by B.B. Wood
A remarkable paper on the power requirements of the two general types of runabouts. The test curves and text matter are of vital importance to the designer or the skilled owner.
Whenever a large ship is proposed which will cost any considerable amount, much time and money is usually spent in making lines and testing models, before a final decision is made as to the exact form to which the ship will he built. Often, as many as a half dozen different models are tested, in order that the resistance may be reduced to the lowest possible point. Thus, as much as ten per cent, or in some cases more, is saved in the horsepower required to make a given speed. A considerable saving in the required power means not only smaller engines and fewer boilers, but also a daily saving in fuel throughout the life of the ship. Hence, the original cost of the model testing is returned many times over. When high speed is involved, this becomes a very important item. The model test not only determines the power required, without any guessing but opens the way for great economies at the outset. Model tests have never been used extensively for small boats. The main reason for this is the high relative cost of the work, there being very little difference in the actual work to be done whether one tests the model of a 40 foot cruiser or that of a 400 foot ship. An error of a knot in the speed of the small cruiser is not so important as the same error would be in the larger and more costly, ship, where everything is measured in dollars. There is no reason, however, why power should not be saved in the small boat as well as the big one.
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