Groupama bites the dust-TJV DISASTER continues!

Just found out on the "multihulls" list and on the TJV website that Groupama has capsized. Franck Cammas is ok but Franck Proffit ,who was at the helm-may have serious injuries. This leaves five of the original nine Orma 60 multi's still racing.I love multihulls and have designed and built a 14 and 20 footer plus numerous RC models but this coming on the heels of the last Transat Jacque Vabre disaster is going to hurt the image of multihulls as safe ocean going boats big time! It was one thing when Orange Project(two broken crossbeams; capsize),Sodebo(port hull broke off), and Foncia(capsized; one crew nearly killed) but Groupama is the best of the best-best funded and some think best sailed and prepared of all the 60 footers and her capsize is an incredible misfortune for everyone involved and for all multihullers to one degree or another.
There have been fantastic multihull accomplishments in sailing around the world but the record in this particular race is abysmal-the last TJV disaster claimed a huge number of boats and now more carnage...
What do the rest of you think about this?

Transat Jacques Vabre
http://www.jacques-vabre.com/pages_u...eil_uk2005.htm

[marshmat]

I agree that this could be bad for multihulls' public image.
But it's important to remember that these were race boats. Race boats in general are built as light as possible and stressed as highly as possible. Many, many components operate on safety factors that no production builder would ever tolerate. Race monohulls break, too. Lots of race boats break, flip and sink. But when something experimental and exotic breaks, that draws a lot more attention than when the same-old same-old goes wrong.

[cyclops]

Racing has always been: " If you take a pound off , I will take 2 off ". Why is anyone even concerned. They love hurting themselves more brutally each year. Let them enjoy themselves.

[Van Nostrum]

Am I correct that none of these trimarans made use of water ballast? if they equalised the forces using water ballast then these capsizes would not have occurred.

Being able to fill compartments in the windward hull of a trimaran would allow for an equalisation of pressure across all cross beams rather than the complete weight being placed on the leeward hull and cross beams, with the wide beam the power gained would be extraordinary. Not only this, you would also have the ability to trim the weight for and aft, thus by filling the rear compartments they would be able to drive trimarans far harder before they nosedived.

The fact is that this kind of continued carnage will spook sponsors and put a severe hurting on offshore multihull racing-that's why people who know and love the beast's should care about stuff like this. Besides Damien Foxhall came damn close to getting killed on Foncia and I don't yet know the facts on Proffit.
I don't know the answer's either but there are some multihull people saying this kind of thing is irresponsible; I don't believe that-yet. These guys are professionals and know what the're getting into. The structural failures concern me more than do the pitchpole/capsizes.
These things are magnificent state of the art sailing machines -for the most part- but this just ain't good press...
============
Van Norstrum: "equalization of pressure"??? You definitely need help-why don't you start another topic on water ballast for multies and maybe you'll get it....

[sailsmall]

People ask those same questions about America's Cup when those boats break. The fact is that race boats are built as close as possible to what the designers consider to be the edge, and sometimes the edge is a little closer than that. And as far as sponsors and the public are concerned, the carnage adds to, not detracts from, their interest.

[Van Nostrum]

Doug, I thought you of all people would understand the benefits of water ballast, with a beam as large as these trimarans have not a lot of water would be required.

The general idea is that you put downwards pressure on the windward side so that the pressure on the leeward hull is decreased, when you decrease the pressure/stress on the leeward hull the pressure/stress on the cross beams becomes much more even, so you have twice the amount of cross beams doing the work of keeping the boat upright and sailing.

[Van Nostrum]

Originally Posted by sailsmall

And as far as sponsors and the public are concerned, the carnage adds to, not detracts from, their interest.

You are correct, the carnage is the reason people outside of sailing watch.

[BrettM]

Originally Posted by Van Nostrum

Doug, I thought you of all people would understand the benefits of water ballast, with a beam as large as these trimarans have not a lot of water would be required.

The general idea is that you put downwards pressure on the windward side so that the pressure on the leeward hull is decreased, when you decrease the pressure/stress on the leeward hull the pressure/stress on the cross beams becomes much more even, so you have twice the amount of cross beams doing the work of keeping the boat upright and sailing.

Um, Putting ballast in the windward hull leads to greater available righting moment at the point of flying hulls, which is generally where multi's are fastest, ie only one hull in the water and near vertical rig.

This righting moment can be used to obtain a compression load from the mast which is applied to the beams as a bending moment using simple beam theory. Increased rm gives an increase in mast compression.

Adding ballast to the windward side increases the max possible loads on the cross beams not decreases.

[Van Nostrum]

It appears that these boats are having trouble with their leeward floats/arms, meaning there is an excess of pressure there, by adding weight on the windward side you help to relieve this pressure, you help by balancing it more across the whole boat.

Flying on only the leeward float may well be fastest, however the way to avoid them falling to pieces is by sailing the boat flat on the central hull, this can be achieved by transferring water into the windward hull/ballast tank, the leeward hull would still be there for those unexpected gusts.

[BrettM]

Adding weight to the windward side allows the crew to drive the boat harder due to the available rm increase. It is a race therefore they will. Your solution is unworkable.

Under what conditions do you think the amas were designed to withstand? wallowing on the centre hull with the pontoons just kissing the water, or a racing condition that can be achieved. Suitable factors of safety added of course.

[Van Nostrum]

yes, there is that issue where the skippers will drive the boat harder

[FAST FRED]

Racing improves the breed.

When these big toys can be driven at high speeds without capsizing or destroying parts, better offshore cruising bosats will result.

Thanks racers ,stay crazy! Stay Competative!

FAST FRED

[SailDesign]

When a multihull is flying a hull, the leeward hull is supporting the full weight of the boat (that much is simple hydrostatics) and the added downforce from the rig being heeled.
If you add water ballast, then the leeward hull is supporting more weight, and the moments on the beams increase. Adding ballast to a multihull is simply not an option, as any multihull sailor (and many others) wil tell you.
Steve

[usa2]

the problem with multihulls is that they are great in relatively flat seas but they are rather horrible at weathering big storms because they cover so much area and are hitting waves with everything. The Open Class monos only have to deal with one wave at a time, but the ORMA multis have to deal with multiple waves at a time and the stresses can become unbearable, as evidenced by this race.