34th America's Cup: multihulls!

Hmmm ...

If we want to have a legal battle ...

I think the Deed requires a 44 foot minimum waterline?

Is it legal to sail a boat such that it is not legal?

Remember the big deal made about the LWL of USA 17 being greater than 90 feet while sailing? Now we have a case where a shorter waterline (or no waterline?) is faster than a longer waterline.

A foiling AC72 has no waterline; foils and appendages are excluded from the LWL measurement. (Refer to the exclusion of USA17's rudders in AC33)

Just saying that I don't think a zero LWL boat can sail for the Cup.

R

 

Static waterline.

Every boat ever with an overhang is designed to increase its LWL when heeled and the boat starts to move.
Every boat in existence has its water line go shorter when it sails over a wave.

you are grasping here.

 

All the rules about LWL are based on the assumption that longer = faster. Sailing over a wave is not a steady state condition.

The Deed requires that the boats have a 44 foot LWL minimum and 90 foot LWL maximum. The extreme overhangs of the past were to achieve a sailing length of more than 90 feet.

I'm not trying to make a point or grasp at at anything. The question is honest and legitimate.

What is the LWL of a boat on foils?

It seems to me that when foils enter the picture LWL ceases to be an indicator of speed potential and it's usefulness as an entry criteria for a sailing event has changed. When any new technology emerges, the rules need to be looked at and in some cases changed to keep the intent intact. I think foiling sailboats are an example.

 

Now you are talking about assumptions backing up a 130 year old document. We can go back and start parsing that the deed guys would never have contemplated a catamaran and therefore it should not be allowed... Thanks, we did all that in 2008-2010. It's a very dead end argument as we all know.

again, static condition is what things are measured in. Static not steady state. If it was steady state, why do measurers not go out sailing with crews with power boats alongside to measure how long a boat is? Or put boats in full scale tanks for testing. Would a rule not specify, the LWL shall be measured in a steady state at a reference boat speed of 8 knots through the water? Not 10 not 6 but 8 knots?

In steady state every boat in the AC has been longer that its measured waterline length and has also been shorter at times. Is measured length absolute, no shorter no longer, of course not. That's why we all pick static LWL, it's the only time things can be nailed down enough to be measured, and its the reference point that all rules use, really only as a starting point.

If you want to parse the rules, post the actual words of the deed, then we can play semantics properly

 

The Deed would certainly have meant that the boats were at rest. Anything
else would be arbitrary, especially in waves.

 

The catamaran question was answered in 1988 or so. It was not new in 2008.

The original deed specified a range of tonnage and did not reference LWL at all. The reference to LWL came in when the handicapping rules of the day used LWL.

The latest shitfights over LWL were the NZ HULA and USA17's rudders. The definition of LWL for AC purposes has been established to not include appendages. Thus a foiling boat has no LWL at all when up on the foils.

The comment about every boat in the past does not apply. None of them were designed to sail with no LWL.

This is something that measurement and class rules have not needed to address before. I think this will be part of sailing in the future as the range for foiling sailboats expands.

This thread seems to be the logical place to bring up the question.

R

 

Rule cheaters (oooops, pardon me - meant to say "creative-minded rule interpreters") have always been part of the AC as well.

The set of rules for this edition of the AC was directed (imo) towards a creation of a fleet of boats with as similar characteristics as possible, with just enough space left for the innovation in the detail design.

The first one (TNZ) which took off on foils has completely spoiled the original intent, but as soon as other teams have adopted the same technology the race was again brought on the same even ground. The LWL problem might have had a relevance if just one boat foiled and the others not. It is not the case here, as they all have the same (almost zero) LWL when on foils.

 

Well that's why they call it LWL, Load Water Line.

E.g. when its loaded in a static condition.

This is why every rule or set of rules usually has two parts, one is the rules themselves, one is the way in which those rules are measured. So show me the part about how LWL is measured on an AC 72. Oh that's right, it's spelled out pretty clearly in the rule, its a static measurement taken with the boat at rest in the water.

"The waterline length (originally Load Waterline Length, abbreviated to LWL) is a measurement of ships and boats. The term denotes the length of the vessel at the point where it sits in the water. It excludes the total length of the boat, such as features that are out of the water. Most boats rise outwards at the bow and stern, so a boat may be quite a bit longer than its waterline length. In a ship with such raked stems, naturally the waterline length changes as the draft of the ship changes, therefore it is measured from a defined loaded condition."

 

Could be. I just think that this AC edition is getting enough stuff for the lawyers to feed their bellies for the next 2-3 years.

 

It was well known by the team that developed the AC72 rule, that everyone would be using foils for some fraction of lift when under way, from zero to some number higher than that. The authors of the rule thought, based on historic examples, that without active control surfaces that nobody would TRY to do fully foiling, because it would just be too risky to the whole show. so by extension they felt that there was no need to specifically ban foiling. They also knew perfectly well that if you built a boat with 90% lift fraction at some speed, a boat like that would periodically fly even a little bit coming out of wave tops etc.

Now the fact is, that there are authors of the rules in the two camps that matter, both ETNZ and OR. M+M had as much input into the rule as did Fresh Ian Burns on OR.

The fact that one team engaged in tunnel vision while the other team took a more expansive approach to the rules, well, that's the AC right there for ya.

 

34th AC

The rules are specific for the 34th AC. See below. The boat is measured "floating in measurement condition". No measurements are taken when foiling.
Remember, this thread is about the 34th AC as it is not how we might like it to be. It's easy to start another thread about a subject not relevant to the 34th AC.......

 

So we are fairly certain that no one is going to ask the question. Cool. It was mostly a Monday morning musing.

 

In fact, we are discussing the AC as it is, Doug.

 

Doug Lord as thread moderator, now we are entering the surreal to the sublime.

 

Now when Swedish Artemis is out of the race they should install vertical control on daggerboards and rudder, "flying moth style" and get the boat to full potential. Would be cool