Gyrocopter

[mundt]

The gyrocopter replaces something which seems relatively simple (a wing) with something which appears to be incredibly complex (a rotor).  I've done a bit of flying in ultralights quite similar to the flights depicted in the gyrocopter vid.  Low level flying is probably always dangerous but i still get the feeling there's so much that could go horribly wrong with that big rotor...  When I look at Mr. Finn's gorgeous, fast proa I always think, "Damn, one more of those beautiful hulls and that would be an incredible trimaran!". I know that particular proa is magnificent as-is but it would be hard to convince me that adding another hull would be that much more expensive/difficult.  Also notable that when the serious people want to do long, super fast crossings they invariably choose the trimaran.  Love to go for a ride on a good proa though.

 

[Boudreaux]

If your planned use can be met with a production boat and you ever want to resell your boat...well that makes it hard to justify a proa.

If you ARE going custom (for specific needs or joy of the design build process) and it is your forever boat...I can see a proa might make sense.

(myself I'm intrigued by proas not for rational economic reason but because they seem to me an elegant solution AND THEY ARE DIFFERENT, I'd pay a premium for a just for me boat that had my fingerprints on the design and build and I'd pay a premium to sail something interesting...but am I willing to pay enough of a premium?)

The "problem" is proas don't fit the needs of the mass charter market (or other large scale market) so they don't benefit from economies of scale of production boats.

Sort of a cath 22, may not be a lot of proas 'cause there are not a lot of proas...

Yes to all of that, but I don't think proas could ever become a mass market boat.  These things are always going to be painful in close quarters, especially when the whole rest of the world tacks when you shunt.  Maybe someone else has some brilliant ideas for a convenient way to tack a proa out of a harbor, but I'm not seeing it.  If it's an ocean greyhound you want and you can compromise in harbor maneuvers, I think the proa is tough to beat.

 

[ProaSailor]

These things are always going to be painful in close quarters

Tacking up a narrow channel in a proa is difficult indeed but they can be stunningly superior in close quarters maneuvering when the wind direction is favorable.  The ability to sail up to a dock, stop on a dime and then reverse is unique to proas.

When I look at Mr. Finn's gorgeous, fast proa I always think, "Damn, one more of those beautiful hulls and that would be an incredible trimaran!".

No doubt that Russell could design and build a beautiful trimaran but slapping another ama on the opposite side of a proa is not how it's done.  Trimaran amas need to be longer and have more buoyancy, at least 100% of total displacement each and often much more on modern tris.  Plus trimarans can have a beamy transom (like cats) to carry more load and offer more interior space in a given hull length.

 

[mathystuff]

Yes to all of that, but I don't think proas could ever become a mass market boat.  These things are always going to be painful in close quarters, especially when the whole rest of the world tacks when you shunt.  Maybe someone else has some brilliant ideas for a convenient way to tack a proa out of a harbor, but I'm not seeing it.  If it's an ocean greyhound you want and you can compromise in harbor maneuvers, I think the proa is tough to beat.

At least for the sailing here, I wouldn't consider that a big problem, as you rarely have to do more than 2 tacks/gybes per day.

Marina space/cost and ability to get a box in some of the nice small marinas on the other hand would be a serious issue.

Long story short: choice of boat is dependend on where you sail. Hardly news.

 

[KC375]

Yes to all of that, but I don't think proas could ever become a mass market boat.  These things are always going to be painful in close quarters, especially when the whole rest of the world tacks when you shunt.  Maybe someone else has some brilliant ideas for a convenient way to tack a proa out of a harbor, but I'm not seeing it.  If it's an ocean greyhound you want and you can compromise in harbor maneuvers, I think the proa is tough to beat.

With those constraints you'd think they would be usefull getting between pacific islands / island chains...

 

[TwoBirds]

At least for the sailing here, I wouldn't consider that a big problem, as you rarely have to do more than 2 tacks/gybes per day.

Marina space/cost and ability to get a box in some of the nice small marinas on the other hand would be a serious issue.

Long story short: choice of boat is dependend on where you sail. Hardly news.

and how fast you want to go and what you want to do and how many you peeps you want to bring along, trailor or mooring etc. etc. etc.

Proas are more specialized is all, and as such are less likely to fit within one's S.O.R. 

 

[Boudreaux]

With those constraints you'd think they would be usefull getting between pacific islands / island chains...

Someone should let the Polynesians in on this!!

 

[boardhead]

Tacking up a narrow channel in a proa is difficult indeed but they can be stunningly superior in close quarters maneuvering when the wind direction is favorable.  The ability to sail up to a dock, stop on a dime and then reverse is unique to proas.

No doubt that Russell could design and build a beautiful trimaran but slapping another ama on the opposite side of a proa is not how it's done.  Trimaran amas need to be longer and have more buoyancy, at least 100% of total displacement each and often much more on modern tris.  Plus trimarans can have a beamy transom (like cats) to carry more load and offer more interior space in a given hull length.

Trying to stay away from this BUT - Why does a trimaran need to have "a longer ama, with more buoyancy, at least 100%" to match proa stability?

An Atlantic proa derives it's stability in exactly the same way as a trimaran - buoyancy to leeward so the the ama design has to deliver all the same requirements.

A Pacific proa utilizes the weight of the ama to provide righting moment and light ship that's pretty modest. By adding weight to weather (climbing up the beam/adding water ballast) the righting moment can be increased.

When the leeward ama is fully immersed (and doing so causes the rest of the structure to lift into the air) maximum righting moment is reached for that given platforms dimensions.

When the windward ama adds ballast (water?) to a point where it's total mass equates to the float of that leeward ama the righting moment is the same so actually the  capacities are the same and the reasons for the ama's design differences are more about reserve buoyancy and diagonal stability.

Problem is - for the Pacific Proa - you are taking the water for a ride and water is HEAVY!

I first sailed on a Pacific Proa over fifty years ago on a brisk day, in big waves, out of Penzance, England with Toy Richardson who subsequently built and circumnavigated in a 45' cat. It was an absolute blast, Toby steering and trimming with me running up and down the aka. We were doing exactly what the Pacfic islanders had perfected so long ago, 

Cheers (an Atlantic proa) did a fabulous job with Tom Follet sailing her in the '68 OSTAR a few years prior.

These are special boats which can be tailor made to satisfy some special needs, I respect that and admire the sailors that have done so but lets be honest, they don't represent some kind of all singing, all dancing breakthrough - rather we are applying known physical properties in a different configuration and if you are just seeking different that's great - ENJOY!

 

[KC375]

vive la différence

 

[Sidecar]

I cant se a proa can be cheaper than a cat for the same money - according to space and speed - building wise... and for the total when you take the 2. hand value into account - its no contest. Gyrocopters I like.... cheaper and can fly... 

My original proa design started out at 8.5 metres length, aimed at complying with the NZ 8.5 class multihull box rule, which are predominantly catamarans. But it ended up needing ~ 200 kilos of correctors to get to the 900kg class minimum.

https://www.multihull.org.nz/8-5-class/

So I gave up and increased the length by a metre. In the same measurement condition, my proa weighs~ 970 kilos, with more (full) headroom and space below. And I get similar speeds, theoretically more, with a smaller (cheaper) rig.

Dollar/kilo, like for like, you get more boat for your money.

Second hand value is another story.... but you could say that about a lot of boats.

I don’t know anything about gyrocopters..... but they have their place.

 

[Tom Kirkman]

A gyrocopter is far, far, far safer than an airplane or helicopter.

 

[TwoBirds]

and for those that can't afford a gyrocopter or don't have a runway

 

[r.finn]

It's always been about one thing for me: reduced beam loads.  If someone can't understand that one simple thing, well that's on them.  Onwards and upwards.

 

[mundt]

I always thought the paragliders looked relatively safe, then I watched a few youtube vids, holy shite, those things can wreck you very quickly indeed!  Maybe a gyrocopter is safe, as sometimes things are truly counterintuitive, like thinking that flying down close to the ground or sailing close to the beach look safe, right?  I have seen vids of some nasty gyrocopter mishaps, and nobody is going to convince me that those blades spinning around up there aren't cause for concern as you plow into the muck.  I would probably go for a ride on one given the chance and I'd absolutely love to go for a ride on a proa.  See, we can have a nice, civilized discussion without eviscerating one another.   

 

[mundt]

r.finn, absolutely nothing but respect for you and your boat, seriously, outstanding in every respect.  I also get the desire for something unique and the perceived advantages of the proa.  Just enjoying the different perspectives during some rare shitty weather.  Thanks. 

 

[Sidecar]

It's always been about one thing for me: reduced beam loads.  If someone can't understand that one simple thing, well that's on them.  Onwards and upwards.

Agree. Reduced loads means less weight. if you crunch the numbers, increase LWL or  SA by 10% or reduce Displ by 10%, easily the best value for money in terms of speed, space and safety, comes from 10%  increased LWL..., ie convert any “saved” weight to extra LWL.

 

[KC375]

A gyrocopter is far, far, far safer than an airplane or helicopter.

As long as you never unload your rotor...if you do recovery is not so likely

 

[mundt]

Ok, so I watched a few gyrocopter vids and here's what i got:  those things crash a lot!  And surprise, surprise!  The pro gyrocopter guys say, "Gyrocopters are incredibly safe, it's always pilot error."  

 

[can-UK]

On a hike the other day I saw a gyrocopter flying past and here's what popped into my head, "That thing reminds me of a proa, lots of effort and danger to come up with something not quite as good as an airplane or helicopter.". The analogy being that the proa, though beautiful, in spite of all the effort by ingenious individuals is not quite as good as a cat or tri...thoughts?

Proas are the recumbent unicycles of the sailing world.

 

[PIL66 - XL2]

It's impressive to set up, fly and pack up in 4 minutes..... 
I'd last less than 4 minutes with him.... I bet he's always that excited....... and quirky, just like proa people ......