50kts -500m!

[BWD]

Well, it's a new era.
Just waiting for the big boats to do it!
I think it will be soon -this year if the weather cooperates, next winter if not....

Inspiration:
http://youtube.com/watch?v=k2gSQXy4-Mw


http://50knots.xs4all.nl:3006/gps-ki...&val=401&uid=4

Name : Tilmann Heinig
Kite number : -
Sponsor(s) : www.kiteplanet.de, Caution!
Home spot : Germany, Westerhever
Height : 178 cm
Weight : 78.0 kg
Age : 46

Session info
Date : Saturday, January 26, 2008
Spot : Westerhever, Germany
Board : Home made Halfmoon
Kite : Caution Answer 9.0
Fin : Home made Stainless Steel 4
Average speed : 50.12 knots (53.1 51.7 50.5 47.9 47.4)
Max. GPS (display) : 55.2 knots
Max. 2 sec. (software) : 54.9 knots
100 m run : 54.3 knots
250 m run : 53.2 knots
500 m run : 50.9 knots
Windspeed : 33 knots
Windgusts : 44 knots

[SeaSpark]

News is traveling fast:

50.9kn average over 500m

50.9kn average over 500m

Congratulations! Will it be ratified as an "Official" record?

[SeaSpark]

From SA by an expert fin builder.

http://www.sailinganarchy.com/forums...howtopic=66692

fins on a kitesurfer are just stabilizers. the work to counter the force of the kite is done by the board itself. The great advantage the kiteboards have is that they don't suffer cavitation problems because they are basically ventilated foils that only work on the pressure side.

Just waiting for the big boats to do it!

We will have to wait a while although i think the newly tuned Hydroptere will have a chance.

[tspeer]

The web page mentions "liquid ice", and in the video when he falls down and gets back up at the end of the run, it doesn't look like he was submerged in the water. The SA thread mentions 9" of water. It may be this record was set in shallow water on top of an ice sheet.

If so, then there could be serious question as to whether the craft was actually supported by water rather than sliding along on ice.

It may be time for the WSSA to define what constitutes an acceptable body of water for a valid record.

[alan white]

When would water sit 9" above ice? Normally, water atop ice is a temporary condition caused by a hole in the ice, and it quickly freezes.
This sounds like a questionable record. The boat doesn't know how deep the water is unless it is in contact with the bottom (ice), or it experiences surface effects (to whatever end).
How about X times as deep as the boat's draft as a minimum? Maybe three or four times.

Alan

[BWD]

Heinig's spot is very shallow over flooded fields; by westerhever lighthouse, germany, which is in the background of the video. The wake as he goes back upwind looks quite muddy. No ice I am pretty sure. And if he is riding 50 through mud, he should get extra credit in my book. Even if it you don't consider it a "real" boat, or a sanctioned record...

My interpretation of his remarks is that "liquid ice" reflects what it felt like. Based on his usual English style, etc.

I know it may take some while for the new hydroptere to do it, but Ill be quite surprised if they fail..
Inspiring to see the envelope stretching, one way after another.....

Edit: By the way the temperature in westerhever has been in the 40 degree F range.

Alan (inter alia), something to ponder regarding depth, to my simple mind, is the fact that boats trim down by the stern more in shallow water, and run less efficiently (in general, with regard to ships and powerboats). So I am not sure if there is an advantage or a disadvantage.
Maybe once trimmed out at speed on the last 10-20% of waterplane, it makes no difference (hunch).

[alan white]

Yeah. The location was most likely chosen for limited fetch to get the highest wind speed to wave height ratio, and not because of depth.

[Ramona]

[quote=
Alan (inter alia), something to ponder regarding depth, to my simple mind, is the fact that boats trim down by the stern more in shallow water, and run less efficiently (in general, with regard to ships and powerboats). So I am not sure if there is an advantage or a disadvantage.
Maybe once trimmed out at speed on the last 10-20% of waterplane, it makes no difference (hunch).[/QUOTE]

This is certainly news to me. When I drive my outboard powered punt at speed in shallow water the punts speed picks up very noticeably. This ground effect I thought was well known. Be crazy not to try speed records in as shallow water as possible.

[masalai]

Fantastic, courage and determination deserves all praise.

[BWD]

Sorry folks, if I muddied the waters with an "unclear" comment.
To clarify:

S/L < 0.9, at depth of less than 10 times draft, resistance is greater than in deep water.

S/L >1, trim change by the stern is greater in shallow water than in deep water (boat requires more water to run).

S/L > 2, resistance in shallow water is less than in deep water.

It is a valid question if records in very shallow water should bear an asterisk.

It's especially interesting in the case of kiteboards:
Sailing at up to 150% of windspeed, at an angle of 145 degrees off the wind, the kitesurfer struggles to maintain enough drag to maintain control.

So a decrease in water resistance may not help him go faster.

Another possibility to consider, is that the steel fin of the kiteboard could dig into the mud of the bottom, supplying needed drag.

Theoretically this might allow the rider to sail a deeper angle reducing the drag from the kite lines and therefore going faster. But I am skeptical of this, because hitting the bottom just a tiny bit too hard at 40-50 knots would not be good.

Could a record be thrown out because the sailor ran aground?

As far as I know racers generally have had no penalty for running aground (or anchoring).

Seeing how the progress in kite speed records over the last year or so has been in tiny increments by different riders in different places with different equipment, I would chalk it up to improvements in board shape and kite design, plus increasing rider experience. I don't know if the location or exact depth of water is the main thing, beyond needing very smooth water.

But you have to wonder about that steel fin....

[Chris Ostlind]

This is the quote from the above mentioned SA thread that hits the nail on the head about as accurately as it can be done:

"Gotta say I've never given kiteboarding much credit or interest.
But.. man.. Huge Dangling Golden Orbs!
Anyone who can hang on to some strings and do freeway speeds on a dinner plate gets props from me!"

The comments that crack me up the most are the one's like this:

"Congrats, I would like to have seen a boat do it first but very impressive!"

We get the props, but the qualifier is sad to read. Kinda like saying to your gal, "yeah, you're a really sexy lady. Too bad your can is so big"

Doug, I'm mystified as to why you are not all over this feat with glowing praise. Instead we see a miniscule and mildly sarcastic, "Congratulations! Will it be ratified as an "Official" record?" This is interesting coming from the guy who posted the unratified, Moth on Foils 27.9 knots (32 mph) Thread. What gives?

Is it because it wasn't one of your fav vessels? Or, has pure speed somehow become less glossy than it was before?

[BWD]

Update:
Tilman today disclosed on another forum his estimate of the Westerhever water depth: 5cm.
With some AOA plus the 4cm fin depth, that puts his fin in the mud-skimming domain. So he may be in effect land-sailing in a lubricated mudslurry! And my theory about why he would do this gains a little support.

I am sure the purists will disapprove even more now!

[masalai]

F.... it he did a terrific job of going so fast by wind power. belated congratulations but definitely in order - ratified by other w... or not.

He did it. who else has been that fast?

[BWD]

Absolutely masalai, still commands respect.
Interesting technically, how he does it.