Shroud Tension

[JaneB]

I am the new owner of hull number 1048 and have many questions which I am looking forwards to understanding as the season goes on. The most pressing question I have is to understand shroud tension.
Currently both shrouds are fully de-tensioned or more accurately totally floppy. This is without sail up and thinking back to yesterday now I re-read the information - with mast raked quite far back (being my first time I was playing chicken with myself).
The tension pin is placed in the next to bottom hole but there feels like 2-3cm of slack to take up before even beginning to induce tension.
Clearly I have a lot to explore but just wanted initial comments before I explore further. Feel free to call me a total numpty - I am new.
Thanks

[Pete1177]

Hi Jane,

I'm sure you'll enjoy your boat once you get it set up correctly. I would assume any boat you get from a previous owner needs to be checked for rig setup - especially so on older boats.

BTW - can you set up a username for your account which is not your email address - this will prevent spam bots from capturing your email address from the website and flooding you with spam emails. You can do this by going into your account details and changing it.

Have you looked at my tuning/rigging guide in the Technical section here https://www.supernovadinghy.org/files/uploads/Technical/Tuning%20and%20Sailing%20Guides/Supernova%20Tuning%20&%20Sailing%20Guide%20v2.3.pdf? There's a step-by-step run through of boat set up including shroud tension. I'm in the process of updating the guide to include more on sail twist and other stuff but the basic section on setting up the boat will remain the same.

You don't want floppy/very slack shrouds unless the mast is raked. Start by setting up the spreaders correctly as this affects the shroud tension you set next. Then get the measuring tape out and set the shroud tension correctly with the mast fully upright (mast top to transom gudgeon measurement 6100mm).

If you are near the bottom of the shroud plate and it's still not tensioned then something is wrong. It's unlikely the shrouds themselves have stretched but if you measure the length with the mast down they should be 4000mm (with both identical, port and starboard). But it could be that the previous owner had the spreaders set really short.

Hope this helps.

Pete
Class Secretary
SN1177

[Steve1142]

Hi Pete
As a heavier helm @ 90kg (Winter has not been kind) Am I better off reducing A on my spreaders, or extending B. To help me increase my upwind speed?
Cheers
Steve

[Pete1177]

Hi Steve,

The spreader deflection (A in the diagram) has more impact on your upwind speed as it controls mast bend fore and aft on the upper section of your rig. So you want to reduce the deflection for a fuller sail. Bear in mind though that this will also affect the spreader length (make them marginally longer which will put more shroud tension on the mast to stiffen it sideways and be less forgiving in gusts). You may have to re-adjust shroud tension and as a consequence, the mast rake settings.

The best advice is to make the one change and see what happens. Ideally you would choose a good sailing day with moderate wind where you are not overpowered and can sail nice and flat. First go out with a buddy (if you can) and sail boat-on-boat with your buddy slightly downwind and aft. Then go to shore, make the change, and do the same again to see if your boat speed improves. That way you get a real comparison. Otherwise time an upwind leg, sail windward-leeward a few times and take the average time.

Hope that helps.

Pete
sN1177