Some of the modifications are classified, but in general terms the mods are like this. Inside the hull local area's that are dominant in determining the amount of flexing have been reinforced. Other reinforcements increasingly prevent the hulls from being strain out out shape and as such increase the net stiffness. A new crossection for the beams is used. But indeed most of the improvements come from very modest but smartly applied local reinforcements in the hulls.

I can't name any actually measurement data or other specifics, because I agreed to not do that. I can say however that the new 2007 Blade is stiffer then the 2006 version which was already stiffer then the 2005 version which was significantly stiffer then the Taipan.

When comparing my own Taipan based F16 (which is slightly stiffer then the standard Taipan) to the new Blade I can say that the new Blade is no less then 4.33 times stiffer. (based on actual measured data). So a factor of 4 and that is ALOT. Phill as a designer was aiming for a factor of 3, but it came out at the above named ratio. So the designers sort of overdid it, not that anyone is complaining, mind you. Again I say that the Blade 2005 version was already significantly more stiff then my Taipan F16. So the difference between different makes of Blades is less overwhelming. Although the first versions of the Blades were less stiff then the Stealth F16's, so to some extend the Blades had to catch up.

More interestingly I think is the fact that at the same time of these increases in stiffness the platform weight has been reduced. And this clearly hints at how smart the reinforcements have been placed. Measurements of the last series of hulls is now typically below 23 kg. Note that the smaller and significantly less bouyant Taipan hulls are 23.5 kg each.

Currently the VWM Blade F16 is lighter, stiffer, wider and more volumous and cheaper then the Taipan design that basically was the best F16 at the start of the class back in 2001. Personally I think it is also significantly better behaved then the Taipan and probably a little faster as well. This total improvement of the basic design on all fronts is something that the group of associated designers really didn't believe to be possible. But as a result of combined efforts it has been achieved nevertheless. To me it is one of the most convincing argument for a formula setup and against an One-design class. A better product for roughly 20 % less cost. I'm personally more then willing to accept the 1 or 2 % speed improvement of the Blade with respect to the Taipan for the ability to carry much heavier crews with a much better feel and a more predictable behaviour for significantly less cost when bought new. In a few years I'll sell my Taipan F16 (that I really do love) to a newby to the F16 class and buy myself an new F16. The price is not prohibitive and the newby will need many years of training before being held back in a competitive sense by the slighly lower speeds of the Taipan.

Which design it will be dependents on who builds the best F16 at that time to my personal liking. Seems to me that Stealth and others are full on designwise as well. And I'll be fully investigating the new AHPC Viper F16 that they'll bring to the Zandvoort event.

I've gotten a little bit of track, but I'm sure you'll forgive in this instance.

Wouter

Eric:

At my weight I think it will be the best choice. Factory boats are made for light weights, and the Tool would be expnsive to get to US. AND he should know all the bells and whisles to add. I can't wait.

Doug

Doug,
Have you spoken to Steve Clark or Lars? Steve owns the molds for the DK17, so your first step is to talk to him. Second step is to get a quote from Lars on finishing the project.

You might want to have those conversations.

Bill

Bill:

When I am ready and have the money, I will get the contact info from you and go from there. Right now it is just a want.

Doug

Wouter: "Personalities differ between sailors and so to the boat types that will give them the most enjoyment."

I fully agree with you on that, you caught me by surprise with that statement as so far I lacked to see that attitude in posts where you seemed to attack other people for sailing (& loving) those boats they do. I just think about your comments to some F18 sailors here and can't get rid of the feeling you try to persuade anyone to get into the F16 too ;-)


Zee:
The advantage of the F16 is also it's biggest weakness: it's neither nor! Any boat which will allow to adapt between singlehanded and crewed sailing will face downsides and that is where a basic decision has to be made.

If someone wants this flexibility there are not many boats around offering this and than the F16 is surely one of the best choices I would think about.

If someone is purely interested in sailing singlehanded, competitive in a well established class with a lightweight boat, fast to sail, fast to setup, easy to righten oneself. etc.., the choice might end up different. So it will be if two heavy sailors search for the best boat to answer their needs. Boats are different, so are people.

I recently sold my Taipan F16 without any tears because it simply never gave me the satifaction I was used from the A. A carbon mast F16 might be better but unfortunately class rules require a strange minimum weight decreasing the benefits the material could offer. So far the F16 class is just starting to establish herself and evolutiuon and refinement is simply not up to the level like th A class narrowed herself in within the last 15 years. Wouter might call it a lack of innovation but seems to lack to notice the far less visible developments in the mast and sail combinations tested and brought a step forward at the ECs and WCs every year. The F16 still bears all this potential and by time it will be discovered. While not all might be there yet, it might be already now a very attractive boat and the best choice for certain people. Again we agree it won't suit all.

A with spi can be done, has been done and has proofen itself as the boat to beat in certain conditions fo anything else in the market up to 20 ft so far. F16 comes with spi, so just buy and go and surely will be fun. Upwind, if you never sailed an 18ft and 25 kg lighter A, it still will feel fine. :-)

If you are still with the A, you might consider that nearly noone is sailing the A2 or A3 in Europe which is not only related to it's price.

If you are interested in a one off and money is no issue, take a look at an M18 too. Its a wider A with spi and 85 kg overall weight. Might be slightly more difficult to righten oneself. The spi drum sucks but for the rest the Marstroem A might look like the most outdated As but their daggerboards are positioned further forward than nowadays other designs which makes these high volume boats specially suitable for spinnaker sailing. The production quality and value for money I still consider the best of all production As. This might balance the believe that the boats as well as the mast sail combinations are said to be not as competitive as they would like to be.

Wouter, can you surprise me again? Maybe try to ignore this post instead of commenting on each sentence I wrote here today. :-) I already live in a country with a lot of censorship... ;-)

Well, considering another few state-of-the-art A-cat carbon masts broken during capsizes at the last Gulfport invitational regatta I think our strange min carbon mast weight limit for F16's (= only 4 kg more then A's) was one of the best choices we as a class ever made.

An F16, as by its target group of future owners, is going to see a whole lot more abuse then the A's.

With respect to the A's. I think it best by far for Zee to get that flight to Dubai and try all these boat types for herself.

With respect to sailing F16's or A-cats in general. After a winter of landyachting I always have to readjust to sailing on the water again. Because nothing on the water feels as nible, fast and easy as a landyacht. And I can rig/derig my class 5 landyacht from its trailer in less then 5 minutes. I really have to be careful to not spoil myself.

And I even miss my old P16 in some ways.

Suggesting the M18 to Zee is not a smart move as she has already tried to contact Marstrom in the past with very mediocre succes. I really don't think that boat type is anyway high on her list anymore. It appeared Marstrom as a company simply wasn't interested enough. This has already been covered on this forum last year.

Wouter

Wouter, how did you measure the stiffness, do you simply lift a bow until the other bow comes off the ground and measure the deflection ? <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

hi, if you are compairing the f16 to the a class, i think the a class is a bit lighter, and more simple with only one sail but if you are mainly sailing in light winds, it may be better for you to get a f16 as they are faster on yardstick texel/portsmouth even 2 up so 1 up they should steam away from the a class, i sail my f18 single handed with the spinnaker flying in light airs, its gr8 fun as long as you have 3 arms, the spitfires and the blades look the best f16 and the spitfires do very well racing in the uk, the f18's find it hard to shake them off untill the wind picks up where as if i am racing against an a-class you can pull away when you raise the spinny, blades sail with a single sail single handed (and i am sure the spitfire is the same, somone on here will know for sure), but you could go with all sails up in light winds

have you seen the roller reefing spinnakers? for single handed cats that is the way forward

Having seen pictures of the DK-17 and seeing Bill's boat before it was finished makes me believe it would be a fast design.
So my question is... How come, if Lars could build a DK-17 cheaper than buying an A3 how come he still sails the A3? I know his boat in modified but is there is the A3 hull proven to be faster than the others? Is it just that the DK is designed for heavier sailors?
-Todd

Support the sterns of the platform and then lift the one bow. The difference between the height of the two bows above their supports is then measured. Best way in my opinion would be to lift both bow clear of their support by picking up one bow, then lower the bow you are holding too such an extent that the lower bow just touches its support again. This will give a measured of the vertical platform stiffness

Horizontal stiffness is measured by pulling on the bridle wires and see how many the bows are pulled inward by the bridle loads.

Wouter

The DK 17 was designed for 100+ kilo sailors. Lars is around 80? kilos. That is about 15% difference in displacement. In terms of an Inter-20 this is changing from 325 lb crew weight to 435 lbs crew weight. Don't ya think the hull shape mightneed to be a little different? I think that Lars feels the A2/3 is the best hull shape for him. The problems with the A2 were build quality not handling characteristics.

Cheers,
Eric

Todd:

I don't know how much Lars weights, <img src="http://www.catsailor.com/forums/images/graemlins/confused.gif" alt="" /> BUT the main reason I am looking at the DK-17, is there is no way I will EVER see 150-160 lbs again. <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" /> The DK-17 was more volume in hulls for us "Lard butts" <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Doug

I guess Marstroem was and is quite busy to produce the Extreme 40, Seacart 30, Tornados and spars for Beijing, recently build Roman Patzkes 90 foot G-cat and there might still be some aerogliders on order too... so could assume their autoclave is quite booked for some time... :-)
but he is not the only builder you have to beg and please to get what you would like...

also agree too many A mast break for to little reasons but it has not so much to do with weight as I haven't heard that the spars got lighter over the years. they became softer, prebend increased, diamonds and shrouds were lowered, sometimes fiitings were bad manufactured etc... there are a few knowledgeable people saying it would be possible to build a 6-7 kg light A mast but it would not survive certain capsizes. anyhow mastbuilders could increase the durability of their masts with some not to expensive additions and my only explanation so far is, they don't do it because neither the sailors (as client) demand unbreakable masts (they should do so so!) nor does a consumer have enough consumer rights in a not so much professional and commercial environment to ask for a new mast once the old broke. I believe mastbuilders do not care to much also as broken mast mean new masts which means ongoing business. the only positive effect is that broken carbon masts offer possibilities for the low budget 2nd hand market. but the durability of a mast depends on it load patterns and detail solutions and just a minimum weight restriction would not solve the problem. and 4 kg is nearly 50% more heavy (for a 6% shorter mast on a 11% shorter boat) than some A masts do weight which survived more than 10 years. In general I have some doubts that adding weight is the smartest way to go to increase the durability of catamarans although the weighty F18 class seems to be bulletproof nowadays... but they say this also about tanks and I don't think tanks sail well.

I am not sure the A masts are anywhere as low as 7kg, maybe with everything stripped off such as diamonds, hounds etc. My Stealth mast which is seriously old and had serious abuse over the years weighs in at a respectible 12kgs complete with all diamonds, halyards, spinnaker halyards, rotating arm, infact ready for sailing. To loose another 5kgs purely in carbon as the A's have to have halyards etc must mean that they are paper thin.

I know the latest Stealth mast ( by far the cheapest all carbon mast on the market with good quality and a fine track record ) has lost a kilo or 2 with all carbon spreaders and reduction in stay wires sizes etc but not 5kg's <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" />

As far as I know current carbon mast on A-cats are in the range 8.0-9.5 kg. I do not see them being build at 6 to 7 kg, now or in the near future. Besides the F16 masts have some extra lines en fittings running up the mast that are included in the tipweight/overall weight. Things like spi halyard and spi gate, extra set of trapezes, often a mainsail halyard as well.


Indeed, a minimum tip weight rule on a carbon mast is not a perfect garantee that the builder will provide an unbreakable mast. Afterall he can still make it 7 kg and put the remaining 2.5 kg as lead in the tip. But this tip weight rule does make it alot more likely that the builder puts something like an extra layer of (glass) laminate over the full length of the mast. This would not change the stiffness much when done right but it will make the a whole lot more impact resistant. He has some weight to play with and can use that the make the mast more stirdy without fearing he will get outperformed by another builder willing to take larger risks with breakages.





The F16 mast also holds up 232% more sailarea, withstands 195% more righting moment, experiences 150% of the mast step loading (axial compression) and is sailed by owners who are several times less inclined to pamper their craft then A-cats owners.

I also seem to remember a certain F16 (and A-cat) sailor who insisted on using a 21 sq. mtr F18 spinnaker with a much higher spi gate on a standard Taipan mast and then double trapezed with it at 160+kg in a blow. Finally the mast let go. I wonder if he will try the same on his A-cat ?

Dirk, when you see this guy in the next couple of days please say hello to him from me. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />


But we are going to put this baby to rest.

Zee should really go to Dubai and flash here eyelashes a few times to get a test drive on all the named boats and then decide for herself what is best for her.

Wouter

some of the latest A's don't even have halyards - you push the main up.

I've got a 2001 Bimare A-cat, and have no halyard on my main sail. Once the bolt rope wears out on the sail, it can become a real bear to push the sail up the track.

I think all of the A's except the Marstrom are "push up". One less thing to worry about. Ed

Zee,

Contact Jay or Pease at http://glasersails.com and they will tell you about their latest thoughts on the a-class sail. Right now I believe the one Lars Guck uses is probably the fastest cut. They will though do some customization for your weight, height, boat and mast. I do not know whether you are looking for new or used, but listed yesterday on usaca.info are 2 A2's ready to rock.

Sorry to keep the tangent going, but I want to toss in my 2 cents. I have inspected and tested the stiffness of 3 Stealth F16s, 3 Taipan 4.9s, and 2 VWM Blades. The Stealths were the stiffest, followed by the Taipans, followed by the Blades. (Note that Wouter's boat is a custom F16 based on the Taipan hull shape but with significant differences from a stock Taipan 4.9.) The Stealths benefit from a butressed beam landing. The Taipan 4.9 benefits from a narrower width and wider hull (and therefore wider contact patch). Having said that, I don't know anything about Blade modifications and I don't wish to imply anything wrong with any of these boats. The Blades I've seen look great and I have nothing but positive thoughts about the designer and builder. I would say likewise about the Stealth (John P) and the Taipan (Boyer/Goodall). The fact is, ALL THREE ARE EXTREMELY STIFF COMPARED TO ANY OTHER 16 FOOT CAT BEING MANUFACTURED!!! Even so, they are not as stiff as the new gel-tek A-class I just saw down in Long Beach <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />...but F16s class does't allow glued beams...just another example of how the F16 class was set up to be fast and welcome innovation but without making boats obsolete before the gelcoat cures. I believe you could take three crews and three boats--a Blade, a Taipan, and a Stealth (all similarly prepared)--and race them, switching boats each heat. Chances are, the same crew would win regardless of the boat under them.