New, fully optimized, Formula 16 design. The Blade F16.

Go to :

http://www.geocities.com/f16hpclass/F16HP_boat_show_dynautic_blade_F16.html

For a closer look.

I've been sitting on this for months and finally got the "go" word to go public with it. The designers wanted to be sure that it was up to specs before going public. If it was not than they wouldn't launch at all.

I saw two video's of it as well and it does indeed turn quickly through a tack. From comments and in video it looks like a really well thought out design. I feared it would spray at speed but it didn't; at least not that I cold tell. A pitty they had no tripod with them when they made the vid's; but they mentioned they were going to bring one next time.

The design will (also ?) be produced in Europe and the builder plans to have two demo boats ready at the beginning of the season (april, may 2004 ?)

And whole lot of other stuff that I may not tell. Man, this is exiting. Would like to see a face off between an F18 and this baby in 2004. When both are in capable hands then this may well proof to be a very exiting match.


Wouter

Wouter,
This is very good news.

I know i've seen that shape before :-)
See attachment

Would AHPC be the builder?

Looking foward to more details. I'd like to see higher aspect daggerboards than what the drawing shows.

Make mine silver !

When will you be able to tell us about 'And whole lot of other stuff that I may not tell' ?

Cheers
Steve

Salt water,

>>This is very good news.

It was about time too stealth launch in januari 2002 and that is nearly 2 years ago.


>>I know i've seen that shape before :-)
>>See attachment


You would think that indeed, however looks can be deceiving. I don't know the Capricorn that well, I do know the flyers FX-ones etc better, but the similarities are the raked back bow/narrow deck (not a design choice !) and the sloping deck. Than the designs start to diverge. The raked back bow is actually a direct result of having a deck that is more narrow than the hull at midheight. You can't have a deck that is more narrow without having a raked back bow. The named new designs all have reduced deck surfaces and therefor all look alike with respect to their bows. The sloping deck is a design choice (to some extend). Point is that these hulls can be as different from eachother as old style hulls despite that fact they all look the same because of that visually dominant raked back bow. An example : There are big differences in the shape of the sterns. A-cat flyer type hulls have relatively high sterns for the width at that point the almost, The FX-one has a more square like stern with straight sides ; a U shape with rounded edges. The Blade has a much larger rounded bottom without straight sides; The curve continues in the sides and there they even falls in to a deck that is narrower. Some wavepiercer copies have reduced their bouyancy in their sterns the blade hasn't, same with the bows despite the similar shape. I had the same impression; the Blade does look alot like the Capricorn; however they are not designed by the same team (Capricorn is designed by Martin Fisher) nor are they copies of eachother as far as I can tell.


>>Would AHPC be the builder?

For Europe, no. For Australia and other regions maybe; this dependents on what the designers want with the Blade.


>>Looking foward to more details. I'd like to see higher aspect daggerboards than what the drawing shows.


Actually; there is some development work going on in this area and I must say that the designers have entrusted me with their results for which I'm very grateful. Tests like these are extremely interesting to advance ones understanding of how catamarans work. Of course this part is confindential. But I can say that one can't always estimate the upwind performance accurately by just looking at the boards aspect ratio. Both the Stealth and Blade designers have made comments were lower aspects boards appeared to have equal or superior performance over considerable speed ranges. Some results were totally unexpected indeed but were confirmed again and again. Still, my guess is that we'll see the Blade be fitted with boards that have an aspect ratio comparable to the other modern designs, with a maximum ratio of 4. Beyond 4 the long boards tend to slow a design down and make it "nervous" especially when singlehanding. The drawing itself is of early 2003 and I'm not too sure that the depicted boards are more than a general idea of how they should look.

I will push the design team for as much extra details as I can.

Ofcourse it is a pure F16 so most of the details are known, they are stated in the F16 rules.

Currently they are working at making some video footage that can be showed to you guys. Like I said in my other post they tried to do it without a tripod last week but one has to have a pretty stable hand to get some smooth video footage. To bad really the wind was howing at 20-25 knots.

I will keep you guys and gals updated.

Wouter

>>When will you be able to tell us about 'And whole lot of other stuff that I may not tell' ?

I expect that just before or after X-mas the designers or I can give you guys some more details.

I hope to have received a video burst before that time; but this is dependent on all sort of stuff so no garantees !

In the new year (januari/februari) it must be possible to tell if one competes at Texel 2004 and how many will be sailing as demo's at the Dutch coast challenge. The travel bookings will have been made final by then.

We'll just have to take it as it goes.

Wouter

I'm not too surprised that low aspect centreboards seemed to work ok. The Mosquitos in Australia have moved to smaller and smaller centreboards over the last 10 years. They are narrower (fore and aft) as well as shorter. Last season I started using them raised 200mm upwind and all the way down downwind (to help balance the spinnaker). This puts more load on the rudders upwind, but sailing cat rigged it really seemed to work (I couldn't say for sloop rig).

What is the reasoning behind the huge long centreboards on the F18s? It was a worry for the F18s at Forster because there are shallows in that lake. Seems a bit of a handicap really.

Tim

Hi Tim,

General aerodynamic / hydrodynamic theory is that high-aspect ratio foils will give the same amount of lift with less surface area of board. This equates to less drag, so you get a better lift / drag ratio - that`s why glider wings are long & thin. So assuming you have 0,25sqm of foil area underwater, and the board depth (immersed) is 780mm, that would be the Mozzie standard according to class rules.
If you could lengthen the board, and reduce the chord, you would have a board with the same surface area (lift-generating surface), but the efficiency would increase because you have reduced drag, which would give an increase in lift.
It still amazes me that you go upwind with boards half-way up, perhaps reducing the drag considerably helps to increase the board efficiency.
It gets a lot more complicated than that, my understanding is that this is the basic principle of how it all works. If any of the Engineers / boat designers respond to this post it will get seriously complicated, but I`d love to hear their input.

Cheers
Steve

That is the general theory however something else is at play also which causes this "law" to behave differently. We don't know exactly what is causing it but things happened that were not really suppost to happen when looking at the generally accepted theory.

Apparently Tim, found similar "freak occurances"

Wouter

The design looks good, but have one gripe. The beams. They sit too high up on the design. To be able to really push the boat hard and still have a super stiff platform best that these are built into the hulls. The A-class does this with the Flyer and a couple of locally built versions of the A-Class have the front beam connect on the top-inside of the hulls. The back beam of the Blade looks like it is sitting on top of the boat. One minor design fault of the T4.9 is that the back beam is too small and not built in. Not uncommon for the rear inside beam bolt to break due to torsional stress on the platform.

Just my opinion

JC

I cant find the reference and I may have made it up. So will ask..
Isnt there a relationship between speed and area needed for lateral resistance. Something like "the faster foil is travelling the less area is needed".

I think you are refering to the situation where you keep the angle of attack constant. When you're not able to decrease the area with increasing speed then the boards will operate at smaller angles of attack which may not be the angle at which the best ration between Lift and Drag is achieved.

Wouter

 
I just had the chance to take the Blade for a test sail.
 
I was a little bit anxious with it being so new and untested. 
It took no time for me to relax.
It sails & feels like a boat with a much longer waterline length.
When going up wind  the boat points and climbs in height
without loosing speed.
When tacking WOW ! seems like no loss of speed. 
Tacks on itself very quickly and scary when you dont expect it to be that quick.
When its time to reach or go  wild no problem being so
boyant in the nose, so you can push, and should you bury the nose (very hard to do) either bear away or de power and out it pops and the ride goes on.
 
My only concern is the rudders.  They are just too short and don't have enough in the water if you lift the transom.
The designers tell me they  already have longer rudders in the making.
The centreboards seem fine with minimal sideways drift.
The boat does not seem to  want to sit still so
holding it on a start line may be a bit of work,but then again the boat is designed to be sailed,
and enjoyed, so I did.
My thanks to the designers for the opportunity.


BTW:- There is a pic in the attachment.

When Richard was sailing some video footage was made, this time with a tripod they tell me. Apparently they now also have an UV filter that improved the pictures even more but we;ll have to wait some ore for that footage I'm afraid.

For now 3 clips without UV filter. The first clip s a bit out of focus or someone overdid it on the compression but I'll linked it anyway because, well, you do see a good deal on it despite the blurred contrast.

Please allow me to linked to the vid's one by one. I want to make sure that we don't overstept the transfer rate with the first few watchers and thus lock up to the webpage for others. If it does lock then this is the reason, I've downloaded all movies from this resource and the resource works. Best you cna do then is try back later or the next day.

So here goes (the first video of the Blade sailing, uni-rigged no spi skipper by Richard who gave his opinion earlier) :

http://home.hccnet.nl/g.ruesink/blade001.mpg

Depending on the Download transfer limit I will put the other two online in the coming days (at least all before X-mas)

Ohhh, Yes there is alot of fog. The winds were about 10 knots I'm told.

Wouter

Wouter and others
i cant get the video to work on my computer, but being on the blade was very good fun i cant see which tack u are refering to but the first tack took me totally by surprise
tacked like a monohull,To the point as the wind came up a bit more i think i was trying to slow the boat before tacking(didnt want to go hosing sails)this is by no means a bad point its just im a little rusty so when the boat is fully sorted its going to be something to watch

Richard,
The videos play fine on my computer using a great little graphic viewer called IrfanView.
You can download it from:
http://www.irfanview.com/
It's free and only about 800KB in size

The boat looks great
I'm looking foward to more information.