Tornado Carbon Mast

Folks,
Just wondering if the profile of the Tornado mast was changed when they went to carbon.
I'd be interested in the the major and minor axis dimensions of each mast.

Just curious as going carbon was a good opportunity to take a careful look atthe profile.

Also any pics of the carbon mast.
I hear they are a work of art.

Regards,
Phill

Ok- I found what I was after.
Minor axis 72-73mm and Major axis 134 - 135.5mm

From this it looks like they kept the same profile.

mast base

That's correct...no changes in profile for the carbon stick. But it is much lighter, stiffer and better controlled as far as flex characteristics. The spreader arms look like airfoils in shape and the diamonds are rod rigging, not stranded cable.

And the bend properties between masts in static tests are really close (les than 5mm variance) but in dynamic use... big differences. <img src="http://www.catsailor.com/forums/images/graemlins/frown.gif" alt="" />

What do you mean with "dynamic"?
/håkan

Dynamic, like in use.

The mast bend on the test bench shows them to be very similar. I think the first 200 masts were within 5mm bend with 50kg hanging off them.

But there are some big differences in the way the masts react when sailing. The differences are not as big as we had with the alloy masts but there are some marked differences between masts.

Some of us are less surprised about this then others.

Wouter

The move to carbon masts made the situation better for the sailors compared to the aluminium mast, or? If I have correct information the carbon mast is lighter, stronger and has less differances between each mast.

But the sad thing is that the this is the last Tornado Worlds with pro sailors....

/hakan

I think you would be in a very small minority...

It's possible to order a Finn mast with less than 1mm variance in bend from spec in both static and dynamic use.

So why exactly is a Tornado mast different to the finn mast in that regard?

Well, let's take a quick look:


Seems to me that the Finn mast is a circular, maybe tapered pole with one small sail on a boat with low amount of beam to counter heeling forces. Should be a lot easier to engineer flex characteristics within a given range than a 30', teardrop section with a taper and diamonds on a 10' beam double trapped cat.

When you introduce fittings for the spreaders and diamond hounds...there will be variation in their precise location. This likely accounts for some of the differences between masts. I've also heard the rod rigging of the diamonds is not always uniform & consistant in size between batches...that's another source of variation. Marstrom also changes the type of cloth being used on the masts at some point.

So what's the problem with some variation in the carbon sticks, dynamic or otherwise? You've stated the range is less than with alloy...and that was the whole point in the first place.

The original proposal was to have a one design mast and that the masts were to be identical (or as close as possible) the expectation was that the scenario the Finns enjoy would occur. A finn sailor can order from one of several builders a mast with exact bend properties and get it.

A Finn mast is actually harder to build with those properties than a T mast. The Finn mast is not circular as you say, but is much more wing like than a T mast or even a A class mast.

Finn sails are amongst the most carefully built sails in the world, luff curve alterations of 1/2mm are common. Having less righting moment actually makes the mast more critical and getting the bend right even harder to do.

How do I know this? Well I coached the Aus Finn team...

The problem with variations in the carbon masts is that it put us in the same spot we were in with the alloy masts! We used to have different mainsails for different alloy masts and now we still have to make different sails for carbon masts.... It would have been much better to be able to take sails to each boat (masts) and have no difference between them. Also would have been cheaper....

Macca,

So are you saying that Marstrom quality control is not up to the Job?

I'm saying that the masts behave in a way that was not expected.

By whom ?

Any properly educated engineer is taught or knows from experience that producing perfectly identical components by intent is a fallicy. Especially when components are very elongated, complex or even bulky.

The Tornado class has been on a OD-design fallicy ride. The "minority" has been on recieving end of scorn for a long time, but I bring back to memory the common industry solution to this problem as was presented to all when the Tornado carbon masts were proposed.

The sprockets used in rear axle differential coupling in cars and trucks are component that require to be very accurately produced for proper operation (low wear). The general geometric shape is such that this is even harder to achieve then with normal sprockets. Hard = prohibitively expensive.

Solution : By understanding that variations in the end product are statistical in nature (as all variations in real life are) one can produce a large number of these sprockets using pretty inaccurate means and then just measure all of them and combine complementary parts into the finished product. Here the inaccuracy in one direction is offset by an equal and opposing inaccuracy of the other part.

This way highly accurate finished products are made using pretty cheaply produced and relatively inaccurate basic components.

Working on this principle it is actually CHEAPER, to have a batch of 40 masts made and have these measured and have one selected to fit a given sail best then to try to produce a sufficiently accurate carbon mast in one try for the same given sail.

This was the way of doing things when Alu masts were still used and it appears that the same procedure is best followed with the new carbon masts as well.

This needs not be a bad thing either. Best any producer can do is just produce a batch of masts and measure them all and have each crew bring a sail (that will all have significant variations as well) and have them select the best mast from the batch. Due to the sail variations it is high probable that each crew will favour a different mast and in the end a very high percentage of the batch of masts will be sold. The remaining masts can then be sold at discount prices to recreational sailors thus earning back the investments.

Industry does this in an overwhelming manner where the components can not be adjusted after they are produced for technical reasons or economic reasons.

Why did anybody believe that the Tornado masts would ever be any different in this respect ?

Wouter

Thanks,

I will let the Finn mast builder know they have been wasting their time and they should in fact be mass producing masts and then just sort through them to find the right one....

Or how about they continue to build masts to spec and save themselves a whole heap of time and money??

You haven't read my post properly. It is actually CHEAPER and quicker for industry to NOT do things in that way.

Just producing masts and pair them up against normal variations found in the other parts, like sails, is the cheaper and easier route.

And it is also the way competitive laser sailor approach the problem for a fraction of the cost.

Actually, when using a sufficiently large "population" (statistical term) you can achieve practically identical combo's. Something you can not achieve EVER in the way the Finn class does it.

That is just the way things are irrespectibally whether the Finn class maybe considered smart of dumb in this respect.

Wouter

Macca

please don't goad the Wouter - we will have to up his medication.

I know it is hard to do for some here, but doesn't anybody entertain the thought that "Wouter without medication" could bloody well be right in these matters ?

A selection of the noteworthy cases involve the LR2 A-cat performance, full foiling (C-class) catamarans, Fosset/playstation short lived round the world record and their snubbing of Jules Verne organisation and the French, 16 footers performing on a par with F18's.

And now we can add the Tornado carbon mast to the larger listing as well.

Does anybody recognize a trend ? <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" />

You guys can keep stumbling about in the dark if your love for hating that bloody Wouter demands it but you will only end up hurting your own toes, knees and chins.

Wouter

DAMN IT, HE'S RIGHT!

All Hail the 'WOUT"!!! <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

"16 footers performing on a par with F18's."

Waiting to see that one!

I love the: "I think I have been right in the past, So I must be right this time" approach....


Dare I ask how the eternal search for a broadseam in a 3DL sail is going....??


Back to the topic rather than some errant ramblings..

If the Finn mast builders can build masts accuratly to spec (and for a good price) why isn't it possible to expect the same from the Tornado mast builder?

I believe the exclusive rights to producing the Tornado class legal Carbon stick expired after 3 years.

One of the big incentives for the class was the need to replace your perfect mast... rarely did a team have two identical perfect masts...

Now... you might not like yourcarbon mast... but it won't break.

So, if marstrom can't get it right (in some people's opinion) .... that's an opportunity... right?

Last time... three teams built their own alu sticks because Marstom could not get it right... (and the class rules were not particularly strngent. The rules were re written and are much tighter now.

Is there a real need to build re engineered carbon masts?

So .... Which teams are doing that in carbon NOW?

That is the interesting question!

Now... it may be a closely held secret... but I am sure there are rumors! spill the beans

Ok, most of the top 20 teams now have more than three times the masts compared to the boats they own....

They has been a lot of mast trading going on allowing people to find a mast that suits what they are looking for.

The exclusive build rights have expired, but there was a lot of delay in getting Marstrom to supply the build spec to ISAF. The first spec was sent in Swedish (handwritten..) and was actually detailing his general build method for any part... only in the last 12 months has a spec and Lam sched been approved by ISAF. This is now available to new builders... not too many are keen to invest in a class thats not Olympic after August.

There were some very high quality builders wanting the specs so they could build masts but now I doubt it will go anywhere.

Abre los ojos !

Wouter

Because science and engineering is never that simple.

Here some more ramblings :

Take a piece of carbon laminate tubing, length 3 mtr.

Say the proces of carbon cloth laminating is accurate in reproducing the wallthickness to say 2% and lets assume for simplicity that this variantion is constant along the full length of the tube and that there are no other factors (in reality there are).

That gives a 2% variation of the tip deflection when the bending radii aren't too large. Say this variation leads to variations in tip flexing in a batch of tube off say 2 mm.

Now take 4.5 mtr tubes (1.5 times the length of the first tube) cut from the same batch of laminated (mother) tubes.

How much will the variation in tip deflection be on a batch of these longer tubes ?

Think about this a little while.


...


...


...

Everybody raise their hand who think it will be 2 * 1.5 = 3 mm ? (Yes, Macca, that means you too)

The real answer is 6,75 mm or nearly 3.5 times as much, despite the tube being ONLY 1.5 times longer and from the same "accurate" batch !

So the same production proces, with identical accuracy, can still lead to surprisingly large variations in the end product depending on simple amplifiers like geometric shapes (length in this example).

That, my dear friends, is called non-linearity.

Perceptive minds reading this will immediately recognize that production related variance can not be solved by any changes in crossection shape, layup or anything like that. It is a property of the production proces and subject to the state of technology at this time. Carbon laminate technology is no different then any other technology in this respect.

Now start adding the natural variations in other components like spreaders and diamond wires and the situation gets increasingly worse.

Each component added to a mast will add another cause for variations and deteriorates the dependability of the end result. Length quickly aggerates the overall effect (=amplifier), Tornado masts are part of the longest and most complex in the business, Finn masts are among the shortest and simplest. (Spreaders/no spreaders etc)

And there your Finn class comparison falls flat, again.

You may be a very good sailor, but you may want to stick to what you known best; driving a boat fast. Because in all honesty you are not very knowlegdeable about any engineering stuff and that includes the 3D sail stuff.

Wouter

Ohh, I'm loving this !

Remember everybody ; "three times the masts ..." at 7500 euro's a pop!

That investment is enough to make a new die, 50 aluminium masts and pay for transport to anywhere in the world !

If these each top crew would have gone down that route, they could have picked the best 5 masts from the batch and sell or scrap the remainder and be MORE One-Design then with the carbon mast upgrade and spend LESS money !

Wouter

Hey, that's the point I was making earlier up this thread...Looks like I scooped the WOUT! <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Do I win some kind of prize? <img src="http://www.catsailor.com/forums/images/graemlins/laugh.gif" alt="" />

Tornado,




Your posts were indeed by far the best in the thread and spot on.

You should earn the respect by everyone for that, but I'll doubt you'll get it.

But at least you have my respect.

Now, if everybody will excuse me. I have to finish the dynamic modelling of a harbour side sea container crane. Was supposed to have that one finished last week, but ... don't tell my boss that !

Wouter

Actually the fact that the Tornado has diamonds makes it easier to control the dynamic bend.

Have a look here for the Tornado mast static bend tests

http://www.tornado.org/html/carbon_mast_data.asp

Also a Tornado mast is nowhere near the "longest in the business" nor is the Finn "among the shortest" as you say...

A Finn mast is just over 6.5m long and a T mast is from memory 9.2m.

As an aside, we had two masts built for an AC boat, we wanted them identical. Guess what! they were, both in static measurements and in use. The methods used to measure those masts were the best possible. The 5 sets of spreaders, running backstays, jumpers, checkstays and other bits I can't really talk about here gives an AC mast a lot more variables than the single set of diamonds on a Tornad mast. Yet its possible to produce two masts with the same bend properties?? defies belief hey!!

So its possble with a Finn mast (6.5m) and an AC mast (32m) and the Tornado mast is somewhere in the middle of those two in length...

Also the section size of the Tornado mast is much larger than the finn mast, both in real terms and as a % of length compared to the finn mast.

Oh, and using extruded alloy tube as an example isn't so good considering alloy tube inconsistencies is the whole reason we went to carbon in the first place!

My mast is #214 on the static load test chart. It's one of the heavier sticks at 15 kg...and it would appear to be on the stiff side of the average. Equal port/starboard bending.

Macca,

How does one derive the dynamic flex measurements? Is it subjective...go out and fit a sail and sail the boat? Do you then take that sail and put it on another mast and try to guesstimate the differences? How are diamond tension, spreader arm angles, hound positions accounted for?

Can the variations been tuned out to fit a given sail via adjustments to diamonds/arms/downhaul?

Most teams take the same sail and test it on different masts, if the diamonds (spreader rake and diamond tension) are the same (hence no longer a variable) and the sail sets up differently then we further investigate the mast.

Measurements are taken with a fixed camera rig mounted on the top of the mast, offsets are measured and the differences are measured.

We also measure the mast in use with load cells attached to the diamonds, mast step, shrouds and forestay. This is recorded and matched to the photos taken at the time.

Interestingly some masts, Such as yours, are stiff in the static tests and soft in the dynamic situations...

Small variations can be tuned out but its hard to get really confident with one mast then change to another. they behave differently accross the wind range. Not so much of a problem if you only have one mast though!

bad form to change a post that has alreay been commented on.... You had alloy as your example before realising it wasn't really working for you hey....




Funny that I get employed to fix problems engineers create then... Still waiting for the proof on the 3DL broadseam too by the way. I have a contact list for North Sails here if you want some email addresses or phone numbers.

Theory is just that... theory. The real world is different to what you have learnt in school. There are some companies and individuals in the sailing world that can and do what you claim is impossible. Well the proof is in the doing and they have done it. BMWO have two masts for USA 87 that are identical in any and all practical ways. The masts are over 32 metres long and have many "variables" like spreaders and associated standing and running rigging. By your reasoning the bend should vary between masts by metres at that length! when in fact the variances are measured in 10ths of a mm.

Stick to school champion, I'll stay out here in the real world. <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

You are correct that the investment is large, but small compared to the rest of the campign costs.

A Tornado mast is not 7500 Euro each though.... more like 3900 Euro a go, but who really cares if you are out by over 50%... wouldn't be the first time.

The whole point I was making is that the masts were voted in to be a one design mast, therefore negating the need to have a quiver of masts like we used to. The project has failed in that regard.

The masts are excellent in all other regards, they rarely break and can take a lot of abuse. The boat is much nicer to sail both upwind and down. rigging is super easy now too <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

Doesn't work that way. That only equalizes the pretension of a spring of still unknown spring constant variation and it is exactly the latter that is most dominant in determinining the dynamic behaviour. In effect the level of pretension has absolutely no effect on the range of the variance of the diamond wires spring constant. Interestingly enough, these rods are either extruded or rolled to their shape; processes where Macca has nothing but disdain for as signalled in oen of his latter posts.

Again this is a perfect example of how a static situation can differ significantly from a "dynamic" situation; exactly the situation we have encountered with the Tornado carbon mast for example.


Or explained by a school level example :

Hang two identical weights from two individual springs (or bungee cords) of unequal length.

The tension in both springs is as identical as the weights are but when you let both systems oscillate up and down then you will see significant differences in oscillation time, travelled path lenght and momentary speeds.

Everybody can do this experiment at home and witness the above results themselves.

We must be careful not to convince ourselves of viewpoints that are not truthful.

Wouter

It is indeed, however

my post was already finalized at : Mon Mar 03 2008 11:13 PM

while your reply was finalized at : Mon Mar 03 2008 11:48 PM

Meaning that according to you I'm now also guilty of being clear voyant !

Wouter

You almost make it look like you feel schooling is a bad thing.

I guess we can't all be be born with superior knowledge pre-installed, so us mortals just have to take the bad (schooling) with the good (times) in this respect.

But to get to your AC mast example. I will garantee you that those are masts are indeed not identical. They are made to behave identically from the viewpoints of the measured values by several fine-tune mechanisms like multiple stays and spreaders. As such they fall under my earlier statement :



As found in this posting : http://www.catsailor.com/forums/sho...umber=136138&page=0&vc=1

Sadly the Tornado mast lack sufficient adjustable mechanism to do the same thing. The most obvious example of that is of course the mast section above the hound and diamond wire fitting. This is a pure cantilever. But also the bottom part is not much different as the mechanism that is avaliable, diamond wires/spreader, is already used up by setting the STATIC prebend. In fact it would be better if the masts were first measured for their dynamic behaviour and then had customer diamond rods selected to complete the variance in these. The choice to go OD down to the diamond wires rod is actually aggrevating the problem as that removes a degree of freedom from the system that could be well exploited.

Explanations exist for all the other questions you keep repeating and I won't refer you to these answering posts anymore because you simply ignore them anyway.

Wouter

Your use of an AC boat mast is a poor example, pay any engineering company enough money and you can get a pretty reliably consistant result in most production methods from being willing to sacrifice any unit not in specified tolerances.

With the AC boat masts my guess is they made 10 or so masts and hand picked the two most similar, probably trashed the rest so that other teams wouldn't be able use them.

To get consistant results within tight tolerances from a budget production method ( marstrom for example ) one would have to over engineer the product so much to over compensate layup differences ( after all humans did design the engineering process )that the end result would look similar mast to mast but not the lightest nor cheapest

Or, look at it another way...Make ~400 AC masts. Now do the measuring...see how many are "identical".

I'm willing to bet at least 2 Marstrom masts are "identical".

Also, pay Marstom a proportional amount of $$$ to build two masts identical and see what happens.

P.S.: Macca & Wouter...please take your long running personnel attacks back to the F16 forum where they came from. They are getting tedious to wade through and I'd hate to see the general forum require moderators.

Macca,

I hope these guys don't deter you too much from posting. I for one enjoy the insight given from someone who is competing at a level I can only aspire to. I'm also an engineer and may not agree with everything you say, but I think you make some very valid arguments and raise some interesting points. It's also interesting to see how if you don't align with some people's personal agendas, they try to shoot down everything you have to say. It definitely provides for some good entertainment.

No no no no we don't want them back on the F16 forum, let them stay please <img src="http://www.catsailor.com/forums/images/graemlins/smirk.gif" alt="" />

Wayne, Whilst there is a lot of money spend by AC teams, I can assure you that they don't apply the "lets make a dozen masts and see which one we like" method!!! An AC mast costs close to 1million Dollars!!! If they spent money on a dozen masts how would they do the important things like pay crew salaries? <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

Wouter: I see no point arguing with you anymore, your point of view is based totally on theory, mine on experience. You will always pull some abstract example to support your point of view and whilst that may make you feel better, it just doesn't have anything to do with what actually happens.

The fact that you can convince people like Wayne that the only way to get two identical masts is to build a big batch of them (costing a minimum of $10 million) and pick the good ones is to say the least, disturbing...

Actually Wouter had very little to do with my post, just good old common sense enginnering dictated that.

Your comment that an AC mast costs in excess of $1000000 dollars sort of confirms things as there certainly isn't that sort of cost in composite materials more like 10K max ( you can buy an awful lot of carbon rovings for 10K ) my guess is that an awful lot of masts are made and scrapped, you just never are told about it.

If the manufacturer struck lucky with the first couple then man he certainly would be makiing fast bucks <img src="http://www.catsailor.com/forums/images/graemlins/smirk.gif" alt="" />

Mmmmmm OK Wayne, if you can order enough carbon for an AC mast for 10k, good luck to you.

And I can assure you there is not a secret pile of discarded AC masts lying around Hall spars or Southern Spars...

I guess this is one of those cases where engineering logic differs from the real world..

Just another thought Wayne, the mast tube for an AC boat weighs over 600kg, Thats a lot of carbon for your 10k....

Which AC team was it last time that broke their ONE new mast and had to use a version 4 mast until it was fixed? Trust me people Macca is right on this, AC teams build only the masts they need. Poor teams build one. Slightly better of teams build 2 (one per boat). Rich teams have one spare maybe two.

It was +39 that had their rig broken in a clash of rigs with the UIT Germany team.

The +39 mast was actually made by Marstrom.

I'm seriously gobsmacked that the carbon in such a small hollow pole weighs 600kgs, surely you must mean inclusive of all the hardware, stress guages, rigging, instruments, pulleys, halyards etc, if so then yes you would need a lot more than 10K's worth of Carbon. On that weight it must seriously strong, sort of a carbon stick on Viagra ? <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" />

I'm out of this discussion.

I have just committed to doing my part in this research project in dynamic stabilizing these 52 mtr long laminate structures by (aerodynamic) trailing egde flap control. I'm afraid that means I'm out of much free time.



So what do I know about these things right ?

Wouter

Wanyne, with all the rigging (fixed and running), spreaders, load cells etc the mast weighs closer to 900kg.

So yes the bare tube is 600kg give or take.

The new mast on Wild Oats (100ft canting keel maxi) is longer and larger but lighter than an AC mast as it uses a higher modulus carbon than is currently allowed in the AC boats. It cost a lot more than an AC mast too...