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336 DEVOTED TO EVERYTHING AND EVERY INTEREST CONNECTED OR_ ASSO- CIATED WITH MARINE MATTERS ON THE FACE OF THE EARTH.» Published monthly by The Penton Publishing Co. : CLEVELAND. BUPBALO. fo. 60.5 oe oe 3 932 Ellicott Square. CHICAGO 6g 555i ses. 1328 Monadnock Blk. CINCINNATI..... First National Bank Bldg. NEW YORK. oc cece. 1005 West: Street Bldg. Pit PEBURG. 36666 Kei ss 510° Park --Bidg: SEATTUEE. sc. Eeghad GMa wees 302 Pioneer Bldg. Correspondence on Marine Engineering, Ship Building and Shipping Subjects Solicited. and Mexico, $1.00 per annum. Canada, $1.50. Foreign, $2.00. Single copies, U. S. and Mexico, 10 cents. Elsewhere, 15 cents. Back numbers. over three months, 25 cents. Subscription, U.S. Change of advertising copy must reach this _ office on or before the first of each month. The Cleveland News Co. will supply the trade ._ with the Marine Review through the regular channels of the American News Co. Burcpean Agents, The International News Company, Breams Building, Chancery Lane, London, E. C., England. Entered at the Post Office at Cleveland, Ohio, as Second Class Matter. _ ' Seaiber 1909, A NEW KINK IN NAVAL ARCHITECTURE. A prominent naval architect used to say that ship building was not an ex- act science, because if it were there _ would be no failures, the personal equa- tion. would be eliminated and _ results could be predicted with certainty. That this is not the case, almost every day furnishes proof. In an address at the joint summer meeting of the Institu- tion of Engineers and Ship Builders of Scotland and the Northeast Coast Insti- tution of Engineers and Ship Builders, held at Glasgow, Dr. G. B. Hunter said: "Ship building is _ This, however, was before the perform- the elsewhere, had come to confound him. an exact science." ance of Monitoria, referred to That a crimp or two in a ship's side, section of a_ battered should have fairly be called such revolutionary ef- fects, is sufficiently startling and, on giving her the washboard, what might THe Marine REVIEW first thought, almost comic. But there appears no reason to doubt the results claimed for it. It is a long time since any innovation of approximate import- ance in ship building came to us, and to cut down fuel consumption 15 per eon and at the same time increase dead weight capacity 314 to 4 per cent is no matter in a cargo ship. It the ship owner than the small means more to advent of the triple-expansion engine. Speculation as to the effect of the corrugations in higher speed vessels of types, interesting, various including side-wheel steamers, iS even if un- profitable, and we may be sure that the possibilities of this departure are not exhausted. THE VIBRATIONS OF SHIPS. Few phenomena have tbeen the sub- ject of abstruse papers or served as a text for learned discussions oftener than the tile of this article." The work of Schlick, Yarrow, 'Taylor, Macalpine, Melville and others forms a formidable array of outgiving on the general subject, while the lectures and inventions springing therefrom are beyond computation. In most, if not all, cases it has been assumed that -the whole trouble lay with the en- gines. In all the treatises on the sub- ject it is treated from this standpoint. satisfied himself that specific case certain observed periods Yarrow tit a of vibration were due to the engines and 'built thereon a theory intended to be applicable to all cases. Schlick also had his theory, based on the as- that the the sole cause of disturbance. Taylor was the first to touch the real trouble and, while attacking it intelligently and ef- sumption engine was fectively, to concede that not only did the causes of vibrat'on frequently lie entirely outside the engine but also frequently were not curable by en- gine treatment. Melville, while anal- yzing the disturbing forces and sug- gesting their treatment says that the so-called "systems" shave their chief value in cases "where it is of import- ance to claim that at least an effort has been made to solve the problem." There is, not a doubt that many an extra has been paid on contracts be- September, 1909 ce cause the engines were to be balanced As a bald matter of fact, there is no known in- on somebody's system. stance where anybody's system either The vibrate neither vibrate to the lack of balance, nor in prevented or cured vibration. fact: (hat a proves absolutely does the fact that she does: prove that the trouble is due ship does not nothing, engines, or fact to anything definite whatever. If, as some assert, the question is solely one of balancing or eliminating dis- turbing weights and forces, why will a given ship which has exhibited no tendency to vibrate in deep water set up violent vibration on entering shoal, condition has been although no changed? Many ships have been known to be perfectly still in shoal water and threaten to 'break in two with speeds exactly the same in each case. when in deep 'water engine Ships with engines 'balanced most carefully and scientifically on well known "systems" have been notorious- ly among the worst offenders, while others in which all system was calm- ly ignored have proven marked suc- cesses. _ Almost all the attempts at sctentifi- dealt with four-crank engines, except possi- cally correct 'balancing have bly Macalpine's, of which, so far as we know, there are no examples, and the system known as Yarrow-Schlick- Tweedy is probably the most widely known. That it or-any other system has ever prevented vibration has yet to be demonstrated. It is not denied that ships with engines balanced on that system have apparently been suc- cessful, 'but it is also true that just as many have not been. Considering that the eng'nes with normal crank arrangement are many times the more the certainly numerous, showing is not convincing. Fighteen years ago D. W. Taylor suggested a method of crank arrange- ment involving no calculation what- ever, which so closely approximates the Y.-S.-T. four-crank engine, and eliminates pos- system for any given sible errors in computation, much of which is estimated, that it is just as likely to be successful as the latter,