KEELS AND ICEBOATS
KEELS AND ICEBOATS
Saw these keel bulbs and fins at the big boatyard in Portsmouth, RI the other day…. The one with the shark’s teeth was on AMERICA3 (“cubed”) and the black one was under the Italian challenger, Il Moro De Venezia.
There are some interesting design differences- the American bulb has a round cross-section, which raises the CG and costs a little righting moment but lowers wetted surface, reducing drag. The Italian bulb has an elliptical cross section, lowering the CG a few inches, increasing righting moment but increasing wetted surface. Trade-offs…. You know the designers at this point were trying EVERYTHING to get an advantage and no doubt put tons of effort into which option was better.
Notice also the fins on the bulbs. On the American version they are long and thin, high aspect, located aft in an effort to minimize vortices coming off the tail end of the bulb. On the Italian version they are stubby, swept back, and located toward the middle of the bulb in an attempt to increase overall span of the keel.
Which one was better? Hard to say- the hulls were also very different (the Americans went narrow and low drag, the Italians really wide and powerful) and the sail programs also varied (the Americans had sails of Cuben Fiber, really strong and light and the hottest new stuff available at the time).
But for all of this design effort and hair pulling the real difference might have been the little blade visible in the last photo- it is a kelp cutter. The blade was on a rod and travelled down a thin slot in the front of the keel fin, slicing away the kelp which was all over the course at the match in San Diego (you can see the tube that housed it extending out from the top of the keel fin in the third photo). While other teams were trying to poke it off their keels with sticks or just accepting it as a fact of life the American team hit on this little solution, now commonly seen on keels and rudders everywhere.
AMERICA3 won that match, taking four out of five races (losing one by only three seconds) over Il Moro. Gives one pause to think that after the millions of dollars and hours spent on boats (I think the US team built three, the Italians five) and gear the difference may have been a simple razor blade on a stick.
Just goes to show that sometimes you need to quit obsessing on the minutia and attack the big issues- applies to iceboating too!
And of course the American boat did have the advantage of an iceboater at the helm, a Skeeter sailor by the name of Buddy Melges.
Seeing these discarded keels is also a good reminder that if you have old gear you aren’t using clean it up and bring it to the swap meet before it ends up forgotten in the weeds out in the yard- there is a subtle nip in the air, the swap meet will be coming soon. OR put it in the classified section of the NEIYA site right now and avoid the rush!
Think ICE! T