Quick question about Tornadoes. (Comes up because the thread about F-16's turned into discussion about how much weight they can handle, and how much they weigh.) I see the Tornado is listed as weighing only 300lbs. But the shorter, and newer designed F-16 Viper is listed at 284lbs, and the modern N20 is listed at 419 lbs. So how did they achieve a weight of only 300 lbs on an older design that is 20' long and 10' wide? I'd imagine they can handle a good amount of weight?

(By the way, posted this link elsewhere, but might have gotten lost in the shuffle, great onboard video of Tornado racing posted just @a month ago: https://www.youtube.com/watch?v=zGM0nSvjGhM)



Edited by CatFan57 on Nov 03, 2018 - 11:52 AM.

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1998 P18.2
Sailing out of SHBCC, NJ
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Minimum weight on the Tornado is 375#'s. Yes, nice big tramp for 2-3 people or 4 for a slug sail. Best sailing cat I've owned. Pete

I dunno, how do they achieve a weight of 400 Lbs on C class cats which are 25 feet long, 15 feet wide, and 40 feet tall? Solid engineering and the mantra that if it doesn’t break, then it’s too heavy....

That’s the difference between a production boat and a custom or semi-custom boat.

sm



Edited by Dogboy on Nov 03, 2018 - 07:57 PM.

pbegle

Minimum weight on the Tornado is 375#'s. Yes, nice big tramp for 2-3 people or 4 for a slug sail. Best sailing cat I've owned. Pete

Since you own one, I don't doubt you know what they weigh. Trying to figure out why pknapp66, in the F-16 thread, said: "On a side note moving our 300 lb Tornado on wheels is pretty easy for 2 of us. " And why this site is listing the Tornado weight at 300lbs: https://sailboatdata.com/…ilboat/tornado-catamaran. ?

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1998 P18.2
Sailing out of SHBCC, NJ
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A Prindle 16 weighs 300 #'s. A H-16 weighs 320 (newer), 340 (older). Does it make sense a "T" would weigh 300 ? These other sources are simply incorrect. Pete

A tornado has a minimum weight of 155kg or 341lbs. This is achievable through the use of a nomex core and prepreg S-glass hull cured in an autoclave coupled with a carbon rig, carbon spin pole and sails that are on the lighter side. This was state of the art in aerospace composite manufacturing techniques at the time and is still a pretty advanced construction method. A-cats are build in a similar manner to achieve their 165lb weight for an 18’ x 7.5’ platform.

The Tornado class rules have the minimum weight: http://www.tornado-class.org/wp-content/uploads/2013/05/Tornado_2016_CR_281016.pdf

Best look at SCHRS data for other boats: https://www.schrs.com/ratings.php

Also the weight of Groupama C was never published but pushed close to 300lbs from what I know. The materials used in their hull were manufactured in Switzerland under a division of North Sails that owns the thin ply production methodology and can create prepreg carbon fabrics in the 20gsm range. You won’t find this on any production boat or semi production boat; Groupama C was a million dollar design and build.

samc99us

You won’t find this on any production boat or semi production boat; Groupama C was a million dollar design and build.

My point exactly...comparing the weights of an F16, Nacra 20, and Tornado is not an apples-to-apples comparison. Each boat has different design considerations, so each is going to have different target weights (and price points). I'm sure a one-off Tornado designed specifically for Olympic competition is going to be right at minimum weight (it also may not last much longer than the specific event it was built for). You can build an incredibly light boat, but the
penalty for doing so is very high cost and limited longevity. C-Class cats are an extreme example of this.

sm

I sail a Marstrom Tornado. Easy to move boat. It may have to do with bow shape. Newer boats have more bow volume, meaning more mass.

Hopefully it will come to SHBCC soon for the Statue race. You guys have a nice club.

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John

Nacra 5.0
CT
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Dogboy

samc99us

You won’t find this on any production boat or semi production boat; Groupama C was a million dollar design and build.

My point exactly...comparing the weights of an F16, Nacra 20, and Tornado is not an apples-to-apples comparison. Each boat has different design considerations, so each is going to have different target weights (and price points). I'm sure a one-off Tornado designed specifically for Olympic competition is going to be right at minimum weight (it also may not last much longer than the specific event it was built for). You can build an incredibly light boat, but the
penalty for doing so is very high cost and limited longevity. C-Class cats are an extreme example of this.

sm

Dogboy,

You are correct that these aren't apples to apples comparisons, however you are missing a key point. F16's, Nacra 20's, even Nacra F20c's are built in production environments where keeping cost down is a major driving point. The quality of most of these builds just isn't there-its hard to achieve when using a low cost workforce and resin infusion rather than a skilled aerospace composites team and high quality pre-preg materials. I could argue that a pre-preg build is lower cost as the labor needed is a lot lower, but the tradeoff is you need enough work to justify the upfront investment in the oven and overhead in space.

A one off Tornado built to 341lbs is going to be plenty stiff and have a near infinite lifespan; that is evidenced by Olympic Tornado teams using the same Marstrom T for 3 quads.I can assure you these boats were at minimum weight, doing pretty insane things like running 1.5-2mm kiteline dyneema for trapeze lines, full carbon snuffer assemblies, carbon fiber mainsheet block systems etc. You could build a modern high volume F18 or 20 footer to this same weight standard but it would require a change in the rules and the price of the boat to go up by about $10k, which frankly isn't very tenable. New boats aren't selling in droves even at the $25k price point.

Also, the C-class catamarans have high lifespans as well; carbon composites have extremely high fatigue i.e cycle life limits. The real issue there is handling/abuse, those sorts of boats aren't going to take kindly at all to even experienced sailors making mistakes.

Bottom line is cost, not weight, is generally the driving factor in composites fabrication.



Edited by samc99us on Nov 05, 2018 - 09:08 AM.

samc99us

You are correct that these aren't apples to apples comparisons, however you are missing a key point. F16's, Nacra 20's, even Nacra F20c's are built in production environments where keeping cost down is a major driving point. The quality of most of these builds just isn't there-its hard to achieve when using a low cost workforce and resin infusion rather than a skilled aerospace composites team and high quality pre-preg materials.

I think there are a few builders out there who would disagree with that statement. Are production built boats of "America's Cup" quality? No, but I wouldn't want to pay for that quality either. I own two boats that Matt McDonald has built and I would consider each boat built to a quality standard above the price point of the boat.

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dk

Blade F-16
Hobie 14
Corsair F-242
Mirage 25 (Sold)
Hobie Tiger (Sold)
Hobie Tiger (Sold)
TomCat 6.2 (Sold)
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Okay, thanks for the replies guys, learned a lot. Checked out the Tornado rules and SCHRS data page linked by samc99us. Being fairly new, I was assuming any particular make/model of boat would have a standard weight and that's the end of it. So I'm gathering that's not always the case, that the weights shown in the specs are minimums, different builds can lead to different weights, and in the future I should check the class rules for the official minimum weight, as some websites can have erroneous listings. Also sounds like maybe it's a little nip & tuck out there when buying newer technology whether you're getting something that will hold up over time or not.

ctcataman

I sail a Marstrom Tornado. Easy to move boat. It may have to do with bow shape. Newer boats have more bow volume, meaning more mass.

Hopefully it will come to SHBCC soon for the Statue race. You guys have a nice club.

Hope you make it, as it would be a pleasure to put an eyeball on the renowned Tornado. There is not one at the club.



Edited by CatFan57 on Nov 06, 2018 - 07:43 AM.

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1998 P18.2
Sailing out of SHBCC, NJ
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dssaak

samc99us

You are correct that these aren't apples to apples comparisons, however you are missing a key point. F16's, Nacra 20's, even Nacra F20c's are built in production environments where keeping cost down is a major driving point. The quality of most of these builds just isn't there-its hard to achieve when using a low cost workforce and resin infusion rather than a skilled aerospace composites team and high quality pre-preg materials.

I think there are a few builders out there who would disagree with that statement. Are production built boats of "America's Cup" quality? No, but I wouldn't want to pay for that quality either. I own two boats that Matt McDonald has built and I would consider each boat built to a quality standard above the price point of the boat.

Yes, Matt's builds are certainly a step above most in terms of build quality. Windrush, Holland Composites (DNA) and eXploder also build quality products. The new Nacra's look pretty good too, as do the Goodall boats. There is a difference between putting out a quality boat and building to aerospace standards however; none of the F16's or F18's are built with pre-preg resin systems to my knowledge, and Nomex is banned in these classes though pretty well understood to be an ideal material from a strength/stiffness point of view at this scale (all the A Cats are built with Nomex cores).

I think the point (at least my point) is that you can't simply assume that since one boat is larger it must also be heavier. There are countless factors that play into a boat's weight. An extreme example (as I mentioned in the earlier post) would be to compare a C-Class cat to a Hobie 18. The C-Class cat is nearly 50% larger in all dimensions, yet both boats weigh (roughly) the same - 400 Lbs. Two totally different design criteria for each boat. The C-Class is a fully custom, purpose built boat for one race. The Hobie 18 is a production boat designed to be bashed around on the beach and in the waves and last decades.

sm

To everything that Sam said, +1.

I've owned two Marstroms (T and an A-cat) and my sailing partner has multiple T's and a semi-custom, Melvin designed, all carbon 20' boat. The last boat weighs in at 250 lbs ready to sail. We've raced that thing HARD; even though it has a massive rig and is ~17 years years old, it is still super SUPER stiff.

Both of my Marstrom's are/were the same way; Nomex boats require a more careful owner, but the longevity is there. Like Sam said, there were plenty of Tornado's that went through multiple Olympic quads and were still fast (won medals) because of the quality of build. This is one of the major arguments that the Nacra 17 class used; "boats will be cheaper because of construction/build materials" (foam/infusion vs. nomex/prepreg).... but... they don't last like Goran's boats did.... So, what is the real cost?

Generally, classes want to keep the boats relevant and balance the price/performance in making these decisions. Could you build an F-18 with more expensive materials, yes; but if you have the same limits on weight, why would you? The result would be a more expensive boat with little/no performance gain.

Regarding boat data; use SCHRS or Texel as they are the best consolidated sources, but the class rules are the final word.