Mast weight and rightability

From the top is my head my, mast fully rigged but EXCLUSING the standing rigging (= forestay/sidestay) but including halyards etc (as the mast should be measured under F16 rules) is 21.7 kg. My tip weight incl. all that needs to be included is 8.3 kg.

My mainsail is about 1 kg heavier then the newer mainsail almost entirely because I full 100% glass battens and those weight alot more the fibrefoam battens.

I can right this rig unaided (righting line) in any conditions incl very light winds and flat seas. The latter is the most difficult to right a cat in. I weight typically 90 kg or just under it. Halve way through the sailing season I'm typically between 87 and 89 kg. In some wind or waves I can right the above rig significantly easier.

Wouter

Hi all,

I would like to ask you if you could tell me your mast weight and if
you are using righting aids when sailing 1up? Of course skipper weight
would be helpful to scale your answers to my own weight (76 kg's
nowdays <img src=

alt=

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G'day Valtteri
I sail with a mate who weighs 75 kgs and he use's 2 cloth shopping bags(they would hold about 6kgs of water each)he has them tied together fills them with water throws them over his shoulder and he can then get the boat up,if he doesn't use the bags he can't get the boat up at all,
Hope this helps
Richard

 

I'm 93Kgs and have no problems righting my Blade without assistance. I have not weighed the mast so I can not help you there. As I get serious about better race results I will start to chase numbers. I have a lot of learning to do before incremental weights are going to make a difference.

Cheers,
Neville

I am 73kg or so and can't right my boat unless there is maybe 10 kn of wind (maybe 8ish?) without some help from someone else or an apparatus. If I weighed 7kg more or so I don't think i would have a problem.
never weighed the mast though.

So let’s take a closer look at the case. If we have an 8 meter spar of 20 kgs and suppose that they are evenly distributed that means the centre of gravity at 4 m it would give us a righting moment of about 80kgm. If my CG is set at 1 m with my 75ks I’m fighting a loosing battle. If on the other hand we had a carbon spar of just 10kgs we would only need 40 kgm to bring this thing up.
So folks it has been suggested before and I take a risk to get banned, but it’s time to put your things on the bathroom scale and see what you are playing with. The naked spar should not be more than 15 kgs if you sail High Performance, otherwise you are sailing Heavy Problem.

Doesn't that make it illegal for you to race single handed? How many other people are in this situation?

So it takes around 80 kg's skipper (+gear) to right your boat. It would be interesting to know if that's measured with older light spar or with newer heavier mast.

Btw, I wish that we would something similar like T's mast data available online that would have helped us.

It’s maybe a little bit more complicated, so if somebody has the hydrostatics for a F16 it would be nice to have the GZ curves for the both cases. It’s affecting a lot more than the righting of the boat.
It will also affect the capsize angle, so a heavy mast will get you into the water a little bit earlier. Me included we are 3 to small guys for the moment on this thread

I'm only 70Kg guys - so you'll understand why I like the fact that the tipweight of my Stealth carbon mast is 6.6Kg and I can right the boat unaided in all conditions. I do have to go out onto the tip of my centreboard if the wind is light though.

I can not speak for Valtteri, but what I am after is a little bit more transparency in stead of protectionism. If somebody wants to buy or build an F16 he should be supplied with adequate information. I’m almost certain that Valtteri and I would have preferred to put the extra money needed to get a Stealth carbon mast and to be able to sail safely one up as it was the problem of crew that did us make the choise. There is also another thing; building away those extra kilos is not possible, and you end up with a fat one.

AFAIK John P charges around £500 for a blank carbon mast. Is that what you mean by transparency?

You make a modelling error. IF the above assumption is true then you would also have AT LEAST 10 kg of tipweight which we know you don't. Even if the mast is 8.5 mtr as the F16 mast are then the tipweight would still be at least be 9.4 kg.

In fact the tipweight is all we need to make the righting calculations.

The minimum tip weight for the F16 carbon mast is 6.00 kg, the Superwings are in the range of 8.0-8.5 kg (Valtierri's is the heaviest I know of so far. This means that the difference in righting weight between the carbon guy and the aly guy is (8.5-6.0)*8.5 = 21.25 kg.

If we assume that 85 kg will do the job in all conditions then the carbon guy (of equal body length)needs to be at least 64 kg to right his boat and not 40 kg or something. In this crude mathematical theory that is as we have just totally ignored the weight of the stays + ails and the fact that water is clining to them. In fact the difference in reality will be less. Even more so when the sail is still curved and pulling the rig downwards because of the little wind that still flow across it. In fact the weight of the mast is not all the weight/force that needs to be lifted, it is only part of it.

The difference is not that much for sailing itself, it is indeed for righting. However I do agree that the F16 alu mast should be about 15 kg for the bare section. The only way to achieve that is to have a new die made. So if everybody will become a paying member of the F16 class then we may well buy a new die as a class and solve this issue.

Wouter

Thanks, that’s good information, but I was more thinking about issues like the fact that you have to weight for ex. min 80kgs if you want an alu mast, and that you will probably end up with a heavy boat.

Scarecrow,

Read the F16 class rules.

It only states you must be able to right the boat unaided. It doesn't specify the way in which you need to do it. As a matter of fact, things like shroud extenders can even make the alu mast rightable by sailor weight below 70 kg.

Wouter

My mast is of 2003

Wouter

The mast Valtteri was referring to is in fact the one of the Sydväst Blade and its 18 kgs tip weight 8.1 on a bathroom scale (they are often under the reality to pleas the one standing on it). So close to Valtteris as they are probably of the same making. So could somebody now for the transparency tell from when this die was used to make the mast and where did the old one go.

Everybody WAS supplied with correct information each time any info was asked. No-one can blame any other person for not supplying info when not asked for it. Also the fact that someone doesn't believe the info supplied doesn't mean that it is wrong or that it is part of protectionism.

The argument for the alu mast was and still is that that mast is the most cost effective way to a given level of performance. At all times it was agreed that it takes more body mass to right when using ONLY a righting line. And at all times it was suggested that this issue can easily be overcome by a righting bag or other aids like shroud extenders. If you are 75 kg then a small bag of 10 liters will easily do the job. Several F16 sailors are doing it this way. When there is some wind you won't even need the bag as with the correct technique the boat will come up with much lower body weights.

I'm truly sorry Gato, but it does really seem that a large portion of the way you view the situation is caused by the fact you look very negatively on the alu mast (incl. all weights and drawbacks you can find) and very favourably to carbon (ignoring all other factors in righting and limits in class rules).

The core of the situation is again the tip weights (yours was 8.0 ?, Val's 8.5 kg ?) The carbon mast tipweight is at least 6.00 kg as per F16 class rules, but these tipweights already exclude 5.0-6.0 in sail weights, 1.5 kg in standing rigging and easily a few kg in water sticking to the top of the rig after a capsize.

I have seen a 85 kg guy being unable to right his Stealth F16 with a carbon mast. We flipped almost simultaniously, I got mine up and he didn't. This is one indication of how important the other factors can be. They were enough to overpower a 2.0-2.5 kg tipweight difference.

While there is definately a difference in righting between alu and carbon it is very easy to over estimate or overvalue it. There are indeed other factors in play that can't be ignored.

Wouter

No records are kept on individual masts. As such I do not know from which batch you mast came from. The mast did come from Catamaran parts stock which may well be a portion of the VWM stock. Masts from these stocks are no older then 2004, although I know that VWM was included in more then 1 production run of masts so your mast can be well younger. In fact I expect your masts to be 2006 or younger.

I don't understand the last part of your question. I'm sorry.

Wouter

It was only referred to one mast option in the building instruction, but I hope when you are selling the same boat you are giving a choice. My hulls will anyway end up with planks nailed across serving as a platform to go into the water after the Sauna, and I am scared that you are about to insert the last nail in the coffin of the F16 class in Finland at least for the moment.

I think everybody would feel sad if somebody has sold you a 18kg tube to put on top of your boat, when you discover that you could have bought a carbon tube for the same price: 500£ What is cost effective in that for the buyer?

It is always somebody else his fault right ? Never your own !

You would maybe have a point if you were adviced to get alu while the persons doing the advising had carbon themselves. But as a matter of fact neither the designer of the Blade F16, the builders VWM, Australian Formula cats and AHPC nor I myself are sailing with anything other the alu.

Forgive us for advising something to you that we felt was good enough for ourselves !

I'm sorry to hear that you are unsatisfied with the Alu superwing mast, that you are unable to build down to minimum weight, that the Pixie and F12 are alot easier and quicker to construct. I'm sorry to hear that this will be end of F16 in Finland, but you really can't lay this on our doorstep. There is such a thing as your own responsibility in these matters. Hell, we also weren't there to tell you that you should have bought a Toyota instead of an Opel automobile.

I'm truly sorry Gato, I'm very happy with my 121.8 kg homebuild F16 with an alu mast and 8.3 kg tipweight. It is the right boat for me and I've never gone this fast on the water for an investment of 12.000 Euro's. If your threshold of satisfaction is so much higher then mine (or others like the Blade F16 designer) then I guess we just have a difference of opinion and the F16 class is not for you.

Wouter

The quotes I held at the time (even from Stealthmarine directly) were considerably higher then 500 pounds.

Wouter

There is nothing wrong with the hulls, it’s what’s “going around”. There is the first A cat coming to Finland so my thoughts are drifting in that direction...

So is it correct that there have been two different dies (I wasn't aware of that), or is that the part of the post you are saying you don't understand?

I've read the thread a couple of times, but I'm not sure I'm understanding your concern Gato. Can you clarify - is it that you feel that you won't be able to right the boat, or that your boat is not going to make minimum weight? Or that you bought a mast that doesn't have minimum tip weight? Or something else?

There are NO TWO DIFFERENT DIES of the superwing mast that I know off.

As far as I can tell there is only one; but while I'm often pretty up-to-date on these matters I can always be wrong.

I have been part of a project to design a new alu mast to replace the Superwing section but that project was put on hold before a new die was made. To my knowlegde this project has not been revived. Maybe that is the source of the rumour ?

Wouter

Well, was thinking to stop, but as you ask, one of the reason is that it’s very hard to get a straight answer to a simple question. Take as an example my question about the die, either the one who knows doesn’t want to answer or has not seen the question or is hiding the truth of some other reason, those who don’t know do better leaving the question unanswered. For me it’s clear, if you take a new die in use you check the result. And as the old die was giving tubes 14-15 kgs you expect something like that when buying no?

The A-cats are excellent boats. It is very understandable to have your thoughts drifting that way. If that class is suiting your mindset better then by all means go for it.

If you want to homebuild an A then I can assure you that the available building plans for A's are alot less complete and alot more dated then the F16 plans. Building a 75 kg timber A-cat to min weight will be alot more challenging then building a F16 down to weight.

But maybe we have another solution. Considering you feel so passionate about a carbon mast and having it replace the aluminium one then why not do exactly that ?

Order 2 carbon masts from Stealthmarine (after getting a definate price quote) and ship the alu masts back to catamaranparts where they are sold off as secondhand. Sure you'll loose some money in the proces, but building c.q. buying a complete new A-cat will cost lots more.

Or better still, sell your alu masts to the Norwegians and Swedes. There is a Swedish Taipan owner who bend his mast when his boat tipped over in a blow. You guys will meet in the spring time for a Scandinavia F16 regatta right ? Maybe the perfect opportunity for selling off your alu masts while getting some good return of investment. Then you can order the carbon masts and be happy again. I'm sure Rolf is interested in the mast, if not his friend who ordered a new F16 design but that still needs to be shipped to him. Removing the mast shipping costs may well be attractive to him.

It's an idea.

Wouter

I'm happy, just started to make the first half of the mast for the DS12.