- BOUGHT WITH THE INCOME FROM THE SAGE ENDOWMENT FUND THE GIFT OF 3Hetirg W. Sage 1891 /' jr'?3, ' 3\TTj<>3 3513-1 ENGINEERING LIBRARY All books are subject to recall after two weeks. Engineering Library DATE DUE ' ^9 54«f THE SCREW PROPELLER, — — — CHARLES GRIFFIN & C O., LTD. PUBLI SHERS. By A. E. SEATON, M.Inst.C.E., M.I.Mech.E., ete. Sixteenth Edition, Revised. Pp. i-xxiv+712. "With :*50 Illustrations, reduced from "Working Drawings, and 8 Plates. A MANUAL OF MARINE ENGINEERING. Comprising the Designing, Construction, and Working of Marine Machinery. "The most valuable Handbook of Reference on the Marine Engine now in existence."— MaHne Engineer. By A. E. SEATON and H. M. ROUNTHWAITE, M.I.Mech.E., ete. Ninth Edition, Thoroughly Revised. Pocket size. Leather. MARINE ENGINEERING RULES AND TABLES. For the use of Marine Engineers, Naval Architects, Designers, Draughtsmen, Superintendents, and others. 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"Should prove of invaluable service . well up to date." Shipping World. By Prof. J. H. BILES, LL.D., etc. In Large Svo. Cloth. In 2 Volumes, each complete in itself. THE DESIGN AND CONSTRUCTION OF SHIPS: Vol. I. Calculations and Strength. Vol. I. With 36 Folding Plates and 245 other Illustrations. Complete with Index. ?7.50 net. WORKS by THOMAS WALTON. Fourth Edition. Profusely Illustrated throughout. *E5.50 net. STEEL SHIPS: Their Construction and Strength. In Haudsome Cloth. Verv fully Illustrated. >:\ .mi net PRESENT-DAY SHIPBUILDING. Ninth Edition. Fully Illustrated. Cloth. #-i 60. KNOW YOUR OWN SHIP. LONDON: CHARLES GRIFFIN & CO., LTD., Exbter Strekt, Strand. PHILADELPHIA: J. B. LIPPINCOTT COM PANY. Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924005016450 h *-^y> THE SCREW PROPELLER: AND OTHER COMPETING INSTRUMENTS FOR MARINE PROPULSION. BY A. E. SEA.TON, M.Inst.C.E., M.I.Mech.E, M. Council N. A., * FORMERLY LECTURER ON MARINE ENGINEERING TO THE ROYAL NAVAL COLLEGE, GREENWICH ; AUTHOR OF "A MANUAL OP MARINE ENGINEERING," ETC. TKflttb Jfronttepiece, 6 plates, 65 otber 3-Uustrations, an& 60 arables. LONDON: CHAKLES GKIFFIN & COMPANY, LIMITED. PHILADELPHIA : J. B. LIPPINCOTT COMPANY. 1909. \ 3/tqt %"t-•V\ii 7: A.a v:n^\ PREFACE. Some thirty-two years ago, when engaged in putting forth the Manual of Marine Engineering, I could not find a single book on the Screw Propeller, or any text book containing such information on it as would enable a draughtsman to get out the leading dimensions, and much less to make a complete design of a screw suitable for any particular ship and conditions. At that time John Bourne's admirable book on the Screw Propeller was not only out of print, but out of date, and T fear no engineer could at any time have designed a screw which would give satisfactory results from what was contained in it. It was, however, many years after that I first saw his work, and my wonder then, as now, is that such a book was allowed to disappear, seeing how much of interest it contained. But perhaps the strongest comment on the knowledge of the screw propeller at that time is in the admission of the then Engineer-in-Chief of the British Navy, that he had settled the design of those for so very important a ship as the " Iris/' intended to be the fastest ship in the Navy, by copying that of H.M.S. "Himalaya," a ship built in 1854, with the result that the British Admiralty, with all its knowledge and opportunities, with all its records of tests and trials, perpetrated a blunder never equalled in the history of steam navigation, although in the mercantile marine there had been not a few mistakes. But even in modern times, notwithstanding the better knowledge and the aid of tank experiments, our best men do sometimes fail to achieve success, but the magnitude of the failure is inconsiderable compared with that of the " Iris." In the Manual of Marine Engineering I attempted to supply the wants of designers by giving a rule or formula for each important dimension, generally based on scientific reasons, and always capable of giving results agreeable with the best and most successful practice. VI PREFACE. Moreover, such rules were generally cast in such a form as to be quickly and easily used. From time to time I have added to them and modified such of them as further knowledge had shown to require it, so that they have become generally applicable to the design of a screw for an Atlantic liner or a torpedo boat. The object of the present work is to amplify and extend what to it was there mostly in skeleton or in rudimentary form ; to add give all that is new and much that is of interest, although old ; and to of importance and necessary to be known by the students, draughts- men, sea-going engineers, designers, and others who have found the Manual of assistance to them. The more abstruse and highly mathematical investigations connected with the theory of the resistance of ships and propellers have been left to be studied in the text-books of the schools and in the valuable papers contributed by Prof. Kankine, Prof. Cotterill, Mr E. E. Froude, Dr Froude, Prof. G-reenhill, and others, to the Transactions of our professional institutions and learned societies. Chapters I. and II. are devoted to the history of propellers in such a way as to give to the reader all the good inventions, their inventors, patent numbers, etc., and at the same time to revive and perpetuate the name of many a good pioneer among engineers. The young engineer of to-day is thus enabled to see what has been done by those gone before him, and to give the credit and praise to the right man. In connection with this it is curious to note how often the important invention has emanated from someone outside the pro- fession of engineering. For example, Francis P. Smith is described as a " farmer," Bennet Woodcroft as a " printer," Goldsworthy Gurney a "physician." The only "engineer" to whom it may be accorded that he did invent and patent a screw propeller as well as invent and make a locomotive engine long before anyone else, is the Cornishman Trevithick. But it is likewise a melancholy coincidence that except Gurney the above-named made no money by these inventions, and died poor men. It is true that poor Woodcroft had a crust given him by the Government in the form of an indifferently paid post in the Patent Office. I am indebted to Mr C. De Graves Sells of Genoa for the particulars of the various groups of most interesting experiments made by his father, as also for other important information respect- — PREFACE. Vll ing the early history of the screw, and I take this opportunity of thanking him for these and some other acts of kindness I have experienced at his hands of a similar nature. I also desire to tender my thanks to several other friends who have been kind enough to furnish me with information such as T was lacking, and which was necessary to my purpose, especially when engaged in determining what was really good modern practice. In conclusion, I hope this book will have accorded to it the same kindly consideration as was experienced with the Manual, and that the readers will regard with favour the attempts to elucidate difficulties and to make known discoveries, rather than to scan too closely the many shortcomings it possesses , in fact, in the words of Prior " Be to her virtues ever kind, And to her faults a little blind." A. K SEATON. Westminster, S.W., March 1909. CONTENTS. CHAP. PAGE I. Early History of Marine Propellers .... 1 II. Modern History or Propellers ..... 13 III. Resistance of Ships ...... 38 IV. Qn Slip—Real, Apparent, Positive and Negative. Cavita- tion. Racing . 54 V. Paddle Wheels . 69 VI. Dimensions of Paddle Wheels . 80 VII. Hydraulic Propulsion : Internal Propellers and Jet Propellers . ..... 91 VIII. The Screw Propeller : Leading Features and Character- istics Thrust and Efficiency. 104 ; .... IX. Various Forms of Screw Propeller . 130 X. The Number and Position of Screws .... 140 XL Screw Propeller Blades : their Number, Shape, and Proportions . .... 153 XII. Details of Screw Propellers, and their Dimensions . 169 XIII. Geometry of the Screw . .... 186 XIV. Materials used in the Construction of the Screw Pro- peller . ...... 194 XV. Trials of the S.S. "Archimedes" and H.M.S. "Rattler" . 202 XVI.