57 Ferry Cat lines

[fede]

Hy Everyone, I'm quickly posting the lines for a 57 Ferry I'm working on,this is supposed to be a planing hull with Max beam being 6.8 mt (22.5 ft +/-) pardon the non refined on the fly quick CAD sketch of the plan.
The client asked for a fine entry and a wallyesque looking profile of the hull (old MAS style)
He has been quiet speific on demi hull beam and he doesn't want it to be more than 2.0 mt (6.7 ft) wide at DWL.
Made in Aluminium it is supposed to carry up to 70 PAX I estimated the max load to be around 23.500 Kg.
He has been strict also about engines,choice being 2 x 440 yanmar that I consider to be at least 2 x 100 hp less than needed.
Deadrise aft is 16 deg.
Hull is very fine at bow and I'm not really shure this will work.
I?m thinking about adding a small 3rd hull in the mid. out of H2O most of the time that would create a buoyancy reserve in extreme following seas situations.
The plan attached is a narrowed version of a first prleiminary that for the client was too beamy.
The ferry is intended for very short coastal cruise around bays etc.
not supposed to face too rough open seas at high speeds.
Any comments suggestions etc. very welcome as always.

[fede]

50 views and no comments ???
Does it suck so bad ?
Is it so good ?

[Paulo Jorge]

Any IGES available?

[fede]

Thanks Paulo, found answers in the towing Tank, hull behave vey well.

[marshmat]

It is indeed very fine forward, perhaps excessively so. It's hard to say for sure at this early phase of the design. I take it that like many fast ferries it's meant for waterjet drives? What's the loaded displacement (ballpark figure, at least)? 2x440hp does sound a bit low for something that size with that sharp a "V" in the bottom, but it'd be nice to know a bit more.

[fede]

Hi Marshmat, thanks for comments, yes bow was indeed a bit too fine and have been changed,as already mentioned tank test have been held for 23.500 Kg and showed very good behaviour for project CG and great
speed for the power installed,I'll post pics as soon as I'll be able to put my hands on the video !
Attached the real tihng under construction a couple of weeks ago.

[Pericles]

Sounds like a Seacat downsized.

http://images.google.co.uk/images?q=...=1&sa=N&tab=wi

Also see here:

http://www.tennantdesign.co.nz/

Best of luck.


Pericles