SNAME Los Angeles Hears Paper On Calculation Of Curves With A Hand Held Calculator

The first regular meeting of the new season for the Los Angeles Metropolitan Section, The Society of Naval Architects and Marine Engineers, was chaired and opened by William A. Hood. He promptly introduced the new officers for the year, Capt. J.E. Kaune, USN, vice chairman, and Charles E.

Heil, secretary-treasurer.

In the absence of the Papers chairman, Captain Kaune introduced the speaker, Paul Cromer of the Long Beach Naval Shipyard.

Mr. Cromer's paper was titled "Calculation of Hydrostatic Curves for Vessels With the Use of a Hand Held Calculator." Mr. Cromer's paper described a program the author had written for a Texas Instrument 59 Programmable Calculator to compute the curves of a hull form from line drawings, tables of offsets or taken off the hull itself. The properties of the trapezoid, with their mathematical expression for summing the longitudinal and transverse moments of inertia of the waterplane areas, form the basis of the program. A separate section of the paper was devoted to the choice of the number and spacing of the stations used to produce offsets or half breadths for entry into the program. No set spacing is required, and the number of such stations may be as large or as small as the required accuracy dictates.

Another section of the paper discussed the principal uses for the p r o g r am in early design stages, to make up a final set of curves or to compute a set of curves for an existing hull where no other drawings are immediately available. The advantages, he nointed out, were that curves could be quickly computed where needed, to an accuracy determined by the number of trapezoids used, and all this done automatically once the basic information is inserted.

His paper was generously illustrated with detailed examples.

The presentation itself by Mr.

Cromer was almost startling with its vivid colors and flow diagrams.

It would have made any system analyst green with envy for its clarity of description of the process and its continuity. As contrasted with the paper itself, his slides were near works of art.

They visually described the concept of this program, and by the familiar line and block flow charts led the viewer through an orderly familiarization with the program concepts, its applications and the i m p l e m e n t a t i o n of its results.

There was little left to one's imagination except actually operating the program through a real life problem.

As would be expected, the subsequent d i s c u s s i o n s , questions and answers from the floor were both lively and extensive. It was easy to see who were most familiar with the techniques and they quickly disclosed how extensively t h e y t h e m s e l v e s had used these or similar computerized methods. Such programming need not be restricted to the hand held p r o g r a m m a b l e calculator.

Computer technology is definitely established in the marine engineering field. This was but another indication of how broadly this system has been assimilated as a design tool.

Other stories from November 15, 1978 issue


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