Taipan 5.7 was advertised at 135 kg and texel measured it at 136 kg. One of the few boats that were actually near their proclaimed weights when checked by Texel measurers.




This is actually quite funny as Marstrom is producing its M20 at ... 127 kg ! (Texel measurement). Marstrom started at 108 kg but over the years the M20 has gotten heavier and heavier. Still I fully believe a 120 kg F18HT is possible. Especially since these boats have no jib and this allows the bow sections to be constructed lighter.





That is no small condition to be met

Wouter

The weight that was mentioned on the Texel M20, was that the boat that Marstrom sailed or not?
You mentioned 108 kg, was that an actual weight of an M20 measured at Texel?

The reason is that I'm a bit curious on how much weight you add with following modifications that some of the M20 have made:
* stainless steel rigging instead of carbon
* mainsheet system with blocks at the end of the boom instead of a cascade system.
* snuffer instead of a snail.
* Mainsail weight, could easily be 2-3 kg extra here, depending on type of cloth and battens.

Other differances:
* External halyard for the spi instead of an internal, no weight differance but it will kill the speed for a uni rigged boat if the halyard is dangling in front of the mast.
* snuffer instead of a snail (again). Lower windage and it keeps the weight of the spi close to the mast when furled.

/håkan

Tim,
I sold my HT and missed it, so I turn around and bought a different one.

I wasn't at the F18 Nationals, that was an effigy.

I like the Nacra F18, its a good looking boat. Simple, clean.

Bill

Wouter



Agreed

Bill

we weighed, the new eagles, new ventilo and the current Javelins.

there are two types of eagle's 18HT, one is build full out of carbon (not the shrouds and the stays)
this boat weighed 125kg with the lighter boards. To measure to our class rules, heiner made two heavy daggerboards filled with some lead.
the glas variation of the eagle had 135kg with the lighter boards.

the new Ventilo (carbon hulls) weighed 133 kg.

to our surpise the new Javelins (glas and vinilesther) were very light, our new boat weighed 128.5 kg.

But I think that it is not too easy to reduce the weight of the whole boat, without making the boats too expensive.
The importand thing for our class is to have affordable boats and a good number of sailors. I think that 130kg is allready quite light.

Hakan and Wouter,

Ref: http://www.marstrom.com/administration/Boats/M20/index.asp

Marstrøm themselves list the M-20 weighting 115kg's (dont know how current that number is). With the modifications Hakan mention, the boat measured at Texel could easily have gained 10kgs.

Hakan, why did they switch the carbon rigging for stainless, and why did they remove the cascading mainsheet? I am a bit surprised that they went for a two-block mainsheet system, as the cascading system has been well tested on the Tornado.


Rolf

Actually I don't believe Hakans modifications can account for 10 kg weight difference.

Hakan names

* stainless steel rigging instead of carbon
* mainsheet system with blocks at the end of the boom instead of a cascade system.
* snuffer instead of a snail.
* Mainsail weight, could easily be 2-3 kg extra here, depending on type of cloth and battens.


Stainless steel rigging weights 2.5 kg or less in total. Carbon rigging something between 0.5 and 0.7 kg
Mainsheet system weights 1.5 kg in total when using a lightweight sheet line like swiftcord. Cascaded system shall not be lighter than 0.5 - 0.75 kg
Snuffer ring and sock are lighter than the Marstrom snail.
Mainsails are surprisingly invariant in weight, this is mainly due to the fact that the reinforcements along the sides account for most of the weight together with the battens. My mainsail is only 8 kg in total, I suspect that the M20 mainsail is only 10 kg in total. saving 2 to 4 kg on a total weight like that is no small modification ! You just don't safe 20%-40 % on an item like that. But even if we could than we'll would end up at (2.5 - 0.5) + (1.5 - 0.5) + (0) + 3 = 6 kg weight difference in the worst case scenaario.

Personally I'm convinced that they are producing the boat heavier, i.e. the hulls etc.

But moreso :



With marstrom I have learned to ask :"is that including or excluding the sails ?"


Wouter

There are several Texel measurements. Starting back in 2001 or 2002 up till now. The first weight was 108 kg and now we are at 127 kg. I seem to remember that we passed 115 kg along the way at some point.

I don't know which boat Marstrom sailed himself.

I think we can trust the Texel measurers to weight the ACTUAL weight of an M20. But then again you never know what happens behind the closed doors. Maybe the boats provided for measurement were weighted down to get a favourable handicap.



See my other post. Quick answer is "Not that much weight". Certainly not 10 kg. Don't forget that the guys owning the M20's aren't skimping on parts. They are not sailing with heavy duty dacron sails if that is what you are asking. All are sailing with modern pentex sails. It is also my experience that sails don't differ much in weight.

Marstrom is simply building these boats at a higher weight than he was in 2001/2002. 108 kg to 127 kg is a big difference; you don't get there (19 kg) with some heavier mainsheet blocks and stainless steel rigging. The difference is just way too big for that.




hummmaaah, this is a bit strong. It certainly doesn't kill the speed. If anything the speed difference is within 0 - 2 % = on a par with a bad tack. And then it also dependents on which tack you are sailing. Having the halyard on the windward side of the sail will hardly make a difference at all. Theory predicts that as well. One reason why to have the halyard on the starboard side of the boat !

We have heard all these claims before and still the spi boats are going strong.




Maybe. Weight spi = 1.2 kg weight snuffer ring + sock (on my boat) = 1.5 kg. Position ring and sock on my boat = on average 0.7 mtr in front of the mast. Net difference between the snail setup and snuffer setup = negigliable. The weight is too small to matter much in the big scheme of things and the difference in leverage (0.7 - 0.4 ?) is too small to result in a meaningful moment difference.

wouter

Wouter

yr statement about mainsails' weight is absolutely INCORRECT.

At 8 kg with battens yr main is VERY heavy. You can save easily 2-2,5 kg on it!
In order to prove my assumption I provide you with some figures (as you know 16HP mains are smaller than 18HT mains, but bigger than A class):

A class mainsails weight (with battens) between 2,0 Kg (Extra-Light Oxosails) to 4,5 kg, the average being between 3,0 and 3,5 Kg

18HT mainsails weight between 4,5 Kg (Ullman Cuben Fiber/RBS carbon battens) to 6,5 Kg (BIMARE Pentex /Fiberfoam battens).

Well, that is what I remember for it. Although I'm now not sure wether this was all the sails together with the bags and boom or just the mainsail and its bag. We'll know tonight.



Doubtful. I have Contender Apen06 pentex cloth mainsail and jib. Made in 2003 (main) and (2004) jib. The are sails made for racing by Redhead sails and Goodall sails. I expect these to make state of the art sails. Besides I know that all the other makes (F18's and such) are using sails made of exactly the same cloth. I lifted more than a few F18 sails this season and none are near 2.5 kg's. My mainsail will certainly not be several kg's heavier than they are.



True, but by far most of the weight is concentrated in the battens, bolt rope and reinforcement patches in the corners. These hardly change when ordering a smaller or bigger sail. Therefor adding or subtracting a sq. mtr. in the middle of the sail will not alter the overall weight much. I fully expect my mainsail to be within 0.5 of the A-cats and within 0.5 kg of the F18's. The difference in area is just to small to account for a bigger difference. But I have never weighted an A-cat mailsail I admit.





2.0 kg for an A-cat mainsail with fibrefoam battens ? You've got to be kidding me mate !

My 17.5 sq.mtr. spinnaker sail (nylon) weights in at 1.25 kg and it has no battens at all. No way you can have a mainsail for only 750 grams more (= weight of a filled beer can)

I think you are making a conversion error here.

Besides on the net sailmakers talk about 30 % reductions in weight when using cuben fibre cloth. Meaning that the OLD sails would only weight about 1.3 * 2 = 2.6 kg. = about 3 kg. No way, I don't believe that,





I think that 6.5 kg is more like it. I will check my own main tonight.

Wouter

I have 4 data points on A cat sails.

Contender AK3 with Fiberfoam battens 4kg.
DP KX06/04 with Fiberfoam 4kg
Bimare 2005 xj main with Fiberfoam - 5kg
Bimare 2004 xj main with Fiberfoam - 5.9kg.

2kg sounds pretty thin....

Remember, most sail makers will built you a sail on the heavy side to be safe. You can't see it stretching and losing shape, but you can see it rip and wear. My personal opinion is that a lighter sail is better because sails stretch, and shrink from day one...so a sail built out of heavier material will only lull you into thinking the sail is still in good shape long after its a piece of crap.

Go with Kevlar, its going to fail (rip) instead of stretch -then you know its time for a new one.

Bill

Wouter,

I regret to prove you wrong but I do repeat my statement.

I had the opportunity to weight up an "Extra-Light" Oxosails mainsail (Cuben Fiber/special Oxosails carbon battens)at an International A class event:
it scaled up at 2,1 Kg.
Oxosails has a remarkable track record for A class mainsails. Have a look at their official website to verify:
http://www.oxosails.com/prod01.htm#a%20class.
The owner, Manuel Vaccari, is a well known and respected A class guru and an excellent A class helmsman too. He is, let's say, a "cutting corners'" specialist.
If you read all the features of his latest A class design you'll find many interesting details and also the confirmation of my statement:
he says that his latest A class main weights from 1,9 to 2,3 kg.

The true is, as Bill underlines, that most sailmakers build you sails on the heavy side only to be safe. However it goes without saying that Oxosails main are not built to last: they actually last 1/3 of BIMARE mains and also BIMARE mains win important A class event (the latest being the 2005 Italian Open).

The choice is upon you

what is the THT2 class?

THT2 is a prototype (not a class!!!) built by Titan, a boatyard located in the small Republic of San Marino producing a few A class catamarans every year.
THT2 stands for Titan High Tech 2 (two crew boat).
Basically is a wider A class platform fitted with a taller mast, an Asymmetric and even a Code Zero.
This design resembles the Marstrom M18 and the Flyer XL, however these latter are intended to be sailed singlehanded.

It is true that the website says 1.9 to 2.3 kg for an A-cat sail including battens, but I'm still very sceptical. I want to hold such a sail and see it handle 15 knots of wind before I'm convinced.

On the same webpage, this sailmaker quotes 3.4 kg (ex battens) for a pentex mainsail comparable to one used on the F18's (Mattia Esse). This is still lighter than any A-cat sail that Bill Vinnig ever measured. His heavy duty dacron-pentex combination mainsail is only 5.5 kg. This all sounds extremely light with what I and other know/have measured.

Personally, I have serious doubts about these sails or these weights. Like I said my spinnaker alone, perfectly dry, is already 1.23 kg, I really don't see any mainsail, capable of handling 15 knots, weight less than two spinnaker sails.

But I'm open to be convinced otherwise, so when I see an oxo-sail I will certainly pick it up.

Personally, I'm not a fan of extremely lightweight sails, They bloody things just stretch very quickly and where I sail you better have a sail that can handle 25 knots with the occasional cannon ball gust. I'm very thankful that my mainsail has survived my crew falling into to it twice this season. (I have to teach her not to do that)

Lets keep this discussion open till I've picked up such an 2 kg OXO sail.

Just quickly meaured my sail package :

I weight 10 kg for

-1- one mainsail pentex
-2- 7 glass battens which I know to be heavier than the fibre foam ones.
-3- one jib sail pentex
-4- an extra set of 3 glass battens as spares and to flatten out the top in heavy winds.
-5- The bag in which the jib is stored
-6- The bag in which the mainsail is stored
-7- a 50 mm by 1.6 by 2.4 mtr alumumiun boom.
-8- a 2.1 mtr glass tiller bar that is used to connect the tillers on the ruddersticks.

All the battens together will be about 1 kg
The boom will be about 1.5 kg
The Tiller will be about 0.75 kg
The jib is 1.2 kg if I remember correctly
The bag together will not be heavier than 1 kg.

Therefor subtract 1 + 1.5 + 0.75 + 1.2 + 1 = 5.45 kg.

This roughly puts my mainsail at about 4.5 kg ex battens or about 5.0 - 5.5 kg with battens depending on what kind one is using. But to be safe we'll just add 0.5 kg as uncertainty margin => 6 kg for my, ready to use, mainsail with heavier glass battens

So the 8 kg figure I gave earlier was indeed for the two sails (main + jib) + battens + sailbags and not for the mainsail alone.

I didn't have time to take out all the stuff from the sailbag and remove the battens to measure the mainsail properly. I might try again this weekend.


Wouter

any details?

12 Kg above an A!! Not too shabby..
How does the Titan A fair in competition.. I guess it doesnt have any killer skippers so taking that into consideration?


Stewart

Sorry but I have no more details.
Keep note that the THT2 is still a prototype.
The Titan A class it is fairly good boat: 3rd at the 2005 Italian Championship and 14th at the 2005 A class World (if I remember well)

Hi Rolf, here my ideas why some customers made changes to their M20.
* Carbon rigging is a bit sensitive and you can easily cut a stay if you get a fast running halyard wrapped around it.
* Most T sailors has switched to a rear block system to keep the tramp clean for spi work, and it also a matter of "fashion", if the top guys use it the rest will follow. The cascading system has a limited "stroke", if you choose 4 times purchase between boom and beam and pull with a 2 times purchase on along the boom you have a "stroke" of boom length / 4. On the M20 casading system they use a 3 times purchase along the boom, a total of 12 times purchase. The limited stroke can sometimes get you into trouble in extream weather.

I don't think the hulls has been reinforced but the rudders and the centerbords are reinforced. The rough conditions in Holland required stronger foils! (Mitch Booth used M20 rudders and centerboards for his experimental Hobie design).
I'm not sure about the mast, it started with a single spreader with double sets of diamond wires to stabilize the mast section but was later switched to single set of wires and high modulus carbon fibre, and maybe more fibre also.

/håkan

The HT class rules dont specify or limit construction material for any of the components.

Sorry I was wrong.
The Titan A class was only 26th at the A class Worlds.