Hreko 1000

Those "bulges" only add a limited amount of initial stability. It ultimate angle of positive stability is dramatically reduced as a result of their use. In other words at small angles of hell they're effective, but when you really need stability is at large angles, at which point they are a determent to stability. The flow lines around the yacht can't enjoy any benefit from them, though rafting up against something would be easier. I also suspect a huge turning moment created when they get some bury under a press. The boat will want to round hard when driven under a good press. These are not desirable attributes for a cruiser.

 

PAR

Boat design I make for fun . How much boats will be made with such concept I do not care, I will die before the nature becomes really angry. I have no intention to earn money with my project . This is my contribution to the nature .
In this moment thousand of tons of lead are unnecessary transported from point A to point B and back . 20 % (what I wrote) is my whish, not the forecast! . I offer the solution to considerable part of sailors, its their turn, they will decide . Some other guys will earn the money, I do not care .



This is for Erik: Quote from Hreko's brochure(PDF)

This concept “ allows HREKO to be twice as light but have superior initial stability compared to a centerboard keel cruiser of same size.(I caled this sailing yacht )
Energy production and low displacement allows up to 50% less fuel consumption!”


haru, if you read Hreko brochure in PDF it will be more easy to understand.
Longitudinal tanks with transverse bulkheads are constructive part of hull without significant increase in weight. If tanks are made of carbon/epoxy or even other composite , they should be not heavier than 50 kg. ( 350 l tanks)
750 l polyethylene sponge is, lets say, 25 kg. This is 75 kg, like one average man!
"are there other advantages in adding those side 'bulges'?" YESSSS, you do not need fenders

 

You do´nt get it. There is no "solution" you could offer!

What PAR wanted to make clear (and several others before), you designed a problem, not a solution.
And your dream of energy production is not mature, it is just a dream.

Multihulls have solved your weight problems some thousands of years ago, they do´nt transport lead ballast.

 

PAR mostly you are right,
Although I shouldn't use words like limited and dramatically. Initial stability of Hreko is much better than initial stability of your leady monohull . After about 60 degrades heeling !!! empty leeward keel works adversely to stability. With such great heeling angle the valve automatically opens and water goes “down” across a large bore tube. The boat becomes more stabile, and this is the moment that you have to reef your sails
The formula is very simple. Underwater bulges take care about initial stability( up to 35 degrades). RIB buoyancy take care about safety ( like safety belt round your neck) and in between you can play with water ballast. Nobody normal sail with heeling angle more than 20 degrees, and Hreko is with 35 degrees angle dramatically stable
A RIB buoyancies are perfect mechanical and acoustic dampers of hull/wave interactions. The final curve, level, position, radius, shape, sponge density etc of buoyancies mast be defined on the sailing prototype.

 

Thanks for explaining.

It sounds nice, but I think for a dynamic system time to react and to restore is critical. So when the boat comes back water will have to be removed or it will make the boat oscillate/swing a bit. Rough weather would be a nightmare. *shrugs*
Maybe (childish idea) a motorized weight moving on tracks across the beam would give quicker control.

 

Ideas like this crop up from time to time. They are usually envisioned by those who have never been in a boat on a churning sea. Had they been in this situation, they'd know how quickly a boat's motion is, how violently fast a vessel can go from one attitude to another. There is no system powered or otherwise, that can compensate for the tossing and twisting a craft does, on a storm whipped sea, at least in the size yacht pictured in this discussion. In much large vessels, you can dampen motion to a very high degree, but practicality steps in on yachts of this size and makes it imposable.

 

:lol:
I assure you my sea experience is far more dramatic than most people.

If ideas were just based on supposed lifely experience than out-of-the-box ideas will never come up. It would be boring.

As I said, in a dynamic system this is difficult and beyond human ability, but as the aeronautic industry has shown fly-by-wire was a solution based on computers and mechanics. It may not be impossible but not feasible with current technology.

 

It's possible, but not likely, nor practical, the motion is too violent. I wasn't speaking of your sea legs, but of Jperkovic's, who's concept this is. In other words, you can dream up a theoretical system to walk on water, but unless you have some experience trying, or more importantly, have the engineering understanding about the principles and concepts involved in such an undertaking, then success will be unlikely.

 

As long as there is no physical law forsaking something there is no reason there is no solution. Therefore I will keep generating random ideas that I evaluated not to be crap. Likewise I'm not forsaking other's ideas, just criticizing their flaws. Don't misunderstand me, I prefer and like critique over everything, because that's where I can find confirmation of flaws or something not thought of.
Yep, experience is important but so is understanding physics which I'm very proud to say I do without thinking. :lol:
I only have experience with robotics, machine-, software engineering, and some aeronautics whether it's in the civil or military sector.

 

Ok guys I give up. Playing with water is stupid. Bat we all do stupid things. If you come in PAR sea conditions ( 50+ knots wind, basic waves from wind direction and huge cross waves ), ballast water should be down in the bilge keels and sails should be appropriate shorted .( < 2m2 )
PAR , I really have respect for you, but try to think a little bit airy, do not think so grey and leady. If I should choose, for ultimate storm I should like to be on Hreko, he looks like recue boat, he looks so floatable.
Today you have perfect satellite weather forecast, and you are not stupid. Today you can choose!
PAR, I know you did it, and you are doing still great with your comments with arguments, bat be aware and realize that time is changing. There is no ideal boat, ideal boat does not exist and should never exist. What is ideal boat ?. Submarine ? There are no waves and you will not capsize . But submarine is not a boat at all

 

We would get rid of you in a moment!

Not that I wish you should be drown at sea!

Your boat though has some of the "best" prerequisites to provide exactly that.

Looking like a rescue boat (which is not the case), does not mean being seaworthy. And this sort of vehicle afloat, is NOT seaworthy. It has the ultimate stability upside down, a quickly diminishing stability at the most important point of heeling angle.

There is nothing left worth talking, when one brings your "design" down to naked facts.

Get it, I was not your enemy here!
I was the enemy of your premature concept!

Bye bye

Richard

 

I'm sure you meant to say something meaningful, but it was just lost in whatever you call that, jperkovic.

Launch your model next to a similarly sized conventionally arranged sailboat, towing each on a yoke. Place each at 15 to 20 degrees of heel and see what you learn, at say a S/L of 1.3 to 1.4. Of course I don't need to do this, I can imagine what will happen, but you seem to have an unreasonable grasp on the dynamics involved, so it's likely only an actual side by side demonstration will convince you. In other words, picture the flow lines once you bury those hull blisters, particularly compared to a conventionally shaped yacht.

 

senseless Paul.....

Boot Düsseldorf . stand 13 D 29

That means he has already invested in getting innocents into trouble!

 

He's got one model, he could very easily get another of similar scale, in a conventional configuration and attach them both to a yoke for towing. The results will be immediately noticed.

 

Thats not a good recommendation Paul.

Ideas, and especially "good ideas" like this one, should not be tested or proven to be right or wrong.
They shall be believed.......................