been made available for engineering applications and the hardware is minimized if the first or but are not all described in detail in this article. minimal non-zero coefficient irreducible poly­ The format of the burst correction tables facilitates nomial in Marsh's or Peterson's tables is used. the selection of a particular code or the evaluation A special-purpose computer has been developed of several codes in that codes are listed in increasing at the Applied Physics Laboratory to perform order of burst correction capability, increasing multiplication and division of polynomials in the order of the irreducible polynomial exponent, and binary number system and in the required algebra increasing magnitude of the check symbols. The when it is desirable to use a shortened code, thus capabilities of very long codes are retained or even eliminating the need for hand computation of increased after shortening the codes to mechanize residues. The same device doubles as an encoder them. This property should be noted. A simple or decoder simulator for generator polynomials mechanization is available if shift registers are used of degree 36 and less. Ways and J. R. Apel Means of The two most beautiful forms in To those who know and under­ the emphasis on speed boats and creation belong to a well-designed stand them, there is real beauty in hydroplanes; and an examination, in sailboat and a well-shaped woman. the lines of a hull or the set of the a bit of detail, will be maeole of a A categorical statement such as this rigging of a boat, be it an 8-foot 150-mph Gold Cup h ydroplane. The would ordinarily bring a flood of dinghy or an 80-foot diesel yacht. presentation of this article will be abuse upon the person who made it, To those who are untrained in things given from the standpoint of one but among judges of boats and nautical but who respond keenly whose vocation (in more fortunate women, the statement goes virtually to the visual arts, it is apparent that times, perhaps) encompassed much uncontested. Though both subjects ships and boats have a high degree of this subject matter, but who is would make an interesting discussion, of functional styling about them. It now reduced to boating and boat this paper will concern itself only takes only a bit of study and ob­ design as an avocation only. So this with boats. servation by the novice to become will be a "hobby" article. educated to some of the niceties of Few of the technicalities of the the business and to become convinced trade will be presented and virtually J. R . Apel, a physiqst in the Plasma that the old saw about boats being no connection will be made with its Dynamics Group, co-authored a paper called "she" has more truth to it mother-science, fluid dynamics. This entitled " Beam-Plasma Interactions" than would appear at first glance. is because first, the technicalities are in the May-June 1964 Diges t. Com­ This article will discuss the de­ not too interesting and second, yacht ing from a boatbuilding family, Mr. sign of pleasure boats and the de­ design is much more nearly an art Apel studied boat design at the signers; it will also discuss the con­ than a science. With the exception vVestlawn School of Yacht Design siderations that enter· into designing of a few craft such as the 12-meter and practic.ed this profession for different types of boats. Examples racing sailboats of recent years, several years. of a few designs will be shown with orderly research effort in pleasure 18 APL Technical Digest boat design (such as aircraft are sub­ boats. They may calculate their load jected to) has not been great. waterline on the hull using Simp­ son's rule (but not know integral calculus from vichyssoise) or they Naval Architecture may take the experimental approach The fundamental problem in naval and paint the waterline on the fin­ architecture is to design a boat or ished boat only after floating it in ship that is seaworthy, safe, and grimy water and letting the line de­ speedy, and that serves some spe­ fine itself in dirt on the hull. Either cialized purpose-cargo carrying, fish­ way is workable and, for boats the ing, racing and so forth. The success size of many pleasure craft, entails with which the problem is solved for comparable amounts of effort and small craft is chiefly a function of expense. One might not trust the the skill and experience of the archi­ practitioner of the second method tect, since the analytical rules of the with any design more complex than game are few and flexible. One re­ a coal barge, but he will make a liv­ sult of this lack of hard criteria is ing nevertheless. that the small boat designer is usu­ ally trained less formally and more Four Pleasure Boats practically than his colleague who designs ships. If properly under­ As an example of the end products taken, the practical training is often of a designer's efforts, four distinct as good or better for the purposes types of pleasure boats are discussed at hand, again because of the large in the following paragraphs. They empirical factor involved. are graduated according to hull type, However, anyone, trained or not, starting with a pure displacement can produce a workable boat. In fact, hull wherein virtually all the lifting with no other type of vehicle does force derives from Archimedes' an­ one find so many nonprofessionals cient law, and ending with a racing audacious enough to design and hydroplane that planes on the sur­ build their own platform and cour­ face and is nearly airborne at top ageous enough to set foot in the speed. thing when it is done. Witness the native with his log dugout canoe, the A Sailboat coastal fisherman with his ungainly Fig. I-Model of a 43-foot sloop designed but stout 50-foot vessel built without Let us return to the statement at for racing in shoal waters. Note the long, benefit of a single blueprint, and the beginning of this article. What graceful lines of the hull and the height of the mast. the basement builder struggling to is it that makes the sailboat hull such loft, or layout full size, the lines of an object of beauty? It is functional­ his 16-foot outboard from plans ism , a design perfectly attuned to the sail under 45° heel, perhaps, with a bought for $5.00 from the hobby element in which it must live. In large reserve righting moment re­ magazine. These people are some­ a sailboat, the requirement of har­ maining for safety's sake. Its masts times indecently successful. Witness mony has ideally resulted in an and rigging must take the strain of a also the degree of refinement ex­ object of sweeping, graceful lines that spread of canvas whose area amounts hibited by Messrs. Sparkman and cases the water around it with min­ to several times the lateral area of Stevens in the design and testing of imal effort, that reacts to heavy seas the hull supporting them. It must their exquisite series of 12-meter with rapidly increasing buoyancy as remain watertight, buoyant, and America's Cup defenders, or the engi­ it plunges in, and that sails almost amenable to control under these con­ neering and skill displayed by an air­ as well halfway over on its side as it ditions and preserve some degree of craft designer, Ted Jones, in concoct­ does upright. In many respects, the creature comfort at the same time. ing the first 200-mph hydroplane, problems facing the sailboat designer H is easy, for example, to design Slo-Mo-Shun IV. These latter are in providing for these ideals are ample righting moment into a boat professionals, of course, and special­ more complex than in any other and make her almost impossible to ized ones at that. Amateurs embark­ marine design task. His product must capsize; without care, however, the re­ ing on this level of activity are likely make efficient use of wind with a sultant response will be so quick that to meet with disaster. speed varying from dead calm to under the influence of a rolling sea For the most part, the boats one greater than whole gale and whose she will pitch crew and crockery sees in the yachting magazines are direction will range from some 30 to athwartships with such force that the designed by people who have learned 40° off the bow to dead astern, using a breakage factor for both will be in­ their trade by observing boats, build­ sail that acts much like a very limber tolerable. That all these require­ ing boats, running boats, and loving airplane wing. It will be required to ments are not always met is obvious November-December 1965 19 enough and the result is sometimes A Power Cruiser the typical cruiser will serve as fish­ less than pleasant for boat and crew. ing boat, a 2-week vacation retreat, During the long evolution of sail­ Proceeding on from sailboats, the a floating cocktail lounge, and an im­ ing vessels, the shapes of hulls and next hull type on our list is the semi­ portant part of the customer-rela­ sailing rigs have been developed to displacement power cruiser, probably tions department of the owner's busi­ a high state of refinement and they the most familiar species of pleasure ness. She does all these things well. are still evolving.