Sailrocket update 38.3 kt . . . with a blown tyre!

by Paul Larsen on 12 Apr 2007 Well that was probably the shortest and wildest ride of my sailing life. It was our 8th day at 'speedspot' in Walvis Bay and conditions were looking good.

We have neap tides at the moment so had to stay away from the shallows. We logged the wind for two minute sessions before and after the run and it showed an average around 17.5 knots. I guessed 18 to 19.

The launch and initial round-up into the wind to get flow attached went as normal. We had seen gusts up to 20 so I stuck out a little just in case. It was obviously quite choppy this far off the beach as Sailrocket quickly lifted onto her planing surfaces.

I began to head down the beach when I felt something knock through the rudder system. Sailrocket slewed to windward and there was a lot of spray. I thought something had broken in the rudder system. It still felt functional and there was no way that I was going to let this boat round up like in RUN 1 when the rig came down.

The Only way out was to put theory into practice and sheet on. This would effectively rotate line of drive from the centre of effort in the wing forward in line with the centreboard and make SAILROCKET more responsive to rudder. It also fully powers the boat up.

I pushed on the left C-tech rudder pedal (I had to use your battens for something now that we have a wing Fraser!) with everything I had and sheeted on hard to assist with the bear away. The shore was coming up quick and the nose was turning away, I felt another thump through the rudder system. This turned out to be the other parts of the aft planing surface breaking away.

I was now just riding on the bottom of the hull with all the bolts and broken parts still attached.

It was effectively a blown tyre.

Sailrocket was now approaching 30 knots and I was committed to a bear away. At a point she just stopped turning away and started pitching and yawing back at the shore. There was a hell of a lot of spray. I had on full lock and full sheet. There was nothing left to do but see what happens.

I had the horrible feeling that I was now a passenger in a big crash. Myself and the craft I am sitting in may be in a different configuration in the next few seconds. I could see the timing hut and Helena in the RIB directly in front and coming up fast (Helena was shooting stills).

Hiskia, our local team member was ready to throw in his SAILROCKET shirt to the RIB and run for it! Hiskia had never been in a boat until we came along. This is his first impression of sailing… a bunch of foreigners spearing towards him in a very pointy boat yelling 'No control, no control' over the radio!

I was still closing on the beach and the boat was still accelerating. I was yelling 'no steerage, no steerage' through the I (can't)COM headset to warn Helena of the predicament. These guys were getting a grandstand view of the action.

There were no clever or refined control inputs here and it was no time to get experimental. We were in shallow water at high speed on a rampant prototype boat that could go either way.

Finally the nose came away and SAILROCKET began to turn away from the shore. I wondered if the rudder was stalled and backed off the pressure for a bit. She instantly began to swing back to the shore like a horse to the barn. I kicked myself for getting out of jail only seconds before and then jumping straight back in. I stomped back on the left C-tech pedal.

I swear that the wing was sheeted past centre now. All this had happened over 37 knots with the last peak at 38.3. When the bow came away this time I went with it. The over sheeted wing quickly stalled and SAILROCKET finally slowed and dropped off the plane.

I breathed out.

It was as if we had just spun off the road, into the trees and somehow come out without a scratch on man or machine.

SAILROCKET sailed back into the shore at a more leisurely pace and everyone came over shaking their heads at what they had just seen. I was buzzing.

Man that was wild and hell yeah, that was fun... but only because we got away with it.

Scary? When we were doing 35 with full lock on heading straight at that RIB and timing hut I can now describe what that run smelt like. S%*t and neoprene!!!

When I went to lift the transom of the boat I realised what had happened to the aft planing surface. I was pretty surprised because it was very strong. The next one will of course be stronger again (it's curing in the vacuum bag as I write).

We got back to the Walvis Bay Yacht Club and began downloading all the data and footage. As a team we had worked really well and for once every device worked (even the I (can't) COM VHF's worked . . . occasionally).

All the data loggers and Supatronix cameras had captured the moment. We were all stoked about this as this takes us as much time as preparing the boat itself.

Now we could dissect the whole scenario.

We are still doing this. From the video it is clear that the rear planing surface blowing out spun SAILROCKET into a situation that was very hard to recover from. From then on in the rest of the run (apart from my little jump back into jail) was just an exercise in doing everything to avoid hitting the shore.

During this exercise, with a bunch of junk acting as a rear planing surface, full rudder lock and a partially stalled wing we still managed a 100 meter stretch at an average of 37.35 knots.

That made me smile.

We missed out on the next bottle of Mumm by only 1.7 knots.

This boat has power to burn. I wouldn't swap it for any of the other boats. If we can survive this HOMETRACK supported development period and work out how to do safe and controlled runs then records will fall.

Sure, we have some issues, but we also have some answers and with every second on the water, more experience.

Boat wise we are ready to roll again. I will keep in the low end wind bracket as it allows us to sail further off the beach because the chop doesn't build. The discussion continues with Malcolm and Chris as to why the boat isn't bearing away as predicted even after we swung the beam 50 cm further forward at the wing end.

We simply can't have this boat wanting to head into the wind because that means the oh-so-close shore and great misery!

I feel that the boat was not in a normal sailing state in that the flows weren't attached as they should be to either the main foil or the wing. We were outside the box. A cleaner run will tell us more.

That run also gives us the clearest warning to tread carefully. This stage of the project is perhaps the most critical as everything is to be gained or lost. Let's face it this is the sort of action we signed on for and now we are getting it in spades.

Brads edited video is up on the website as is the one of the Day 1 crash.
We are getting good at supplying data off the boat so now you can all come along for the ride.

Let's hope the next one is a bit more controlled.