I have broached the subject of the 4 AA battery rule with quite a few people and I realize that it is hard to challenge the orthodoxy on this subject. I hope that the reader will approach the considered arguments put forward here with an open mind and accept that my concerns have some merit.
The idea behind the 4 AA battery rule was to have this one rule control two aspects of Footy design. One was to limit the amount of electrical power available to the electronics, and the other to put a physical limit on minimum weight on the theory that such a limit would level the playing field for builders of different skill levels. AA batteries are currently widely available and accessible which meant that they passed the kid friendly litmus test. The 4 AA battery rule predates the current Footy rules as part of the draft set of rules that were posted on the Highlander Yachts website along with plans for the BobAbout.
I believe that both tiers of this rule don’t really accomplish their stated goals. I have always had a problem with rules that contain levels of subterfuge, intended or not, inherent in their writing.
First, other than classes of model yachts that come from a single manufacturer, the Footy is the only class that specifies electronic equipment that the builder must use. In the long term this is not very foresighted as the purchasers of 8 track tape decks, Betamax, and vinyl LPs can attest. Technology moves ahead at ever increasing rates, records that were the norm for most of my life time have given way to CDs and MP3 format. Newer electronic equipment use proprietary rechargeable battery packs. Most of the kids in the current crop of potential Footy skippers most likely use cell phones, MP3 players, and laptop computers that do not use individual non-rechargeable battery cells. The next generation following them may not only be unfamiliar with AA batteries, there may not be AA batteries at all. Positioning the Footy Class for longevity means reconsidering the battery rule.
When the draft rule containing the first mention of the AA battery rule was posted, the assumption was that sailors would use throw away alkaline cells, or rechargeable NiCad or NiMh. These would provide 4.8 volts of power to the r/c gear. In turn this would limit the amount of torque that the sail winch servo could output. Sail area isn’t measured in the rules, but sail winch power can have the same effect as putting a upper limit on sail area.
Along with the power limitations the AA cells mentioned above are heavy, a NiMh pack I have measures a whopping 120 grams (4.23 ounces). The weight of AA batteries was thought to be an equalizer. After all, if the pro-level builder produces a boat weighing 350 grams (12.35 ounces) there will still be that 100+ gram dead weight in the hull. That would effectively ruin their overall weight to ballast ratio, a sort of penalty for building too light. Interesting idea, only it doesn’t work.
Lithium Energizer cells have upended the apple cart. Four AA Lithium Energizer cells weigh in at 70 grams or there about. They deliver 6 volts of power rather than the 4.8 volts of the other battery types mentioned above. They make a 350 gram boat feasible. But, they also come at a hefty price. Four Lithium Energizers sell for about $20. They last for three or four regattas depending on their current draw. That translates into a $5 a sailing day cost. Central Park MYC sails 35 Saturdays in a season. That would make sailing there add up to $175 a season, making the Footy the least expensive boat to build but the most expensive one to sail competitively.
The Achilles Heel of the Footy is the overall weight (displacement) to ballast (counterweight at the base of the keel fin) ratio. The Footy is a tender craft. The most popular means of addressing this weakness is the McCormack rig. This uni-rig features spring loading that spills wind when the wind becomes too strong. While a nifty “after market” solution to the tenderness issue a more concrete and comprehensive way to address the problem and a more cost effective one battery-wise would be to remove the battery specification from the rules.
A 6 volt AAA pack that I have weighs in at 67 grams, less than the Lithium Energizer cells. On a Footy of 500 grams displacement the 50 gram weight savings of either the 6 volt AAA pack or the Lithiums would transfer 10% of the all up weight to the bulb, and that would go a long way to increasing the resistance to heeling and the upwind performance of the average Footy. Alternatively, it would allow the less experienced builder to sail his craft at a lighter displacement offsetting to some degree an overly robust construction.
If the concern is that lifting the battery specification will benefit those semipro builders and launch a race for the lightest boat or “battery wars” (as if we aren’t in one already), well maybe. There is a certain point where building light produces a fragile boat that won’t survive the rigors of a season of fleet racing. But if we don’t want to see where this tipping point is a much more straightforward means of controlling how light our best builders can go is to set a minimum overall weight limit for the Footy Class.
It is time to reconsider the AA rule. We should be forward looking and shape our class to be flexible and responsive to new technologies. Tying the Footy’s viability to the continued availability of an energy cell that is an old designation and whose fate is in the control of manufacturers, not ours, means we will have to address this situation in the future anyway. It would be better to do it now, in the early stages of class development, than to confront it later when it may become a crisis.