind with following seas was more difficult than I had imagined, personally I think the best attribute of a proa is the lack of sea sick inducing motion.  

I have now sold her and am just waiting for the new owner to arrive and handover. 

Ryan I wish you all the best on your next record attempt if that's still happening. You said in your email that this site is theoretical with people who have a teaspoon of experience which is probably true but it would be much more beneficial to the Proa community and yourself if you empowered those of us having a go at proa sailing with your knowledge rather than whatever you are doing now.

Cheers Jo

 

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19 minutes ago, Jo R said:

Ryan I wish you all the best on your next record attempt if that's still happening.

wait...what? I am confused.  Ryan... and r.finn aren't the same person are they?

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Ok this is an excerpt from pm by Ryan, MY BAD.

"I was delivering a 55' beneteau from Florida to new Orleans when you sent this.  I saw it in my way out but didn't have time to answer as I was just leaving the harbor, and I forgot to get back to you.  After arriving with little sleep a couple days later I totally forgot to check SA for messages and handle your questions.  I didn't ghost you.  I didn't even read your message.  I simply saw it was long and would require a keyboard when I got back. "

 

So my apologies to Ryan I just made an assumption and they always end up biting me. One day I'll grow up and learn that lesson.

Cheers Jo

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28 minutes ago, unShirley said:

wait...what? I am confused.  Ryan... and r.finn aren't the same person are they?

We are not the same person.  Jo was mistaken.  

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Oh Boy How I stuffed up there.

Again Sorry Ryan Finn, I must admit that message did seem out of character. 

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9 hours ago, Ryan.. said:

Balance is in all dimensions no just windward leeward. Think about where your pivot point is, your CR, (hint: on a proa that's not in the center athwartships). And were your vector is going from your CE. 

You are stating the blindingly obvious. I tried to simplify the discussion for your benefit. I spent a long time with CE and CLR vectors and as I alluded upthread, Sidecar is not quite there yet.

BTW…. Sidecar is an experimental prototype with, to my knowledge, the only biplane rig currently in the Proa world, and the only one with the ability to adjust CE both longitudinally and transversally.

Early days, I am still learning things after long, slow, rudder setbacks. And there are dozens of modifications/options I would like to try…..

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2 hours ago, Jo R said:

Wow Ryan, sounds like you might be struggling personally at the moment.

Maybe you are too?  You sound very confused.  Let's review: this thread was started on August 27, 2020, roughly five months before you bought GalasDream in January, 2021?  Yet your first post here wasn't until June 1 of this year, ~10 months after the thread started.  Now, less than two months later, you are telling us today that you have already sold the boat, less than seven months after you bought it?  That was quick!

2 hours ago, Jo R said:

this is an excerpt from pm by Ryan, MY BAD.

It's always bad form to publish the contents of a PM.  It's called Private Message for a reason Jo.

Hope things get better for you.

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At least the PM was published for the right reason, even if it was bad form. 

These forums always devolve quite quickly, but I find that I can at least gain a bit of knowledge by picking through all of the infighting. I get that some of you have your livelihoods on the line and you are trying to be good salespeople. I get it because I am also a salesman, but I also think that some people, and I'm sorry but Denny in particular, get a little too greasy for my liking. Everyone has a different approach to these wacky designs, but there must be a lot of unstoppable forces and immovable objects on here because we always end up in a stalemate with people chucking insults back and forth across no man's land which is neither productive nor attractive to new people who may be exploring the world of modern proas for the first time. Can you blame people for taking one look at one of these threads and giving up? 

There are a ton of good ideas on here from all sides. I think that Sidecar is a fantastic looking vessel that clearly sails well enough and has a super innovative rig (if a little confusing on first inspection). I think that Russell Brown's more traditional pacific proas have more than proven their seaworthiness over the years and miles that they have been sailing. Based on the number under construction, there are clearly people out there who are more than eager to trade beauty and perhaps efficiency for the space, stability, and affordability of a Harry.

Perhaps the infighting will never end and everyone will just continue slinging the same arguments back and forth over those of us caught in the crossfire. The fact of the matter is that, for the ones like Ryan and I who have no stake and can draw ideas from every different design, the slate is blank, and we have the choice of so many different foil arrangements, hull layouts, and rigs. Who knows, maybe everything works best when you mix and match. 

 

Time to sit back and get out the popcorn.

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1 hour ago, ProaSailor said:

Maybe you are too?  You sound very confused.  Let's review: this thread was started on August 27, 2020, roughly five months before you bought GalasDream in January, 2021?  Yet your first post here wasn't until June 1 of this year, ~10 months after the thread started.  Now, less than two months later, you are telling us today that you have already sold the boat, less than seven months after you bought it?  That was quick!

It's always bad form to publish the contents of a PM.  It's called Private Message for a reason Jo.

Hope things get better for you.

I'm Not confused except I did mistake Ryan.. for RFinn.  I have apologised and used that excerpt  from a PM to try and clear up any confusion, I guess we would need to ask R Finn if it bothered him, I hope it didn't.

I can tell you what I did find confusing and that is sailing a proa. Owner before me had it for 9 mths I had it for 7mths, maybe the new owner will be longer who knows.

Thanks for your concern.

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Ryan,

Thanks.

Jo,
Oops!  That generated a grin.   :-)
Sounds like the advice you got about sailing Gaia's Dream/Big Red Boat was incorrect.  Maybe suggest to the new owner that he contact me if he wants a second opinion.    

Hell-bent,
Sorry you find me "greasy".  If you ever do decide to build, maybe read Kevin O'Neill's view (Oct 3 last year, this thread) when you need advice.  

"Can you blame people for taking one look at one of these threads and giving up?" is incorrect in my experience.  I don't advertise anywhere, and use the forums to explain my boats.  Most correspondence from forum readers starts by thanking me for all the information I provide and admire my ability to talk boats, not personalities.   They give up on the threads, but not on the boats.  

Some people prefer "beauty"  over  "space, stability, and affordability of a Harry".    But the vast majority of those who actually build or buy a proa for more than off the beach use, opt for the latter.  

I'm happy to discuss "efficiency" if you can describe what you mean by it.

ProaSailor,
 Your web site contains more general proa information than any other, but not so much on the screw ups and experimental side of things (see 2 below).  Thanks for your policing efforts with Jo.   Pity you were not here on June 9th.  

Sidecar,

I could not open your attachment.  Is it available in another format?   You did not respond to my June 20 post.

1) There is a big difference between Harryproas for fast, low cost, safe and simple cruising, (Ex40, C50, C60, O80),  one offs to enable an idea (which failed) to make multihull racing possible for everyone (Bucket List), entries in a design competition with some peculiar rules (the Volvo foiler),  and zero emissions work boats for servicing remote villages (Mini Cargo proa and CargoFerry). Cross referencing one type with another and looking for similarities/differences to complain about is a waste of time.


2) The Harryproa web page arguably contains more proa build, sail, screw up, try new stuff information and details than any other proa site.  However, as I said about your "same as, but not copied from Bucket List" rudders, I encourage people to copy my ideas, but contact me first as it is impossible to put everything on the web page, especially when it is for a prototype which gets changed a lot.  Doing so saves you a lot of trial and error which we have often already done.

3) I have no control over what owners do to Harryproas, and encourage them to try different stuff.  Rick's comments on Harryproas, rudders, propulsion, hull shapes, rigs, sailing, etc are on the chat group

4) This is a discussion forum.  I put up ideas for discussion (unstayed masts, rocker, rudders, beams, daggerboards, steering, weight to windward, etc) along with why I like them and why I dislike the alternatives, usually based on experience with both.  Your answer that "the alternatives are what everybody does"  is neither productive nor conducive to discussion.  Nor is calling me names.     

Nothing is a "no-no" on a Harryproa, but it has to be there for a reason, not convention.     
Unstayed rigs are not "fastest".  They are, or can be, "lightest, cheapest,  and safest".

5)  An experimental Harryproa triscarph foiler is being built in the USA.     The Bucket List story is  at http://harryproa.com/?p=424     I had no trouble steering/turning the non foiling Bucket List in the 30m/100' wide canal when motor testing the foils.

6) You are confusing the prototype cargo proa I am building with the concept boat on the web page.  I explained this in my post on the Proa Question thread, which you also haven't responded to.  A precis of the cargo proa part follows:

Last year I was in the Marshall Islands showing them how to build a cheap and cheerful 10 sheets of ply cargo carrier.  More are being built.  The criteria and the results can be seen in Ch 4 of this publication which is worth a read if you are interested in green shipping in developing countries. 

The 24m/80' cargo proa may be the next step in this process (see the end of chapter 3) but rather than wait for them to decide, I started on the the prototype.  My money, time, labour and ideas.  I don't expect everything to work straight away and welcome suggestions to improve it and questions about it.  It is a work boat, so the finish is rough and fit out minimal.  

Launch later this year, testing and correcting, maybe a little racing here, then trial routes in Fiji, the Marshalls and Solomons.    

If successful and the politics can be navigated, more may be built, with changes learnt from the trial routes.  Given the lousy shipping options at present and the enthusiasm of the Pacific Governments and donor organisations for reducing diesel use and emissions, servicing remote villages, setting a green example to the rest of the world and providing employment for their citizens, the bar for success is pretty low.    We shall see.

The lee hull has sufficient volume to carry 10 tonnes of cargo in sheltered waters, less offshore. 11527162_ScreenShot2021-08-01at3_36_39pm.thumb.png.58f407fdedbee0864c4f00656a138b51.pngAny more volume would be superfluous and make the uncored build method unfeasible.   

The 24m/80' prototype has fore and aft rudders, 2.5m/8.5' deep x 0.5m/20" wide so should steer ok.  If not, I will make adjustments.  The rudders are liftable for shallow water (200mm/8" draft empty) and combined with the balance options with the schooner rig, allow careful sailing in shallow water.  

The hulls are rockerless (faster, less draft, less pitching, more load for a given draft) and box section to make them easy to build.  2 x 65+ year olds have built the prototype in 13 months, 3 of which were spent building the 28' tender, and another 1-2 on experiments.  

The boat is a test bed including ideas to make it perform well (essential so it can handle upwind/downwind routes) and be easy/cheap to build and sail.  eg infused coreless flat panel hulls, telescoping wing masts,  simple kick up/ liftable rudders and steering, near 'idiot proof' anti capsize device and others which can be read about on the build blog.     We will find out what works and what doesn't before heading for the Islands.  I will make any changes and repair/replace anything that breaks.   

We have just mixed our 900th kg of resin.   The boat only contains fibreglass, resin, and ~200 kgs/440lbs  of pultruded carbon for the beams, rudders, and masts.  If the resin:glass ratio was optimal (66% glass, 33% resin) throughout the boat (it is in the infused panels, not in the rest), there was no wastage and we hadn't used any for test pieces, it would weigh 900kgs/2,000lbs (resin) + 1,800kgs/4,000lbs  (glass) + 200 (pultrusion) kgs.  Plus another 40kgs/90 lbs for powders, foam crash bows and stringer formers and it is under 3,000 kgs/6,600 lbs.    

There is a bit to go plus sails, deck gear, ropes, navigation and safety gear, but sub 4 tons for an 80' sailing work boat with 10 tons/tonnes capacity would be nice.   

Materials cost so far is $AUS40,000/$US30,000.  

I got fortunate with the shed and overheads.  University of Queensland provided them gratis in exchange for giving composite engineering students some hands on experience.  

A race version of the prototype could be maybe a ton lighter (narrower and lower cored hulls, carbon skins, better build, smaller ww hull and different rig), and more sail area, if the telescoping wing masts work.   It'll be fun finding out.

Also in my reply to Sidecar from that thread: 
Re me being constructive vs pissant (funny choice of word, given our exchange on his thread on June 13th): I offered you cheap materials,  offered to help you with your "similar to, but not copied from Bucket List" rudders, told you where to find my latest rudder designs, thanked you for recommending a harryproa to your mate and posting the drawings and have tried to be constructive informing you about your misconceptions, based on my experience.  All despite you twice making my private emails public.  Not sure what else I can do.      

You seeing this as a "point scoring" contest says more about your attitude than mine.   Nevertheless, there is a faint chance I will be in Hobart at the end of the year, maybe we could have a coffee and see if I am as awful as you think I am?

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On 7/30/2021 at 12:57 PM, Jo R said:

I'm Not confused except I did mistake Ryan.. for RFinn.  I have apologised and used that excerpt  from a PM to try and clear up any confusion, I guess we would need to ask R Finn if it bothered him, I hope it didn't.

I can tell you what I did find confusing and that is sailing a proa. Owner before me had it for 9 mths I had it for 7mths, maybe the new owner will be longer who knows.

Thanks for your concern.

Can you elaborate more on why you sold it...?   What sailing have you done prior to this red boat...?
Just trying to get my head around it all

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What I meant is confusing re Proas is that it's nothing like tacking a symmetrical boat, and I swing from loving the concept to not so much. I've spent 7 mths full time on board with my family so have a reasonable amount of experience I suppose. We only ever set out to own for a year and sold in 24 hrs, a lot faster than anticipated. I believe as Russell has stated the sweet spot is around 38 ft. GD is like your own personal aircraft carrier!

Cheers Jo

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23 hours ago, harryproa said:

Hell-bent,
Sorry you find me "greasy".  If you ever do decide to build, maybe read Kevin O'Neill's view (Oct 3 last year, this thread) when you need advice.  

"Can you blame people for taking one look at one of these threads and giving up?" is incorrect in my experience.  I don't advertise anywhere, and use the forums to explain my boats.  Most correspondence from forum readers starts by thanking me for all the information I provide and admire my ability to talk boats, not personalities.   They give up on the threads, but not on the boats.

Rob,

I've been in sales for a while (big corporate chain) and have seen a lot of different approaches from my colleagues, competitors, and indeed myself. What I meant by my statement is that you take the exact same approach every time in that you go a little over what would be considered an acceptable response. I also have seen many examples where you have reused the exact same phrases, often in the exact same order in multiple posts. I'm pretty sure I've seen examples that in this very thread not too far back. ^^^ This may be part of what frustrates some of the other entrenched contributors about your replies. Now I have done this exact same thing before so don't get me wrong, I understand the approach and I understand why you do it, I'm just saying that anyone employing this technique is going to wind up sounding a bit like some of the folks down at my used car lot here. I understand that, as you say, you are using the forum to explain and share your experiences, not to sell, and there is plenty of explanation to be found. Despite this stance, I'm just pointing out in the nicest way possible how some of these practices come across to the rest of us. 

As for giving up on the threads, that's exactly the problem. Maybe for many, they end up on your site instead, which is obviously good for business and I won't fault you for that, but it means fewer people who might feel inclined to make their views and ideas known to the rest of the community directly.

Also I'll confess I do not understand why you have referred my to this specific post by KONeill as it does not seem to be particularly relevant to the rest of your comment. Maybe I am missing something?

23 hours ago, harryproa said:

Some people prefer "beauty"  over  "space, stability, and affordability of a Harry".    But the vast majority of those who actually build or buy a proa for more than off the beach use, opt for the latter.  

I think there my have been a misunderstanding here, as I made this exact same point. You have many more large boats under construction than anyone else here (perhaps infinitely more, since new pacifics and atlantics seem to be in short supply), so that proves that the majority of people prefer the qualities that your boats offer (and the easily available plans don't hurt either).

I personally have invested a lot of time, effort, and thought into Harrys as you may or may not know (life has been busy and I haven't been active on your discussion groups in a while) and while I may not agree with all of your ideas, I do agree that there is some merit to them, especially those looking for a bit more comfort and security. My problems will forever lie with the aesthetics (although you and Steinar have done the best you can with the dimensions of your boats) and the fact that the long, flat-bottomed, rocker-less hulls would make me nervous in bad weather offshore.

Additionally, you rudder setup for larger boats, which has come under much scrutiny on here, also perplexes me a little. It is not well documented in your drawings, renders, or writings, so I still have no idea how the actual articulation will work in a way that simultaneously allows for remote steering (with wires or rods connecting to a wheel or remote tiller), accommodates the kick-up functionality, allows for sufficient rudder/control travel without protruding too far from the hull, and allows for the foils to be effectively balanced, all without creating significant water ingress points on the side of the hull or kicking up so much spray that the lee hull becomes a water park. I'm still a big fan of rudders in trunks at either end combined with another board or structure somewhere else dedicated to leeway reduction. Build the trunks and skeg/board assemblies strong enough that they don't hole the boat if you touch bottom and then just watch your charts and your sounder and add 15 seconds to each shunt to switch rudders. I'm personally not super confident in how well a rudder on a bi-directional kick up mechanism like yours would fare in a hard grounding or collision with a submerged object at speed. If you have any documented real-world tests in this regard then maybe I am just not nearly as good at doing research as I thought.

I find that as my desire for adventure reemerges I am drawn back to proas once again and I may actually be going deeper into your world than my arm chair in the near future, maybe with some long-term cruising plans as well (he says, hopefully).

Cheers,

Willem

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On 7/31/2021 at 11:15 PM, harryproa said:

Some people prefer "beauty"  over  "space, stability, and affordability of a Harry".    But the vast majority of those who actually build or buy a proa for more than off the beach use, opt for the latter.  

Also just tacking something on here, but I don't actually know if they really need to choose. Beauty is of course in the eye of the beholder and while myself and many others find some of the newer, larger Harrys to be unappealing, I personally find some of the design work on these boats to be very clean and aesthetically appealing.

Where did you hide this one away Rob? I just dug this beauty out of the files on an old iPad from back in the day since I cannot find pictures of it anywhere online anymore, but this boat is so pretty I could kiss it. I especially like the way the windows are integrated seamlessly into the character line. Minimalist design at its finest right here. I actually wanted to do a 3D model of this one so I could 3D print it and put it on a shelf with some of my other models, but it was too difficult to get the dimensions and the proportions correct. If I was to build something, and I very well might, I'll definitely be looking here for some inspiration. I assume this is a 40-footer or close to it as it appears to have the exact same layout as the Ex40.

IMG_0277.PNG

IMG_0281.PNG

IMG_0282.PNG

IMG_0279.PNG

I assume this got turned into the custom 20m being built in Norway? I also find that one to be quite attractive.

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