Concept 50 foot deplacement

[Jon E]

My big dream is once to own a allweather deplacement cruicer built to my own idea. Speed around 9-10 knots with at 100 hp diesel, length 45 to 50 feet buildt in all steel. Since i am not an 3D-artist, and certainly no engineer, i have "drawn, cut and paste" different images from boats and ended up with a "shiluette" i like very much.



I'm thinking of an extremely slim, but deep hull impossible to capsize(!). Does anyone have any ideas around this shape? I know it will be "cropped" if many people onboard, but look at it as a two person ego trip boat with extreme sea capabilities.

Hopefully some have any ideas if this design is totally silly, or if it looks nice and possible. Some might offer to draw it 3d in in a computer, and you will be rewarded, off course.

[Cary]

The more a boat weighs, the more water it displaces and the more power it will take to push it through the water.
Try to find an old sailboat hull around 50 ft.

[FAST FRED]

Speed around 9-10 knots with at 100 hp diesel, length 45 to 50 feet buildt in all steel.

You may find you wont like the fuel required for 9 or 10K .

About the sq rt of the LWL is about what is rational to consume offshore.

Some will run Sq rt lwl X 1.15 , but thats about as fast as you can go with out a THICK wallet.

FAST FRED

[Jon E]

Hi. Thanks for answers. The speed is not essensial, it was just i figure i hoped for. If 7-8 knots is more realistic - ok... But more importaint, strengt, shape etc. for this all weather boat. And if someone could help me to draw it a little more realistic, possible in 3D. If you are a boat 3D-designer and would offer your servises, i would love to hear from you.

[Wellydeckhand]

Send info to wellydeckhand@yahoo.co.id we design based on Singapore dollars...... I will want to hear what you want, maybe talk a bit on the phone. Later draw 3 non color sketch before into 3D digital drawing.......

If you think you need low cost 3D email me....... wellydeckhand

[FAST FRED]

"I'm thinking of an extremely slim, but deep hull impossible to capsize(!)."

You can not design a small vessel that will NOT capsize.

The only thing you can do is have suficent stability so she comes back upright in a rapid time, with no damage.

Unfortunatly this requires more complex (but not that much more costly) machinery and deck arangements.

The cabin top and ESP the glass areas will need to be rather heavy (1/2 in glass IS heavy ) .

A simple example is the use of thru the deck ventilation.
Instead of a std vent with a Dorade box the offshore vent will have piping almost to the bilge, so when the boat is inverted the internal end is above the inverted water line.

Look really well at USCG and other world cllass lifesaving boats , that regulary run inlets .

The CG of the world have combined thousands of years experience , worth copying.Esp the machinery and water tight integrity designs.

FAST FRED

[Cary]

You could build a 50' diesel/electric submarine, just bring some nice folding lawn chairs for nice weather

[Jon E]

Many good ideas here(...), i would bring some more images of my ideas. Fast Fred; i ment self-righting - your absolute correct. The orange cockpit is found here: http://www.norsafe.no/img/rescue_p/1200munin.htm

I like the slim "aggrssive" shape. To me design is mostly about lines, not always easy to combinate with space onboard... Anyone would like to play with this design. Length 15 - width around 2.5 - 3 metres(!), depth 1 - 1,5 metres.







The grey collage images is my 15 metre version of superyacht ICE/AIR..! The arrangement drawing is not mine. As in my first post: i have "drawn, cut and paste" different images from boats"...

[SeaSpark]

The topsides in your design seems quite high so does the superstructure this will have a negative effect on speed in rough conditions . In calm water a well designed 50ft hull will be able to reach 9 knots with 100hp. Upwind against the seas under rough conditions is a completely different story.

One of the most efficient hulls that also works under rough conditions is Nigel Irens iLAN VOYAGER. (no self righting possibilities in this design it's a tri)

http://www.nigelirens.demon.co.uk/FRAMEpower.htm

Adrian Thompson designed a wave piercing powerboat or vsv (very slender vessel) that could be made self righting.

http://foxxaero.homestead.com/indrad_033.html

[Tad]

Jone,

Hey! I recognize that arrangement drawing! NP, but credit where due is appreciated.

On the styling of your boat. To paraphrase Colin Mudie, " the pokey looking classic cruiser that can jump up and fizz off at 40 knots is a good joke, the racy looking quasi-military patrol boat than can only do 9.5 knots is a bad joke!"

Styling makes promises, or it can surprise, but it had best be in a good way.

Tad

[FAST FRED]

My 2c on "style" is a vote for the early "commuter" yachts.

The great thing is many have a foward cockpit that uncovers when needed, with real {auto) seats and a windscreen.

With todays reliable autopilots and Murphy gages to automatically watch the engine room , you can do without the paid hand.

The early commuters had huge handycaps , compared to todays vessels,.

Engines are more reliable & powerfull at 1/6 the weight , and aluminum simple hull construction is about 1/4 the weight of 1920s std carvelle construction.

Will it fit in a Sea Land container , so you can cross oceans in a couple of hours , and ship the boat for less than the food bill of DIY?

I'm tired of crossing oceans in small boats , my "Victory as Sea" casette is getting old.

FAST FRED

[mark424x]

Why steel? just curious. Wouldn't aluminum give a little better strength/weight and lower cost?

Since you don't require high speed, also check out

the Displacement Glider http://www.alsphere.at/dg/index.shtml
and PowerKeel http://aviadesign.com/powerkeel/index.htm
http://aviadesign.com/powerkeel/p36-1%20side%20view.jpg