End game...

 So here we are. VESTAS Sailrocket 2 has finally begun the big reveal of the beast within. From our perspective, the speed wasn't any accident and certainly wasn't unexpected. We have been working in this direction for a long time now. We always said that we were aiming for speeds over 60 knots and that in the current speed sailing context it simply wouldn't be worth building a boat unless you were. I don't think anyone is really sure of what the potential of the kiters really is. Even the windsurfers are now showing that they had what it takes to get well over 50 knots. Everything about VSR2 was focused on 60+. We just hadn't found the right combinations to unlock the boats real potential. Being stuck in the low 50's was frustrating on one hand but very educational on the other. To be fair, the new foil didn't get stuck there for very long. We just needed to get enough runs in to work through a few theories. The change in performance once the fences were added was pretty remarkable. The way that the low wind performance changed was a big indicator that something fundamental had changed and we were itching to see how it would effect us in stronger winds. 

 

The last two runs were brilliant. That last run was truly great. It represented a real and undeniable breakthrough for sailing where the previous limiting factors were overcome. The good thing was that we did it in a pretty civilised manner on an open water course in winds that only averaged 24.5 knots on the shore station. I'm sure that we hit our peak speed in the high part of that average i.e. 28 knots but I'm also sure that that is about all we need to go even faster. The wind was ranging between 21 and 28 knots for those who are interested with a True wind angle of 99 degrees.

THIS IS THE LITTLE GPS WHICH WE TAKE ON THE COURSE TO INDICATE WHAT WE JUST DID. THE ACTUAL RECORD DATA IS ON THE BIGGER, MORE ACCURATE TRIMBLE GPS... BUT THAT DOESN'T HAVE A DISPLAY. IT INDICATED A LITTLE FASTER THAN THIS AS A PEAK ALTHOUGH THE 500 METER AVERAGES WERE ALMOST IDENTICAL. (I BELIEVE THAT SEB CATTELAN HAS HIT A SIMILAR PEAK BEFORE ON A KITEBOARD. I'M NEVER REALLY FOUND OUT WHETHER HYDROPTERE DID OR DIDN'T HIT 61 I.E. WAS IT A "SOMEONE-THOUGHT-THEY-SAW" SPEED OR WAS IT ACTUALLY LOGGED. I ONLY SAY THIS BECAUSE YOU HAVE TO BE CAREFUL ABOUT WHAT YOU SAY IN THIS GAME AS EVERYONE WANTS TO RUN WITH THE BIGGEST NUMBER AND THAT CAN LEAVE THE REST CHASING A MYTH... JUST LOOK AT THE ICEBOATING RECORD!

 

The target performance for VSR2 with these foils is 65 knots in 26 knots of wind. We figured that this should give us sufficient margin to get a 60 knot average and that we could make up for any unplanned inefficiencies by sailing in more wind if need by. You have to appreciate that you never get a solid 26 knot wind. Even on only a 500 meter run you might see 23 and 30 knots. At the true wind angles we are sailing we are bi-secting the gusts at a pretty rapid rate... not running along with them as you would on a deeper downwind course.

Now that we have looked at all the data we have seen that very little needs to be changed. The little 'yaw-string' wind indicator in front of the cockpit showed me that the fuselage was lining up with the apparent wind nicely. That's a good sign of the boats efficiency. The rudder loads and foil base pressures were all pretty good and the leeward pod was looking after itself nicely even at 60+ knots. 

TWO TEAM SHOTS. THIS ONE WITH BEN ON THE END AS HE JUST WARNED ME THAT I DON'T WANT TO MESS WITH HIS MUM BY EXCLUDING HIM FROM TEAM SHOTS... AND THE NEXT ONE...

WITH WALLY... THE NEW TEAM GOOD LUCK MASCOT. LAST TIME WALLY CAME OUT WE DID THE 54.4 KNOT PEAK WITH ADAM FROM 'WIRED' IN THE BACK. HE ONLY TURNS UP WHEN THERE'S A WHIFF OF FINE FRENCH CHAMPAGNE IN THE AIR. ANYTIME WALLY!

 

THE 500 Meter AVERAGE.

This was pretty interesting and gives a great indication for what is to come. The speed graph is more of a spike than a solid average. We were accelerating all the way from 47 knots to nearly 62 throughout the average. VSR2 was still accelerating hard when I finally pulled the pin and eased the wing. In fact she kept accelerating even as the wing was going out. I have no doubt she was on her way to a much bigger number if more runway was available... and quickly. When I saw the gust I knew I wanted it. I had to see what it would do. We were already going quick and accelerating. That last bit was like a turbo kicking in. I hung on for a couple of long seconds whilst my mind raced through the rapidly developing issues. I was happy we had broken into new territory but was also determined not to do anything gung-ho-stupid and destroy the foil. It was nearing low tide and flamingoes were standing in the shallows at the far end of speed spot. If I ran up there I could easily destroy the foil and end this record session. Fortunately the whole show was brought to a stop in the usual manner albeit with a little more distance involved. I knew it was 60. It had to be. It's what I imagined 60 would be like. Hard and fast. The ride firms right up and the chop turns into a rapid chatter. VSR2 just locks into a course and begins to feel lighter as the loads she is torn between get bigger and bigger.

So the peak was 61.92 knots (71.3 mph or 114.75 kph). The average was 54.08 knots over 500 meters and the best 5 second average was 59.08 knots. As mentioned, the low speed on the 500 meter average was 47 knots. Even if we don't go faster, it shouldn't be hard to bring that 47 up into the mid 50's. That should do the trick.

The thing is that I don't trust the kiters. They make me feel uneasy. They're hungry for this game and they are not going to give this speed mantle away without a fight. I'm not sure what their real limits are yet. For all this time we have been trying to bag this outright world record but even now... before we have even achieved that... I am wondering if that will make me happy. I guess this challenge has turned into something bigger than the actual record. With this boat we want to push the limits of the sport itself. The performance of the kiters has forced us to build this wonderful machine and to aim high. With that last run we entered a whole new world of performance. It's a fascinating world full of possibilities. In one way it is akin to when sailing boats realised they could follow their powered brothers from displacement mode to planing mode. Our new foils have many similarities to that analogy. They no longer have long thin transoms but are actually at their thickest there with the aim of getting the water to seperate cleanly. It's no longer just water down there but now it is air and vapour mixing in weird and wonderful ways. These can be played with using all sorts of 'bolt-on' devices. It really is fascinating. I've been lost in this world for the last year and am still only just realising how little I know about it.

So I expect the kiters to oneday reach an average of 60 knots. I don't know how or when... but that's what I expect. I'm not entirely sure of what their physical limits are but I know they are hungry. We want to get to a 60 knot average now. I don't know if mother nature is going to help us out here but we will be on standby for any and every opportunity.

As we sprayed the Pol Roger champagne over the main foil the other night I joked that I hoped that this was the only type of cavitation that this foil would ever see.

Only yesterday when we hosed it all off did I really see/feel a certain 'chalkiness' to the normally super-smooth surface near the tip of the foil and along the suction surface near the TE. I'm pretty sure that this is pitting caused by cavitation. The interesting thing is why we haven't seen this before i.e. when hitting the 'glass-ceiling' at 52 knots? It makes me wonder yet again about what we are looking at.

I'm now sure that we can smash the existing record. VSR2 has showed her hand and it's holding some aces. I will also be the first to acknowledge that we haven't done it yet. there's a heap of ways not to get the record out there. I still have that slightly edgy feeling that comes when you have it all to lose.

WARM FRENCH CHAMPAGNE IN RESIN MIXING CUPS. WE TRY NOT TO TEMPT FATE ANYMORE BY CHILLING THE CHAMPAGNE BEFORE WE GO OUT. I'M NOT SUPERSTITIOUS... BUT I CAN'T AFFORD TO BE WRONG!

 

Despite our expectations, this is all new to us. Lying awake in the middle of the night and not having to wonder if the boat will ever really do it is a wonderful new sensation. I live and breathe this boat. It's great to be where we are at right now... with the expectation AND the knowledge. Yeah, we are aiming high... and yes I will be real happy when we grab that title for the first time.

 

One of these days this ride home is going to be that little bit more special.

Cheers, Paul

p.s. thanks for all the messages of support and encouragement. I read them all and reply to as many as I can. Many of you have been backing us for a long time. You're all part of this snowballs momentum.

Comments

You beauty!

Well done to all! Years of hard work have paid off. Time to celebrate success!

Entrainment and cavitation

I was fortunate to be present at the Depressurised Wave Basin for some tests, that is part of the Marin facility in Holland.

The tank is built to look at cavitation on propellers and is able to reduce the pressure in the towing tank to 25mBar - and they were running a test on a propeller with waves so they could see for the first time the impact of entrainment with cavitation. What was unexpected was that the entrainment was significantly different and more severe in normal pressure.

Of course it is not the cavitation that will damage your foil but the collapse of cavitation bubbles close to the foil surface, so what you are seeing with abrasion on the foil is probably just bubbles forming and collapsing not a full ventilation of the back surface.

Note that the abrasion due to the cavitation bubbles collapsing will abrade the foil very fast. You can turn the back edge of a bronze propeller into Swiss cheese in just one trip on a boat.

I look forward to you getting this amazing beast up to 60 knots for the whole run!

Kiter vs Sailrocket

Hi Paul,

I like your sailrocket very much. But our fight would only be a fair and true one if the depth rule is finally abolished. This rule has nothing to do with reality. It´s pure sailing politics. So we can always say: "You are only the fastest, because the WSSRC/ISAF (the sailing establishment) protects you from us."

cheers
tilmann

Oh the suspense

The technology of SR2 has now been proven.

It has a top speed well above the record.

It may have a top speed up into the mid (or high??) 60's before some limit is approached without any real tuning.

Getting a good wind and the stupid stuff (a random shroud failure, a bad choice that breaks something, etc.) are the only things standing in the way of victory #1 (the new outright record).

Assuming any gremlin induced show stopper does not happen, the Walvis wind is almost certain to give the team their victory #1 in short order.

Paul's nervousness of the kiters is well founded. When he first sailed a record challenger, the talk was about breaking the 50 knot "barrier". How far to push may be an interesting choice.

Unless the SR2 team bags a really big run while going for victory 1, I am really eager to see them push forward and try to find out what their new "weapon" will do. They have done all of the work to enable showing off a real leap in performance. I just hope it all comes together and they get to show it off.

Almost there...for sure!

Every time I open my emails I look forward to seeing that special one from Vestas Sailrocket2, now I am even more excited as all too soon it will be the 'We have the record' email.

Go you good things!

Looks good

Hi Paul,

It looks great. I hope you make it and take the record.

Regards,

Walter Hart

Very finny!

Interesting you mention fences.

The fastest skeg I ever ran on my Porsche Design sailboard was a smallish, thickish stepped trapezoid (from the side) with two fences, and a flared foot. It didn't make any sense, but I actually got going fast enough to JUMP that 12' 6" longboard, even at my 180# weight. I was using a huge 6.6 meter area full batten sail, and standing way back on the square stern, with the fully retracted daggerboard (I modified it).

Maybe you should look up the designers of the PD sailboard and pick their brains. The board was a tour de force of D2 design!

Ready for blast off

You know things are getting serious when the pilot is wearing a full face helmet. What's next, an ejector seat! When will you rename the speed strip Woomera? http://homepage.powerup.com.au/~woomera/

Roo

Congratulations!!!!

Paul-
It's just fantastic to see your dream coming into view!! Over 61 knot peak is astounding, and your average is just beginning at 54 knots.

To see that your design is super stable at speed leaves no doubt that you can safely push this to entirely new ground when the wind gives you the opportunity.

So a big cheers to you and your team from the US!!
Mark Massmann
Seattle, WA USA

PS- I personally am not concerned about the kiter's speed records, based on what I understand. The drag on the kite and the rider are going to limit their top speed- drag that you have already overcome with your design. Maybe that thought can help you rest a bit easier?

Legend

Paul, you are a f#cking legend!

Thank you for sharing so clourfully and completely and allowing me (us?) to experience these moments vicariously through your excitement.

Access and information

Thanks for giving us so much!

Like watching sport on ceefax

Congratulations to your team.
I hope you have the media in place to show the world what you have been working so hard towards over the last few years.
There is something unique about your project it reminds me of watch sport on ceefax (uk teletext) I am glued to my PC waiting for the next tweet.

I am a teacher and have showed the 60 knot clip to over 100 students this week the response is amazing. These are students that don’t sail and struggle to understand why 70mph is fast on the water but I have spent significant time explaining the project. I just need a way to relate it to my IT syllabus now.

I hope just one is inspired by what they have seen to go on to push the limits further.

Good luck I hope the next trip is the one.

Ian (Devon)

Brilliant

Paul I so wish I was back in Walvis right now. I feel you are about to realise a dream and only wish I could be there to see it and the look on the faces of you and Helena plus the team.
Good luck to you all.
Morgan.

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