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Old 30-04-2015, 17:46   #76
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Re: extending the saloon

Valhallah
Harryproa short hulls are 11:1 length to beam ratio or narrower, so hull speed is not a constraint. The short hull in the sailing at (or near;-)) wind speed video is 10m/33' long. the boat weighs 3 and a bit tons. A 10m/3 ton cat would not be this fast. The same with the 4m hull on my 7.5m test boat which does high teens with both hulls in the water. The windward one does not seem to slow it down. There is not a burst of speed (or a change in helm balance) when it flies. At least no more than is expected from the increased wind that caused it to fly. This boat was as fast as a Tornado (6m/20') cat on a reach. Given the less efficient rig on the proa, similar weight and sail area, I attributed this to the extra length of the lee hull.

Fully deployed sails are much less of a problem on an unstayed rig in high winds as the mast bends, depowering the top of the sail. The windage and weight of a tall mast do have a negative effect, particularly when deep reefed.

I would love to see your research, either privately in confidence (harryproa@gmail.com), or publicly. Given how little of practical use you can fit in the hull ends, how detrimental weight is in that location and how uncomfortable end of hull sea berths are, the accommodation will be the same. The differences are the weight (which also impacts on the beams and rig) and windage. Not a huge difference, but as the proa costs less as well, and the motion in waves is nicer, and shunting is safer, it is my preferred layout. I have drawn a number of "harrycats" (various points along the transition from conventional cat to harryproa) for various clients, but all of them, bar one who is still thinking about it, have ended up preferring the proa configuration.

As discussed above and shown on the harrys built so far, the expense over the whole boat is lower and the stronger structure localised in the lee hull is less than the overall structure required for a stayed rig. The mast is larger, but does not have the drag of the stays and spreaders a conventional mast has, so the drag is arguably less, not more. Try dragging 60m of 5/16"/8mm rope through the water sideways to get a feel for this. I'm not sure what other negatives the "etc" covers? Regardless, my point is that the negatives are far outweighed by the positives, especially for cruisers. "Somewhat easier" does not come close, particularly in stronger breezes. There are many posts on this forum about rig problems, both sailing and maintainence. Very few of the problems apply to unstayed rigs.

A properly maintained, regularly inspected stayed mast is less likely to fall down. However, an unstayed mast does not need any maintenance or inspection. Nor do you have that nagging "I wonder if I missed something last time I was up the mast looking for micro cracks in the fittings" feeling every time the wind gets up.

If you get to Holland on your European trip, let me know and I will introduce you to Nol, the skipper of Blind Date (a 50'ter designed to take blind and handicapped people sailing) and see if we can organise a sail.

Msponer
Glad you like it.
The boats are engineered by Etamax, who have done a great job on all the harrys and a bunch of masts (stayed and unstayed), rudders and beams for other boats. The Cruiser 60 is ground breaking in a lot of ways, so we have been cautious with the structure, particularly in the high load areas. One of the advantages of highly localised loads (masts, beams and rudders all very close to each other) is that very little extra weight significantly strengthens the structure.
Etamax and I would welcome input from other NA's and engineers.

The dinghy motor for propulsion on this boat is secondary. Primary is the motor on the pod mentioned in post #71. The dinghy as a sled is more efficient than any other outboard solution as it doesn't ventilate or break the surface. A big tender, large outboard and a safe and easy way of storing it are, in many ways, much better solutions than a small outboard/tender option

As the windward hull is always to windward while sailing, water getting through the leeward facing doorway is unlikely. There is a generous lip and a substantial door to seal the cabin and large drains in the outside solid areas. For waves to enter the cabin, they have to come over the top of the other hull, 5m/15' away. If the wind and waves were at 90 degrees to each other, with the waves coming over the lee hull, it would be a fairly simple exercise to change the drogue to the other "bow" to get them coming over the ww side. By altering the bridle angle, it would also be possible to slew the boat by as much as 45 degrees.
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Old 01-05-2015, 02:21   #77
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Re: New style Harryproa cruiser

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On first take, I really like the boat.

I would worry about the engineering. ...

For my own style, I would want a better way to motor than dropping the dingy partly in the water. ...

And I would be a little worried about water coming into the saloon. ...
msponer, thank you very much for your comments. Your experience as a cruiser is very valuable. The points you bring up crossed my mind too. This is comforting. I gladly adopt your conservative and paranoia attitude. There is nothing better for worst case analysis.

Thank you Rob for the explanations. In my reading, the HarryProa is an innovative design but only in its combination of features that each in their own right remain well far from the bleeding edge. The combination in itself is simple and transparent enough to stay out of the esoterics of structural engineering.
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Old 01-05-2015, 04:17   #78
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Re: New style Harryproa cruiser

Once I see zero maintenance is needed, I know what I'm dealing with.


You've clearly found a way to overcome the laws of physics at a fraction of the price, so I will bow to your greater knowledge. I expect within a few years marinas will be full of proas as the only logical choice.
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Old 01-05-2015, 07:16   #79
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Re: New style Harryproa cruiser

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Once I see zero maintenance is needed, I know what I'm dealing with.
...
Valhalla, May I invite you to look beyond communication style. As I acknowledged in the beginning of this thread, industrial quality statistics about reliability like MTBF etc... are lacking in general. So one has to revert to less hard criteria. Popularity is one. Design philosophy is another one. Comparing representative cases is again another one. And there are no absolutes. All is relative.
I had always thought that triangulated structures were stronger than others for the same weight till I read about the reasoning for mounting the gigantic Danish style windmills on massive, tapered concrete masts while the Eifel tower, the Golden Gate bridge and high tension pylones are sticks and wires.
In any case, guiding are always the SOR's and the SOR's are case specific. My priorities are safe and easy. So the questions are: are stayless masts safer to sail with than others (given they are engineered lege artis)? Are stayless masts easier to sail with?
If both questions are answered yes then the next question is: Is the difference in cost of ownership worth the advantages. There are strong indications that maintenance is easier and lower due to the low number of parts (of course it is never nil but concentrated on a few key items only). Stayless masts are heavier than unstayed masts but there are good indications that the weight of a boat with stayless masts is not that much heavier if at all than one with stayed masts. So it is not a matter of choosing camps. So the question to the forum is evidence or reasoning corroborating or not the less hard criteria.
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Old 01-05-2015, 10:58   #80
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Re: New style Harryproa cruiser

I would much rather have an unstayed mast.
I find the rigging of a stayed mast is just plain ugly.

A stayed mast will be cheaper, lighter and taller than an unstayed mast, and that makes for a faster sailboat, there is just no question about that.
But if you want to go slower, have more weight, and spend more and get a less cluttered boat,
an unstayed mast is great. Cruising isn't about speed.
Is then a Proa the right design for cruising?
Is it about sailing speed?
Is it a design looking to justify itself?

My cat Gary Lepak's Dragon Wings had two unstayed masts, and a junk rig.
I note that one broke and came crashing down and almost killed my nephew while we were transporting it, without a sail an unstayed mast will whip/flex in rough seas that has large forces, so unstayed mast is not any safer in my view.

Let me add I also think hanging laundry from poles a rather old fashioned and antique method of propulsion...

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Old 01-05-2015, 13:11   #81
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Re: New style Harryproa cruiser

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I would much rather have an unstayed mast.
I find the rigging of a stayed mast is just plain ugly.

A stayed mast will be cheaper, lighter and taller than an unstayed mast, and that makes for a faster sailboat, there is just no question about that.
But if you want to go slower, have more weight, and spend more and get a less cluttered boat,
an unstayed mast is great. Cruising isn't about speed.
Is then a Proa the right design for cruising?
Is it about sailing speed?
Is it a design looking to justify itself?

My cat Gary Lepak's Dragon Wings had two unstayed masts, and a junk rig.
I note that one broke and came crashing down and almost killed my nephew while we were transporting it, without a sail an unstayed mast will whip/flex in rough seas that has large forces, so unstayed mast is not any safer in my view.

Let me add I also think hanging laundry from poles a rather old fashioned and antique method of propulsion...

Thank you for reporting about your experience. I read about Lepak's Dragon Wings. The original mast was a 35 foot Douglas fir. As she was a one off I suppose there was no investigation at to the cause of the demasting. How old was the mast? It surprises me that a bare mast would more readily crash down than with the sails up. Would that not suggest an issue with vibrational flutter? The Dragon Wings was not meant to be fast nor especially light being a spin off of a Wharram. And I doubt is was costly to build despite the unstayed masts. I am not sure what lessons to learn from this case with design, build and materials of an earlier generation. Am I missing something?

Cruising is not about raw speed, but it is about average speed after it is proven safe, easy and comfortable first.
The fastest sailboat is a proa, but this not mean that the proa planform is only about speed.
The Harryproa cruiser is a cruiser, not a racer. It appears to be at least as safe as a biplane rigged catamaran. It is definitely easy and forgiving to sail as a cruiser (not for racing round the buoys). Its long hull promises to be more comfortable in rougher conditions and its windward hull protects the helmsman against the elements.
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Old 01-05-2015, 14:16   #82
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Re: New style Harryproa cruiser

The point is an unstayed mast can sway back and forth and when it gets in resonance with the wave motion, the forces are very large to snap it off,
and there is no warning when it happens, and it is the worst situation, running under bare poles in strong winds and rough seas, and suddenly the mast just breaks off. Particularly carbon fiber is stiff until it just snaps.
Now of course you can build a mast strong enough for that force, the fact is it will be much much heavier, and now I've said this for a third time, there will not be a fourth time.

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Old 01-05-2015, 15:23   #83
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Re: New style Harryproa cruiser

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The point is an unstayed mast can sway back and forth and when it gets in resonance with the wave motion, the forces are very large to snap it off,...

Resonance is not particularly associated with unstayed masts. It is potentially associated with any tensile structure. The Tacoma bridge was due to a combination of vortex shedding and torsional flutter generated at relatively low wind speeds. I find the analogy to work as well for stayed masts. And I also fail to see that carbon masts would be more prone to this problem. The material characteristics of carbon like torsional stiffness are specific but finite element analysis does take these into account. Even larger planes are built in carbon. So the material is not the determining factor in itself. You may be right but I fail to interpolate sufficient intermediary conclusions to string out a complete path of reasoning from A, unstayed masts, to the conclusion B, unsafe. I also do not have the impression that I skewed your statements. I wished the topic was simple enough to lead to a straightforward conclusion.
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Old 01-05-2015, 15:33   #84
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Re: extending the saloon

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As the windward hull is always to windward while sailing, water getting through the leeward facing doorway is unlikely. There is a generous lip and a substantial door to seal the cabin and large drains in the outside solid areas. For waves to enter the cabin, they have to come over the top of the other hull, 5m/15' away. If the wind and waves were at 90 degrees to each other, with the waves coming over the lee hull, it would be a fairly simple exercise to change the drogue to the other "bow" to get them coming over the ww side. By altering the bridle angle, it would also be possible to slew the boat by as much as 45 degrees.
So you can't/don't sail DDW?

And in conditions where a drogue or sea anchor is needed, I doubt switching ends would be "a simple exercise".
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Old 02-05-2015, 03:17   #85
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Re: extending the saloon

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So you can't/don't sail DDW?

And in conditions where a drogue or sea anchor is needed, I doubt switching ends would be "a simple exercise".
Let me translate: "always" to windward means 179/180 of the time and 1/180 it does go DDW, fine.

I suppose that nothing is simple in conditions that require a droque. The exact quote is "fairly simple" and this is I presume in comparison with other boat planforms. This is the advantage of the fore aft symmetry: there is no preferred direction. Does that make sense?
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Old 02-05-2015, 06:25   #86
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Re: extending the saloon

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So you can't/don't sail DDW?
Sure can, with the sails wing and wing, eased out to 90 degrees (or more) to the boat. In the unlikely event (the wave will lift the stern before it gets to the beam) of a wave coming over the back, the cockpit is 380mm deep and 1m wide so there would not be huge pressure against the door. If conditions were such that pooping was likely, I would steer or set the drogue a few degrees upwind so the ww hull took any breaking waves. And the door was to leeward of the cabin.

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And in conditions where a drogue or sea anchor is needed, I doubt switching ends would be "a simple exercise".
"fairly simple". Take the bridle that is up wind, pass it under the bridge deck (float a mouse line through on a fender) and attach it to the drogue line. Luff the boat and ease the original bridle lines. Continue turning and the new bridle lines pass under the shallow, rudderless windward hull and take the loads and the boat has rotated through 180 degrees. Not something you would do very often (the scenario was for large waves at 90 degrees to a strong wind), but fairly simple if you had to.

Nimble,
Gary is a nice bloke and DW did a lot of miles. Thanks for the example. Not something I have experienced, although a Hughes cat recently broke their unstayed mast, which could have been caused by a similar event. Would attaching the topping lift or halyard to the end of the hull and sheeting it down hard stop the whipping?

Valhalla,
By zero maintenance, i mean the same maintenance as a spinnaker pole (not the ends, just the pole). Every 10 years you might give it a shine or a coat of paint. But apart from that, there is nothing to check on an unstayed mast, so no maintenance is required.
The wishbone boom sits on integral chocks on the mast, so nothing to check there. The wishbone means no lazy jacks, which also makes raising and lowering the sail easier. There are two halyards (one is a spare), so I guess the sheaves are something you might check, but not very often. The main halyard attaches to a cleat bonded to the mast which has a block on it for taking the halyard to the winch. There are integral halyard lock points on the mast at each reefing point. The actual locking device is a fail safe attachment on the head of the sail. The downhaul and outhaul/reefing line (one line and no need to lower the main to rethread it) are multipart purchases bonded to the mast just above the deck. Not much you can do to maintain any of these.
Of course, you can add stuff to it to make maintenance. eg expensive bolted on alloy tracks and rcb cars, but with a rig where the sail is always hoisted/lowered/reefed head to wind, these aren't necessary. Slugs in the integral carbon track work fine.
Probably going to have to wait a while for a marina full of proas. The first cruising cats appeared ~60 years ago.
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Old 02-05-2015, 16:01   #87
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Re: extending the saloon

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Let me translate: "always" to windward means 179/180 of the time and 1/180 it does go DDW, fine.

I suppose that nothing is simple in conditions that require a droque. The exact quote is "fairly simple" and this is I presume in comparison with other boat planforms. This is the advantage of the fore aft symmetry: there is no preferred direction. Does that make sense?
No, not really, because with a cat (or a tri, or a mono) there would never be a need to swap ends with a sea anchor. So even "Fairly simple" would be a lot more difficult....

And my experience has obviously been different from yours. I find myself sailing DDW a lot more than 1/180 of the time. Probably closer to 1/3.

A few of us have the saying - In Qld the wind only comes from two directions. In your face, or up your arse.
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Old 02-05-2015, 23:44   #88
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Re: extending the saloon

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No, not really, because with a cat (or a tri, or a mono) there would never be a need to swap ends with a sea anchor. So even "Fairly simple" would be a lot more difficult....
This statement makes sense to me if "never be a need" is replaced by "never have the option", otherwise, this is not clear to me.

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And my experience has obviously been different from yours. I find myself sailing DDW a lot more than 1/180 of the time. Probably closer to 1/3.

A few of us have the saying - In Qld the wind only comes from two directions. In your face, or up your arse.
I have to remember that whenever I am in Qld, where ever that is, vowels are in disuse, angles are measured at only 60 degrees increments and proa's are at an advantage not caring which end is which.
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Old 03-05-2015, 15:15   #89
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Re: New style Harryproa cruiser

I guess if you're going to play dumb, the conversation is over.


But just in case there is some thought going on - no, never have the need is correct. With a cat there is no specific windward or leeward hull. So you never have the need to swap ends with your sea anchor. With a proa, you might need to in order to ensure the windward hull remains to windward, and despite what mr Denny says, in storm conditions it will not be an easy exercise.


But seriously, go build a proa. You're obviously convinced, to the point of ridiculing any contrary opinion. I don't even know why you started the thread, to be honest. You're not looking for a discussion. You already know it all.
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Old 03-05-2015, 17:09   #90
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Re: extending the saloon

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Sure
Valhalla,
By zero maintenance, i mean the same maintenance as a spinnaker pole (not the ends, just the pole). Every 10 years you might give it a shine or a coat of paint. But apart from that, there is nothing to check on an unstayed mast, so no maintenance is required.
The wishbone boom sits on integral chocks on the mast, so nothing to check there. The wishbone means no lazy jacks, which also makes raising and lowering the sail easier. There are two halyards (one is a spare), so I guess the sheaves are something you might check, but not very often. The main halyard attaches to a cleat bonded to the mast which has a block on it for taking the halyard to the winch. There are integral halyard lock points on the mast at each reefing point. The actual locking device is a fail safe attachment on the head of the sail. The downhaul and outhaul/reefing line (one line and no need to lower the main to rethread it) are multipart purchases bonded to the mast just above the deck. Not much you can do to maintain any of these.
Of course, you can add stuff to it to make maintenance. eg expensive bolted on alloy tracks and rcb cars, but with a rig where the sail is always hoisted/lowered/reefed head to wind, these aren't necessary. Slugs in the integral carbon track work fine.
Probably going to have to wait a while for a marina full of proas. The first cruising cats appeared ~60 years ago.
So it's exactly as I said, there is a little less maintenance but not a significant savings.

Again, you've done nothing to debunk the principal that you could just as easily decide on accommodations and build a cat with longer hulls to achieve better sea keeping and speed for about the same price.
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