IT’S OFFICIAL! The new world record has been ratified by NALSA (North American Land Sailing Association). After detailed analysis of the data, the final figure turns out to be 126.2 mph.

Many Many thanks to Bob Dill, the Nalsa secretary and GPS guru who has painstakingly analysed the accuracy of various GPS units and overseen the speed measurement of all my efforts over the years. Bob designed and built the Iron duck (previous record holder), but has been tremendously helpful to me throughout the project. He has hung out with me for weeks at a time at the various locations around the world including Australia (exactly the opposite side of the world from his home in Vermont), at his own expense, to oversee the attempts as an official observer. As it turns out, we managed to do it in front of the whole Nalsa Committee, but if the weather had played it’s hand in one of the remote locations, Bob was there on standby to be the official witness. Thanks for all your support and company over the years, Bob.

Here is the official Statement of ratification as well as the supporting documents submitted to the Nalsa Committee; The measurement report (PDF, 784kb) and the GPS data (Excel, 81kb) from the fastest run.

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Dear NALSA,

The NALSA Board of Directors has ratified a new world record for speed in a landyacht of 126.2 mph by Richard Jenkins in Greenbird on March 26, 2009 at 11:04 PDT on Ivanpah Dry Lake California.
The wind at the time ranged between 30 and 40 mph with occasional higher gusts. As required by the NALSA Regulations for Speed Record Attempts, the top speed was measured over three seconds during which the yacht traversed about 560 feet. Speed measurement was made by a total of five logging GPSs which agreed within 0.1 mph and which all have a demonstrated accuracy (U at 95%) of 0.2 mph (well under the NALSA requirement of 0.5 mph). Additional information can be found at NALSA.org.

Bob Dill
NALSA Secretary

Well I arrived back in England yesterday after an excellent trip back. A great mate from University who is a pilot and now flies for BA apparently managed to find out what plane I was on and get a message to the flight crew. They not only found an empty business class seat for me, but announced to the whole plane the new British held world record. A great honour and hugely appreciated so many many thanks to BA and the whole crew who treated me like royalty and looked after me superbly.

The Greenbird is now in San Francisco awaiting transport back to the UK. Really sorry I could not stay another week at Ivanpah for the Kite buggy Expo. The kiters are a great bunch who have been incredibly helpful in the past and I have made some great friends there, so sorry to miss you this trip.

I have now had some time to digest the record day and the craft performance. I cannot tell you how satisfying it is, from a technical perspective, that it worked exactly as planned. No wear, no breakages and total control at all times. Once I had got to grips with the sensitivity of the sail control, I was able to ‘fly’ the outrigger pod consistently above the ground, which is the perfect situation for least drag, with only two wheels touching the ground. The gusty wind made it slightly more tricky, but even when it looks like the wheel is touching, it really is only just touching, so very little rolling drag.

The biggest problem on the day was the blowing dust, which made visibility very poor. After setting off for the first time, I was completely blind and had to stop for about 30 minutes until visibility improved. The dust also likes to stick to the windscreen, which makes the situation worse, I think you can get a good idea of this from the onboard camera. At times visibility was down to 40 feet, so I waited and once I could see the silhouette of the hills once more, I set off. The first run was a test to see how much room I had with this unusual wind direction. All went well so I turned around and made my way back to the top of the course. This time I gave it full throttle and ‘went with it’. As the craft became overpowered, rather than de-power, I bore away, sailing more downwind. Looking down at the Driftbox GPS, it was reading 126, seemingly for some time. Bailing out of the run and trying to avoid the various obstacles on the lake, I stopped by the camera crew for verification. It all happened too easily and quickly in the end.

Parallel to the road is a pipeline to Vegas, which has various (solid) obstacles along it. These would be fatal if hit at speed so I was pretty careful to try and bail out of the runs into a clear area, but being so low to the ground and in so much dust it was hard to see where the edge of the lake and these obstacles were. Looking at the GPS track now, I am amazed to see how much space we did have left and just how short the record run was. The whole run was completed in about 1.5 miles. Which is pretty amazing acceleration. If I had an in-cockpit position display I probably could have used another 0.5 miles. Here is the GPS track and the acceleration curve:

GPS Track

Acceleration Curve

It clearly shows that there is a little more potential left in the yacht and a figure of 130 mph is probably achievable with a little more time and room.

So should I have pushed harder on the day? Possibly, but the design speed of this vehicle was 125 mph. This is not to say it won’t go faster, but the structure was not yet load tested for speeds above this and the safety factors were definitely small, so to push it much harder, I would like to do more static tests first. Also, now that we know our predictions were spot on for 125, we can certainly make modifications to tune the aerodynamics for 135 mph and have another crack at it.

So the vehicle and me are still in one piece and ready to fight the next fight. It could have easily been very different had I ventured into unknown territory and pushed it beyond the limit, but i guess we will never know! Such is the fine line of record setting and I am very pleased to be on the right side of that line for now. I may have taken a different view 6 years ago, but after many crashes, I guess that is what experience does for you!

Regarding the wind record, I have to say I screwed up here. In all the commotion after the record I did not download the wind data until a few days later. I had not fully realised the memory capacity of the unit when set to maximum data detail, which is only a couple of days. This meant the data from record day morning had already been over-written. All I can say is that it was windy! Averaging 30-35 mph with higher gusts. I guess we will never know exactly what it was during the record run, other than to say it was enough! The speed multiples are normally pretty reliable, and we can consistently do 3.8-4.1 times the wind speed on dirt, so an average windspeed somewhere between 30 and 35 mph is probably a pretty reasonable guess.

Here is the course for the entire days sailing:

All day course GPS track

^{Photo credit – Peter Lyons}

Back in the UK now. I’ve been on holiday for a week, which is a rare event (ask my partner… ) and sod’s law determined that an even rarer event would coincide with that – the perfect conditions for a land speed record attempt.

My disappointment at not being there though was marginal compared to the huge excitement of the result – the smashing of the record.

All the credit for this goes to Richard Jenkins of course (with just a little to the gods of wind… ).

Richard’s the guy who’s been pursuing this dream for a decade. To say he’s dogged would be an enormous understatement. (more…)