Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 26-09-2013, 01:17   #676
Senior Cruiser
 
44'cruisingcat's Avatar

Cruisers Forum Supporter

Join Date: Sep 2006
Posts: 7,454
Images: 69
Re: Twenty Knots

Hope all the critics are enjoying their meal of crow.
__________________

__________________
44'cruisingcat is offline   Reply With Quote
Old 26-09-2013, 01:52   #677
Registered User
 
DumnMad's Avatar

Join Date: Mar 2012
Location: Nelson NZ; boat in Brisbane
Boat: 45ft Ketch
Posts: 1,247
Re: Twenty Knots

2) Is there anything more that ETNZ could have done in the last week? Dana Johannsen & Paul Lewis

PL: Nope - they'd run out of money and they simply couldn't do whatever it was that OTUSA did to make their boat faster.

DJ: Probably not. Team NZ led the development curve in the new AC72 class the entire way, but Oracle, with their superior money and resources, caught up with them and overtook them in the nick of time.
__________________

__________________
DumnMad is offline   Reply With Quote
Old 26-09-2013, 02:27   #678
Registered User

Join Date: Nov 2011
Location: Fethiye Turkey
Boat: Lagoon 440
Posts: 3,164
Re: Twenty Knots

ETNZ hit their ceiling whereas the others continued chasing and succeeded congratulations
Attached Thumbnails
Click image for larger version

Name:	1378199_10151886650723685_535294427_n.jpg
Views:	65
Size:	40.5 KB
ID:	67905  
__________________
"Political correctness is a creeping sickness that knows no boundaries"
Lagoon4us is offline   Reply With Quote
Old 26-09-2013, 04:23   #679
Registered User
 
Jimbo485's Avatar

Join Date: May 2010
Location: some ocean down under
Boat: Kelsall Suncat 40
Posts: 1,247
Re: Twenty Knots

Beautifully put, Frank!!!!!

But I think a little thanks should be given to the cashola providers.

Maybe tomorrow......
__________________

Jimbo485 is offline   Reply With Quote
Old 26-09-2013, 06:49   #680
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 3,099
Re: Twenty Knots

Gratzz to USA!!! Crew do a fantastic job..

But to me something smell really bad ....


The notes were dated September 23, 2013, but were received by Sail-World mid-morning today.

This afternoon, an Oracle spokesman said that the team used the same set of foils through the regatta and that the 'special foil adjuster system, was there before the regatta started'.

The matter was taken by Emirates Team NZ to the International Jury on September 3, and a Decision issued on September 6, just one day before the regatta started, was rejected on the basis on being filed outside the allowable time, but added a rider, that had it been issued inside the time limit, but on the basis of what had been heard, the application would have been unlikely to have been upheld.

Emirates Team NZ's Ray Davies said 'their boat is rock steady up wind, that takes us a lot of effort, and we have been trying to it for a long, long time, and yet they master it in just a few days.

It is well recognised that Oracle was having serious foiling stability difficulties at the outset of the regatta and that their performance could not match that of ETNZ.

Half way through the series it was acknowledged that Oracle had fitted an automatic control to their hydrofoil trim, and that this modification was approved by the measurement authorities.

Since this modification Oracle's performance has almost unbelievably improved. This has been 'explained' by skipper Jimmy Spithill as being due to the superhuman efforts of the crew to improve their handling skills. However, in view of the intensive training Oracle were able to do, prior to the regatta, with their highly skilled team partner, it seems unlikely that only now have they discovered the 'magic bullet' they they clearly have. It is much more likely to be the result of the modifications, possibly enabled by their surprising decision to use their lay day card and the subsequent lucky postponements.

It must be remembered that this is the first time that this contest has been sailed by yachts 'flying ' on Hydrofoils and it is probable that new and different criteria should have been applied.

In the aeronautical world it has long been known that the stability of swept wing aircraft can rapidly be lost by uncontrolled yaw leading to a dangerous situation known as 'Dutch Roll'.

A device known as 'Little Herbie' was developed during the commissioning of the Boeing 747 Jumbo Jets over 40 years ago, to over come this tendency. Little Herbies, or 'Stability Augmentation Systems' (SAS) as these are now designated, are equipped with sensors such as Accelerometers and Gyros which can detect and instigate corrections to stability with a speed and accuracy which exceeds the ability of even experienced airline pilots. They are therefore now installed in virtually all swept-wing aircraft.

The 'legality' of this device has been justified and accepted on the basis that it does not actually 'drive' the trim of the foils.....this is still performed by the muscle power of the crew, via hydraulic linkages. That may be so, but the device, using it's sensing and directives, has been described as 'automatic'. This implies that the trim of the foils is determined by what can only be described as 'superhuman' technology. If this technology has ben used to overcome the foiling stability difficulties of Oracle it will have enabled the use of higher speed/lower drag foils which the crew would otherwise be unable to manage. This would give a significant speed advantage during foiling. This has been clearly in evidence since the modification. Improvement in stability and speed has been staggering.

The high speed/low drag foils do have a downside in light conditions where, due to their lesser lifting characteristic, foiling is difficult or impossible. This was also clearly seen in the abandoned Race 13 when ETNZ were only 4 minutes from the finish, with a lead of over 1000metres.


Oracle Team USA have not provided any official comment on the system they used.

While it would seem that the actuator device is legal if it is attached directly to its own power supply, the wider question remain is whether a boat should be raced with a computer, rather than a human, driving a primary control function.

__________________
neilpride is offline   Reply With Quote
Old 26-09-2013, 07:08   #681
Registered User
 
Jimbo485's Avatar

Join Date: May 2010
Location: some ocean down under
Boat: Kelsall Suncat 40
Posts: 1,247
Re: Twenty Knots

Could get interesting now....
__________________

Jimbo485 is offline   Reply With Quote
Old 26-09-2013, 07:14   #682
Registered User

Join Date: Jan 2010
Location: Narragansett Bay
Boat: Able 50
Posts: 3,057
Re: Twenty Knots

I thought I read somewhere that motors were banned. This foil adjusting system has to be controlled by motors.

Call the lawyers ?
__________________
savoir is offline   Reply With Quote
Old 26-09-2013, 07:47   #683
Registered User
 
Jimbo485's Avatar

Join Date: May 2010
Location: some ocean down under
Boat: Kelsall Suncat 40
Posts: 1,247
Re: Twenty Knots

Powered by the grunts on the coffee grinders.
Controlled by a computer, APPARENTLY.
__________________

Jimbo485 is offline   Reply With Quote
Old 26-09-2013, 07:48   #684
Registered User
 
Jimbo485's Avatar

Join Date: May 2010
Location: some ocean down under
Boat: Kelsall Suncat 40
Posts: 1,247
Re: Twenty Knots

...and installed by kiwis....
WOW!
__________________

Jimbo485 is offline   Reply With Quote
Old 26-09-2013, 07:52   #685
Senior Cruiser
 
colemj's Avatar

Cruisers Forum Supporter

Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,049
Images: 12
Re: Twenty Knots

If it is present, it is immediately controlled by the hydraulic grinders, not electric motors. Motors are specifically banned, as are any type of stored energy (battery, hydraulic pressure tanks, etc) used for moving anything other than opening/closing solenoids and other valves.

From the class rules:
18.1 Rigging, sails, rudders and daggerboards shall be adjusted only manually, and the use
of stored energy is prohibited, except:
(a) for springs, shockcord, and similar devices;
(b) low pressure hydraulic or gas accumulators of less than 6 bar which provide back pressure to a hydraulic system to prevent cavitation, but do no significant work themselves;
(c) batteries to power electric bilge pumps, provided the total capacity is not greater than 200 l/min; and
(d) batteries to power instruments and ACRM media equipment.

So it is possible that some type of control computer can be run off batteries, and it could control electric solenoids connected to hydraulic circuits that were powered by humans.

It would be a steampunk kind of thing.

Mark
__________________
www.svreach.com

You do not need a parachute to skydive. You only need a parachute to skydive twice.
colemj is offline   Reply With Quote
Old 26-09-2013, 08:17   #686
Registered User
 
Jimbo485's Avatar

Join Date: May 2010
Location: some ocean down under
Boat: Kelsall Suncat 40
Posts: 1,247
Re: Twenty Knots

Mark, one part from your post that stands out.....

"18.1 Rigging, sails, rudders and daggerboards shall be adjusted only manually,"

How can that be interpreted? A computer is allowed to adjust the foils while the power comes from the grinders? A computer is considered to be "adjusted only manually"?

Interesting times afoot...
__________________

Jimbo485 is offline   Reply With Quote
Old 26-09-2013, 08:55   #687
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 3,099
Re: Twenty Knots

If is true, it could be a hack trick, anyway, a giro computer to trim the foils by hydraulic presure or dc voltage is not allowed? or yes?

Looking at the last races with the cams under the trampoline in OTUSA and TNZ i notice Oracle flying higher in the foil , with the last delays in last races by windlimit or wrong direction seems to me some expensive people work hard in Oracle foils ... Just saying.
__________________
neilpride is offline   Reply With Quote
Old 26-09-2013, 08:55   #688
Senior Cruiser
 
colemj's Avatar

Cruisers Forum Supporter

Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,049
Images: 12
Re: Twenty Knots

A computer can electrically control solenoids or other valves (both teams have oodles of electrically controlled solenoids on board). Those valves can be part of a control system, but all the translation power must come from humans, and none of the human generated power can be stored in any way.

Like I said - steampunk!

Mark
__________________
www.svreach.com

You do not need a parachute to skydive. You only need a parachute to skydive twice.
colemj is offline   Reply With Quote
Old 26-09-2013, 08:59   #689
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 3,099
Re: Twenty Knots

Yes but a computer controlling solenoids need store power, or the crew brains conected to the computer??? or??
__________________
neilpride is offline   Reply With Quote
Old 26-09-2013, 09:09   #690
Registered User
 
SV Maclas's Avatar

Join Date: Oct 2012
Location: Canada
Boat: Sinek, Pilothouse, 43ft
Posts: 105
Re: Twenty Knots

Given how the series unfolded, I am certain there will endless speculation on exactly how Oracle made the comeback. This is very fascinating!
__________________

__________________
SV Maclas is offline   Reply With Quote
Reply

Tags
knot, paracelle

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
The Death of the Ketch ? europaflyer Monohull Sailboats 496 23-12-2015 13:17
Six Year Refit . . . Is 3.5 Knots Under Power Too Slow ? akio.kanemoto Propellers & Drive Systems 50 20-08-2015 22:12
Twenty Boats Sunk or Damaged in Chicago Harbor Due to High Winds teneicm General Sailing Forum 1 26-10-2011 04:52
Cairns to Perth Part 1 Bartlettsrise Sailor Logs & Cruising Plans 1 11-09-2011 00:38



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 05:32.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.