Page:Popular Science Monthly Volume 90.djvu/877

 Popular Science Monthly

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��Old construction. Frames were made of short pieces laid out from templets and sawed to shape. Both longitudinal and lateral strength were lacking

not know how to make them larger. Experience has taught us that the larger the ship the less the cost per ton carried. As long as the tonnage of the wooden ship remained small, it could not compete with the steel vessel whose

tonnage capacity was many times greater.

Wooden ships could not be made larger

because our naval architects did not know

how to make them long and still rigid

���The layered or laminated sec- tions are notched into both straight sections of the frame

��New construction. Frame members are made from square mill timber. All parts are stressed to increase rigidity; ample provision for transverse and longitudinal strength

��enough to stand up under the load and the vibration of the engines. i The secret of Donnelly's success lies

in the fact that he has applied the principles of steel-ship construction to the wooden vessel. The American Bureau of Shipping, which insures ships, after the fashion of Lloyds of England, has given the vessel an Al rating for fifteen years.

The special characteristic of the Donnelly design is that it is made of straight pieces of stock which can be turned out at any sawmill without any tapering or special forming work. This particular characteristic is of the greatest importance at the present time. It enables

���The Donnelly ship is a standardized vessel made up of parts which can be duplicated in any sawmill, shipp)ed to the nearest shipyard and put together in much the same way as the parts of a cheap automobile

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