hreko

"So the dinghy will be built to the same scantlings as the mothership?"

Yes, here you can see how it will be supported. When you lift the dinghy you have to lift les than half weight a few inches, then you have to pull. Other person can use dinghy bow line through block on the targa (in the middle of the stern frame there is one block to fix dinghy when sail or in harbor when dinghy serve as a gangway)

 

This is not competition boat. I wrote in one previous post that inner ballast of Hreko is quite big because of high comfort you have on this boat. Imagine 30 kWh electric energy on disposal.

For unlimited ocean sailing it should be redesigned, certain things should be changed. This is concept boat. Lot of things will be changed and accomplished as Viking north said.

This boat is unsinkable with his weight of about 3,5 t and about 4,5 m3 displacement wen completely submerged. It means about 1000 kg positive buoyancy when completely filled with water.

 

Dear friend, you have no idea what you're talking about. Any boat, except submarines, when completely submerged, displaces much more water than its weight. So, to sink, requires that its internal volume is flooded with water. Your boat, when filled with water, it will sink like any other boat. (despite the floatation bag located at the top of the mast)
I advise you to read a book about physics, fluid mechanics, for starters. You know what Archimedes' principle is?

 

Neither is the didi, more a fast cruiser. I used IMS trim since it seems more indicative of actual boat weight and is a useable standard for comparison. 4-5000kg is really pretty standard displacement for a moder 35-40 foot boat. Not saying your 4000kg weight is bad, but you might want to stop claiming it as a lightweight boat. Your are certainly not 40% lighter than similar boats as your website claims.

 

Hreko's displacement is about 3,5 m3 salt water ( its about 3570 kg)

Hreko has >1500 L closed air in bilge keels and water ballast tanks, > 2000 L air closed in dinghy, > 1000 L closed air in corecell foam built into the boat structure. This is 4500 L air ( + 25 l CO2 in airbag )

 

I took sum of displacement of 30 most popular +/-38 feet cruisers from Nautic Expo and divided with 30. The result was 7150 kg!!!

Performance cruisers of same size would be probably round 6000 kg average. 3,5t is about 60% of 6t and 4t is 60% of 7,1 t.

Hreko is 4,2m wide with spacious cabin, has 11,2 m long WL what means 40 foot range boat!

I took also draft, the result vas 175 cm average.

 

Many boats had huge reserves of buoyancy and now they lie at the bottom of the sea. You know the story of the Titanic?. The builders said it was unsinkable.
Again I recommend you study a bit about boats and so (maybe) you´ll see that all boats have some of the advantages that you say only have the Hreko and others are not such advantages, but disadvantages.
Years ago you started a thread on a Hreko boat and did not end amicably. Try, please, that this does not happen again.
Cheers

 

I recommend you not to bother with this failed design. There are so many great projects on this net where you can demonstrate your knowledge and talent for discussion. Farewell my friend, I will not miss you

 

First post :

But when we try to make you understand that the project is crazy, you get angry.

 

I am agree, 150 pounds is too optimistic (expensive carbon version?)
I am not an engineer and even less naval architect but whole load of American Cup catamarans with 40 knot speed rests upon "several" square feet of dagger boards and rudder blade horizontal hydrofoils. I do not believe those two parts weight much more than few hundred pounds.

Inspiration to design HReko 1ooo was east coast of Adriatic Sea. There you have "never" waves higher than 3 m and B Stix category is more than enough. If you wish to use this concept for unrestricted ocean sailing tender as an extension of the stern is probably not the best solution. Also there is no need such a large area solar panels. Lateral solar panel should be sufficient for the fridge, water maker, autopilot and instruments. Electric pod propulsion is definitely not good solution, but who knows.( maybe this cocept: http://greenstarmarine.se/en/greenstar-20d/ ) Hreko is designed for coming 10-20 years and improvement in electric propulsion can be challenge to became independent of fossil fuel. It would be great feeling if that succeed.

 

http://www.boatdesign.net/forums/boat-design/hreko-44713.html

There is the "same" thread from 2009

Not all over again, ahahaaa. Last time he ended up getting himself banned