Opinion requested - new design

[NewIdiot]

Came up with the idea of building my own boat to sail away when I retire. This led to what may be a new design.

Limitations: Have a garage to build a seaworthy boat in. Have to transport on inland highways. Have to build from inexpensive components.

Idea: Build 3 hulls for a trimaran, each 20 feet long. Outside hulls equipped with personnal watercraft for propulsion on calm days. For inland water use, have outer hulls mate together for a 20' by 8' catamaran.

Next, build middle hull with deck extending 4' from center line on each side. By designing so the center hull is 12' ahead of the outside hulls, I end up with a trimaran 32' long and 16' wide.

I hope I have explained this well enough. Will this design work?

[kengrome]

I have some questions:

1- Will the boat be a sailboat or a power boat?

2- Why do you want a trimaran when building three hulls is so much more expensive than building only two ... or one?

3- I don't get the idea of the personal watercraft in the amas. Arre they there to use instead of a normal engine when there's no wind? If so, they will be VERY inefficient and cost you a lot for fuel ... and how to you plan to control them?

4- Max. transport width on U.S. highways is 8.5 feet so how are you going to transport three hulls when the vaka is 8 feet wide and each ama is apparently 4 feet wide as well? That's a total of 16 feet of hull width! Are you going to put them on a LONG trailer or on a double-decker trailer?

[NewIdiot]

Primary power by sail. Power for manuvering and windless days.

Three hulls to add size and stability. Have 20 feet of working space. Three hulls enables extra length by moving center forward.

Personnal watercraft was an idea for concealed power that would fit within the cat hull dimensions.

Transport vaca seperately from the ama. Trying to design so that it can be assembled after launching each section. Also use the amas as a catamaran on smaller waters.

Thank you for replying. My hope is to find out if this design would be feasable. All questions and criticisms are welcome.

[kengrome]

I think that in sailing trimarans you may find that all three hulls are best positioned inline with each other, rather than putting the vaka so far forward. It seems to me that having the amas so far behind the vaka will encourage the boat to bury its leeward aka then trip over it.

[Petros]

Hey NewIdiot,

I like the idea, though as pointed out it takes more material to build this way and two different hull designs. also to design a method of attaching the various hulls and beams together it adds weight and cost for a simple "quick connect" type attachments.

I want to build a 20x12 trailerable cat and I am trying to come up with a simple AND lightweight attach method and I can not find one that does not add a lot of weight or cost. A complex one (lots of small fasteners) can be done, but that would add a lot of time to assemble it once I get to the launch point.

You might consider making it a catamaran (only two identical hulls to build 24-26' long), and have a large center cabin that "attaches" to the cross beams for multiday cruising, and just have an open deck for day sailing (leave the cabin at home those days). For transport the cat hulls sit side by side on the trailer with the cabin transported stacked on top. Build the hulls and sailing rig first, and you can use it day sailing, building sailing experience while you take your time to build the cabin. less to build, lighter and almost as much cabin and deck room. The cabin of course would be limited to about 8 feet wide, but the assembled boat could be 14 to 16 wide. I would buy one of those!

Great idea! Good luck with it.

[NewIdiot]

kengrome - Thanks.

Petros - Build the 20x12 using pipes for the beams, then cut it in half. Slide pipes into pipes to reattach. One cable running across should hold enough tension on the structure to make it stable.

Thanks for the replies.

[tom28571]

Maybe I am missing something. Moving the vaca forward does not make the boat longer. Just makes it take up more room. Also makes it much more susceptible to pitchpoling without the buoyancy of the amas out there to prevent it. Also makes the akas more difficult to build, design and likely less strong. Doesn't sound like a good idea. Dito remarks about the jet skis.

[LFH Fan]

I expect the jet skis will weigh too much and so the sailing qualities would be severely hurt. Nice thought but I suspect not practical. If the boat is well designed and built she will move in light air (tri's are nice that way) so use of engines will be rare. Maybe better to have a simple outboard. To hide the beast maybe you could work a housing whose profile fits nicely with the rest of the design. Maybe combine the housing as a lazarrette or small cuddy aft for fenders, lines or other storage needs. Perhaps the foreward end could be a seat back for the helmsman?