New Zealand's "Hula"...

Hello,

Just curious as to what design restriction exists on the ACC boats that forbid them from forming the hull to the desired shape *without * having to use an appendage? Presumably, if the current shape (with the appendage) were in fact one piece, the hull would be illegal? Why?

Thanks.

Robert

 

Have a look here !
http://www.cupmediacentre.com/dscgi/ds.py/Get/File-246/ACCRule.pdf

T.R.

 

i wonder how well it will work, seening as how many problems already have shown up in there boat

 

Well Looking at this last race it seems that the speed difference is quite small.
A well developed "normal" design such as Alinghi seems to be doing very well thank you compared to the kiwis.

On the other hand, the extensive matchracing experience of the swiss team gives them an unrivalled tactical and practical experience with the boat.

On the first race one thing struck me. Before they started to take in water over the side, I thought that they where pitching a lot more in the waves then Alinghi did. I guess this could have to do with their long bulb, it ought to increase the pitching moment in the kiwi boat.

And why DID they take in water? just a "user error" ie to much sail area or the wrong sails for the windy race or is it something else?

No answers just questions...

Erik

 

The short answer to the original question is that the enclosed canoe body of an IACC yacht is not allowed to have any hollows. Before measuring it the measurer takes a straight edge, which he can orient in any direction, to any part of the hull that he thinks might have a hollow, and if there's one found he will refuse to measure the boat until the hollow is filled with fairing compound and the hull re-faired. By complying with the definition of an appendage incl. allowing water to flow between it and the hull the hula is not counted as part of the enclosed canoe body. This allows the aft overhang to be at a shallower pitch while still maintaining the underwater (faux) volume aft for an optimised prismatic coeff.

 

Shame for them that it doesn't seem to have worked: 3 - 0 to the "Swiss" so far.....

 

The "no hollows" rule is what drove the hula as much as anything.

The other way to look at it is the hula allowed them to build the hull shape they really wanted, including a small bustle. Then by cutting slots in the hull down to 250mm from centerline, they effectively moved the measurement point inside the hull contours so the boat would measure in and the canoe would have no hollows. They figured the drag of the slot was worth the improvement in the hull shape.

The boat actually seems very close to Alinghi. They seem to be the only ones that can hang on to Alinghi upwind, although the Swiss did seem to be out pointing them slightly in the last race.

BTW, did you catch the water squirting from the hula slot on the upwind legs? Every time a wave crest passed, it was followed by a stream of water coming out of the forward edge of the hula.

 

did you notice that that water was not under pressure though??
it was only running out not jetting out so would only be natural for water to fill in that area between the hull and hula and when hull lifts out of water it would run out anyway!!!??>
don

 

i thought that the rules were suposed to create advances in boat design to benifate alll "around the boies" racers, if designers have to go around the rule to create the best design the maby the rules arent working?? excuse my spelling

 

Alas, with not so much as an Aussie challenger to the cup (and I guess with our all-conquering sportsmen & women winning every other contest under the sun ) our apparently land-locked media haven't seen fit to show more than the odd snippet of the racing....

 

An advance? Not in this case. The hula is a gimmick to exploit a loophole. I agree with Bruce Farr when he says he's surprised it was allowed.

 

our apparently land-locked media haven't seen fit to show more than the odd snippet of the racing...

.Not here either!

 

Any rule that claims to allow advances to benefit all boats, and has more than 1 line (usually stating something like "Max length to be........" is automatically lying. Restrictive rules (like the IOR) will always produce boats that exploit loopholes. When all the boats racing are designed to exploit the same unfillable loophole, then the Rule is dead, and we go on to the next "perfect" rule. After 100 years or more of this, you'd think we would have learned, but alas, we have yet to find a viable alternative.
Dang! That was negative, but it's been that kind of day. ;-(

 

I can,t say anything about boat speed but if New Zeland doesn't get agressive it will follow Alinghi around for five races. She definetly isn't faster with 1800 #of water on the winch deck.

 

whats with the experimintal boom that broke? whats the advantage of it?