Bob Perry

Something different for CA

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PhotozHinds-GerS33.JPG

 

Some German ones had the forward fin too. Forward rudder to help when docking?

. I think I remember Herreschoff saying something about the Germans traditionally looking for a tactical advantage with speed, smoothness of ride and handling in crappy weather.

 

President Kennedy opined the same about a WW2 German PT boat during a tour- he would have known. Just before he was assassinated, JFK did a drawing of a small sailboat in rough water (not the Rice Hotel doodle). It is remarkably accurate, and sensitive to the feel of it. Remarkable man.

 

Too bad he didn't get to go sailing with Teddy after his presidency....

Yeah, baby! http://www.janelmer.com/gallery/schnellboot_5.htm

The S-100 was driven by three Daimler-Benz MB 511-V 2500 hp Diesel engines providing an overall power rating of approximately 7500 hp. This translated into a speed of approximately 43.5 knots (briefly accelerating to 48 knots).

sample_pic_gallery_12.jpg

 

ptboats07122102_1198209084.jpg

 

 

As to 16 knots cruising speed, that sounds slow for a modern, expensive power boat. Boston Whalers and many common crab and fishing boats will power circles around that speed - in the ocean, not protected waters. For $949K, you can buy a 2014 model MJM 40z (mentioned earlier, 2 X 370 HP)) that burns 11.9 GPH (1.3 nmpg) in the speed range of 13 to 18 knots. Top end speed is twice that fast (38 knots). At 32.5 knot cruising speed, it gets 28.6 GPH / 1.1 nmpg.

 

Sure, you can beat those figures with a longer boat and less power. But at what price? At times, speed is safety.

 

And it's trailerable:

 

40z_trailer.jpg

 

 

As to the side doors, KISS!

 

40z_door.jpg

I may as well throw my $.02 cents in :)

 

I think the German boat (3 & 4 pics up) shows that a forward silhouette can be sexy, and it would open up the aft deck for more than the dinghy. (Amati is 1/2 aft cockpit, and I think she looks ok ;) )

 

As long as I'm sticking my nose where it doesn't belong might a slightly raised more monolithic cradle for the dinghy look nautical, and make loading unloading easier, if done right? Be someplace to sit when the dinghy is in the water and possible storage for dinghy stuff too. A raised dinghy might raise the aft aero enough to smooth the flow over the boat as a whole, esp. if there were a cover on the dinghy.

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Vamoose, by Herreshoff for William Randolph Hearst, 1891.

220px-Vamoose.jpg

 

Another Herreshoff, labelled 'torpedo boat style'. Name possibly Silleto? Year unknown.

10013932_845914528754830_181266913738849

 

Found more info on Stiletto. 48', 7' beam, 25 knots, 250HP Yanmar, 4 gal/hr at cruising speed.

http://www.offcenterharbor.com/flotsam/herreshoff-torpedo-boat-stiletto-nice-aerial-footage/

Vamoose: https://en.wikipedia.org/wiki/Vamoose_(Steamship)

 

Vamoose.jpg

 

 

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PhotozHinds-GerS33.JPG

Some German ones had the forward fin too. Forward rudder to help when docking?

It also has a keuschheitsstrut

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Stiletto out of water. Note planing surface aft, at waterline, so stern doesn't squat.

325843825_LMyoH-L.jpg

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Y'know, the cradle for the dinghy could be a double couch (facing each other) when the dinghies in the water......

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Y'know, the cradle for the dinghy could be a double couch (facing each other) when the dinghies in the water......

Hmmm, I think you're on to something. Seats facing each other, the 'cradle' parts between seats that holds the dinghy can fold flush into floor when not needed....or lifted out and stowed under seats.

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Maybe the launch ought to be CF (lapstrake/clinker-ish lines if you please.)

 

The PT skiff approximates a decent line - they just stopped before they got it right. Better a launch with RHP lines no matter whether the build is ply or CF.

 

Not secret - I am not a fan of CNC component stuff - just too much opportunity to clean up the lines gets lost with CNC component builds.

 

Kiwanda

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Vamoose, by Herreshoff for William Randolph Hearst, 1891.

220px-Vamoose.jpg

 

Another Herreshoff, labelled 'torpedo boat style'. Name possibly Silleto? Year unknown.

10013932_845914528754830_181266913738849

 

Found more info on Stiletto. 48', 7' beam, 25 knots, 250HP Yanmar, 4 gal/hr at cruising speed.

http://www.offcenterharbor.com/flotsam/herreshoff-torpedo-boat-stiletto-nice-aerial-footage/

Vamoose: https://en.wikipedia.org/wiki/Vamoose_(Steamship)

 

Vamoose.jpg

 

 

 

Wow, that's lovely.

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Maybe the launch ought to be CF (lapstrake/clinker-ish lines if you please.)

 

The PT skiff approximates a decent line - they just stopped before they got it right. Better a launch with RHP lines no matter whether the build is ply or CF.

 

Not secret - I am not a fan of CNC component stuff - just too much opportunity to clean up the lines gets lost with CNC component builds.

 

Kiwanda

 

 

 

Carbon fiber lapstrake? Interesting idea. Each strake vacuum bagged? I can see it.

Maybe female Nor'Sea 27 style? Either way I am in

OMG, now this thread has jumped the shark.

 

PT Spear

 

DSC06153.jpg

 

shapeimage_5.png

 

DSCN0280.jpg

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Vamoose, by Herreshoff for William Randolph Hearst, 1891.

220px-Vamoose.jpg

 

Another Herreshoff, labelled 'torpedo boat style'. Name possibly Silleto? Year unknown.

10013932_845914528754830_181266913738849

 

Found more info on Stiletto. 48', 7' beam, 25 knots, 250HP Yanmar, 4 gal/hr at cruising speed.

http://www.offcenterharbor.com/flotsam/herreshoff-torpedo-boat-stiletto-nice-aerial-footage/

Vamoose: https://en.wikipedia.org/wiki/Vamoose_(Steamship)

 

Vamoose.jpg

 

 

https://www.youtube.com/watch?v=Le0nsvUQJOo

Wow, that's lovely.
I think when kimbottles sees the stern he'll have a canoegasm.

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Y'know, the cradle for the dinghy could be a double couch (facing each other) when the dinghies in the water......

Hmmm, I think you're on to something. Seats facing each other, the 'cradle' parts between seats that holds the dinghy can fold flush into floor when not needed....or lifted out and stowed under seats.
My take is that if you have move or fold stuff, it won't be used but rarely. And moveable stuff always fails when things are getting knocked about. Cushions? Sure. You can throw those things.

 

I suppose you'd need to take the lines of the skiff and see what they look like as a mold for a couch. My first take is that the bottom and first chine would make an ok floor, and the deck height might make the actual seat, and then you could add the backrest, so the dinghy itself would nestle close to the deck, and you'd have enough footroom. That would also give you a lot of locker space for life jackets, the sail, etc.

 

But frankly, at the this budget level, what would it take to have Russell do a small sharpie with a flat bottom that really would be part of the couch under the seat level-

 

so, a very crude diagram- in cross section at the widest point:

 

The boat \___/

 

The couches without the back in cross section ''''''\___/'''''. Add backs, which I can't figure how to do with diacriticals. Without the boat, it would be like a semi abstract boat sculpture, with nice gentle lines which would fit with the lines of the big boat, and you could pile a bunch of pillows in the bow part of the boat shape. Or just leave the bow part out for access to the couches. Wouldn't be a bad couch, and it sure would hold the dinghy in place in a seaway. Nice flat bottom 15' sharpie? Good load carrying, and they sail great. Might be a nice fit for Kim's early American aesthetic sense. I can picture it in white. With a bright wood interior. mmmmmmmmm. I wonder if the pillows could do double duty? Maybe just flat fenders, cut to shape? Put pillows on top when sitting.

 

:)

 

Edit- couch without seat backs, but with the very, uh, back, so you can see what the lockers might look like. |''''''\____/''''''|

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Stiletto out of water. Note planing surface aft, at waterline, so stern doesn't squat.325843825_LMyoH-L.jpg

Back to the future -( Vingt et Un had one of those too- :) )

 

http://www.star-board-windsurfing.com/2017/products/boards/phantom-race

 

Bat Wings !!!!

 

 

Looks like that fin/skeg goes pretty far forward---in line with Kent Island's suggestion...

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It would make a nice hot tub too. ;)

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It would make a nice hot tub too. ;)

Hmmmm...my own preference would still be atop the lounge hardtop, launched with a mast/gin pole...but I'm not the customer.

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Cool as all those Herreshoff boats are, I think most designers would say they are from the era before anyone knew how to design a really good powerboat. And the weight-to-HP ratio of the powerplants was too poor to let anyone design a boat that is acceptable by today's standards.

 

BP's drawing looks more like a very elegant enlargement of a flat bottom skiff.

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Kent:

I'll take your advice to heart.

I think what I have drawn now is closer to what you are suggesting. It looks right to my eye.

 

Love that German profile. How about the rake on the smoke stack!

Apparently they did not feel they needed much skeg at all. Long, skinny boats like to go in straight lines.

 

I need to do some research on rum runners. Anyone have have a link?

I would bet there is a book. Kim must have it. He has all the books.

Relative to the amount of top sides, those old torpedo boats have more hull underwater then your high tech, light weight hull which appears to have minimal hull underwater...

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Y'know, the cradle for the dinghy could be a double couch (facing each other) when the dinghies in the water......

Hmmm, I think you're on to something. Seats facing each other, the 'cradle' parts between seats that holds the dinghy can fold flush into floor when not needed....or lifted out and stowed under seats.
My take is that if you have move or fold stuff, it won't be used but rarely. And moveable stuff always fails when things are getting knocked about. Cushions? Sure. You can throw those things.

I suppose you'd need to take the lines of the skiff and see what they look like as a mold for a couch. My first take is that the bottom and first chine would make an ok floor, and the deck height might make the actual seat, and then you could add the backrest, so the dinghy itself would nestle close to the deck, and you'd have enough footroom. That would also give you a lot of locker space for life jackets, the sail, etc.

But frankly, at the this budget level, what would it take to have Russell do a small sharpie with a flat bottom that really would be part of the couch under the seat level-

so, a very crude diagram- in cross section at the widest point:

The boat \___/

The couches without the back in cross section ''''''\___/'''''. Add backs, which I can't figure how to do with diacriticals. Without the boat, it would be like a semi abstract boat sculpture, with nice gentle lines which would fit with the lines of the big boat, and you could pile a bunch of pillows in the bow part of the boat shape. Or just leave the bow part out for access to the couches. Wouldn't be a bad couch, and it sure would hold the dinghy in place in a seaway. Nice flat bottom 15' sharpie? Good load carrying, and they sail great. Might be a nice fit for Kim's early American aesthetic sense. I can picture it in white. With a bright wood interior. mmmmmmmmm. I wonder if the pillows could do double duty? Maybe just flat fenders, cut to shape? Put pillows on top when sitting.

:)

Edit- couch without seat backs, but with the very, uh, back, so you can see what the lockers might look like. |''''''\____/''''''|

Personally, I would have a VX Evo on the back, just sit on the gunnels. Ok, not really I would have an A-Cat on the back and turn the area in front of the cross beam into a lounging area, and anyone who sits on the hulls gets keel hauled. If you go with a Cat, then the runners the cross beams rest on could pretty easily pivot outboard to act as a backrest, and underneath the hulls put some seats.

 

One of these days I need to figure out how to draw, at least a little, to explain myself better.

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Kent:

I'll take your advice to heart.

I think what I have drawn now is closer to what you are suggesting. It looks right to my eye.

 

Love that German profile. How about the rake on the smoke stack!

Apparently they did not feel they needed much skeg at all. Long, skinny boats like to go in straight lines.

 

I need to do some research on rum runners. Anyone have have a link?

I would bet there is a book. Kim must have it. He has all the books.

Relative to the amount of top sides, those old torpedo boats have more hull underwater then your high tech, light weight hull which appears to have minimal hull underwater...
The torpedo boats had to carry a couple of triple-expansion steam engines, boilers full of water, several tons of coal, several torpedos, and several deck guns and shells. No shit they needed a lot of displacement to carry all that weight. They were also about 10 knots faster than battleships of the period, despite having about a third the length. They looked cool, also. :)

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The standard tender will either be a PT-11 Nester or a PT-11 Spear.

They weigh under 100 pounds each.

I can still easily handle such a tender even at my advanced age.....

And I will have a winch at the front of the cockpit

And given that I already own the Hadlock 23, she will be the alternate tender.

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Cool as all those Herreshoff boats are, I think most designers would say they are from the era before anyone knew how to design a really good powerboat. And the weight-to-HP ratio of the powerplants was too poor to let anyone design a boat that is acceptable by today's standards.

 

BP's drawing looks more like a very elegant enlargement of a flat bottom skiff.

The black one is more recent, just in the style of the old boats. I think it's pretty light, although still wood construction. 250HP Yanmar is certainly a contemporary powerplant.

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Cool as all those Herreshoff boats are, I think most designers would say they are from the era before anyone knew how to design a really good powerboat. And the weight-to-HP ratio of the powerplants was too poor to let anyone design a boat that is acceptable by today's standards.

 

BP's drawing looks more like a very elegant enlargement of a flat bottom skiff.

 

You think that powerboat design has actually advanced since Herreshoff? I think powerboat design has gone far astray since then.

Monster trucks and modern powerboat design make me froth at the mouth. They both thumb their nose at efficiency and the environment and modern powerboats are generally just incredibly ugly. More like shoe boxes with racing stripes.

Sorry, I don't have strong feelings on this subject....

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You think that powerboat design has actually advanced since Herreshoff? I think powerboat design has gone far astray since then.

Monster trucks and modern powerboat design make me froth at the mouth. They both thumb their nose at efficiency and the environment and modern powerboats are generally just incredibly ugly. More like shoe boxes with racing stripes.

Sorry, I don't have strong feelings on this subject....

Ah, but you do have strong feelings on this subject, Russell. Just not positive ones. :)

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Cool as all those Herreshoff boats are, I think most designers would say they are from the era before anyone knew how to design a really good powerboat. And the weight-to-HP ratio of the powerplants was too poor to let anyone design a boat that is acceptable by today's standards.

BP's drawing looks more like a very elegant enlargement of a flat bottom skiff.

 

You think that powerboat design has actually advanced since Herreshoff? I think powerboat design has gone far astray since then.

Monster trucks and modern powerboat design make me froth at the mouth. They both thumb their nose at efficiency and the environment and modern powerboats are generally just incredibly ugly. More like shoe boxes with racing stripes.

Sorry, I don't have strong feelings on this subject....

Your input on this project would be welcomed as always Russell.

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Russell raises a real point regarding powerboat design "evolution." Even 20 years ago, Dave Martin pointed out the seemingly inexorable trend toward high and higher displacement/(Length^3) ratios, with more and more power. He presented an interesting paper at the Phila section SNAME monthly meeting, showing efficiency results of real boats, all plotted against Crouch curves. (Mr. Crouch was one of the great early powerboat designers and he originated the idea of plotting efficiency curves on axes of BHP/LB versus MPH.)

Bob's design would be considered a ULDB if it were a sailboat. There aren't many modern boats to compare her against for performance characteristics, but there are plenty from before the war.

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Cool as all those Herreshoff boats are, I think most designers would say they are from the era before anyone knew how to design a really good powerboat. And the weight-to-HP ratio of the powerplants was too poor to let anyone design a boat that is acceptable by today's standards.

 

BP's drawing looks more like a very elegant enlargement of a flat bottom skiff.

You think that powerboat design has actually advanced since Herreshoff? I think powerboat design has gone far astray since then.

Monster trucks and modern powerboat design make me froth at the mouth. They both thumb their nose at efficiency and the environment and modern powerboats are generally just incredibly ugly. More like shoe boxes with racing stripes.

Sorry, I don't have strong feelings on this subject....

Monster trucks aren't intended to be aesthetic, practical, or efficient. Theyre a totem symbol, a public declaration of the tribe the owner belongs to.

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The standard tender will either be a PT-11 Nester or a PT-11 Spear.

They weigh under 100 pounds each.

I can still easily handle such a tender even at my advanced age.....

And I will have a winch at the front of the cockpit

And given that I already own the Hadlock 23, she will be the alternate tender.

And you, sir, are the client.

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What kind of "tribe? would that be?

The "let's burn all these complex hydrocarbons that we might need in the future to make cool stuff that we might use to escape the prison of our gravity well in the name of personal power (or is it personal expression?)" tribe.

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Cool as all those Herreshoff boats are, I think most designers would say they are from the era before anyone knew how to design a really good powerboat. And the weight-to-HP ratio of the powerplants was too poor to let anyone design a boat that is acceptable by today's standards.

BP's drawing looks more like a very elegant enlargement of a flat bottom skiff.

You think that powerboat design has actually advanced since Herreshoff? I think powerboat design has gone far astray since then.

Monster trucks and modern powerboat design make me froth at the mouth. They both thumb their nose at efficiency and the environment and modern powerboats are generally just incredibly ugly. More like shoe boxes with racing stripes.

Sorry, I don't have strong feelings on this subject....

Your input on this project would be welcomed as always Russell.

 

 

I am totally in favor of the concept and aesthetics of what has been proposed. I think it would be a strong statement about efficiency and aesthetics.

Personally, I would like to see it built with wood/epoxy because it would make much less of an impact on landfill and could be almost as light while being so much warmer below. Long, narrow boats carry weight well, so a small weight penalty wouldn't be bad and you aren't competing in the AC. Carbon is cool, but wood is so much better in almost every way, in my obviously very humble opinion.

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Cool as all those Herreshoff boats are, I think most designers would say they are from the era before anyone knew how to design a really good powerboat. And the weight-to-HP ratio of the powerplants was too poor to let anyone design a boat that is acceptable by today's standards.

BP's drawing looks more like a very elegant enlargement of a flat bottom skiff.

 

You think that powerboat design has actually advanced since Herreshoff? I think powerboat design has gone far astray since then.

Monster trucks and modern powerboat design make me froth at the mouth. They both thumb their nose at efficiency and the environment and modern powerboats are generally just incredibly ugly. More like shoe boxes with racing stripes.

Sorry, I don't have strong feelings on this subject....

Your input on this project would be welcomed as always Russell.

I am totally in favor of the concept and aesthetics of what has been proposed. I think it would be a strong statement about efficiency and aesthetics.

Personally, I would like to see it built with wood/epoxy because it would make much less of an impact on landfill and could be almost as light while being so much warmer below. Long, narrow boats carry weight well, so a small weight penalty wouldn't be bad and you aren't competing in the AC. Carbon is cool, but wood is so much better in almost every way, in my obviously very humble opinion.

+++++++++++++++

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Cool as all those Herreshoff boats are, I think most designers would say they are from the era before anyone knew how to design a really good powerboat. And the weight-to-HP ratio of the powerplants was too poor to let anyone design a boat that is acceptable by today's standards.

BP's drawing looks more like a very elegant enlargement of a flat bottom skiff.

 

You think that powerboat design has actually advanced since Herreshoff? I think powerboat design has gone far astray since then.

Monster trucks and modern powerboat design make me froth at the mouth. They both thumb their nose at efficiency and the environment and modern powerboats are generally just incredibly ugly. More like shoe boxes with racing stripes.

Sorry, I don't have strong feelings on this subject....

Your input on this project would be welcomed as always Russell.

I am totally in favor of the concept and aesthetics of what has been proposed. I think it would be a strong statement about efficiency and aesthetics.

Personally, I would like to see it built with wood/epoxy because it would make much less of an impact on landfill and could be almost as light while being so much warmer below. Long, narrow boats carry weight well, so a small weight penalty wouldn't be bad and you aren't competing in the AC. Carbon is cool, but wood is so much better in almost every way, in my obviously very humble opinion.

Thanks Russell, I will give that some thought. We should visit together again soon.

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Kent:

I'll take your advice to heart.

I think what I have drawn now is closer to what you are suggesting. It looks right to my eye.

 

Love that German profile. How about the rake on the smoke stack!

Apparently they did not feel they needed much skeg at all. Long, skinny boats like to go in straight lines.

 

I need to do some research on rum runners. Anyone have have a link?

I would bet there is a book. Kim must have it. He has all the books.

I have no actual fact book to suggest but Clive Cussler's Bootlegger is a decent yarn with some period boats. http://www.goodreads.com/book/show/18079599-the-bootlegger

 

I always imagined if I was by some mistake of the gods made mega rich I'd want a motor yacht modeled after a pre WWI destroyer, as well as the ultimate old school ketch. I've lowered my expectations to wanting more days off.

 

Cool premise, can you design a hydraulic CB or drop down steering thruster to allow her to spin as well as fly straight? Of course it needs shallow draft otherwise, :)

 

Edit. Can you get an azipod to act like an outboard, and let it spin on the CB like a dinghy?

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Cool as all those Herreshoff boats are, I think most designers would say they are from the era before anyone knew how to design a really good powerboat. And the weight-to-HP ratio of the powerplants was too poor to let anyone design a boat that is acceptable by today's standards.

BP's drawing looks more like a very elegant enlargement of a flat bottom skiff.

You think that powerboat design has actually advanced since Herreshoff? I think powerboat design has gone far astray since then.

Monster trucks and modern powerboat design make me froth at the mouth. They both thumb their nose at efficiency and the environment and modern powerboats are generally just incredibly ugly. More like shoe boxes with racing stripes.

Sorry, I don't have strong feelings on this subject....

Your input on this project would be welcomed as always Russell.

I am totally in favor of the concept and aesthetics of what has been proposed. I think it would be a strong statement about efficiency and aesthetics.

Personally, I would like to see it built with wood/epoxy because it would make much less of an impact on landfill and could be almost as light while being so much warmer below. Long, narrow boats carry weight well, so a small weight penalty wouldn't be bad and you aren't competing in the AC. Carbon is cool, but wood is so much better in almost every way, in my obviously very humble opinion.

I agree. Perhaps strip-planked with 2 45s cold-molded on the exterior. Some carbon pieces might be used, like the cabin house, to reduce weight up high. That would also allow molding in special details.

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More efficient power voyaging?
Apr 11, 2012 BY DAVE GERR
http://www.oceannavigator.com/March-April-2012/More-efficient-power-voyaging/


The 1907 Bermuda Powerboat Race had two entries, Ailsa Craig and Idaho. Both were long, slender 60-footers. Ailsa Craig was powered by a single 65-hp gas engine, and Idaho by a 25-hp machine. You’d think that Idaho wouldn’t have stood much of chance — with that power difference — but there was a handicap formula that gave Idaho a reasonable shot to win on corrected time. Nevertheless — in this case — Craig (skippered by none other than Day himself) did win. Winning time was two days, 16 hours, and 20 minutes — a nice, leisurely ocean passage.
[...]
In 1912, Dream — a 40-footer with just a nine-foot beam and a single 16-hp engine (yep, only 16 horses) — beat its 50-foot competitor, the 25-hp Kathemma. These power ratings give one indication of the reason it’s such a pity that the Bermuda Powerboat Race has been forgotten. Ailsa Craig, with 65-hp (the most power entered in the race’s history), consumed about four and a half gallons per hour, burning up a total of 290 gallons on the entire trip!
[...]
A modern cruising Ailsa Craig, around 13,700 pounds, would be fitted with, say, a single 300-hp diesel or twin 150s. Cruise would be around 13 knots making the trek from New York to Bermuda in just over two days. This would cost you no more than 520 gallons of fuel for the hop over...
[...]
Almost any knowledgeable designer will tell you that just three basic things make for efficiency:
1) Going slower
2) Long, slender hulls
3) An efficient propulsion package
I’d like to make this seem more complicated, but that’s it. Yes, you can improve efficiency with tweaks and adjustments to the hull form. Also, certainly, the hull form must be properly matched to the intended operational speed, but hull-shape refinements add small percentages to efficiency, the three items above are — by a good margin — the overriding factors.


Stock Photo - Powerboat Ailsa Craig winning off Bermuda

powerboat-ailsa-craig-winning-off-bermud

 

https://books.google.com/books?id=yz1AK9gyOIEC&pg=PA19&lpg=PA19&dq=Ailsa+Craig+yacht+bermuda+race&source=bl&ots=2PCu0y5jcD&sig=YN0r7zg5x3bSgoy_wOz5vPNPbgk&hl=en&sa=X&ved=0ahUKEwjfnruPkNDSAhUD-GMKHaOIAs8Q6AEIJjAE#v=onepage&q=Ailsa%20Craig%20yacht%20bermuda%20race&f=true

 

Ailsa_Craig_desc.png

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Kent:

I'll take your advice to heart.

I think what I have drawn now is closer to what you are suggesting. It looks right to my eye.

 

Love that German profile. How about the rake on the smoke stack!

Apparently they did not feel they needed much skeg at all. Long, skinny boats like to go in straight lines.

 

I need to do some research on rum runners. Anyone have have a link?

I would bet there is a book. Kim must have it. He has all the books.

Relative to the amount of top sides, those old torpedo boats have more hull underwater then your high tech, light weight hull which appears to have minimal hull underwater...
The torpedo boats had to carry a couple of triple-expansion steam engines, boilers full of water, several tons of coal, several torpedos, and several deck guns and shells. No shit they needed a lot of displacement to carry all that weight. They were also about 10 knots faster than battleships of the period, despite having about a third the length. They looked cool, also. :)

 

Kocher,

Yeah, no kidding! Torpedo Boats were generally the most heavily armed per ton of displacement of any Naval Warship...All I meant by that comment was that they maybe didn't need a skeg or keel in any way, as they had enough of that long narrow (slab sided) hull immersed that they got all the directional stability they needed as a result (or maybe too much, hence the forward rudder/fin). Bob's design for Kim, being so much lighter relatively, with less underbody immersed, might (I'm not an Designer, NA, or anything of the sort, just an "observer') benefit from some skeg/fin etc.

Crash

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Kent:

I'll take your advice to heart.

I think what I have drawn now is closer to what you are suggesting. It looks right to my eye.

 

Love that German profile. How about the rake on the smoke stack!

Apparently they did not feel they needed much skeg at all. Long, skinny boats like to go in straight lines.

 

I need to do some research on rum runners. Anyone have have a link?

I would bet there is a book. Kim must have it. He has all the books.

Relative to the amount of top sides, those old torpedo boats have more hull underwater then your high tech, light weight hull which appears to have minimal hull underwater...
The torpedo boats had to carry a couple of triple-expansion steam engines, boilers full of water, several tons of coal, several torpedos, and several deck guns and shells. No shit they needed a lot of displacement to carry all that weight. They were also about 10 knots faster than battleships of the period, despite having about a third the length. They looked cool, also. :)

Kocher,

Yeah, no kidding! Torpedo Boats were generally the most heavily armed per ton of displacement of any Naval Warship...All I meant by that comment was that they maybe didn't need a skeg or keel in any way, as they had enough of that long narrow (slab sided) hull immersed that they got all the directional stability they needed as a result (or maybe too much, hence the forward rudder/fin). Bob's design for Kim, being so much lighter relatively, with less underbody immersed, might (I'm not an Designer, NA, or anything of the sort, just an "observer') benefit from some skeg/fin etc.

Crash

I agree, Bob-Kim's Turbinia is going to need a skeg. This would also add a good deal of strength to a long, skinny, lightly built,

hull.

 

As an aside....here's another Herreshoff, this one by Sidney:

5cwntl.jpg

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I know this has been commented on before, I used to own a 45 ft powerboat of a similar design foam core construction and very light. Docking in any breeze was extremely difficult. I always wondered if it would be possible to construct a ballast tank in the bow with a Venturi system like a dinghy that flooded going slow and emptied under power to stop the bow from blowing around when going slow

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Too much crap in the water around here- sightlines from the helm as drawn will leave you blind for the 100-150' in front of the boat. Older eyes don't see the stuff until you're almost on top of it, and at the design speeds you're talking about (16 knots) a hundred feet disappears in less than 4 seconds. Yes, it looks low and sexy but I would move the seated helmsman's head up.... or the bow down a bit. Check the line of sight for Mr. Perry's design verses the other examples of similar boats shown.

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Cool as all those Herreshoff boats are, I think most designers would say they are from the era before anyone knew how to design a really good powerboat. And the weight-to-HP ratio of the powerplants was too poor to let anyone design a boat that is acceptable by today's standards.

BP's drawing looks more like a very elegant enlargement of a flat bottom skiff.

You think that powerboat design has actually advanced since Herreshoff? I think powerboat design has gone far astray since then.

Monster trucks and modern powerboat design make me froth at the mouth. They both thumb their nose at efficiency and the environment and modern powerboats are generally just incredibly ugly. More like shoe boxes with racing stripes.

Sorry, I don't have strong feelings on this subject....

Your input on this project would be welcomed as always Russell.

 

 

I am totally in favor of the concept and aesthetics of what has been proposed. I think it would be a strong statement about efficiency and aesthetics.

Personally, I would like to see it built with wood/epoxy because it would make much less of an impact on landfill and could be almost as light while being so much warmer below. Long, narrow boats carry weight well, so a small weight penalty wouldn't be bad and you aren't competing in the AC. Carbon is cool, but wood is so much better in almost every way, in my obviously very humble opinion.

 

 

Is it a bit early to decide what will happen to this boat after its service in the Zombie Fleet?

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My thoughts on some of the suggestions:

I prefer carbon. Kim is talking to Jim Betts. Betts builds carbon boats.

If would composite is the chosen method we will need a different yard.. I have done several boats with Jesperesens. They would be a very good choice. But the required budget would almost double. Small consideration. Worth discussing with Betts.

Amati's suggestion of turning the engine box into settees is one I have also had but first I need to know what engine it is and how much box I need to accommodate it. First things first. Good idea though.

If sight lines forward are a concern, and they are for me, then I suggest Kim goes with the fly bridge version that I originally drew. 98% of the power boats in the PNW have FB's. Some very nice Monk cruisers do not and they survive just fine. As drawn now the sight line fro the inside helm allows you to see 66'2" in front of the boat, not the 100 to 150 claimed. Fly bride reduces the "blind spot" to 22'5". People make the mistake of assuming you look over the tip of the bow. You don't.

Semi: the hull form has a lot of shape. I am not at all inclined to post the hulls lines yet but if I did you would see anything but a "fat bottomed skiff".

 

Many thanks for all the energy the group is putting into this.

I agree very much with the comment Russell made about progress in powerboat design. Most of that "progress" has been about shoving a bigger and bigger box through the water with bigger and bigger engines.

 

Note fly bridge:

PB%20FB%203_zps2l3g3z64.jpg

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My thoughts on some of the suggestions:

I prefer carbon. Kim is talking to Jim Betts. Betts builds carbon boats.

If would [wood] composite is the chosen method we will need a different yard.. I have done several boats with Jesperesens. They would be a very good choice. But the required budget would almost double. Small consideration. Worth discussing with Betts.

[...snip...]

 

Hard to believe that building in carbon is cheaper than wood?

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Cool as all those Herreshoff boats are, I think most designers would say they are from the era before anyone knew how to design a really good powerboat. And the weight-to-HP ratio of the powerplants was too poor to let anyone design a boat that is acceptable by today's standards.

BP's drawing looks more like a very elegant enlargement of a flat bottom skiff.

You think that powerboat design has actually advanced since Herreshoff? I think powerboat design has gone far astray since then.

Monster trucks and modern powerboat design make me froth at the mouth. They both thumb their nose at efficiency and the environment and modern powerboats are generally just incredibly ugly. More like shoe boxes with racing stripes.

Sorry, I don't have strong feelings on this subject....

Your input on this project would be welcomed as always Russell.

 

 

I am totally in favor of the concept and aesthetics of what has been proposed. I think it would be a strong statement about efficiency and aesthetics.

Personally, I would like to see it built with wood/epoxy because it would make much less of an impact on landfill and could be almost as light while being so much warmer below. Long, narrow boats carry weight well, so a small weight penalty wouldn't be bad and you aren't competing in the AC. Carbon is cool, but wood is so much better in almost every way, in my obviously very humble opinion.

 

+1 :) You've cheered me up, I also despair of our wasteful approach to life.

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Blitz:

I don't think so unfortunately. The clear coated carbon would requite too much maintenance. I don't think that's what Kim has in mind. But, you never know. It would be spectacular.

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1937 powerboat:

1043572_0_160820101345_1.jpg&w=924&h=693

Specs
Builder: Elco

Dimensions
LOA: 53 ft 0 in
Beam: 14 ft 6 in
Maximum Draft: 3 ft 6 in

Engines
Total Power: 250 HP

Engine 1:
Engine Brand: Detroit Diesel
Engine Model: 453
Engine Type: Inboard
Engine/Fuel Type: Diesel
Location: Port
Engine Power: 125 HP
Engine 2:
Engine Brand: Detroit Diesel
Engine Model: 453
Engine Type: Inboard
Engine/Fuel Type: Diesel
Location: Starboard
Engine Power: 125 HP

Cruising Speed: 10 mph
Maximum Speed: 12 mph

(guessing 3-4-5 GPH??)

 

Modern Powerboat - if my dog was this ugly I would shave his ass and make him walk backwards.

5947600_20160923055640401_1_XLARGE.jpg&w

 

Engines

Total Power: 1450 HP

Engine 1:
Engine Brand: Volvo IPS
Engine Model: 2 x Volvo IPS 950 (725hp D11)
Engine Type: Inboard
Engine/Fuel Type: Diesel
Drive Type: Pod Drive
Engine Power: 725 HP
Engine 2:
Engine Brand: Volvo IPS
Engine Model: 2 x Volvo IPS 950 (725hp D11)
Engine Type: Inboard
Engine/Fuel Type: Diesel
Drive Type: Pod Drive
Engine Power: 725 HP

Cruising Speed: 23 knots @ 200 RPM
Maximum Speed: 30 knots

 

(guessing 130-180 GPH??)

 

Progress?

I think not.

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FYI:

 

There still is a powerboat race to Bermuda.

 

http://www.boatingmag.com/how-to/conquering-bermuda-challenge

 

Interesting. Under "Boats" ( http://www.boatingmag.com/boats ), I see the MJM 40Z - I like that boat! At ~13 knots (12.56), it consumes fuel at almost exactly the same rate (4.9 GPH, 1.26 nmpg) as the 1907 65-hp Ailsa Craig, which "consumed about four and a half gallons per hour". Let's give credit where it's due, gentlemen! Modern, efficient power boat that looks great and is capable of nearly 40 knots when pushed.

 

http://www.boatingmag.com/mjm-yachts-40z

 

mjm40zspecsb.jpg?itok=1qDS0pLa&fc=50,50

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Kent:

 

Interesting contrast.

 

That Elco is a beauty. It has about for more feet of beam than I have. This makes a twin engine installation in Kim's boat a challenge. For simplicity sake I'll stick with one engine.

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Blitz:

I don't think so unfortunately. The clear coated carbon would requite too much maintenance. I don't think that's what Kim has in mind. But, you never know. It would be spectacular.

I can't imagine how big a pain in the but stripping the clear coat off every 4-5 years and recoating would be. Talk about unforced errors.

 

If you want to have the carbon look, you could get a vinyl wrap with the carbon texture printed on it. It looks like clear coat carbon but wears like any vinyl wrap, meaning you probably need to replace it every 4-5 years, but it's easy to do. Just pull off the old and reapply. Cost wise it's probably far less lifetime cost than even paint.

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More like this?

4922210_20150122103046669_1_XLARGE.jpg&w

 

Boat Name
Blue Mist

Dimensions
LOA: 52 ft 0 in
Beam: 11 ft 6 in

Engines
Total Power: 152 HP

Engine 1:
Engine Brand: Cummins
Engine Model: 6BT 5.9
Engine Type: Inboard
Engine/Fuel Type: Diesel
Engine Power: 152 HP

Kent:

 

Interesting contrast.

 

That Elco is a beauty. It has about for more feet of beam than I have. This makes a twin engine installation in Kim's boat a challenge. For simplicity sake I'll stick with one engine.

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My thoughts on some of the suggestions:

I prefer carbon. Kim is talking to Jim Betts. Betts builds carbon boats.

If would composite is the chosen method we will need a different yard.. I have done several boats with Jesperesens. They would be a very good choice. But the required budget would almost double. Small consideration. Worth discussing with Betts.

Amati's suggestion of turning the engine box into settees is one I have also had but first I need to know what engine it is and how much box I need to accommodate it. First things first. Good idea though.

If sight lines forward are a concern, and they are for me, then I suggest Kim goes with the fly bridge version that I originally drew. 98% of the power boats in the PNW have FB's. Some very nice Monk cruisers do not and they survive just fine. As drawn now the sight line fro the inside helm allows you to see 66'2" in front of the boat, not the 100 to 150 claimed. Fly bride reduces the "blind spot" to 22'5". People make the mistake of assuming you look over the tip of the bow. You don't.

Semi: the hull form has a lot of shape. I am not at all inclined to post the hulls lines yet but if I did you would see anything but a "fat bottomed skiff".

 

Many thanks for all the energy the group is putting into this.

I agree very much with the comment Russell made about progress in powerboat design. Most of that "progress" has been about shoving a bigger and bigger box through the water with bigger and bigger engines.

 

Note fly bridge:

PB%20FB%203_zps2l3g3z64.jpg

Bob's "fly bridge" is still under serious consideration.

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My thoughts on some of the suggestions:

I prefer carbon. Kim is talking to Jim Betts. Betts builds carbon boats.

If would [wood] composite is the chosen method we will need a different yard.. I have done several boats with Jesperesens. They would be a very good choice. But the required budget would almost double. Small consideration. Worth discussing with Betts.

[...snip...]

 

Hard to believe that building in carbon is cheaper than wood?

 

At Jespersson's it would be absolutely perfect in wood, but more money.

 

Schooner Creek? Steve has handed over ownership. Bunch of phenomenally talented guys.

 

Hagadone does really beautiful work, but can be a bit heavy at times. I have no idea how you'd get her over to the wet side.

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The 16 knot cruise speed came from Paul Bieker, who once suggested to me that 16 was a very efficient cruise speed for a powerboat.

 

After 18 years and well over 7000 crossing of Puget Sound during my former daily commute, I gradually slowed down from an average of 20-25 knots to more like 15-18 knots. The extra time spend going slower was rewarded with less noise, less vibration, better fuel economy and generally a more comfortable ride. And now as an old retired guy I have the extra time.

 

Nothing about this project is set (except Bob, he is my yacht designer and the design vision that this will be the FRANCIS LEE of powerboats.) We are still in the exploratory/investigation stage where I am considering every idea that comes my way.

 

I appreciate the various suggestions and ideas (even the nutty ones, this is suppose to be fun).

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My thoughts on some of the suggestions:

I prefer carbon. Kim is talking to Jim Betts. Betts builds carbon boats.

If would [wood] composite is the chosen method we will need a different yard.. I have done several boats with Jesperesens. They would be a very good choice. But the required budget would almost double. Small consideration. Worth discussing with Betts.

[...snip...]

 

Hard to believe that building in carbon is cheaper than wood?

At Jespersson's it would be absolutely perfect in wood, but more money.

 

Schooner Creek? Steve has handed over ownership. Bunch of phenomenally talented guys.

 

Hagadone does really beautiful work, but can be a bit heavy at times. I have no idea how you'd get her over to the wet side.

Jim Betts, Eric Jespersen, Steve White, Lynn Bowser, they are all great builders, I would be comfortable with any of them. I have not yet met the people who took over Schooner Creek, I will have to schedule a road trip.

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Interesting. Under "Boats" ( http://www.boatingmag.com/boats ), I see the MJM 40Z - I like that boat! At ~13 knots (12.56), it consumes fuel at almost exactly the same rate (4.9 GPH, 1.26 nmpg) as the 1907 65-hp Ailsa Craig, which "consumed about four and a half gallons per hour". Let's give credit where it's due, gentlemen! Modern, efficient power boat that looks great and is capable of nearly 40 knots when pushed.

 

http://www.boatingmag.com/mjm-yachts-40z

 

mjm40zspecsb.jpg

First half, 40z in rough seas, narrated by Bob Johnstone. Some commercial crap in the middle, then the construction process in the second half:

 

 

Here's one showing the interior:

 

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Instead of a flying bridge (and dual steering, controls, electronics) how about just a sliding moon roof over the pilot house? Do it just like a car.... Opening windshield too.

Edit: if the pilot house is as small as BPerry drew, then slide the whole roof or even house back to open.

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The 16 knot cruise speed came from Paul Bieker, who once suggested to me that 16 was a very efficient cruise speed for a powerboat.

 

After 18 years and well over 7000 crossing of Puget Sound during my former daily commute, I gradually slowed down from an average of 20-25 knots to more like 15-18 knots. The extra time spend going slower was rewarded with less noise, less vibration, better fuel economy and generally a more comfortable ride. And now as an old retired guy I have the extra time.

 

Nothing about this project is set (except Bob, he is my yacht designer and the design vision that this will be the FRANCIS LEE of powerboats.) We are still in the exploratory/investigation stage where I am considering every idea that comes my way.

 

I appreciate the various suggestions and ideas (even the nutty ones, this is suppose to be fun).

Well Kim, since you asked... ;o)

 

I'd propose a re-think of the turtleback foredeck. One of the Streams' great pleasures over our all-too-brief summer is to put a couple of comfy chairs up on the foredeck in the late afternoon and enjoy a bottle of wine as the light slowly fades. I don't know if you and SWMBO like the same but that'd be difficult with a turtleback. Seems a shame to have form (dare I say it?) trump function with so much prime real estate.

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Cool as all those Herreshoff boats are, I think most designers would say they are from the era before anyone knew how to design a really good powerboat. And the weight-to-HP ratio of the powerplants was too poor to let anyone design a boat that is acceptable by today's standards.

 

BP's drawing looks more like a very elegant enlargement of a flat bottom skiff.

 

You think that powerboat design has actually advanced since Herreshoff? I think powerboat design has gone far astray since then.

Monster trucks and modern powerboat design make me froth at the mouth. They both thumb their nose at efficiency and the environment and modern powerboats are generally just incredibly ugly. More like shoe boxes with racing stripes.

Sorry, I don't have strong feelings on this subject....

 

 

 

The WWII PT boats were pretty brutal on their crews, but I'm pretty sure they performed better in a sea than the WWI versions. Neither was especially effective as a weapon platform.

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Here is a Bolger design for a somewhat similar spec, although this one was for lakes and canals in NY, so rough water performance was not as big an issue.

 

SamClyde

This is the Samuel Clyde design. It's 31' LOA, and 8000lbs displacement. On sea trials, she made 23 mph (20 knots) with a 160 hp Mercuriser-Chevrolet I/O drive. Bolger expected more speed, but he usually under-estimated HP requirements.
Somewhere above, Whispers made a comment about difficulty docking a light boat in a cross wind. Here is what Bolger had to say:
Aside from the slightly disappointing speed, which did not matter much since she had 7 mph in hand above here designed cruising speed, the only complaint about the Clyde is that she blows away like a dry paper bag in beam winds. Not only is hull very shallow (which is why she's as fast as she is), but its sectional shape drives side-ways with exceptional ease. The cure would be a centerboard, but in very fast boats it's tricky (though possible) to prevent high water pressure from building up inside the trunk. The pressure can be relieved by a powerful spurt out of the hoist opening.

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The 16 knot cruise speed came from Paul Bieker, who once suggested to me that 16 was a very efficient cruise speed for a powerboat.

After 18 years and well over 7000 crossing of Puget Sound during my former daily commute, I gradually slowed down from an average of 20-25 knots to more like 15-18 knots. The extra time spend going slower was rewarded with less noise, less vibration, better fuel economy and generally a more comfortable ride. And now as an old retired guy I have the extra time.

Nothing about this project is set (except Bob, he is my yacht designer and the design vision that this will be the FRANCIS LEE of powerboats.) We are still in the exploratory/investigation stage where I am considering every idea that comes my way.

I appreciate the various suggestions and ideas (even the nutty ones, this is suppose to be fun).

Well Kim, since you asked... ;o)

I'd propose a re-think of the turtleback foredeck. One of the Streams' great pleasures over our all-too-brief summer is to put a couple of comfy chairs up on the foredeck in the late afternoon and enjoy a bottle of wine as the light slowly fades. I don't know if you and SWMBO like the same but that'd be difficult with a turtleback. Seems a shame to have form (dare I say it?) trump function with so much prime real estate.

Forward cockpit........

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The 16 knot cruise speed came from Paul Bieker, who once suggested to me that 16 was a very efficient cruise speed for a powerboat.

[...snip...]

 

I find it interesting that, above ten knots, the MJM 40z gets the same optimum NMPG (nautical miles per gallon) from ~13 knots up to ~21 knots (1.28 nmpg). And it doesn't drop much until you get to 30+ knots! It has 11+ times the horsepower of Ailsa Craig, yet it's a near match in fuel consumption at 12.56 knots.

 

Is there any other modern power boat (monohull) this size with similar efficiency? And speed potential, comfort and price?

 

 

Here is a Bolger design for a somewhat similar spec, although this one was for lakes and canals in NY, so rough water performance was not as big an issue.

 

This is the Samuel Clyde design. It's 31' LOA, and 8000lbs displacement. On sea trials, she made 23 mph (20 knots) with a 160 hp Mercuriser-Chevrolet I/O drive. Bolger expected more speed, but he usually under-estimated HP requirements.

[...snip...]

Direct link to a more readable image: http://forums.sailinganarchy.com/uploads/gallery/album_727/gallery_5724_727_196566.jpg

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I've been doing much more thinking about a 'retirement' power cruiser for the PNW of late--this despite just getting a new boat that the Admiral thinks is the 'Last One'.

 

While I lean toward a narrow powerboat, I'm willing to entertain a monohull. I share Kim's preferences for long, lean and light. However, someone upthread mentioned that this looked a lot like a 'flat bottom' boat, without chines of course.

 

That 'flat bottom' comment gives me pause. Light weight, for the most part, is less expensive since boats ultimately cost by the pound. (Extreme light weight starts the price curve back up again of course) However, despite being narrow and having a narrow flat bottom, I'd think that the extreme shoal draft of the hull and the overall length, necessarily means that there will be days where punching into a head sea will be bone jarring. I think the efficiency comes more from being narrow than just being light so I'd lean toward a bit deeper forefoot and subsequently heavier overall displacement. My guess is that ultimate comfort is also a function of displacement and that 'my' boat would be somewhat heavier with a deeper hull.

 

Kim/Bob- I'm sure you're way ahed of me but I'd be curious as to whether you think the narrowness will render this concern moot or whether the overall PNW conditions just don't make this concern a priority. Going up North of Vancouver Island would shift that latter concern I'd think.

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I've been doing much more thinking about a 'retirement' power cruiser for the PNW of late--this despite just getting a new boat that the Admiral thinks is the 'Last One'.

 

While I lean toward a narrow powerboat, I'm willing to entertain a monohull. I share Kim's preferences for long, lean and light. However, someone upthread mentioned that this looked a lot like a 'flat bottom' boat, without chines of course.

 

That 'flat bottom' comment gives me pause. Light weight, for the most part, is less expensive since boats ultimately cost by the pound. (Extreme light weight starts the price curve back up again of course) However, despite being narrow and having a narrow flat bottom, I'd think that the extreme shoal draft of the hull and the overall length, necessarily means that there will be days where punching into a head sea will be bone jarring. I think the efficiency comes more from being narrow than just being light so I'd lean toward a bit deeper forefoot and subsequently heavier overall displacement. My guess is that ultimate comfort is also a function of displacement and that 'my' boat would be somewhat heavier with a deeper hull.

 

Kim/Bob- I'm sure you're way ahed of me but I'd be curious as to whether you think the narrowness will render this concern moot or whether the overall PNW conditions just don't make this concern a priority. Going up North of Vancouver Island would shift that latter concern I'd think.

I think most Australian Development Dinghy Sailors would disagree about a deeper forefoot necessarily being heavier- ever sailed a Tasar upwind in a chop

post-906-0-71101500-1489346319_thumb.jpg

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I can remember the boat type name, and can't find in in a Google search, but many years ago Wooden Boat did an article on a powerboat type that had a much deepened forefoot that flattened quickly, such that the C/L in profile view had a pronounced hook. Buttocks were more normal. Said to cut through a chop nicely for a shallow Vee hull in a moderate speed planing hull. It was a very interesting shape, but I can't find it again.

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I can remember the boat type name, and can't find in in a Google search, but many years ago Wooden Boat did an article on a powerboat type that had a much deepened forefoot that flattened quickly, such that the C/L in profile view had a pronounced hook. Buttocks were more normal. Said to cut through a chop nicely for a shallow Vee hull in a moderate speed planing hull. It was a very interesting shape, but I can't find it again.

The Axebow. Patented by a European guy at/for Damen.

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Cool as all those Herreshoff boats are, I think most designers would say they are from the era before anyone knew how to design a really good powerboat. And the weight-to-HP ratio of the powerplants was too poor to let anyone design a boat that is acceptable by today's standards.

 

BP's drawing looks more like a very elegant enlargement of a flat bottom skiff.

You think that powerboat design has actually advanced since Herreshoff? I think powerboat design has gone far astray since then.

Monster trucks and modern powerboat design make me froth at the mouth. They both thumb their nose at efficiency and the environment and modern powerboats are generally just incredibly ugly. More like shoe boxes with racing stripes.

Sorry, I don't have strong feelings on this subject....

 

The WWII PT boats were pretty brutal on their crews, but I'm pretty sure they performed better in a sea than the WWI versions. Neither was especially effective as a weapon platform.

Both were suited to their use. The British and German torpedo boats were better sea boats, able to handle North Sea conditions. The U.S. PT boats were better suited to relatively calmer seas and shallow waters of South Pacific. US Boats were also intended to be cheaply and quickly built, and utilized aircraft gasoline which was in good supply.

IIRC, only the Italians had any success actually sinking a capital ship with torpedo boats, but the others were effective in disrupting enemy formations. US was badly hurt by defective torpedos in the early years. US boats were very useful in picking up downed pilots and inserting/withdrawing coast watchers, and with heavier guns were useful Gunboats against coastal barge traffic.

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I can remember the boat type name, and can't find in in a Google search, but many years ago Wooden Boat did an article on a powerboat type that had a much deepened forefoot that flattened quickly, such that the C/L in profile view had a pronounced hook. Buttocks were more normal. Said to cut through a chop nicely for a shallow Vee hull in a moderate speed planing hull. It was a very interesting shape, but I can't find it again.

The Axebow. Patented by a European guy at/for Damen.
thankyou very much. I was absolutely drawing a blank.

 

Edit: That wasn't quite what I recall, but similar concept. Boats I remember had a more rounded forefoot, similar to William Atkin's Ripalong...

https://m.facebook.com/home.php#!/richiehavens/photos/pcb.10154444042801134/10154444020996134/?type=3&source=48&refid=28&_ft_=qid.6396494739045837649%3Amf_story_key.-8369351998196327202%3Atop_level_post_id.10154444042801134

Difference was that the hook was further forward, such that the aft sections were a constant Deadrise with straight and parallel buttocks.

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Pilot boats seem to be quite good at cutting through the chop. At least as seen from outside!

 

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Cool as all those Herreshoff boats are, I think most designers would say they are from the era before anyone knew how to design a really good powerboat. And the weight-to-HP ratio of the powerplants was too poor to let anyone design a boat that is acceptable by today's standards.

 

BP's drawing looks more like a very elegant enlargement of a flat bottom skiff.

You think that powerboat design has actually advanced since Herreshoff? I think powerboat design has gone far astray since then.

Monster trucks and modern powerboat design make me froth at the mouth. They both thumb their nose at efficiency and the environment and modern powerboats are generally just incredibly ugly. More like shoe boxes with racing stripes.

Sorry, I don't have strong feelings on this subject....

 

The WWII PT boats were pretty brutal on their crews, but I'm pretty sure they performed better in a sea than the WWI versions. Neither was especially effective as a weapon platform.

Both were suited to their use. The British and German torpedo boats were better sea boats, able to handle North Sea conditions. The U.S. PT boats were better suited to relatively calmer seas and shallow waters of South Pacific. US Boats were also intended to be cheaply and quickly built, and utilized aircraft gasoline which was in good supply.

IIRC, only the Italians had any success actually sinking a capital ship with torpedo boats, but the others were effective in disrupting enemy formations. US was badly hurt by defective torpedos in the early years. US boats were very useful in picking up downed pilots and inserting/withdrawing coast watchers, and with heavier guns were useful Gunboats against coastal barge traffic.

 

Kocher has it right. As a weapons platform vs. capital ships, PTs, MTBs, and S-Boats were not particularly effective. As scouts, radar pickets, rescue boats, insertion and extraction boats, they were highly effective. Also they were very effective once up gunned...and all were as the war progressed, against coastal trade..barges, lighters, small coastal freighters, etc. Anywhere you didn't want to hazard a Destroyer (shallow, close to shore) they more than earned their money...

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First off, the turtle deck fore deck stays. Debate the details all you like I want full control over hull form and aesthetics.

 

Veegs:

Pause away!

This is NOT a "flat bottomed" boat. I have no idea where that came from. There is not a flat section anywhere on the bottom. There is a lot of shape to this hull form.

The bow is very fine and I have no concerns about it at all going into a chop. Depth of forefoot is just one view of a 3D shape. Yes, I have owned and sailed a Tasar upwind in a chop. Fabulous boat. As now drawn I have soft V sections in the bow that are giving me the Cp and LCB I am after. But as I have said a few times, we are still in preliminary design stage.

 

I think performance in a steep chop is paramount around here. Steep chop defines our dominant condition when there is a breeze. That is exactly the condition I have at the top of my list. But consider this, as drawn my half angle of entry is 9 degrees! "What chop?"` Do I expect the boat to perform in a chop like a 50,000 lb. trawler yacht? Hardly. Lack of rocker, much like Frankie or any ULDB has, means we will pull the bow clear of the water from time to time. The trick is to get the bow to go back into the water with little fuss. Our bow is like a knife.

 

The Atkin boat that Kocher posted is in some ways kind of like a longitudinally "squashed" version of what I have although my bow sections are softer and my bilge turn aft firmer.

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Yves-Marie:

Why two boards? Are they intended to act as stands when the boat takes to the mud.

Nice design BTW.

 

Thank you bob.

About the G.L.C

The client ambition is to do the "Great Loop Cruise" with the occasional mud bank indeed.

post-32003-0-76115200-1489355259_thumb.jpg post-32003-0-40357900-1489355295_thumb.jpg

About Rhum Runner11.

Found derelict upstate N-Y. Rebuilt with plywood and glass.

post-32003-0-29791500-1489355733_thumb.jpg

post-32003-0-66119700-1489355805_thumb.jpg

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First off, the turtle deck fore deck stays. Debate the details all you like I want full control over hull form and aesthetics.

 

Veegs:

Pause away!

This is NOT a "flat bottomed" boat. I have no idea where that came from. There is not a flat section anywhere on the bottom. There is a lot of shape to this hull form.

The bow is very fine and I have no concerns about it at all going into a chop. Depth of forefoot is just one view of a 3D shape. Yes, I have owned and sailed a Tasar upwind in a chop. Fabulous boat. As now drawn I have soft V sections in the bow that are giving me the Cp and LCB I am after. But as I have said a few times, we are still in preliminary design stage.

 

I think performance in a steep chop is paramount around here. Steep chop defines our dominant condition when there is a breeze. That is exactly the condition I have at the top of my list. But consider this, as drawn my half angle of entry is 9 degrees! "What chop?"` Do I expect the boat to perform in a chop like a 50,000 lb. trawler yacht? Hardly. Lack of rocker, much like Frankie or any ULDB has, means we will pull the bow clear of the water from time to time. The trick is to get the bow to go back into the water with little fuss. Our bow is like a knife.

 

The Atkin boat that Kocher posted is in some ways kind of like a longitudinally "squashed" version of what I have although my bow sections are softer and my bilge turn aft firmer.

You already have full control over the hull form, I was simply offering a suggestion for discussion in the spirit of the WLYDO.

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I've been doing much more thinking about a 'retirement' power cruiser for the PNW of late--this despite just getting a new boat that the Admiral thinks is the 'Last One'.

 

While I lean toward a narrow powerboat, I'm willing to entertain a monohull. I share Kim's preferences for long, lean and light. However, someone upthread mentioned that this looked a lot like a 'flat bottom' boat, without chines of course.

 

That 'flat bottom' comment gives me pause. Light weight, for the most part, is less expensive since boats ultimately cost by the pound. (Extreme light weight starts the price curve back up again of course) However, despite being narrow and having a narrow flat bottom, I'd think that the extreme shoal draft of the hull and the overall length, necessarily means that there will be days where punching into a head sea will be bone jarring. I think the efficiency comes more from being narrow than just being light so I'd lean toward a bit deeper forefoot and subsequently heavier overall displacement. My guess is that ultimate comfort is also a function of displacement and that 'my' boat would be somewhat heavier with a deeper hull.

 

Kim/Bob- I'm sure you're way ahed of me but I'd be curious as to whether you think the narrowness will render this concern moot or whether the overall PNW conditions just don't make this concern a priority. Going up North of Vancouver Island would shift that latter concern I'd think.

 

Heavy and narrow makes a VERY comfortable boat that is quick, if you add enough waterline. Just don't ask it to plane.

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Yves-Marie:

That RHUM RUNNER II fore foot is about what was suggested earlier with fore foot depth carried to the max. I kind of like it. It would move some volume forward. Maybe I'll see what it looks like on my hull. It would mean adding 8" of depth forward. That's pretty radical. In carbon it would require a "false stem" piece kind of like we have in the CF cutters. Which also acts as a crash box and in this case that may not be a bad thing.

 

Maybe I'll try an additional 4" of forefoot depth and see what the numbers do. Start there anyway.

Some times someone will suggest something and I'll blow the suggestion off. Later I find myself going back to the suggestion and pondering the change. I've pondered this for 6 hours. Might also help with keeping the bow from blowing down when docking.

 

Don't care for that spray knocker running all the way to the stem. Looks clunky.

 

Ok, I dropped the forefoot. From about Sta. 3.8, max hull depth, to the stem the profile is now near horizontal. I filled out the sections just a wee bit to avoid that anemic look you see in the sections of RHUM RUNNER II. The change added 35 lbs. of displ and do not change the Cp enough to register. Booger. I'll stare at it a while. For now I kind of like the look. It sharpens the knife!

 

Fiddled around a bit more and got the Cp from.672 to .674. Whoop de doo!

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