Jones Sponsons

by Don Mock

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A lot of questions and controversies continue about models of unlimiteds with modern Ron Jones sponsons. What are their actual dimensions and allowed modifications on the model? About ten years ago, when many new unlimiteds were built with the non-symmetrical sponsons, it was agreed by the R/CU Board that this gave the boats a distinctive "look" on the water. With a large outside and narrow inside sponson, it was decided that models in the club should also have the same look. Full-size Jones sponsons measure 38" for the left or inside, and 48" for the outside.

 

At the same time, racers began showing up with models of these new boats with their sponsons the same width. It turned out that a few fiberglass builders and designers around the country offered the boats with symmetric sponsons.

 

When the R/CU rule book was revised in 1992, a rule was added to require models to also have non-symmetrical sponsons if the full-size boat had them. A couple of people discovered the loop-hole in the rule. Applying the 10% width rule, they found that by shrinking the big sponson 10% and increasing the small one 10%, they ended up with nearly equal size sponsons (the math works out to about 1/4 inch difference). This didn't go over too well with the purists, so a rule update was added requiring that the difference between the two sponsons could not be less than 3/4 inch (the actual scale difference is 1 1/4 inch).

 

Somehow during the re-vamping of the rule book last year, we overlooked the "3/4 inch" minimum, and re-wrote the rule to require that if modified, both sponsons must be of equal percentage in the same direction. I think this addition was a mistake. It actually makes several perfectly good-looking boats in the club illegal. Steve DeSteese has proposed changing the rule back to the "3/4 inch" version which I, and I'm sure the other board members will support.

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