New Miss Bardahl Due [1966]

U-40 Miss Bardahl (4) 1966
U-40 Miss Bardahl (4) 1966
New Miss Bardahl Due
Miss Bardahl is Giving Trouble

The next time the "thunderboats" roar, June 12 in Tampa, Florida, Unlimited Hydroplane fans will see a new Miss Bardahl make her debut, a Miss Bardahl so new and different that she may revolutionize the sport. Ole Bardahl's latest challenger in the big league of powerboat racing boasts the first major changes in design since the old Slo-mo-shun IV of the early 1950's.

Designed by Ron Jones of Sunnyvale, California, the new Green Dragon is a rear-engined, low-profile craft with her driver's cockpit ahead of the engine, near the bow. Except for the basic shape of her hull and the Rolls Royce-Merlin engine which powers her, Miss Bardahl bears little resemblance to any of her competitors.

Jones's design for the new boat follows his theory for getting greater straightaway speeds, faster turns and better lap times from an engine that has almost reached its peak of power output. His theory is that by making a hydroplane fly even more than usual, water resistance will be cut and speed increased correspondingly, and by lowering the center of gravity, faster turns will be possible.

To make Miss Bardahl fly, Jones enlarged the column of air she rides by widening and lengthening the air tunnel between the sponsons, and shaped the deck like an airplane wing to create lift. To lower the center of gravity, he placed the engine as far aft as he could; this necessitated locating the cockpit in the bow.

The details involved in making these basic changes were extensive. For instance, the transom had to be widened considerably to keep the engine from sinking the stern of the boat and to increase the lift area. The tail, usually a flat board, became aerodynamically designed, like an airplane tail. The sides of the afterplane, instead of being essentially vertical, are steeply canted to keep water resistance from flipping the boat in a fast turn. Even the propeller strut (usually vertical) is changed to a V-shape, so lift is increased. The gearbox was the major problem; with the engine so far back, the propeller shaft would have been set at too steep an angle, so a V-drive gearbox had to be custom-built, and the propeller shaft run under the engine.

The V-drive gearbox built by Casale was a major engineering feat in itself. Having a 15-inch driving gear with a 3-inch tooth face, this unit is the largest V-drive Casale has even been called upon to design. Shaft centers are 10 inches apart, with the lower shaft emerging at an 8-degree angle. A gear ratio of 3.175:1, with the 3400 horsepower engine turning 4400 rpm, will deliver a prop shaft speed of 13,970 rpm. If they want to fly, this should do it. Special high speed ball and roller bearings are used to carry the load. The gear case, besides being water-cooled, has two integral oil pumps, one to supply the bearings and the other to pump the oil from the gear case sump to an external reservoir. Casale also supplied the steering for this boat.

(Reprinted from Eric Rickaman's "Rooster Tales" column in Hot Rod, June 1966, pp.94-95)

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