Dear Mr. Sidecar

MultiThom

Super Anarchist
1,747
392
Benicia, CA
The company who made the prototype touts the design as better than the ones previous because of the three modes (water, foil, fly) vs 2 modes previously (water, fly). They are also getting on the treehugging bandwagon and using emotors and pointing at development of commute vehicles using waterways. Supposedly have 600B$US in orders.
 

Laurent

Super Anarchist
2,302
1,966
Houston
The company who made the prototype touts the design as better than the ones previous because of the three modes (water, foil, fly) vs 2 modes previously (water, fly). They are also getting on the treehugging bandwagon and using emotors and pointing at development of commute vehicles using waterways. Supposedly have 600B$US in orders.
As in Billions, with a "B"???
Really?
 

munt

Super Anarchist
1,229
245
The belt
AC foiling boats aren't carrying innocent passengers at hundreds of mph. Nobody has posited a rational explanation of why its desirable to be a few feet off the surface instead of just flying like a normal aircraft. I get it that it's doable, it can work... But why, what's the advantage that makes instant death an acceptable risk?
 

Dex Sawash

Demi Anarchrist
2,575
801
NC USA
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Fixed for sidecar thread
 
AC foiling boats aren't carrying innocent passengers at hundreds of mph. Nobody has posited a rational explanation of why its desirable to be a few feet off the surface instead of just flying like a normal aircraft. I get it that it's doable, it can work... But why, what's the advantage that makes instant death an acceptable risk?
WIG aircraft using a reverse delta wing are extremely stable, and the volume of air being compressed beneath the wing generates a stupid amount of lift at cruising speed and has a rather low stall speed, so much so that it's almost impossible to nose a reverse delta wing ground effect craft down, which is part of the reason why the Airfish 8 has such a large horizontal tailplane. The Airfish in particular is so stable that you can cut the engines and let go of the controls completely and it will land itself. It's not as comfortable as a controlled landing, but it is safe for the airframe and passengers.

I'm working on my canting daggerboard idea today, should have some idea of what it might look like by tomorrow.
 

munt

Super Anarchist
1,229
245
The belt
Plowing it in being only one of a thousand possible ways things could go wrong. For example, name one navigable body of water where you could travel at high speed for any period of time without the high probability of an object (boat, Supper, kayaker et. al.) meandering into your path? In an airplane, at altitude, you have radar and visual plus the ability to avoid trouble in 3 dimensions as well as the notion that people stay in their lanes. Where I'm currently hiding out many boaters think it's amusing to dart directly in front of ships. Imagine a sailboat, operated by the average chump, sitting behind his all encompassing dodger, putting himself in the path of a ground effect craft doing 200 mph. Those things appear to require a substantial distance to execute meaningful maneuvers. And I still can't think of a situation where requiring a very large, flat, unoccupied body of water to navigate upon is going to be worth the trouble. Why not a helicopter or fixed wing aircraft? I restate my analogy just to engender more fear, anger and hatred:
Catamaran=Good
Trimaran=Great
Proa=Why?
Airplane=Good
Helicopter=Great
Ground effect=Why?
Burn me at the stake!
 

MultiThom

Super Anarchist
1,747
392
Benicia, CA
AC foiling boats aren't carrying innocent passengers at hundreds of mph. Nobody has posited a rational explanation of why its desirable to be a few feet off the surface instead of just flying like a normal aircraft. I get it that it's doable, it can work... But why, what's the advantage that makes instant death an acceptable risk?
According to the blurb, there are efficiencies in surface effect flying not available to higher up. Don't want to know the physics, personally...have enough issues just figuring out how sails work.
 
Catamaran=Good
Trimaran=Great
Proa=Why?
Airplane=Good
Helicopter=Great
Ground effect=Why?
Burn me at the stake!
They can travel at much higher speeds far more efficiently than any fast boat or slower amphib aircraft (and especially helicopters, as an efficient WIG can fly for an hour on the same amount of fuel it takes to keep a helicopter of equivalent capacity in the air for only a handful of minutes, and most of them run on cheaper non-aviation fuel), and carry more weight than a conventional aircraft of similar size and performance.

Much like a proa, it is in theory the most efficient use of the available resources in order to accomplish the desired effect and just like proas, there are some notable downsides, maneuverability being one.

That's probably enough thread drift from me for a while...
 

Sidecar

…………………………
3,137
1,501
Tasmania
According to the blurb, there are efficiencies in surface effect flying not available to higher up. Don't want to know the physics, personally...have enough issues just figuring out how sails work.
There is a divide between aerodynamicists and sailmakers. I can give you any number of aeronautical studies which say two wings produce less lift than one wing, whereas North Sails clearly state in their techno blurb, that two sail interacting together as one, produce more lift than one. A bit like Fowler flaps on aircraft perhaps. And I can see some other reasons why that may be so. Get a boat big enough, (eg round the world racers) and you are into “triplane” and more sails working together for specific purposes and practicality.

Written for model aircraft hobbyists, but one of the simplest overall explanation of biplane/triplane effect:

And North Sails (Sails in Combination section):

The sheer variety of sail profile shapes and proportions, cambers, twist, leading edge sweep and spacing between them makes it all more complex to study and understand, unless you narrow it down to a specific situation, eg AC or RTW box designs, or one designs, where a lot of the rig and sail parameters are fixed and you play with the rest.

Sail boats operate at the interface of two mediums, which makes it more complex again, the AC 75 foilers are giving some clues. As do reverse bows and heavily tumble homed topsides forward which deflect air up into the sails and reduce wind shadow on foresails.

Proas, because of their unique geometry, really are a Pandora’s Box, with even more possibilities.
 
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MultiThom

Super Anarchist
1,747
392
Benicia, CA
And North Sails (Sails in Combination section):



Proas, because of their unique geometry, really are a Pandora’s Box, with even more possibilities.
North's blurb, while easy to understand is not exactly true. It is the explanation I used to use to explain why my submarine got sucked up to the surface when a periscope depth...but I was wrong then too. Something about air having viscosity that is much harder to visualize is the real deal. http://gentrysailing.com/pdf-magazines/1-How-Sails-Really-Work.pdf
 
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munt

Super Anarchist
1,229
245
The belt
You guys and your scientific mumbo jumbo! Next thing you'll be trying to convince us that the Earth is a sphere and the Sun is the center of the Solar system!
 

Sidecar

…………………………
3,137
1,501
Tasmania
Catamaran=Good
Trimaran=Great
Proa=Why?
Airplane=Good
Helicopter=Great
Ground effect=Why?
Burn me at the stake!
Follow the money….

Seacart 30, vacuum bagged, autoclaved carbon composite has a Base Speed of ~ 13.0 knots white sails only.

Sidecar (31) carvel plank timber, home built under a verandah has a Base Speed of ~ 11.4 knots white sails only.

Base Speeds are all for single handed. Could you singlehand sail a Seacart, off docks, off moorings or anchor? Happy to bet not as easily as Sidecar even if you could. Space and liveability down below? Sidecar wins hands down.

As it happens they are also both the same overall weight. Vacuum bag and autoclave a Sidecar in carbon composite and you have two choices:

A) Save the weight, say 300 kg, and keep everything else the same: Base Speed: 12.3 knots.
B) Keep it the same weight and rig, make the main hull longer (say 12m): Base Speed: 12.8 knots. Put another 2m2 sail on it (ie 5% extra) and Base Speed is 13.1 knots. Shit hits the fan, would you rather be in a 30ft boat with a huge tall rig or a 40 ft boat with a tiny short rig by comparison? Never mind the extra windage in the windward dihedral ama and crossbeams on the Seacart.

Rigs.

Seacart 30 to get to its Base Speed needs 60% more sail area on a 60% taller and heavier mast than for Sidecar to get to its Base Speeds. You know where most of the money is in a sail boat? Spend the cash difference to make Sidecar bigger again with a little more sail? What Base Speed would you like?

So for ~ 88% of Seacart speed (arguably more, because Base Speed doesn’t account for the additional windage and pitching) and a small fraction of the cost, a more easily handled boat with a more liveable/usable interior, which one offers the better value for money? Proas aren’t “faster”, just potentially more efficient for a given amount of resources than other boats.

Pay your money and make your choice.

Plus I often have to do a fair amount of tacking in gusty, shifty conditions in and/or out of the Sound, which is fairly narrow but thankfully currentless, which is why I have the rig that I have. And it is cheaper than a “conventional” rig In any case.
 
Plus I often have to do a fair amount of tacking in gusty, shifty conditions in and/or out of the Sound, which is fairly narrow but thankfully currentless, which is why I have the rig that I have. And it is cheaper than a “conventional” rig In any case.
It works quite well for that purpose, and is really no more difficult than tacking a conventional boat without a self-tacking headsail, especially if your conventional boat has a traveller and you actually use it...
 

munt

Super Anarchist
1,229
245
The belt
Good answer! I've actually had the pleasure of sailing a Seacart, incredibly fun, incredibly well-built, but built for a fairly specific purpose. Very powerful but certainly could be singlehanded though you'd have to be on your game. Your answer really is enlightening Mr. Sidecar. Therefore I must humbly retract my misinformed statements regarding proas. I actually should have known better as Mr. Finn more than thoroughly established the abilities of the proa on his recent journey. I still think flying a ground effect machine a couple feet off the water at high speed is ridiculous though. Thank you, Mr. Sidecar, for once again bitch slapping me back to reality!
 

MultiThom

Super Anarchist
1,747
392
Benicia, CA
Proas are nice boats and suitable for sailing lots of places and making passages. Wouldn't want to race against one unless it was windward leeward course - especially in a channel such as where I sail. Last outing I was bucking a 2.5 kt current going to weather. Took 50 tacks to get 5 miles upwind (hugged shore for current relief). Sidecar and Jzero are good examples of what a recreational proa is like. Jzero is for sale if anyone is interested in a turnkey boat suitable for sailing to Hawaii and beyond.
 
I simply must come back to sail the boat again at some point as I've purchased a drone and am now reasonably good at flying it, certainly good enough for some simple aerial shots under reasonable conditions. It's also a cheap enough drone that losing it to the cruel clutches of the sea, while upsetting, wouldn't hurt all that badly in the long run...
 

Sidecar

…………………………
3,137
1,501
Tasmania
^^^^ @Hell-Bent, You are welcome any time….. February/ March generally has the best all round weather. Boat is out of action until Xmas.

Open invitation:

If anyone can spare the time and money to get to Tasmania, we will put you up, give you a tour of the Tasman Penninsula, and do some sailing on Sidecar, weather permitting.

Sidecar is what it is, far from perfect, but hopefully of sufficient interest to make it worth your while.
 




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