J/30 Class Association Forums J/30 Forum One Design Class Rules Admin Error found in Class Rules for J Dimension

J/30 Class,

Charlie Stoddard - Falcon #229 found an administrative error in the class rules that goes back at least to the 1997 version. The listing for the "J" dimension is properly called out in paragraph 5.7.3 as 3505mm +/- 13mm or 11'6" +/- 1/2", and is correctly stated in the Frequently Used Measurements table at the end of the rules. In the 2009 Basic Specifications table it is listed incorrectly as 11.5'

The class web site with the rules will be updated this week to correct this error and eliminate confusion.

There's nothing wrong with current or previous rules. J is a standard measurement and as such is a single number, like LOA. So 11.5' (or 11' 6") is accurate. J/30 Class rules allow for 13mm or 1/2" for the tolerance in measurement (rule 4.1). I'd be surprised if the LOA is within +/- half an inch. Also, don't expect to get 11.5' measuring along the downward sloping deck from mast to stem as J is the horizontal distance between the two.

Bob - I must have been spaced out when I read Charlie's email. For some reason I read 11.5 as "11 feet 5 inches" and not "11 and 1/2 feet".

Never mind.... everything is just fine as written in the rules.

I believe there still is a problem with the J measurement in the class rules. The class rules state:

5.7.3 Position of the mast shall be fixed at the deck 3505 mm plus or minus 13 mm from stemhead tip to the front edge of the mast.

The proper measurement of J is the horizontal distance between the two not a diagonal line as the rules state.

Rusty

Just rereading the post above, and the ISAF Equipment Rules of Sailing that control measurement specify:
H.3.4 Unless otherwise specified, longitudinal measurements shall be taken parallel to the longitudinal major axis.

Class rules do not say to measure diagonally, so it appears there is no problem.

Edit: As always, official rules interpretations must be made by the Chief Measurer per J/30 Class Rules:

1.6 Official interpretations of these rules shall be made by the Chief Measurer of the J/30 Class Association who may consult with the Class Board of Governors or the Class President or the International Sailing Federation (ISAF). Fleet Measurers shall consult with the Chief Measurer when making interpretations of these rules at the local level. Interpretations of local rules shall be made by the Fleet Measurer who may consult with the local fleet organization.