Thursday 1 November 2012

Vestas Sailrocket 2, update from Paul Larsen's blog

It seems the Vestas Sailrocket 2 team are experiencing one of the most frustrating issues for a sailing speed record attempt, a lack of wind! 
 
Bouncing off the ceiling!
The Walvis Bay wind machine seems to have broken down. The powers that be that make this one of the best and most consistent speed sailing venues in the world have taken a break and left no message as to when they are coming back. It has been 11 days since we have had enough wind just to get started in and the forecast doesn't indicate anything strong enough on the horizon. It's very unusual for this time of the year. In my four years on location here I haven't seen it this 'flat' before. It's weird. It's slightly depressing to be honest.

As mentioned in the previous blog, we have had to commit to booking a WSSRC ratified world record attempt without even knowing if we have the performance to achieve our goals. VSR2 is still very much being dialled in. We have only done 5 runs since we arrived, 2 of which we didn't even get going over 10 knots. The last run was pretty good in 'boat' terms... but pretty average in 'Outright' record terms.

As a team, both here and in the UK, we are all scratching our heads as to why we are hitting this 'glass ceiling' at around 52 knots. Consider the simple facts we have seen to date...
- 2 different boats with 7 wildly different foils have all hit this speed
- The boats have been sailed in winds from 22-34 knots and only twice just exceeded this speed. Remember that in theory a 30 knot wind has nearly 50% more power than a 25 knot wind.
- Both boats accelerate very hard up to this speed and then flat line.
- VSR2 is designed to sail at over 60 knots and is sheeted accordingly. If anything she is a little oversheeted at 50 knots. The tell tales are all flying and she accelerates from 40 knots up to 50 with the same sheeting angle. We have eased the wing out a few degrees to allow for the fact that we aren't achieving the polars.
- The foils are specifically designed not to cavitate until at least over 60 knots. They are base ventilated wedges and we have gone to greast lengths to prove that the base is ventilated well down to tolerable/expected pressures throughout the run.

The entry continues on Paul's blog here


 

No comments:

Post a Comment