Main width measurements

[Steve S (Guest)]

[John Chalker]

Steve,

My sails are actualy new not second hand and were cheap (relatively)because they are cut to the old rules and no on else wanted them at the end of 2006. I  wrongly assumed that they would comply with the new rules.Our boat is 22 years old so the latest cut of sails didn't seem important. Will get my tape measure out at the weekend...and perhaps the scissors!

John

[Steve S (Guest)]

John,
My interpretation would be that if the mainsail was cut in 2006 to the old rules, but to suit the same foot measurement as you currently have you may be lucky that the 1/4 height cross width was so far inside the old limit that it is within the new limit. If the 1/4 height width is too big then you can move the black band until it fits. It is possible that this BB movement will mean the jib that goes with that sail may be too big and may require adjustment to reduce it's area.
My interpretation would be that once you have adopted the new rule cross widths according to rule 11.3.6 even your old sails will have to comply. If you have to move the foot BB to achieve this then your old jibs will be too large and would require adjustment. This is only my interpretation and I know there are others with a different view.

Regards,

Steve
N3436

[John Chalker]

Steve

 Good news! Measured sail as best I can on my own in windy garden. 1/4 width  in by about 15-20mm. Bad news 1/2 and 3/4 widths could be bigger. How close  to the max widths do sails normally measure? Still need to check all other dims and a collar a measurer at waldringfield next week perhaps. Might even get the boat out if it's not too cold.

John

[John Meadowcroft]

An interesting thread.  I think that instead of concentrating on the cross heights you should consider the Luff (L) and Foot (F) measurements as these determine the area of the sail and the allowable cross heights are just derived from measurement F.

You are allowed one set of bands - ie one L and one F.

Dependent upon the date that the sail was measured you are allowed different cross heights.

When I check measure a rig I would.
1- Check L and F.
2- Determine what is marked on the sail - both measurements AND the date.
3- Measure the sail myself
4- Compare my measurements to those marked
5- Compare my measurements to those allowed by reference to the original measurement date.

So from 2007 onwards you have one set of bands (L and F) but potentially two sets of allowable cross heights.

In 2007 you can build a main sail which likely has a similar 1/4 height to your existing main sail (as few were built to maximum) but can have a lot more at the 1/2 and 3/4 than you were allowed.  You do not need to change either L or F.

The real issue pertains to 11.5.5 which is a subsection of 11.5 MARKING AND RECORDING OF SAIL MEASUREMENTS.

11.5.5  Mainsail area, maximum permitted jib area, together with L and F measurements and maximum permitted mainsail cross widths shall be recorded on the certificate. The sail plan may be altered within these Rules, provided that the sails and spars are re-measured by a NTOA Approved Class Measurer. The new details shall be entered on the certificate and the old dimensions deleted.

I think that there is a potential ambiguity in the wording of the rule as it clearly only allows one set of cross widths to be recorded on the certificate and I do not believe that this is the intention and that common sense should be applied.  Alternatively the rule could be amended to read as follows

11.5.5 SUGGESTED REWORDING Mainsail area, maximum permitted jib area, together with L and F measurements shall be recorded on the certificate. The sail plan may be altered within these Rules, provided that the sails and spars are re-measured by a NTOA Approved Class Measurer. The new details shall be entered on the certificate and the old dimensions deleted.

I would stay with the former as in the long term the recording of cross widths helps the use of the certificate, even if a little confusing during change over.

John