Discussion - Increase Jib Window Area

Contents

Experimental #1 Increase Jib Window Area

Can larger windows in Albacore sails improve sailing safety through greater visibility while maintaining sail durability and not affecting sail cost? This was the basic question raised by Andrew Callum and Jeff Beitz in their proposal to the International Rules Committee (IRC) of the International Albacore Association (IAA) for an experimental evaluation of sails with larger windows. The IRC welcomed this initiative and, noting that some other classes such as the Thistle and 505 have also tried larger windows, approved an experimental jib development program. The rationale, program details and process are outlined briefly below.

The current rules permit a single jib window with a maximum area of 0.19 m2 in a sail made from a soft, single ply woven material. Typically, current sails have windows which are substantially smaller than the current rules permit. The problem in the past has been that the window material stretched differently with the sailcloth and, therefore, jibs with large windows lost their ideal shape relatively quickly. Thus, larger windows reduced sail durability. With the development of new transparent window materials, it is reasonable to ask whether the use of new materials and, perhaps, a double window design might create much greater visibility without sacrificing sail durability or increasing sail cost. This is the rationale for the experimental jib program approved by the IRC. Sailors and sail makers are invited to develop experimental jibs with larger windows. The sail must comply with all of the current rule requirements except for the limitations on window size and number. Thus, the aerodynamic performance of the experimental sail will not be affected and anyone using such a sail will have no performance advantage beyond having better visibility. However, since these sails do not measure in according to the current rules, they cannot be endorsed on the boat's measurement certificate. Cost and durability issues precluded the expansion of the test program to include Mylar or other 'exotic' materials.

The process involves having an experimental sail built, measured as done normally, marked clearly with a large X near the clew and keeping a log of sail use, wind conditions and perceived value of improved visibility. This step depends on the willingness of individuals to put up the money necessary to purchase an experimental sail. Clearly, the IRC has no control over this and, since the equivalent of a full sailing season is required for a proper durability assessment, the time limit on this experimental study is open but will be considered complete not more than 1 year from the date of measurement of the first experimental sail. Upon completion of the testing, the experimental sails will be remeasured and compared against a standard sail for stretching and shape distortion. The cost will be known and an informed decision can be made regarding the desirability of changing our rules regarding window size and number. At this point, a wide and informed discussion by Albacore sailors in the various countries can take place and, if deemed appropriate, a new rule can be framed. In accordance with the IAA Constitution, this would have to be approved by the AGM's of IAA member countries before the rule change would become valid.

This is an excellent opportunity to determine whether sailing safety can be improved through better visibility with minimum or no cost in terms of sail durability, price increase or rendering obsolete existing sails. However, this experimental program can only be successful if some sailors are encouraged to work with sail makers to develop and test new sails within the restrictions of this approved study. It is equally clear that the endurance of the experimental sails can only be properly tested if the sails are well used in all wind conditions. Since the jibs authorized for use in this study offer no performance advantage and their use in racing is essential to the success of the program, Race Committees are encouraged to authorize the use of experimental jibs in regattas over which they have jurisdiction. We believe that this experimental jib program is in the best interests of the Albacore Class and hope that it attracts the interest and full support of Albacore sailors.

Anyone wishing to participate in this study by ordering an experimental sail should contact the IRC member in their country for further details: George Roth (Canada), Rolf Zeisler (USA) and Michael McNamara (UK) or myself.

David Weaver IRC Chairman