Wednesday, 3 April 2013

Vestas SailRocket : Over 60 knots

by Paul Larsen

24th November 2012. This is the day that VESTAS Sailrocket 2 took speed sailing into a whole new era. Having already broken the existing Outright world speed sailing record by the biggest margin in the records history a little over a week earlier, the team took to the waters of Walvis Bay in strong winds to try and be the first to take the sport over the 60 knot average mark.

This video shows the third run of the day. The record attempt had been plagued by unusually light winds but they knew that on this day, Walvis Bay was going to deliver the goods. After 11 years of hard work on a 'roller coaster of highs and lows'... everything was in place for something big to happen. Founder and co-designer of the Sailrocket project, Malcolm Barnsley, had flown in to see his dream play out before his own eyes. VESTAS Sailrocket 2 has put a mark way up on the graph to show everyone what is possible.

Vestas SailRocket later reached 65.4 knots - more again!

This is the complete birds-eye view footage of Vestas Sailrocket 2 nailing the Outright world speed sailing record on 24th November, 2012.

We had discussed the possibility of getting aerial shots for many years. The trouble is that there are no helicopters stationed anywhere around Walvis Bay in Namibia. The fact that we are sailing in cross-winds of 25-30 knots adds to the difficulty factor.

Swakopmund local, Bernt Bruns owns an RC model shop and we would often talk about the problem. He reckoned that he could do it with one of his RC planes which was modified to carry a GoPro in its nose. We were a little sceptical. As VSR2 began to hit its stride at the end of our last record session we all began to take it more seriously. Now or never. Bernt turned up on the last big day of sailing when we knew we were going to go all out. We dropped him off near the timing hut and got on with sailing the boat. It was an epic and historic day for us. I was faintly aware of what Bernt had been doing. Later that day as the triple rum and cokes and champagne flowed freely, Bernt downloaded the footage in our container at the Walvis Bay Yacht Club. He managed to film all three runs improving all the time.

This is the final and fastest run. His plane does 110 kmh flat out. The timing for our 500 meter record run on the boat actually began as we pass the timing hut on the shore. We are doing over 120 kmh there and top out at 128 kmh. The plane can't keep up.

There are many interesting aspects to this footage. You can see the angle that the plane has to 'crab' along at in order to follow us in the strong crosswind. Notice how this matches the angle of the fuselage on Vestas Sailrocket 2. At this speed this is about the angle of the 'Apparent wind'. I can also see that the low speed rudder has dropped down and is dragging behind the rear windward pod. I can see how much closer I could come into the shallow water and how the wave height increases off the shore. I love the rainbow in the boats rooster tail and especially love how far behind both the kitesurfer and the support RIB are considering we all take off together.

Bernt did a brilliant job nailing this shot and assures me I won't beat his next plane. He refused payment. Capturing this great footage of a very difficult subject was the icing on the cake of an amazing day.

Note from SailRaceWin
We had enquired of the America's Cup techies some while ago as to whether they intended to develop this type of technology for the media, as small unmanned craft to capture close video images of racing would not interfere with the wind for competitors in the way that full size helicopters and other, manned, planes may do. Small helicopters may also be used, in addition to planes. The main issue with the technology these days is the battery power making only fairly short flights feasible. However, we have some ideas about developing self-renewable battery power, which would also be useful for e.g. offshore racing, to resolve this issue...

Vestas SailRocket