The crucial factors that have contributed to better performance are:
- The boat now weighs 59kgs down from 64kgs - a weight saving of 5kgs. A light boat is a fast boat.
- New carbon fibre foils are half the weight (3kgs) of the old wooden foils (6kgs) and are a very accurate commercially produced aerofoil shape. The boat steers better, points much closer into the wind and the feel on the helm is light and balanced. The small bucket I felt we were always towing has vanished.
- The hull has been repaired and faired, capturing the true shape of the hull minus any corrugations and imperfections.
- An adjustable mast step allows various raking angles to suit various wind conditions.
- I am now using a 'TacTic' digital compass which makes the detection of wind shifts a doddle. I should have had one years ago. The tactical usefulness of such a compass cannot be emphasized enough.
- Adjustable hiking straps makes fine adjustments during or between races very easy ensuring more comfortable hiking positions.
There are a few more tweaks that I will do to squeeze out a bit more boat speed. Overall I am pretty pleased with the performance. I haven't produced a super yacht, rather I have produced a level playing field. Slipstream is now as up to date as any of the other 'flash Harry' Zephyrs racing. The winning difference will now depend on the nut holding the tiller, time on the water and a fair old wodge of luck.
The next race in the series is in a fortnights time at the Marsden Yacht Club - I'll be there.
6 comments:
Good results! Well done..
Thanks Steve. Win or not, it's simply great to be out on the water (despite the winter temperature) and sailing again.
Next, the Auckland nationals in 2021 to extend your domination of the Zephyr.
Yes the Nationals will be in Auckland at the Manly Yacht Club on the Whangaparoa Peninsula. "Extending your domination" LOL is a relative term. I was 60th out of 73 boats in the Nationals in Wellington in 2018 - if I can move myself up even one place from 60th I will have improved and there is some chance in that happening in a now fully renovated boat that is showing an improved turn of speed. But old sailors are a bit like old marathon runners; the competition is basically against yourself and your last contest placing rather than establishing world domination - but thanks for the implied vote of confidence :> )
Hi Alden,
This looks great!
You improved a lot and you and Slipstream show great potential.
Will you be competing in the Auckland nationals in 2021 ?
I like the technology of fluid and air mechanics and how to put it in practice. I envy you, there is a lot to learn from experimenting there I guess.
Success!
Hi Ben,
Thanks for your compliment.
Yes, the boat has a really improved turn of speed, and of course the more I sail the boat the more I improve as well. Since this Blog posting I have had 3 more wins in the Winter series with all of the races being won by 3 to 5 minutes, margins big enough to fend off the other boats handicaps.
Yes I am definitely going to compete in the Nationals in 2021 - can't wait to have a go again in the big fleet racing. I am on a bit of a mission at the moment trying to get as much sailing practise and racing as I can.
I have learnt a lot about the slipstreams that my boat 'Slipstream' generates since the renovation. The fairing of the hull has taken out quite visible corrugations in the hull which has diminished drag through the water. Also I have installed some foam 'fairing' in the bottom of the centre case which reduces turbulence between the centre board (or correctly the 'dagger board') and the hull.
But the biggest improvement has been the performance of the new carbon fibre foils (rudder and centreboard). The lack of drag compared with the old heavy 'agricultural' wooden foils can been palpably felt when sailing.
Paying attention to each of these areas obviously adds up to measurable performance gains.
I read a book recently about the development of the British World War 2 'Spitfire' aeroplane. Considerable speed advantages were obtained by paying attention to drag - a smooth optimum shaped wing is a fast wing - which proves the case with Zephyr foils as well.
And the experimenting continues - there are a few areas where I will be looking at some weight saving and further drag reduction.
The most pleasing thing with the speed I am now getting from the boat is that spending 12 months doing the renovation has not been in vain.
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