Speed Dream 27 Prototype

[fng]

Did a canting keel job a while back where the designers drew some fancy hollows in the hull fairings to try and get 55 degrees cant. It looked great on the plans out side, until I asked what about the keel clearance inside the boat.
This thing looks the same if the renders are anything to go by

[Doug Lord]

Originally Posted by fng

Did a canting keel job a while back where the designers drew some fancy hollows in the hull fairings to try and get 55 degrees cant. It looked great on the plans out side, until I asked what about the keel clearance inside the boat.
This thing looks the same if the renders are anything to go by

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Gee, Wild Oats and several other Reichel-Pugh CBTF boats made 55 degrees.
Haven't heard much lately about "Q" going for 90 degrees......

[Andy]

This project is COOL as fcuk. BUT, 1000 miles in a day and 50 knots? How about a little less 'marketing' and a little more boat building/proof of design? I have a lot of time for Vlad's designs, loved Fazisi when she arrived on the scene and would have been interesting to see how she would have gotten on with a proper budget. But the claims being made here are setting someone up for a lot of egg on their face. The design aspects are very interesting, but not so much discussion on them so far. So I'd like to ask Vlad:

Do you forsee any problems with balance as the keel dips in and out of the waves? Seems to me like the difference of the drag of the bulb in air then water then air then water etc is going to play havoc with the yaw balance of the boat?

The permanent step would seem to be a big drag at lower speeds...will this present a problem with attaining the higher speeds envisaged by causing too much drag as the boat begins to accelerate? In tyhis respect, wouldn't a retractable step work better?

I'll have other questions soon. Just please less propaganda and more technical details...

Edit: Have you got a polar diagram we could look at? And how about some chat about your speed prediction methodologies?

[Steve Clark]

I have some concerns here as well. Steps work well to make a long boat think it is two short boats. Which when planing above a certain speed id a good thing. But otherwise is a pretty big problem. The only stepped sailboat hulls that have been successful are those that operate in a limited speed regime, like the speed trials. Otherwise, on balance, they seem to have been negative. I'm not sure what there is about this design that will mitigate that.
I also predict that the keel root will want to translate about the hull as "Q's" does.
This will provide more wave clearance, which in my view will be critical to success. The problem with that, is of course structural and also it severely restricts the hull form in the way of the keel.
On the other hand, I admire bold design and action. So I am watching with interest.
SHC

[sean9c]

Originally Posted by Steve Clark

I have some concerns here as well. Steps work well to make a long boat think it is two short boats. Which when planing above a certain speed id a good thing. But otherwise is a pretty big problem. The only stepped sailboat hulls that have been successful are those that operate in a limited speed regime, like the speed trials. Otherwise, on balance, they seem to have been negative. I'm not sure what there is about this design that will mitigate that.
I also predict that the keel root will want to translate about the hull as "Q's" does.
This will provide more wave clearance, which in my view will be critical to success. The problem with that, is of course structural and also it severely restricts the hull form in the way of the keel.
On the other hand, I admire bold design and action. So I am watching with interest.
SHC

It'd be interesting to see the structure in Q, they've basically cut the boat in half with the keel, and you gotta keep it light.

[Doug Lord]

Originally Posted by sean9c

It'd be interesting to see the structure in Q, they've basically cut the boat in half with the keel, and you gotta keep it light.

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Lots about 180 degree flying canting keels here: Flying Canting Keel-Extraordinary Innovation!

Much about Q on the last few pages, but Q is not the only boat designed with this type of canting keel.......

[Doug Lord]

Unfortunate development:

Many of the parts for our SpeedDream27 are coming to Lyman Morse in Maine where the prototype is being built, from far away places. The sails are under construction at Doyle Sails in Salem, Massachusetts. The keel bulb has arrived from Canada, deck gear from Harken in the Midwest. Our crew clothing is being sent from Zhik in Australia.

Two of the most critical pieces of equipment were manufactured in Romania and that’s where our story takes a sharp left turn. This week the beautiful carbon mast and boom arrived at the yard; damaged in transit.

more here: http://speeddreamblog.blogspot.com/

[sharpii2]

A very interesting article.

I don't agree with the upside down bow.

I think something I call the 'V' Deck is a better solution.

With this system, the sheer at the bow is exaggerated, creating a very tall stem.

What I call a 'Peak Board' is added to the top of that stem, extending aft, parallel to the waterline. Connecting this to the sheer line, on either side, is decking, which slopes downward at an exaggerated angle.

The 'Peek Board' can extend as far as the designer wishes.

For a design like Vlad's, I would extend it 25 to 35% aft.

Now. Instead of subtracting buoyancy from the bow, to keep the fore deck from acting as a dive plane, we have now added some, keeping the same effect.

Below is a crude lines drawing of my 'Lola 520' design. Here the 'Peak Board' is extended all the way to stern. But the 'V' is much shallower than what Vlad would probably need. For 'SD', I would go with as much as 30 degrees. Then the stem would be so tall that it may not go completely under in the first place. Maybe 20 degrees would be sufficient for this reason.

The 'L520' is not a performance boat, but an easy to build, 'mini' ocean going design which is supposed to inexpensive to build. I only post it here to illustrate what I'm talking about.

[Doug Lord]

Pulled! From SA this morning-click on image:

[sean9c]

Originally Posted by Doug Lord

Pulled! From SA this morning-click on image:

Cool looking wood boat in the background. I've been in that LM building. It's amazing. That's a boat shop

[Doug Lord]

Video of the (hot looking) boat being turned from Vlad:



Did you see the step?

[sharpii2]

Originally Posted by Doug Lord

Video of the (hot looking) boat being turned from Vlad:



Did you see the step?

The glare off the finish makes it all but invisible.

[Doug Lord]

Originally Posted by sharpii2

The glare off the finish makes it all but invisible.

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There are steps and there are steps. A few years ago I discovered Eugene Clements whose powerboat steps were quite unique in that they are so small.
I thought then that might be the way to go with a sailboat if you didn't use variable geometry like Hydroptere.ch does. No idea(for sure) what Vlads thinking is but I sent him Clement book some time ago. Hope it works out.

[sean9c]

Originally Posted by Doug Lord

Video of the (hot looking) boat being turned from Vlad:



Did you see the step?

I didn't see any steps. I'd think they'd be easy to see in the reflections

[Doug Lord]

Well, the one step is clearly there-you have to look hard-its small.