Looking for a N.A. for 85' passagemaker

Bruce,
That is a subdivision issue, not a material based issue. If the vessel had proper subdivisions this should be nothing more than a hole in the hull. A pain granted, but it should not be catastrophic.

 

kc,

As boats get larger various things happen....but no matter how large they are it still seems you're (the designer) fighting for every inch. Short answer is that the higher sole is wider (due to hull flair). This just increases interior options.

The under sole volume is indeed required for tankage, also for electrical/plumbing/HVAC services, and storage areas. Equipment like the bow thruster, active fin stabilizer gear, and numerous pumps and black boxes also require space and maintenance access......It's pretty full down there......

As these designs are narrower than average one must resist the urge to increase height and add further decks.....they raise VCG and increase motion. Limiting interior volume is the way to get (relatively) light-weight high performance cruising boats.

 

This is meant to indicate plans can be supplied for either cold-molded wood or aluminum construction. The cold-molded version would be round bottomed with a skin of 2.25" and little framing except internal bulkheads. The structural weight will come out close to a aluminum hull with web frames and longitudinal stringers.

3355HP is obviously a typo, correct power is twin 355HP, as mentioned further down the page. This the E rating on your attached data sheets, which was requested by the client at the time. Personally I'd have a single 855 Cummins in there....or an 8cylinder Gardner....

 

Most of today's contemporary production passagemakers like Nordhavns and Krogens are not very comfortable nor efficient sea boats. The short, fat, bluff bowed passagemaker is great in port but makes for a rough ride at sea, particularly when going to weather. While roll control devices are wonderful for increasing comfort, they don't do anything for pitch, and the flare and reserve buoyancy forward has them going up and down nearly as much as going forward. Seemingly all for the sake of keeping the foredeck dry. As a guy who builds submarines, I think dry foredecks are over-rated.

We've experienced both the FPB 64 and the 83 and their real world performance is remarkable. In a time when so few designers spend any significant time at sea in the boats they design, the Dashew's are a real exception. I met a couple of the FPB 64 owners at the Anacortes Trawlerfest last month and they could not have been happier with their vessels after sailing them back to the U.S. from New Zealand. However, the Dashews won't build another 83, you can't put a sub on a 64 and the new 115 is, at an estimated $10 million, way over our budget.

The new design is coming along well. 90' LOA and 89.5' LWL, triple chined, longitudinally framed hull to reduce structural weight and the sub will stow aft below decks. It looks like we'll come in under the 180,000 lb estimate.

 

I would say that the market for real ocean going motoryachts is far smaller than that for boats which can cross oceans but really spend their lives tied in a marina. Maximum accommodations in minimum length (moorage cost) seems to sell boats......

Here is one of my notes from the Minimum Passagemaker thread.......

I did some research of the current 15 Nordhavn listings of 50' or less, not including the 35' coastal cruiser. They range in age from 3 to 20 years, and engine hours (time under way) ranges from 83 to 530 hours per year, but these are extremes. The average for 15 boats is 284 hours (11.83 days) under way per year.

So of those 11.83 days at sea per year, one would probably have good weather......? ......60-70% of the time? So....say 4 days per year when weather is less than optimum.......to me this sounds like one or perhaps two storms per year....or perhaps none?

So how much do you slant the design to weather the ultimate storm when the boat will only go out in the ocean for 12 days per year?

 

You must have a pretty plumb bow if your LOA is only 6inches longer than your LWL

 

Tad, that's a very good point. But I think that if people had the opportunity to compare the direct experience going to sea in the two very different vessel types, they would pick the long, lean variety every time. Having your own boat designed and built is a lot of work, particularly if you don't have much experience. Most would just like to order a Nordhavn and not have to worry about all the details, even if they know that their purchase is supporting a massive advertising budget!

I think a long, lean production passagemaker could do quite well. Dashew is certainly selling the FPB 64.

 

The largest problem with limiting interior volume is you no longer have any benefits over a catamaran.

 

kc,

Every boat is a compromise. I'm of the opinion that the perfect boat drinks 6, feeds 4 and sleeps 2 ;-) Performance and seagoing comfort are my most important criteria. My wife and I and one crew should be pretty comfortable in a 90' passagemaker with a stabilization gyro. So long and thin works well for us while it might not for others.

 

A cat can cram more accommodation into a shorter length, but beam will be greater....perhaps causing berthing problems in typical marinas. And surface area is usually much higher, a 46' power cat of my design has 1/3rd more surface area than the PL56 design, both having roughly the same interior and deck space. This means the shell of the cat could cost 1/3rd more.....a significant difference......

 

What I am trying to say is a catamaran and PL with the same internal volume are both going have problems in todays marinas. A cat will be too wide and a PL will be too long given the same amount of interior space. Its no more than a compromise/trade off. The only other option would be to go up.

 

Building a boat based on its cost to berth does not seem very sensible. Buy a waterfront condo instead. Long thin boats rule when it comes to seakindly-ness and efficiency.

Beating into headseas in a typical production passagemaker is tedious beyond bearing.

 

I won't deny that as long as we are talking about mono-hulls. However internal volume cannot be completely sacrificed just in the name of efficiency as a Cat can have those same efficiencies, same lack of internal space, while having even more deck space.

 

Here's a profile image of the Triton 90:



90 feet LOA, 89.5 feet LWL, and only 75 tons.

Paul Bury has done an incredible job in the first step of translating the brief into a design.

 

kc,

I've sailed on some big cats. I'm not a fan of the motion, the wave slapping on the bridgedeck and the great stability they have when up-side down. We're building two to carry subs on a coastal basis but they're not for me on transoceanic passages.