Feedback on John Holtrop design for circumnavigation

[njoy]

Hi,

Can I please have your opinions on Trident 46:

http://web.archive.org/web/20101213...stuff.com/Boat Designs/TRIdent 46/trident.htm

" The TRIDENT 46 wave piercing (WP) catamaran design looks like a normal catamaran when viewed from the rear, but from the front it shows a sharp, slender third hull which drops down from the center of the boat and runs forward to a position slightly ahead of the outer hulls. This center hull is very narrow, with fine, sharp sections that are designed to "split" oncoming waves before they reach the outer hulls. This lowers the forces on the boat and spreads them out over a longer period of time. The result is that the boat has more time to respond to the wave action and moves with an easier motion. Since the center hull contributes considerable flotation, the forward sections of the outer hulls can also be finer than normal. The combination of staggered, fine sections on all three bows lets the boat punch through waves with less violent motion, and reduced pounding. In short, a better ride, improved seaworthiness, and reduced crew fatigue. One of the more successful applications of this technology has been in the area of high-speed ferryboats, where several types of WP designs have proven themselves seaworthy under some very stressful conditions."

I'm looking for a live aboard/circumnavigator

Thanks

N

 

[Milehog]

He has... How do you say in Canberra? Interesting designs.
To me most of them seem to have a quirk that is a deal breaker. On this one He'd have to prove that bow steer and weather helm wouldn't be an issue. Would the rudder see non turbulent water while under way?
Has anyone ever built one successfully?

 

[gonzo]

That is not what a wave piercing hull looks like. They have some kind of protrusion below the waterline which pierces the waves. The design you posted is pretty conventional and archaic.

 

[njoy]

Thanks gents, I agree with the issues you raise. Its a design I first found in 2005. Its quirky and not one I was keen on, but I thought I'd see what forum users thought.

Johns website is off the air now. I did write to him and he said a couple were being built but none had been finished date. I think one was destroyed by a hurricane whilst being built in the US. I can't find any references to Trident 46's on the net, so it does not look like anyone has finished one.

Its too risky spending the time and money on building an untested design.

P.s. Milehog, Canberra is the capital city of Australia

 

[Mark Cat]

Would it be possible to summarize your sailboat circumnavigation Cat requirements?

In relation to the design presented, I cannot comment on the hull performance. Perhaps a NA could comment. I would like to see the wave making simulation and then some tow tank, and random wave tank trials, before making any claims about advantages in different sea states.

I can provide some trends that I see for Aluminum hull circumnavigation cats 63 to 76 ft. LWL. I am sure there are many NAs out there that have more experience in the actual layout than I have. But, I will try and provide what I see.

Weight is a challenge. For circumnavigation the equipment and supplies fully loaded can be substantial but necessary.

I would prefer to see a slightly elevated fully enclosed bridge (helm).

Two propulsion engines one in each hull for speed and redundancy (normal for a CAT). The drawing you provided has only one engine. The engines should be large enough to outrun the weather in rough conditions.

Two generators one in each hull for redundancy.

Blended Keels and Skeg rudders (prop protection skirts?). Build for grounding if necessary.

Main cabin roof solar panels. Twin wind generators aft.

Collision bulkheads forward (and aft?).

Tender chocks.

I am sure I am missing something. So hoping some of the NAs will comment.

All for now,

Mark Cat

 

[805gregg]

I would want beds that didn't require 1 person climbing ove the other to exit

 

[njoy]

Good point

Thanks for the tip. Its not just a comfort issue, its also a safety issue.