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Old 06-21-2016, 10:06 PM   #321
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Just saw this update on Facebook:

"Dennis Harjamaa, still inspired by classic designs ranging from George Buehler’s “Troller Yacht” concept to Nigel Irens and Michael Kasten, even Philip Stark’s futuristic designs, has several designs on the drawing board, including a 20.8m and a 24m cruiser that will have 2 cabins, 2 heads, 2 engines (1 main and 1 get-home.) Currently designed for Mr. Park —whose requirements now include a crew member— we expect to see this yacht in production very soon."

Read the full story and info here:

DOMINO 20: BROADSWORD - The Ultimate Passagemaker




"He is now running Artnautica Yacht Design in Auckland, New Zealand. Four years ago, he started designing the LRC58 for himself, perhaps to prove the point that “LESS IS MORE.” With hull # 1, KOTI (“Home” in Finnish) on the launching block, Harjamaa had triggered enough of Mr. Park’s interest to start building hull #2, BROADSWORD (launched last September 2015.) Hull #3 is currently under construction at Dickey Boats. Another hull will be starting construction in Holland within a few weeks."
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Old 07-29-2016, 01:17 AM   #322
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Leidos completes initial performance trials of US Navyís first ACTUV Sea Hunter

Just saw this update on the sea trials of the US Navy's long, thin drone ship:

Leidos completes initial performance trials of US Navyís first ACTUV Sea Hunter

The technology demonstration system trials were conducted off the coast of San Diego, California, US.



During the trials, the 132ft-long trimaran vessel met all performance objectives for speed, manoeuvrability, stability, seakeeping, acceleration / deceleration, and fuel consumption of the vessel.

The test also intended to evaluate the vesselís mechanical system reliability while at sea.

Leidos is planning to conduct further tests in the coming months to validate the vesselís sensors, autonomy suite, and compliance with maritime collision regulations as well as proof-of-concept demonstrations for a range of US Navy missions.

Full story here:

Leidos completes initial performance trials of US Navy’s first ACTUV Sea Hunter - Naval Technology
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Old 07-29-2016, 07:05 AM   #323
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Quote:
Originally Posted by LRC58Fan View Post
Just saw this update on the sea trials of the US Navy's long, thin drone ship:

Leidos completes initial performance trials of US Navy’s first ACTUV Sea Hunter

The technology demonstration system trials were conducted off the coast of San Diego, California, US.



During the trials, the 132ft-long trimaran vessel met all performance objectives for speed, manoeuvrability, stability, seakeeping, acceleration / deceleration, and fuel consumption of the vessel.

The test also intended to evaluate the vessel’s mechanical system reliability while at sea.

Leidos is planning to conduct further tests in the coming months to validate the vessel’s sensors, autonomy suite, and compliance with maritime collision regulations as well as proof-of-concept demonstrations for a range of US Navy missions.

Full story here:

Leidos completes initial performance trials of US Navy‚€™s first ACTUV Sea Hunter - Naval Technology
The Actuv is strikingly similar to the Kurt Hughes motor tri design, which bodes well for its pracitality as a workable seaworthy boat; I think that's a given with Kurt's extraordinary high profile reputation in multihull design.



you only need about 20hp/ ton in a multihull to achieve 15kts cruise , a steel low cost tri would make perfect sense as its only going to need a few extra HP to compensate for the extra weight.

Here in Europe you can get a steel hull fabricated in any yard for about €1k/ft, less than half the cost of alloy; even less if you can build yourself with steel at €300 /ton!

38' x 8' tri hull to fit standard 12mtr mooring : €40k
Cummins 6bt 210 HP remanufactured: €20k
Windows : €5k
Wiring , tanks: €5k
Cross beams /AMA's: €5k

...say €80k ready for fitout....
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Old 07-29-2016, 08:14 AM   #324
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Quote:
Originally Posted by LRC58Fan;453892[url=http://dominocatamaran.blogspot.com/2016/06/broadsword-ultimate-passagemaker.html
DOMINO 20: BROADSWORD - The Ultimate Passagemaker[/url]
Took a quick look at your LRC58, but I see a few issues with it as an open ocean cruiser:
  • No dedicated pilothouse. Having completely darkened steering at night is vital.
  • Lack of a transom door with that huge opening will lets tons (literally) of water onboard during rough water.
  • Displacement of 14 tons is about equivalent to a 35ft heavy trawler. Since that's spread out to almost 60ft that vessel is going to have very high accelerations in all directions.

Would be interesting to see how it handles on its trans-pacific voyage.
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Old 07-29-2016, 09:10 AM   #325
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Quote:
Originally Posted by LRC58Fan View Post
Just saw this update on the sea trials of the US Navy's long, thin drone ship:

Leidos completes initial performance trials of US Navy’s first ACTUV Sea Hunter

The technology demonstration system trials were conducted off the coast of San Diego, California, US.



During the trials, the 132ft-long trimaran vessel met all performance objectives for speed, manoeuvrability, stability, seakeeping, acceleration / deceleration, and fuel consumption of the vessel.

The test also intended to evaluate the vessel’s mechanical system reliability while at sea.

Leidos is planning to conduct further tests in the coming months to validate the vessel’s sensors, autonomy suite, and compliance with maritime collision regulations as well as proof-of-concept demonstrations for a range of US Navy missions.

Full story here:

Leidos completes initial performance trials of US Navy‚€™s first ACTUV Sea Hunter - Naval Technology
Quote:
Originally Posted by Rustybarge View Post
The Actuv is strikingly similar to the Kurt Hughes motor tri design, which bodes well for its pracitality as a workable seaworthy boat; I think that's a given with Kurt's extraordinary high profile reputation in multihull design.



you only need about 20hp/ ton in a multihull to achieve 15kts cruise , a steel low cost tri would make perfect sense as its only going to need a few extra HP to compensate for the extra weight.

Here in Europe you can get a steel hull fabricated in any yard for about €1k/ft, less than half the cost of alloy; even less if you can build yourself with steel at €300 /ton!

38' x 8' tri hull to fit standard 12mtr mooring : €40k
Cummins 6bt 210 HP remanufactured: €20k
Windows : €5k
Wiring , tanks: €5k
Cross beams /AMA's: €5k

...say €80k ready for fitout....
Here's a link on the cost of a suitable narrow beam steel hull , but obviously would need modification to make it into a trimaran using thinner plate and different underwater sections.

10, 11 and 12 ft Wide Canal Boat Prices
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Old 08-02-2016, 01:18 PM   #326
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The lack of a pilothouse seems to work in a lot of these long thin designs - I think they have "red" LED lighting that they use in the "great room" when they are passagemaking at night.

I like this design approach because it keeps people together and doesn't break up what is already a relatively small space into even smaller spaces. You can see it also in the Dashew designs as shown below - and his boats are well proven passagemakers - more so than most pilot house designs I think. I like the clean modern and open design. Obviously this is from a set of large boats (the Dashew 97 ft and 70 foot boats) so more space than in the LRC 58 - but the concept is the same.







(from the setsail.com web site here:

http://www.setsail.com/category/wicked-fpb/

and

http://www.setsail.com/fpb-78-1-coch...or-first-look/

The Artnautica LRC 58 has some sort of pull up rear transom door - as can be seen here:

https://www.facebook.com/30024314000...type=3&theater

The issue of "high acceleration" (which I take it to mean roll period) is, it seems, a big of an issue right now - but the designer seems to be addressing it as you can read about on his Facebook page:

https://www.facebook.com/Artnautica-...0243140002724/

"Lengthening the roll period would be a nice option to have. I have been thinking of a tank like you mentioned, also adding weight to the ends of the booms might work well since when they are all the way out they are five metres off centreline. I will get a pair of flopped stoppers soon to stabilise eth boat when anchored. Wakes of passing boats can make for a bit of discomfort from time to time."

The "Hard Chine" design would seem to contribute to this issue.

I agree about the the need for much more data on the success and comfort and safety of the transpacific performance of the design. I am watching to see as more data is released.



Quote:
Originally Posted by makobuilders View Post
Took a quick look at your LRC58, but I see a few issues with it as an open ocean cruiser:
  • No dedicated pilothouse. Having completely darkened steering at night is vital.
  • Lack of a transom door with that huge opening will lets tons (literally) of water onboard during rough water.
  • Displacement of 14 tons is about equivalent to a 35ft heavy trawler. Since that's spread out to almost 60ft that vessel is going to have very high accelerations in all directions.

Would be interesting to see how it handles on its trans-pacific voyage.
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Old 09-02-2016, 02:52 AM   #327
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Originally Posted by MurrayM View Post
Posted by makobuilders
I received a quote to build a 70' long skinny boat for about the same cost as a 50' wide fat one. Same displacement. I am not going to be a full time live aboard, so when I start budgeting for marina fees in various ports the numbers are a true deal-killer!


MurrayM: Even after factoring in the smaller engine(s) and reduced fuel costs?
I happened to come across this old thread. As I've restarted negotiations with the other shipyard for a "long, skinny" boat, we are now considering powering. The powering of the high L/B boat is lower for the same speed as the low L/B vessel. Taking into consideration the difference in power required to overcome headwinds/seas/etc., it's at a point where we can drop to a 4 cylinder engine versus 6 cylinder for the fat boy.

An extra $5k saved here and there does add up, as is the big difference in fuel economy. So I'm giving it serious consideration.
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Old 09-02-2016, 05:38 AM   #328
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An extra $5k saved here and there does add up, as is the big difference in fuel economy. So I'm giving it serious consideration

At displacement speeds wetted area , skin friction is about equal to wave making resistance.

Long and thin has higher wetted areas so is less efficient at low displacement speeds.

In terms of economy a beach ball underwater would be winner .
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Old 09-06-2016, 01:03 PM   #329
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I anchored next to these two "trawlers" earlier this summer in Panarea, in the Aeolian Islands off the northe-east coats of Sicily. Sort of like the beauty and beast!

The skinny trimaran is Adastra and has been commented on earlier in this thread. The converted tug is named Vervece.

I looked them up and they both have 1000 hp motors but Vervece has two of them and cruises at 12 knots while Adastra has one and cruises at 17 knots. While the lengths are not terribly dissimilar (42.5 metres for Adastra and 30 metres for Vervece) the big difference is tonnage: 68t for Adastra and 250t for Vervece.
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Old 09-06-2016, 01:08 PM   #330
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I see two beasts.
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Old 09-06-2016, 02:03 PM   #331
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Weight is a dirty (and unsafe) condition for a multihull.

I think the monohull might have 5 times the room as well as 5 times the cruising range .

Even at low speeds the wave forms will cause more rapid accelerations on the try.

At $7,000 each Stidd seats to keep the spine intact could pay for a bunch of fuel.

In the 1960's I owned a Hedly Nichol 45 ft Voyager try.

Good speed under sail, 15+K required winds that made it uncomfortable at sea.
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Old 09-07-2016, 02:35 PM   #332
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Weight is a dirty (and unsafe) condition for a multihull.

I think the monohull might have 5 times the room as well as 5 times the cruising range .
Actually - the range of the Adastra is 4,000 miles at 17 knots - significantly better than the monohull with a range of 3,000 miles at 12 knots.

I like both of them but if I had the money I'd go for the Adastra.

More info here:

Adastra Superyacht, Zhuhai - Ship Technology
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Old 09-20-2016, 02:44 PM   #333
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Nigel Irens, S, Dashew etc. produce nice designs but it is possible to design smaller, efficient LDL boats.
See this one for example:
SeaPiper 35 - Modern Compact Trawler - SeaPiper
(not my design)
I have a 30 footer on the drafting table, should come out next year.
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Old 09-22-2016, 02:18 AM   #334
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Hi Jacquesm,
Can you share some preliminary details?
I'd love to see them.
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Old 09-22-2016, 03:25 AM   #335
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Re. The severe pitching problems with long slim hulls, here's a very interesting read by the famous Grainger designs; the fine narrow hulls of trimarans and cats are their forte.

Optimising Hull Lines for Performance - Grainger Designs Multihull Yachts

His conclusion : you need a fat stern with a fine entry bow to stop pitching ..... NOT the Dashew & Artnautica 'wine glass' hull shape with a tapered stern.
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Old 09-22-2016, 05:08 AM   #336
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The Sea Piper is a very interesting boat , but I think hard to market in the USA.

Most Trawler owners seem to be interested in maximum interior volume and seem to prefer 2 or 3 layers of boat , up above and away from the water .And 50% more beam.

The design looks fine for a traveling couple , that will venture out in Blue water , although the speeds will still be displacement to obtain good range.

No matter how well done the boat , speed costs bigger fuel burn.
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Old 09-22-2016, 07:56 AM   #337
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The Sea Piper is a very interesting boat , but I think hard to market in the USA.

Most Trawler owners seem to be interested in maximum interior volume and seem to prefer 2 or 3 layers of boat , up above and away from the water .And 50% more beam.

The design looks fine for a traveling couple , that will venture out in Blue water , although the speeds will still be displacement to obtain good range.

No matter how well done the boat , speed costs bigger fuel burn.

All correct and for a designer, the marketing problem is major.
The concept is intelligent, the boat logical but I know from experience that when a couple looks at a boat, the husband will ask for more speed and the wife for more room.
No preliminary design at this point, just an idea that has to mature.
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Old 09-22-2016, 08:45 AM   #338
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Thanks for the pointer to Elling. I was not familiar with them. Very nice to see that they are actually demonstrating the self-righting ability:

Self-Righting E4 To Be Tested Publicly | | PassageMaker

Test video YouTube

And new Ellin E6 real ocean boat...
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Old 09-22-2016, 09:47 AM   #339
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Originally Posted by jacquesm View Post
Nigel Irens, S, Dashew etc. produce nice designs but it is possible to design smaller, efficient LDL boats.
See this one for example:
SeaPiper 35 - Modern Compact Trawler - SeaPiper
(not my design)
I have a 30 footer on the drafting table, should come out next year.

I too like the concept of Seapiper though I wonder if the design would accommodate moving the pilot house forward to expand the interior living space and move the outside space aft.

Seems to me it would be a more livable space for almost every use.
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Old 09-22-2016, 11:41 AM   #340
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Originally Posted by Rustybarge View Post
Re. The severe pitching problems with long slim hulls, here's a very interesting read by the famous Grainger designs; the fine narrow hulls of trimarans and cats are their forte.

Optimising Hull Lines for Performance - Grainger Designs Multihull Yachts

His conclusion : you need a fat stern with a fine entry bow to stop pitching ..... NOT the Dashew & Artnautica 'wine glass' hull shape with a tapered stern.
But if only there was better marketing these would be flying off the shelves! !
Pitching be damned.
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