New design - opinions / idea's wanted

[Steven Prince]

I have given up trying to find a design that satisfy's all my needs, and I'm unwilling to settle for something that i am not completly happy with.

This is why I've decided to start designing my own catamaran. I have taken a few screen grabs of what i've done so far. It is far from being completed. I would like to hear people's thoughts so far and know if there is any naval designers willing to work along side me to get the design proven.

The design is going to be used as my final project for my degree course.

The boat design requirements are

Length around 55ft
max draft 3ft
Hull Beam max 6ft 6
Overall Beam 27ft

I'll put down the other requirements as the posts come in.

Boat is to be a sailing catamaran with a wharram style Dutcg Gaff Rig.

[mikereed100]

Steven,

Good for you! The preliminaries look beautifull. I wish my hulls had those lines. I particularly like the use of flat panels on the cabin. Makes life much easier for a one-off. I think the Dutch gaff is a great choice as well. If I may be so bold, have you considered a smaller boat? 55' is quite a beast and you may be able to get by with a much smaller, cheaper, easier to maintain boat. On the other hand, if you go with that size (or even a 45 footer) one thing you might try is a small forward "working cockpit" just behind the mast. Check out the Gunboat 48 or Bob Oram's designs to see what I mean.

I'm definitely no Naval Architect but I found myself in the same situation as you and have been designing my own boat around some hulls and a rig that I picked up for cheap. It's great to be able to put together an interior and deck layout to suit your needs rather than the charter industry. Best of luck and keep us posted!

Mike

[dana-tenacity]

Did you consider the bi plane rig a la Radical Bay.

[beau]

If you are going to ALL the expense and time building a new boat I suggest going with a proven design (resale value) or at least the latest technology available that suits your application.
Particually with Multihulls there have been a number of improvements ib hull designs over the last twenty odd years.
Remember the design costs and The Hull construction will be the least amount of expense when building a boat.

[beau]

Steven,
why 55 ft.
55 ft is a very large catamaran and will be very expensive to build.
Give us a list of what you want in a design and this forum, which has much experience may be able to sort out your ideas.

[lovinlife]

Well i'm all for a nice big 55 footer, she will be expensive but if you can afford a vessel that size i see no reason to hold back. I've found that multihulls over 50 feet just take the sea so much better than smaller boats. And then there is always that comfort factor, when it comes to interior space.

[The South African]

55 ft is fine for circumnavigating I guess, as long as you dont intend to tie up to a mooring anywhere.

[cat man do]

Originally Posted by The South African

55 ft is fine for circumnavigating I guess, as long as you dont intend to tie up to a mooring anywhere.

Boat's are made for using, not for tying up.

The bigger boat's can carry a decent dinghy, so anchoring out is no longer an issue.



Dave

[beau]

To cat man do, it sounds like you are trying to justify your LARGE catamaran. You do have to tie up somewhere,sometime.
Which is why I opted for a trimaran with swing outriggers.

[mangomuffins]

I applaud your vision. Really consider Mike's suggestion about the forward cockpit. When I first gandered the Gunboat 62 (my dream vessel) and saw that forward pit, I says to myself, "Self, that's the most sensible design innovation in many years." 55'?? If you can manage it, go for it!!
Any building experience??
resale value?? Who cares?? This will be a project of love...
MM

[cat man do]

How go'es it Beau,

We only plan on parking on a berth when refueling, so no cost for berth there, and while at it get a bit of water.

Shopping and washing can be done via dinghy any where I have travelled so don't see an issue there.

As you know berth's vary in price up and down the coast, so when I do decide to pick up a berth for a day, it will be somewhere like Bundy or Gladstone, and run off a brew while there so it will be a worthwhile exercise.

Forward cockpit's................they can be very wet, and cold.

Dave

[Steven Prince]

The reason for 55ft is that the boat is to be used for a circumnavigation and I would like to be able to pick up souvenirs along the way.

Also 55ft gives you that extra comfort whilst sailing and gives me the room for a family one day. Would prefer to build the boat for the future than have to look into getting a bigger boat when the family has come along.

55ft also allows for friends to come and visit.

I would go with a proven design if there was one i liked. Some have come close but not close enough. Resale value. The plan is to have this boat for the rest of my life, hence to size, shouldn't need a bigger boat unless I have 3 or more kids ( which isn't happening).

I'm only 23 so have got the time to build the boat, and pick up any skills I haven't already got.

I'm a Engineer for Land Rover, and deal with the building of vehicles. I know a boat isn't a car but there both complex things in there own rights. I'm going to design the boat so its basically one big mecano kit. The wood will all be cut to the size's required. I have a small amount of experience with fibreglass, i.e. repaired several dinghies and replaced a felt roof for a fibreglass one.

[Steven Prince]

Other ideas I looking at employing are Electric propulsion using a similar system to that of the lagoons. The major difference will be that I'm looking at using a water jet drive instead of a standard propeller.

The reason I'm investigating jet drives is because of the reduced drag whilst sailing and the reduced chance of damage when operating in shallow waters. The reason for choosing a catamaran is the fact of the minimal draft, and the advantages it has. I.e The cat can be beached for provisioning the boat rather than shuttling things on board with a dinghy. The use of a marina should only be needed when filling up the diesel tanks.

The jet drives are also alot quiter than a standard prop and reduce vibration aswell.

As mangomuffins said this is going to be a project of love.

[Tnflakbait]

I think its a good idea to create your own design. Catamaran design is still very young. If you use ideas and methods proven in other designs you should be fine. Designing boats is 90% art and 10% science.
I think the Wharram rig may not be a great idea. Two reasons; performance and resale.
Remember to keep the boat light, and the windage low. Give it high bridgedeck clearance.
Try not to use too many features of the modern Condomarans as they are poor performers and generally slow. (Fat hulls, High displacement, High windage) It is my opinion that a catamaran is not worth having if it is not a good deal faster than an equal length monohull.
As far as a forward cockpit goes I would be carefull. It would be nice to have a forward and an aft cockpit. Being exposed to spray and wind for a very long passage could be tiresome.
I would consider an aft trampoline, they are awesome and rare.

55' is a great length. It gives you the ability to carry a decent
load without overloading. Don't worry about docking it. When you cruise you don't dock. You anchor 99% of the time. Otherwise your doing old people cruising or "marina hopping".

Good luck!

[cferger]

I love the Gunboats, but I am not sure that I would want a forward cockpit. The inside stearing might be nice on occasion, but I think i would prefer to be outside. Also any time you go forward to adjust a line the wind is going come screaming through the entire pilot house area every time either of the doors are opened...