AC boat, what went wrong here?

[ltcom]

I don't fully understand the buoyancy of these boats obviously because I can't figure out how this boat wallowed like a pig to sbd the to port with foils going up and down like insect legs before it got under way again............ in perfect conditions..............no sea at all. Can anyone explain what is going on? Are these simply great foilers and rubbish seaboats? tia.

 

[Tomahawk]

Talking with ine of the aero designers last week.He says the boat is more difficult to get up in low winds. Of you look at the hull, it appears to have a traditional keel. Obviously not as such but part of the aero package to develop lift once she is out the water. The problem being it. also helps stick in the water... (although the ideas was the opposite).

But once out thee water the boat is faster ... The problem is to keep it out the water which relies on crew work being perfect all the time.

 

[TernVI]

Looks like one of those moments when I catch a load of weed on the centreboard of my Laser.
Were they racing at the time? Maybe just chucking the boat around testing controls?
(I have no audio on this PC).

 

[Chae_73]

That was during a race. I seem to remember that they said there was a problem with the foil controller, and Team Ineos / Sir Ben blamed the NZ team for late release of a software update for this "one design" element of the boat.

Somewhat ironically, the nearest we came to a yacht race involving Ineos, was when there was insufficient wind for either boat to foil and Ineos proved to be quicker than the opposition in displacement mode. Maybe the keel came on handy? However the race timed out with neither boat completing the course.

 

[halcyon]

I don't fully understand the buoyancy of these boats obviously because I can't figure out how this boat wallowed like a pig to sbd the to port with foils going up and down like insect legs before it got under way again............ in perfect conditions..............no sea at all. Can anyone explain what is going on? Are these simply great foilers and rubbish seaboats? tia.

From memory, the boats weight around 7 ton, of that each foil weights about 1.5 ton so big ballast keels sticking out either side, so moving foils to stabilize the boat ? If day one they had major foil computer problems, were scratching up till the last minute.

Brian

 

[halcyon]

That was during a race. I seem to remember that they said there was a problem with the foil controller, and Team Ineos / Sir Ben blamed the NZ team for late release of a software update for this "one design" element of the boat.

Somewhat ironically, the nearest we came to a yacht race involving Ineos, was when there was insufficient wind for either boat to foil and Ineos proved to be quicker than the opposition in displacement mode. Maybe the keel came on handy? However the race timed out with neither boat completing the course.

Then NZ pointed out the email with the updates in had been sent Friday, we were then Monday ? when they had the problem.

Brian

 

[Laser310]

Talking with ine of the aero designers last week.He says the boat is more difficult to get up in low winds. Of you look at the hull, it appears to have a traditional keel. Obviously not as such but part of the aero package to develop lift once she is out the water. The problem being it. also helps stick in the water... (although the ideas was the opposite).

But once out thee water the boat is faster ... The problem is to keep it out the water which relies on crew work being perfect all the time.

i think all the boats have some sort of bustle below - UK's is maybe bigger and for sure is more angular

i think the main problem will come down to foil shape and/or foil control

 

[ltcom]

Thanks. 1min 13 secs as they rolled to port I thought at least the stbd foil is up [could have done with some crew standing on it too] and then they put it down? only to find that didn't work and then raised it again to regain the ballast.
Bit like watching remote controlled boats on a lake rather than sailing vessels. Looked a bit Laurel and Hardy too.........sure I would be a lot worse.
I am surprised they sail at all [looking very tender] in light air. They look like surfboards [but even less stable] with the only ballast being the foils held out horizontally.
At least previous AC boats were a bit more seaworthy. Bring back the J Class.
It is no fun when electricity on boats fail.
Poor Alex T with his radical boat didn't finish the Vendee because too many dangle things were vulnerable and one was hit. Ok if you want to break a record, but I think he just wanted to win this time didnt he? Thread drift there.
From America's Cup: The first week - two very different AC75's compared.
The US Challenger's hull is almost scow-like being with the beam being carried down the topsides before quite a hard turn of the bilge into a nearly flat bottom. While some through the fence images had emerged of the New York Yacht Club's Challenger, the full extent of the unorthodox hull shape was not revealed until Friday, when she was photographed under tow and also on the hard, at her base in Newport RI.

Emirates Team New Zealand launched last Friday, with some interesting hull features the most obvious of which is a bustle down the centreline of the hull, and two deep trench cockpits with a flat sweeping deck area between.

Yes it is a race of designs, not sailing ability and skill now.

 

[Laminar Flow]

At least previous AC boats were a bit more seaworthy.

Does that include the Australian 12m that broke in half?

 

[Bobc]

Does that include the Australian 12m that broke in half?

I think that was an IACC rather than a 12m

 

[Rum_Pirate]

Thanks. 1min 13 secs as they rolled to port I thought at least the stbd foil is up [could have done with some crew standing on it too] and then they put it down? only to find that didn't work and then raised it again to regain the ballast.
Bit like watching remote controlled boats on a lake rather than sailing vessels. Looked a bit Laurel and Hardy too.........sure I would be a lot worse.
I am surprised they sail at all [looking very tender] in light air. They look like surfboards [but even less stable] with the only ballast being the foils held out horizontally.
At least previous AC boats were a bit more seaworthy. Bring back the J Class.
It is no fun when electricity on boats fail.
Poor Alex T with his radical boat didn't finish the Vendee because too many dangle things were vulnerable and one was hit. Ok if you want to break a record, but I think he just wanted to win this time didnt he? Thread drift there.
From America's Cup: The first week - two very different AC75's compared.
The US Challenger's hull is almost scow-like being with the beam being carried down the topsides before quite a hard turn of the bilge into a nearly flat bottom. While some through the fence images had emerged of the New York Yacht Club's Challenger, the full extent of the unorthodox hull shape was not revealed until Friday, when she was photographed under tow and also on the hard, at her base in Newport RI.

Emirates Team New Zealand launched last Friday, with some interesting hull features the most obvious of which is a bustle down the centreline of the hull, and two deep trench cockpits with a flat sweeping deck area between.

Yes it is a race of designs, not sailing ability and skill now.

I'd support them returning to mono hulls like the J Class yachts.

It is a 2017 article in the New York Times however : America’s Cup Will Return to Monohulls in 2021 (Published 2017)
"The Cup in 2021 will return to monohulls, the boats with deep keels that were part of every America’s Cup from 1851 to 2007 and are still the main ride for the Sunday sailor."

Sad that the rule 'journeying to the challenge on their own hulls' was eliminated.
Now the designs are not that seaworthy in comparison.

 

[scruff]

Sad that the rule 'journeying to the challenge on their own hulls' was eliminated.
Now the designs are not that seaworthy in comparison.

I agree with you there!

 

[Laminar Flow]

I think that was an IACC rather than a 12m

Australia One, was the name of the boat I believe. Pretty sure she was a 12m.

Seaworthiness in AC went out the window when the rule that you had to arrive on your own keel was dropped. Ironically it was this that enabled the Americans to hang on to the cup for as long as they did.
If there had been any type of rating in the day, the yacht America would have never won the race as a British yacht, Aurora if I recall correctly, passed the line less than 8 minutes after America. She was nearly a third shorter on her waterline than the American and by today's standards would have won easily by some 35 min. on handicap.

 

[Laser310]

Sad that the rule 'journeying to the challenge on their own hulls' was eliminated.
Now the designs are not that seaworthy in comparison.

that rule provided an insurmountable advantage for the defender

 

[scruff]

that rule provided an insurmountable advantage for the defender

potentially easily overcome - one regatta at the Defender's Yacht club and a second at the Challenger's. Boat's must sail between the two - either racing or in delivery mode.

 

[Laminar Flow]

Be that as it may, I find the foilers completely fascinating, in a technological sense. Not sure though, how soon the technology will trickle down to the average cruising boat with it's apparent potential for Max jet worthy software failure.

 

[Laser310]

New video of INEOS - presumably after some work...

looks like more wind than they are likely to have in the regattas

 

[RJJ]

New video of INEOS - presumably after some work...

looks like more wind than they are likely to have in the regattas

For me this is the problem with this boats, and it seems an inherent feature of the design. If you optimise for a certain wind strength then in anything below that fall off the foils, the losses are colossal. It appears you could be (with a given set up) unbeatable in (say) 14 knots, but literally dead in the water in 10-11. The racing is interesting when boats are evenly matched, or when the speed differential is marginal, but nobody wants to see races won or lost by a leg and a half

With the cats, the hull displacement drag was so much smaller that you might fall off and lose a few seconds, but not minutes.

Presumably less of an issue the windier it gets.

For me, bring back the elegant IACC.

 

[TernVI]

...

Presumably less of an issue the windier it gets.

For me, bring back the elegant IACC.

It looks like they'd have trouble keeping the bow out of the water if a little more wind brought some chop with it?

 

[Laser310]

It looks like they'd have trouble keeping the bow out of the water if a little more wind brought some chop with it?

i think that they can choose how high to foil - within limits obviously...

they want to foil as low as possible, but if they needed to foil, say 6in higher.., they could do so.

also, the bow-down attitude is deliberate, they trim for it.., but are not forced to adopt it.