Canting Keel and Mast on a mini 6.50

Hi guys

I am new to this design stuff but am competent on the composite build stuff.

I have a mini transat boat - Berret design - ATOMIC that I have been sailing. Its a wooden ply build with an epoxy skin.

I am getting her ready for next season and the old keel which is a lump needs to go. Its big-Horrible and does not look fast. there fore how do I design an appropriate keel that will be ok - could I put a canting keel in or will i need to reposition the keel box?

Also how do you work out where a mast should go in relation to the keel.

One last question is how do you work out how much carbon or glass to use in the construction of say a boom or spinnaker pole.

I am not an engineer so laymans answers and simple maths if I get any answers to these vauge questions at all

Thanks

Nick

 

6.50 Keel Mods

Hi Nick,

For all the structural and performance issues on a boat of this type, I would hope that you would be consulting a highly competent, naval architect with experience dealing with the issues of canting keels and rig relationships, if not the original designer himself, before carving off a hull section for a remodel job.

There are amazing forces at work in these indicated mods and for a boat of this type and potential power, the stress loadings and structural requirements are not insignificant.

Take a look at how much trouble the current crop of Volvo Ocean Racers had during their early shakeout segments on the open sea and you'll see why the correct calculations are critical.

My favorite naval architect for issues such as these would be Jim Antrim out of San Francisco. You may already have someone in mind, closer to your home, who is capable of doing the proper job on this complex set of interconnected issues.

Chris Ostlind

 

Canting keel and mast

I agree that contacting a naval architect and marine engineer is important in this case. I've discussed mini 6.5 design with Eric Sponberg of St. Augustine ,Fl.. and he's got some really state of the art ideas regarding mini's including using an unstayed wing mast as well as some interesting canting keel solutions and other race proven ideas. Eric is one of the foremost authorites on unstayed carbon masts and his engineering expertise on canting keel design has been published in Professional Boatbuilder. You can contact him thru his website: www.sponbergyachtdesign.com or you can call him at 904-460-9494 or write him at: 50 Ocean Court,St. Augustine, Fl.,32080 The consultation involved will SAVE you big bucks and lots of trouble. Good Luck!

 

Nick,

Best source for information on mods to minis is Leo http://www.minitransat650.com/
There may be people doing just what you are someplace and Leo will know about it.

There is also a open source mini design project site here http://www.zwakenberg.de/mini/index.html
They may be of help.

There is also a mini design thread on this forum, use the search.

Tad

 

Hi

I have same expirins with Mini 56 "ATOMIC"
It is a good Berret design... but it is a old race yacht...
I remember, that the playwood construction of hull was not really strong...

I was a co-skipper on ATOMIC in 2004. In 1/2 of sailing seson we had to repire yacht in shipyard.

You have to contact with some yacht enginer, but personaly I think that is pasible only with modifications on plalwood frams.

the photos you can find here:
http://waligorski.pl/pl/index.php?d=galeria