Recon diary

[enigmatically2]

The problem with the orange is that when the jib sheet is anywhere but dead central and aligned with the orange it will torque the car on the tracks and jam.

They could maybe do a more elaborate job with the tracks to resit that torque. But you'd have to weight up the weight and friction of more sets of bearing / rollers versus this set up.

I sailed a merlin this weekend which is a 3D jib angle adjuster (not self tacking). But one problem with the system was that it twisted and became hard to move using only a central puller.

I did wonder about that, not sure what the loads are on these thing, but I do note that the main traveller movements don't look smooth in all cases as if the load is holding them in place a bit.
So the hydraulics could just be for smooth movement. But no-one else seems to have a problem, and although Ineos are moving the sheet angle, they have 2 tracks which I would have expected would reduce the risk of jamming more than adjusting the sheet angle is increasing (basing that on no more than engineering hunch)

 

[Dogfish]

If it can jam it will "sod's law".

 

[captainSackSparrow]

Like I talked about earlier. No pumping needed.

The leading edge of the foil could be filled with a fluid that holds it to the rounded shape of a typical foil. When at speed, a value could be opened (or pressure activated) and the fluid would be pushed back into reservoirs in the foil or foil arm. The leading edge of the foil distorts into a cutting edge that is defined by some framework within the foil … from ( to < …. The fluid reservoir could be under pressure such that it would flow back into the cutting edge and reform the original shape when the boat slows down to a certain speed.

The idea is to try to transform a normal foil into a supercavitating foil when the boat reaches the speed where it could use it.

Another idea is maybe just parts of the foil length are shaped as supercavitating (Zones), would that work?

That is my rough brain fart, what do you guys think

Like I talked about earlier. No pumping needed.

The leading edge of the foil could be filled with a fluid that holds it to the rounded shape of a typical foil. When at speed, a value could be opened (or pressure activated) and the fluid would be pushed back into reservoirs in the foil or foil arm. The leading edge of the foil distorts into a cutting edge that is defined by some framework within the foil … from ( to < …. The fluid reservoir could be under pressure such that it would flow back into the cutting edge and reform the original shape when the boat slows down to a certain speed.

The idea is to try to transform a normal foil into a supercavitating foil when the boat reaches the speed where it could use it.

Another idea is maybe just parts of the foil length are shaped as supercavitating (Zones), would that work?

That is my rough brain fart, what do you guys think?

This is fun thinking.

My thoughts would be this would lack enough control through tacks and gybes and also I'm not sure how you would manufacture this

 

[nav]

^ One wacky, overly complex and non-rule compliant suggestion after another and it's been repeated cup cycle after cup cycle, what drives these fantasies?
Perhaps follow a truly unrestricted class if this is what 'floats' your boat

 

[Stingray~]

10.6 The only foil arm movement permitted relative to the hull is cant, being a rotation about the foil arm cant
axis, a longitudinal axis whose position is defined in Figure 10.2.

This rotation rule relates to the foil arm only and so it's at least conceivable that the foil could pivot off the end of the arm.

10.1
Each foil shall comprise only:
(a) one foil arm and one foil wing, which shall be connected to each other according to a detail provided
within the foil arm stock specification.
(b) one foil flap; and
(c) one or more foil systems.

So, the pivot might be legal below the connection.

Some amount of pivot would allow you to for example keep the foil horizontal no matter the arm's rotation - if you wanted that flexibility.

 

[Mozzy Sails]

Big month for INEOS... only Magic put in more time on the water. The downside for INEOS is their manoeuvre rate and foiling manoeuvre % is pretty similar to Alinghi, rather than the other returning teams.

Even comparing to where LRPP were after a month of sailing their LEQ12, INEOS seem to be a way behind.

Magic again smashed the month. Most time on water, most manoeuvres, slightly less manoeuvres per hour and slightly lower success rate than ETNZ, but very close.

 

[Stingray~]

Do you have a graphic of nm's sailed?

 

[Mozzy Sails]

Not yet, will try to get it from GPS of recon boats in future

 

[Stingray~]

Not yet, will try to get it from GPS of recon boats in future

Awesome. With that GPS data you could derive other things too - including the recon boat speeds.

Sometimes the daily recon reports include nm's sailed, not sure how consistently they do so; and it's of course just an estimate.

 

[ChairborneRanger]

Awesome. With that GPS data you could derive other things too - including the recon boat speeds.

Sometimes the daily recon reports include nm's sailed, not sure how consistently they do so; and it's of course just an estimate.

it's pretty rough. The recon boat is pacing them sometimes, but then other times it's sitting at a mark, waiting for the right shot, cutting corners to catch up, etc.

 

[Stingray~]

it's pretty rough. The recon boat is pacing them sometimes, but then other times it's sitting at a mark, waiting for the right shot, cutting corners to catch up, etc.

For sure but on long runs by the recon boat it could be fun to see how fast they had to go, trying to keep up

Since Mozzy has access to that data, may as well have some fun with it if possible. It could even be animated into Google Earth or just Google Maps. @dorox for example has done some good stuff with GPS data.

 

[JALhazmat]

This rotation rule relates to the foil arm only and so it's at least conceivable that the foil could pivot off the end of the arm.

So, the pivot might be legal below the connection.

Some amount of pivot would allow you to for example keep the foil horizontal no matter the arm's rotation - if you wanted that flexibility.

Why would you want to keep it horizontal when every performance foiling craft has the foil angled relative to the surface on every point of sail

 

[Stingray~]

Why would you want to keep it horizontal when every performance foiling craft has the foil angled relative to the surface on every point of sail

Fine. Then use the imagined pivot to keep that foil angle where it's most optimal at the time. 'Horizontal' was simply my attempt to describe the idea.

 

[JALhazmat]

You can’t have a pivot.

 

[Stingray~]

You can’t have a pivot.

Am guessing you are right but I did not see anything prohibiting it among the rules posted above. So long as you connect to the arm in the manner detailed, you could apparently articulate under that.

Remember that the farther outboard the foil arm has the foil riding at, the more RM you get for the same foil lift - if you can get that same lift.

 

[enigmatically2]

I only posted a small selection of the rules

 

[JALhazmat]

ok fine they can pivot, flex, morph and do all the other bat shit stuff. I am done

 

[Stingray~]

^ There is a long history of rule benders in the AC. Some relied on a single word.

As examples even in only ETNZ's case, the cyclors in Bermuda relied on 'manual' and they did an end-around by using gantries on an AC45F to mimic the WL of an AC50 and (big one) somehow even pulled off within the rule the ability to foil an AC72.

It's not that far-fetched to imagine foil geometries will evolve in surprising ways. We are seeing it already in sail controls.

 

[enigmatically2]

The foil wing has to be connected to the arm as per the arm spec. We haven't seen that as yet, but all the evidence suggests it requires it to be fixed.

Foil wings and foil flap segments are components segments. So they cannot morph. And as there is only one wing that cannot pivot in the middle or anything. Flap segments can only rotate around one axis There is allowed to be a flexure area across them but there are limits on that too

 

[Kiwing]

They made the 72 foil in the face of a lot of rules making it impossible?