Forums > Windsurfing   Gps and Speed talk

Game Over 65 knot 500m

Created by Roo > 9 months ago, 25 Nov 2012
Roo
461 posts
> 9 months ago, 25 Nov 2012 00:33
Thumbs Up

Sail Rocket has gone ballistic and posted a 65 knot run with a peak over 67 knots. The speed game as we know it is over, they've raised the bar so high the kiters will not even bother jumping for it.

"Ok mental speed,s!!! On the GT-31 gps 67.74 and an average 500m 65.37! Yihaaaaaaaaaa..." www.sailrocket.com/

Roo
461 posts
> 9 months ago, 25 Nov 2012 04:49
Thumbs Up

Update from Trimble WSSRC certified GPS, 65.45 over 500m peak of 68 knots. Outstanding performance and how do you beat it?

AUS02
TAS, 1750 posts
> 9 months ago, 25 Nov 2012 09:12
Thumbs Up

OMG

shear tip
NSW, 1078 posts
> 9 months ago, 25 Nov 2012 09:37
Thumbs Up

Unbelievable speeds!



So... 50 was the new 40 a month ago, now it's 70???

choco
SA, 3115 posts
> 9 months ago, 25 Nov 2012 09:11
Thumbs Up

WOW! now what can we learn transfer technology wise from the rocket to windsurfing?

stringer
WA, 689 posts
> 9 months ago, 25 Nov 2012 08:47
Thumbs Up

choco said...
WOW! now what can we learn transfer technology wise from the rocket to windsurfing?


Go-go gadget arms and legs

vando
QLD, 3308 posts
> 9 months ago, 25 Nov 2012 11:23
Thumbs Up

Wow

hardie
WA, 3830 posts
> 9 months ago, 25 Nov 2012 10:06
Thumbs Up

A Triumph for Technology, Skill & Engineering, and congratulations to all that made it happen, well deserved

One downside being that windsurfers and kite-surfers will probably never be able to match this, whereas in the past someone with kit worth around $5000 could break a world speed-sailing record.

CJW
NSW, 1391 posts
> 9 months ago, 25 Nov 2012 13:13
Thumbs Up

vando said...
Wow


Quoted for truth

Roo
461 posts
> 9 months ago, 25 Nov 2012 10:25
Thumbs Up

hardie said...
A Triumph for Technology, Skill & Engineering, and congratulations to all that made it happen, well deserved

One downside being that windsurfers and kite-surfers will probably never be able to match this, whereas in the past someone with kit worth around $5000 could break a world speed-sailing record.


Hardie it's been years since that happened, you then had to build a canal or rent one to attempt the record as windsurfers did starting back in 1988. After the windsurfers lost it in 2009 the kiters built bigger and better canals to get their record. Sad thing is with the overall record now way out of their reach there is no more need for the canals and events like we are seeing in Luderitz. The only reason the windsurfers were invited was to finance the ditch Seb built, there weren't enough kiters willing to pay to make it viable. Now the record is so high I doubt they will bother next year. This may well be the only chance for windsurfers to set some of their own records.

Haircut
QLD, 6048 posts
> 9 months ago, 25 Nov 2012 12:30
Thumbs Up

insane

and it doesn't appear to be mirror flat "kitesurfing record" water either which is awesome - meaning hopefully the tech can be put to real world use for transport etc

Glitch
QLD, 279 posts
> 9 months ago, 25 Nov 2012 19:52
Thumbs Up

Does this mean we need to go back to solid asymmetrical wing sails for serious speed sailing. After all our current single surface soft sails are really only efficient up to about 30 - 40 knots.

boardboy
QLD, 553 posts
> 9 months ago, 25 Nov 2012 21:00
Thumbs Up

well the outright record may be out of reach for now - but who nows what technology some smart cookie will come up with to put us back in the game!

In the meantime you may like to take solace in the fact that though Sailrocket II may be faster, it can't sail back.

swoosh
QLD, 1617 posts
> 9 months ago, 25 Nov 2012 21:05
Thumbs Up

Thats awesome, shows that the technology exists to well and truely smash the 50kt barrier.

Wasn't it only a week ago that the speed record was 55ish knots? I don't think many people expected these guys to put another 10kts on top of that! I guess in perspective 65 knots is 120 kph!!


Bonominator
VIC, 5477 posts
> 9 months ago, 25 Nov 2012 22:47
Thumbs Up

Glitch said...
Does this mean we need to go back to solid asymmetrical wing sails for serious speed sailing. After all our current single surface soft sails are really only efficient up to about 30 - 40 knots.


Awesome record!

Glitch, our sails are not the problem. They could easily go 60 knots on a broad reach. Our real problem with going much faster is a fin at 90 degrees to the water surface prone to cavitation and a board that actively creates drag and a pressure bubble underneath and ahead of it. The location of our mast base relative to our feet and the fin is also a major problem, meaning the transfer of forces is inefficient and relies heavily on the skill of the sailor. Sailrocket almost eliminates all these problems, with a perfectly balanced rig system that extracts incredible drive out of the sail and hydrofoils. Sure a solid wing sail would be slightly faster, but at what cost to the average sailor? The time for windsurfers holding speed records is long past, unless someone takes a risk and tries something genuinely new, but then it may not be a windsurfer anymore. For the time being, I love the sport and what I can achieve on a daily basis, for little expense.

Ian K
NSW, 2208 posts
> 9 months ago, 25 Nov 2012 22:48
Thumbs Up

Worth recalling how it works. They say it's unlike 99% of other sailing craft. That's an underestimate. They've taken righting moment out of the equation. If you ignore spars and the bits required for steering, stability, housing the skipper and floating it when at rest, it just boils down to a foil in the water connected along a straight line to a foil in the air. It's not riding on that angled foil, that L-shaped foil in the water stops it being hauled out of the water by the foil in the air.

It helps that they also have a huge engineering background, they've also installed 47,000 wind turbine generators in the last 30 years.




Glitch
QLD, 279 posts
> 9 months ago, 25 Nov 2012 22:30
Thumbs Up

Bonominator said...
Glitch said...
Does this mean we need to go back to solid asymmetrical wing sails for serious speed sailing. After all our current single surface soft sails are really only efficient up to about 30 - 40 knots.


Awesome record!

Glitch, our sails are not the problem. They could easily go 60 knots on a broad reach. Our real problem with going much faster is a fin at 90 degrees to the water surface prone to cavitation and a board that actively creates drag and a pressure bubble underneath and ahead of it. The location of our mast base relative to our feet and the fin is also a major problem, meaning the transfer of forces is inefficient and relies heavily on the skill of the sailor. Sailrocket almost eliminates all these problems, with a perfectly balanced rig system that extracts incredible drive out of the sail and hydrofoils. Sure a solid wing sail would be slightly faster, but at what cost to the average sailor? The time for windsurfers holding speed records is long past, unless someone takes a risk and tries something genuinely new, but then it may not be a windsurfer anymore. For the time being, I love the sport and what I can achieve on a daily basis, for little expense.


True that a sail can go faster but the single surface sail is inefficient. Hang gliders and ultralights only use single surface wing for designs that are made for low speeds, ie up to about 40 knots maximum . Any thing quicker is double surface. A wing sail wouldn't be any good for the average sailor, only someone wanting to go fast in one direction . Still I don't have any answers to stop cavitation of the fin.

sailquik
VIC, 3245 posts
> 9 months ago, 26 Nov 2012 01:27
Thumbs Up

Glitch said...
Does this mean we need to go back to solid asymmetrical wing sails for serious speed sailing. After all our current single surface soft sails are really only efficient up to about 30 - 40 knots.



Please define what you mean by 'efficient' in this case, and why this 'efficiency' is limited to '30-40' knots.

elmo
WA, 7538 posts
> 9 months ago, 25 Nov 2012 22:53
Thumbs Up

Awesome result

Glitch
QLD, 279 posts
> 9 months ago, 26 Nov 2012 05:36
Thumbs Up

Aerodynamically inefficient, not user friendly inefficient. I don't have any data to back myself up but if you look at the history of hang gliding, the first single surface gliders had a lift to drag ratio of about 4:1. Later the leading edge was cleaned up (a bit like a cambered sail) and the LD went to about 10:1. Now the top gliders have more of a conventional wing section and the LD is about 15:1.

Ian K
NSW, 2208 posts
> 9 months ago, 26 Nov 2012 10:00
Thumbs Up

Sailrocket has also lifted aeordynamic efficiency to another level. Check the masthead shot on this video Sailquick posted on the other thread.



The streamlined hull is not aligned in the direction of travel, it is aligned into the apparent wind! It tracks down the course at the sheeting angle of the sail( less the sail's angle of attack). When you look at the streamlining issues of windsurfers - it's a big gap to make up.

And unlike windsurfing, because they've eliminated the righting moment, they'd go a little faster with a lighter skipper. They must chuckle when they take note of the weight belts used by some speed sailors.

sailquik
VIC, 3245 posts
> 9 months ago, 26 Nov 2012 11:01
Thumbs Up

Glitch said...
Aerodynamically inefficient, not user friendly inefficient. I don't have any data to back myself up but if you look at the history of hang gliding, the first single surface gliders had a lift to drag ratio of about 4:1. Later the leading edge was cleaned up (a bit like a cambered sail) and the LD went to about 10:1. Now the top gliders have more of a conventional wing section and the LD is about 15:1.


OK. So what we really have is an inefficient foil no matter what the speed. I agree.

slowboat
WA, 529 posts
> 9 months ago, 26 Nov 2012 08:30
Thumbs Up

These guys put an enormous amount of effort into getting the concept working. So many variables to control in a lightweight structure, that need to be tuned within fraction of a degree for the potential speeds to be unleashed.

It makes for a complicated design, with a lot of things to potentially go wrong. Paul has got some balls to push that thing so hard.

Its taken him many years of hard work and sacrifice to earn this real prize. I reckon its just awesome that they got on with it and got it done. Without Paul's seemingly endless enthusiasm, and "right lets just get it done" attitude despite the hardships this would never have happened. I mean, the dude was living in a sea container in the arse end of the world when this all started.

If you didnt know, Paul is from Perth, and also windsurfs...

Eel
NSW, 39 posts
> 9 months ago, 26 Nov 2012 16:34
Thumbs Up

Incredible!

latedropeddy
VIC, 417 posts
> 9 months ago, 26 Nov 2012 17:15
Thumbs Up

Awesome - those speeds are mental. Can't wait to see the video.
I think this record will stand for a long time (but I could be wrong).

sailquik
VIC, 3245 posts
> 9 months ago, 26 Nov 2012 19:34
Thumbs Up

latedropeddy said...
Awesome - those speeds are mental. Can't wait to see the video.
I think this record will stand for a long time (but I could be wrong).



Well, you could be wrong, but I very much doubt it. There is nothing around I can see that is in the same ballpark. Even if someone was to design and build something along the same lines, it would probably take at least a few years to sort it out. This is a bit like the Yellow Pages situation, where YP set the bar so high that their record stood for about a decade.

swoosh
QLD, 1617 posts
> 9 months ago, 26 Nov 2012 18:54
Thumbs Up

Ian K said...
Worth recalling how it works. They say it's unlike 99% of other sailing craft. That's an underestimate. They've taken righting moment out of the equation. If you ignore spars and the bits required for steering, stability, housing the skipper and floating it when at rest, it just boils down to a foil in the water connected along a straight line to a foil in the air. It's not riding on that angled foil, that L-shaped foil in the water stops it being hauled out of the water by the foil in the air.

It helps that they also have a huge engineering background, they've also installed 47,000 wind turbine generators in the last 30 years.







seems like a similar configuration to a kitesurfer?

Kimba
SA, 448 posts
> 9 months ago, 26 Nov 2012 21:28
Thumbs Up

Interesting write up on sailrocket and the history of speed sailing...

www.gizmag.com/new-world-speed-sailing-record-6537kts-75mph-121kmh/25065/

stroppo
WA, 379 posts
> 9 months ago, 26 Nov 2012 19:38
Thumbs Up

That gizmag site is good and full of details

Ian K
NSW, 2208 posts
> 9 months ago, 26 Nov 2012 22:59
Thumbs Up

A little bit similar but the major difference is that gravity is part of the equilibrium in the kiter's case and hence the kite can get overpowered. That single red arrow through the big hooked fin in the sailrocket diagram does most of the work, and as long as the super high strength material doesn't fail it will hang in there when a gravity balanced craft gives up.


The kiter diagram shows that the force, shown by the red arrow, which is equal and opposite to the aerodynamic lift, is the sum of two forces in the kiters case - gravity and hydrodynamic lift.

For sailrocket the majority of the hydrodynamic force is generated by that one hooked foil to balance the aerodynamic force. One foil in the water one in the air, (with a few other control foils that do relatively little work). It's a concept that has been around for a long time, just nobody thought it was feasible or was brave enough to take it on until now.

jsnfok
WA, 898 posts
> 9 months ago, 26 Nov 2012 20:30
Thumbs Up

CJW said...
vando said...
Wow


Quoted for truth


quoted as a witness to the truth told by the truth tellers, truly....



Subscribe
Reply

Forums > Windsurfing   Gps and Speed talk


"Game Over 65 knot 500m" started by Roo