measuring the rocker

[alejandroe14]

I’m building a Sabre for my son and need info on measuring the rocker. I’m half way built and keen to check it before proceeding any further.The book seems to have the following missing- height of string from transom,and distance foward from transom for the foward rocker measurement .
Any help here?

Cheers
matt
1697
Zahir

[dulciechristense]

Matt

Look at Rule 5.7 in the Red book P.91, Yellow & Green books P.68.

It gives the string position as 102mm above (keel at the) transom and resting on (tangential to) the highest point of the keel. Measure rocker at a point 3048 from the transom.

The table also requires rocker to be measured at 708 mm and 1416 mm from the transom.

It is my understanding that, inter alia, the keel must form a fair curve over its whole length and departures from this would be viewed as an attempted circumvention of the rules and the measurer may not pass the boat as meeting measurement standards.

Phil may pick up on this – keep your eye out!

Mike Simpson

[alejandroe14]

Thanks for the info Mike. I wasn’t trying to alter the rocker but rather to check it fitted in the rules. The template shapes i used for my previous Sabre made the rocker come out very close to to tolerance.
Thanks again.
matt.
1697
Zahir

[dulciechristense]

Matt

I wasn’t meaning to suggest you were fiddling but including measurement information which isn’t all that clear in the rules and notes.

When I said Phil may pick up on it I meant on the thread.

Regards
MRS

[darrenwhitten8]

Mike got it right. All the measurements are in the latest rules.

Phillip Johnson
National Measurer

[Author]

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