All I know is: That's a beautiful boat and AHPC has excellent quality in their builds of the Taipan line.

Generically speaking..... what do you guys think the average number of hulls/boats built before the bugs are worked out?

Too many boats, too few $$$$$$ ......

I have always wondered why the rear beam on my Snake was so small....they certainly fixed that problem.

Quote:

--The Viper is designed to be 125kg with a crew weight of 120 – 140 kg. The hull buoyancy and shape is designed around this.




Notice how this leads to the following situation :

boat weight + max crew = 125 + 140 kg = 265 kg

Were the other F16's will have :

110 + 155 kg = 265 kg

Basically what AHPC has done was to take out any excess weight of the Viper itself from the maximal competitive crew weight. The final overall weight remained the same.

Please note that the Aussie Blade was sailed by a man who weighs OVER 120kg as well - so the Aussie Blade would seem to NOT have any weight carrying problems?

The all up weight might be the same with a lighter crew on a viper, but the crew on the Viper can move less of it around so generating less RM and so less power and so less speed.

Yes, but RM is not important in lightwind which Greg was careful to focus on. So his statement is still basically correct.

Wouter

So are you saying that the ideal weight for na F16 is more than an F18???? Taipan 4.9s are best around 120 kg and I would imagine that the F16s would be better suited to about 120 to 130. Sure you can race at 155, I raced the F18 at 184 initialy before we trimmed right down to 160. However we are still just a little too heavy for the F18.

No, as the ideal weight for the F18 is centred around 150 kg with a span of 15 kg to either side.

F16 is centred around 140 kg with again a span of 15 kg to either side.

The two weight ranges overlap but the F16 range is not situated above or beyond that of the F18.


We must really not forget that the F16 rig has evolved beyond the Taipan rig and it requires 143 kg on two trapeze wires to hold it down when a 150 kg F18 crew holds down their boat. In the way of hull volume (and related drag) the F16 achieves F18 equivalence (F18 with a 150 kg crew) when it is sailed at an overall weight of 245 kg. Basically this means a 138 kg crew is the F16 is at minimum boat weight.


No I know that many people "feel" that this must be different, but then again 90% of the world simple "felt" that the world had to be flat 6 centuries ago. Feelings are often not very dependable.

Also we must not continue ignoring hard statistic data that directly disproves your "Taipan 4.9s are best around 120 kg" claim. It may be so that YOU "feel" that 120kg is optimal for the Taipan but this was not found to be the case in the scientific analysis produced by Elliot Tonkes. You can read that article here :

http://www.geocities.com/f16hpclass/F16HP_optimal_crew_weight_analysis.html

I should at this point probably also add that Jim Boyer and Daniel van Kerckhof were adament that sailing the Taipans as light as 120 kg (= crew) was not an advantage in their perception.

As this theme is recurring every couple of months I would like to lay this issue more broad then just as a reply to your post Stephen. As such the next comments may well not applying to you personally Stephen.

I found that far too many people simple look at the hull length of the the F16 and feel that they "understand" the boat in every aspect and "know" what it is like and what it likes. This may work surprisingly well for some of the 70's and 80's boats as build by Nacra and Hobie but with the Taipan and F16's you'll be deceived completely. As you would be with many other Australian designed catamarans.

The Taipan and F16's are simply on a different tangent from the basic catamaran design and fail to live up to such crude rules of thumb. Although there are also many people who apply the "maximum hulls speed rule" to cats so there is plenty of ignorance going around.

In the end of the day. The Taipan and F16's are much more powered up then their size suggests. With the new large squaretop sails (incl Taipans now) and spinnakers you want some body strength on board. Not plenty of it but still an ample amount. Being below 130 kg means you that start lacking in that area. Being 120 kg and less means that you ARE lacking in that area. I've sailed/raced often enough with 60 kg and lighter crews on my F16 to have learned that. As I'm 90 kg and sufficiently endowed I can then help out when needed. If I had been 60 kg skipper myself then well ...

Basically what I'm saying here is that every time we focus far to much on one single aspect. In this case we ONLY look at how a 120 kg crew is lighter then a 140 kg crew and concluded that they are therefor advantaged. But the real world is never as clear cut. Every advantage comes with a disadvantage. You pay for every achieved benefit by accepting a drawback. The real trick (performance) is in balancing the factors of the these groups. This is also why a crew weight somewhere in the middle of the competititve range has the best potential over all possible weights.

Many believe that competitive crew weight ranges run from the lightest crew being maximally favoured to the heaviest crew being maximally disadvantaged, but this is simply not the case.

A real life competitive range runs from light to heavy crews in a dome shaped arc with its peak somewhere in the centre. The crews at the extremes being more or less equally disadvantaged. Most likely being so in different conditions, but over the whole still equally disadvantaged. A scala of factor causes this result and crew weight is only one factor out of several. Interestingly enough crew weight can actually work out in both direction, advantagious and disadvantagious, depending on the conditions. And even there it is not as simple as light wind favours light weight and heavy wind favours heavy crews. For example, heavy crews in light winds but heavy chop can be advantaged again as the boat has more momentum to punch the waves. In heavy winds and large waves the light crews are able to catch the wave easier then a heavier and get a speed boost that way.

Basically, things are never as simple as many rules of thumb suggest they are. And yes F16's do have an optimal crew weight range that many feel is almost the same as the range for the F18's. It is my personal opinion that far more people underestimate the optimal crew weight for the F18. Certainly in the USA they do. Many of these boats are not featuring 10:1 mainsheet tackle systems for nothing. Now I can work my 7:1 F16 mainsheet singlehanded during a 3 hour distance race (with intermitted cleating), when I had to do so on a nacra F18 with a 9:1 tackle system in the same conditions, I had to use both hands and was worn down afterwards (again despite intermittend cleating). And this is one of the most often quoted reasons why crews below 135 kg really don't race the F18 very hard in anything over 12 knots. Same with respect to women. It is a body work-out. Very light weight crews (below 120 kg) on the F16 will experience similar drawbacks. Of course there are always some exceptions but these don't not really disprove the general trend.

Wouter

Agreed, but at that point a team at 130kg sailing a F16 down to weight will be carring 18 kg less around the course sailing a Viper.

Carrying 18kg extra around the course (same crew sailing a boat at 125 kg vs 107 down to weight boat) cannot be good for speed !

[

Just to be clear, I think you meant "will be carrying 18kg less around the course than sailing a Viper. For a moment when I first read that sentence I took the opposite meaning.

And I didn't really understand Wouter's comment that Greg was focusing on light wind. I thought the real focus was downwind in heavy air.

Guys,

Good discussion here but I want to point out something to lurkers and other folks reading about F16s and wondering about the class:

The F16 class offer a tremendous range of flexibility in terms of being competitive at different crew weights. Probably as much flexibility as the F18 and A-class and way more flexibility than virtually any of the one design classes. Let's not lose sight of this as we count grams!!! I sailed head to head, bow to bow with a fellow F16 who weighs 40 lbs less than I.

Stealth has had a carbon stick for years.

Eric,
Like you said Stealth have had carbon masts for years, in fact they come standard, and I believe have come standard with carbon masts since the beginning.
John P's price on carbon masts is really very good.

Regards,
Phill

Carbon mast is Standard on all the (current) Stealth range.

Never had a carbon mast before and I have to say I'd find it difficult to go back to Alu now.

It's better in the light stuff and it's also better in the big stuff. Win-Win !

I asked Matt about carbon Blade masts last week. He said an A cat mast (longer than F16) weighs about 20lbs. while the alum. Blade mast weighs about 38lbs. So certainly, we would all love to drop that extra 18 lbs. on the stick. BUT...the F16 class has a "tip weight" rule that would off set the lighter carbon mast benefits. ALSO, Matt said that at today's carbon prices, a new carbon Blade mast, fully rigged and ready to step, would cost pretty near $5,000!

Now, I'm all in favor of a lighter mast, and I've had two cats with carbon masts, never had a problem, never even seen one break, but for $5,000, I'm not sure that's the direction I want to go right now. New sails would be much less and I could spend the rest of the money for hotels at regattas! <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

How about importing stealth masts? I do believe the stealths are offered at a very good competitive price and include carbon mast. That would be an option.

I wonder how much it will cost to ship a mast from the UK to central FL?

My mast is slightly lighter than the A class wing masts foot for foot simply because there is less cloth in it as it is oval instead of a proper wing as per the A's.. It does require a little corrector weight, but not much.

As for the mast price of about 5000USD (2.5K GBP) is about right for the A class section, you pay your money, you take your choice, A carbon mast is sooooo much better (as I said before) and it allows a lighter person to sail the boat (single handed) as theu can right the boat (Class rules require this).





Talk to John P; I'me sure he would do an order of (say 10) as a job lot to send to the USA.

This is quite an interesting point. My Carbon mast had a tip weight of 5.25kgs. Therefore, I added 750grams of lead to measure prior to racing at the Global Challenge. I heard that Hans's Carbon masts had a tip weight of exactly 6kgs. The Stealths center boards were also lighter than Hans's and yet the Blade had an all up weight of under 104kgs and the Stealths was 112kgs. How come Hans's Blade appears to be lighter than most other Blades and approx 4kgs per hull lighter than the Stealth's?
As for carrying crew weight singlehanded the Global challenge proved that F16's have an enormous competitive range anything from 73kgs (Me, Stealth) to over 120kgs (Marcus, Aus Blade). Although, the winner (Hans, VWM Blade) was 90kgs.

Mark,

It must be down to contruction techniques and/or less cloth and resin and/or lighter beams.

1, Lighter beams (any idea how much yours weight ?)
2, Less cloth in the hulls (so possibly less strength or hull longeivity)
3, Less surface area of the hulls (so less cloth, resin and foam)
4, Lighter layup (Are the blades Autoclaved ?)
5, Wet layup vs pre-preg (I think wet can be done lighter with the appropiate skill level)
etc...

pre-preg should be lighter..

Mark my carbon mast was not at the exact weight, i had to add also a corrector weight in the top of 600 grams to meet the required tip weight.
My total boat weight was 105,8 kg but i had to add a corrector weight in total of 6,2 kg incl 600 grams of te mast.
My boat weight 105,8 - 6,2 kg = 99,6 kg originaly as a one up. This was measured after sailing almost year so the boat sucked up some water. When the boat was just finished in the workshop the boat weighted 97,8 kg. The point that i also used a carbon spinpole and some other carbon parts like tiller this will reduce the weight ofcourse. <img src="http://www.catsailor.com/forums/images/graemlins/tongue.gif" alt="" />

Regards,
Hans