The class is aware of an ongoing keel width problem in the field on completed boats. This problem has been known since the 95 Standard program began with manufacturers. Due to the length of time the problem has existed a large majority of the 95 Standard boats exceed the maximum 2.1 inches stated in Section 2.5 of the class rules. This was, and is, a problem that was not controlled and through no fault of EC12 owners. It is also a problem that cannot be corrected within reason on the existing fleet.

The database from a survey of 96 hulls and boats has revealed some interesting information and thoughts to the cause of spreading keels. All the hulls without lead measured within the rule and only 13% to 35% of the completed boats measured with lead installed could possible comply. The reason for the error tolerance was in the inability to get a correct measurement in the field with an electronic digital caliper. 13% is real and 35% is speculated because repeated measuring produced varied numbers. Here are some speculations to the cause:

•  It can be understood that each hull produced from an authorized manufacturer will be different in small ways because they are handmade through a lay-up process.

• This process can leave “nibs” that rise ever so slightly above the inside surface of the keel area during curing.

• It has also been noted that the installation of the keel seam tape with resin can leave raised edges at the width of the tape.

• It is reasonable to assume that the amount of resin remaining on the surface can vary slightly the thickness of the hull inside the keel area. This being after the removing excess resin following the cloth wetting process.

• The placement of lead in the hulls come from many sources and are cast in the hull or from a mold made from a cast that was poured in place.

• Some cast lead pieces are used in many different hulls and from different manufacturers.

• Lead that is poured in the hull it will reside is removed after it cools and is installed later in the process of building.

Hence:

• It is felt that lead poured in a hull and left there would cause insignificant movement of the keel width. The removal and reinstallation later cannot be perfect and the introduction of an adhesive certainly does not allow the lead to seat where it was poured.

• A cast lead that was prepared by one manufacturer from a mold of their hull and used in subsequent hull production cannot establish a perfect fit because of variances in the lay-up process stated above.

• A cast lead that crosses the lines of manufacturers must certainly not establish a perfect fit, not only in variances in the lay-up process but that each manufacturer produced their own hull molds from daughter plugs supplied by the class. And there were several daughters from more than one manufacturer. They were standard but not the same.

• It is common knowledge that cast lead placement requires some force and/or pinching of the hull to get the piece into the keel. This is because the keel is narrower at the top. What insures the keel returns to where it was when manufactured?

• To a contributing degree the class beam tolerance of .25 inches seems large but at the keel represents little change. But change is not part of a perfect fit.

Therefore, a speculation:

• It is reasonable to expect that an improper fit through positioning or the many variables mentioned here will exert pressure to the sides of the keel. A constant and continuing pressure must surely find relief by moving the laminate outward. The degrees of this pressure will vary through the different cast pieces available to the class and the variances in the hull through the lay-up process.

• This could be supported through the database where all but 1% of the boats measured fell within 44 thousandths of an inch over the rule. The others had issues not related to the matter.

• The affect of temperature induced expansion and contraction of the lead must certainly exert pressures on the laminate. It is speculated that expansion of a polyester laminate may not completely, if at all, contract with the ballast when it cools.

• Builder efforts to increase more lead lower in the keel by opening the keel by pinching the hull at the sheer would be counter productive. While an insignificant gain in righting moment may be gained increased drag will result and increase further in time due to outward pressure on the keel.

Conclusions:

Whereas, delivered hulls have tested within the rule and to have over 65% of the finished boats fall outside of the rule, it is reasonable to assume other factors create conflict with the rule. Additionally, being a builder’s boat, the vast majority of the owners do not have the tools to monitor this rule nor control of this condition. Therefore, the current rule is outside of reason to be followed.

The class administration recommends a rule change and during the time for the process to be completed act to mitigate the condition. It is speculated that slightly reducing the width of the cast lead ballast will lessen pressure against the keel and reduce this drag inducing condition to a reasonable tolerance.

Should the class pass this rule it will not become effective till the first of 2007. It takes that long to follow the proper process for a rule change at this time of year.

Because manufacturers are just beginning deliveries of hulls produced from the class owned hull program, a new study can begin to monitor efforts to place some controls on the condition.

The CS has ordered fixed keel gauges to pass over keels in four different sizes; 2.100, 2.125, 2.135 and 2.145 inches. This will debut at the 2005 NCR in Orlando during measuring. This will not be a pass/fail check but to increase the database and to inform owners where their boat keel falls.

The CS will provide the gauges for sanctioned events and those traveled to monitor the condition and prepare for a review at the end of 2006 to where we stand with the rule.