High Speed Aluminum Hull

[StianM]

10-12 meters long 2,5 meters wide and 2x250hp outboard engines.
Steped hull is not a option and topp speed shuld be 50kn with 1 metric tonn of load.
Anny thoughts how to acheve this?
Annyone with or know someone with exsperience with a hull design that can do this?

[Wellydeckhand]

How much you offer for the building of hull?

[StianM]

I'm not looking for the build.
I'm hoping someone can help me find someone that can provide knowledge how to build this (license a build). The speed is crutial and the hull should be at international safety standards.

[Wellydeckhand]

How many boat you are thinking to make?

[dimitarp]

This is not so comlicated work, 50 knts with two engines?One easy to apply method is the parametric method to design hull.

[StianM]

Originally Posted by dimitarp

This is not so comlicated work, 50 knts with two engines?One easy to apply method is the parametric method to design hull.

2x250hp is no problem yes, but outboard and with proppeler guards is.
900litres off fuel and 4-6 people onboard.
I'm worried about the weight.

The boat would nead to be way below 1500kg I belive

[Wellydeckhand]

for register designer look up in the directory and view work at gallery

[dimitarp]

Originally Posted by StianM

2x250hp is no problem yes, but outboard and with proppeler guards is.
900litres off fuel and 4-6 people onboard.
I'm worried about the weight.

The boat would nead to be way below 1500kg I belive

I estimate that such boat 10m long and 2.5 beam, made from aluminium without the fuel thank, fuel nad engines will weight about 1300kg, even below.
The proppeler guards will make no problems for speed.

[StianM]

would it handle ABS, DNV demands?

[dimitarp]

Yes, DNV

[StianM]

Annywhere I could find more info? anny companys building this kind off boat out there?

Anny pictures off sutch vesel?
I would like to see what the aluminium reinforcemnt's look like.
My estimate is it would weight close to 2 tonn's
What would be the Aluminium thicknes? 3 or 4mm?

[RANCHI OTTO]

To reach the speed of 50 knots the max. displacement is of 2500kg. abt.
Subtract the 1000 kg payload the displacement is 1500 kg.
Subtract the 1500 kg of the hull weight and the displacement is 0....!
You can save some weight in the structure..perhaps 200 kg but you have to added:

2 outboard engines
3 extinguishers
safety equipment
crew (2)
gasoline tanks (2)
gasoline
steering cables
starting batteries
electrical cables
mast
navigation lights
VHF + antenna
anchor
anchor chaine + rope
mooring rope
bits
paint (?)

1000 kg payload for 2500 kg fullyloaded displ. is out of norm.

[StianM]

It will nead 1000litre fuel tank and then it's 2400 allready.
To adapt a exstremly flat bottom is posible to get few more kn but it will provide a rough ride.
Steped hull is also posible but it's a big chance we will balance the boat wrong or that the balance will be disturbed off people and equitment moving around.
Lets say I'm able to build it at 1300kg and then it's 2200 with 1000 litres off gasoline, then come the engines and 6 pasangers 6x70kg and there is problem with the weight allready and I did not even fitt steering console and navigation equitment yet.

[RANCHI OTTO]

The solution is to install 3 engines. (3 x 250 hp)
So doing you reach a top speed of 50 knots with a displacement of 4000 kg abt.
Increase the length to 12 m at the same time.

The structural thicknesses for 50 knots are as follows:
keel plate > 5 mm
W.T. bulkhead > 4 mm
deck > 4 mm
side shell > 4 mm
bottom plating > 5 mm
wheelhouse floor > 5 mm
transom > 5/8 mm

[RANCHI OTTO]

Here you have a speed vs power diagram for outboard engines propulsion.
Using this diagram, based on sea trial results, you have the possibility to check rushly the performances of your boat