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MARINE 1901.] REVIEW. 25 emphasize the advantage of better protection of the machinery of a triple-screw ship. But, as such considerations are more or less theo- retical, each one may indulge in them according to that part of the subject in which he is most interested. For me it is more important at present to point out the tactical advantage of the triple-screw system based on practical experience that has so far been gained on the Kaiser Friedrich III, the first triple-screw battleship that has been assigned to service with the home squadron. For a clearer understanding of the subject of "'ability to maneuver,' the following particulars of this ship are given: Kaiser Friedrich III has a ratio of length to breadth of 5.6 to 1, (Brandenburg has 5.4, Sachsen 5.4 to 1.) The after body of the ship under water is*rather fine. The wing screws are covered by the hull, The rudder is half balanced, similar to those of the Brandenburg class, and rests upon a support below the central screw. The steering engine is worked with surprising ease through operating gear that is supported in'ball bearings along its entire length. The engines are triple- expansion, with three cylinders, the wing screws turning outward and the center one left handed. The convergence of the shafts of the former is such that their axes prolonged would meet within the ship about 180 ft. from the bow. Friedrich (IT. Brandenburg. Sachsen. Baden. Number of screws) .2.425.0. 3 : 3 2 2 2 DMsplacement,< 5.0.06 nates 11,180 10,033 7,400 7,400 balled seg cteee'; 50 is NOR sia a es 13,000 9,000 9,600 6,200 SPCC tases isis Gece Beek 18 16 14 17.3 bianker capacity acc joe ese 650 800 700 ~ 700 Friedrich III cruised with the Brandenburg and the Sachsen, and excellent and extensive opportunity was given for comparing them. Besides, there were on board of her two experienced officers who had commanded vessels of the Brandenburg class, and watch officers who had served as such on the Baden. The following account of the evolu- tions is based upon the unanimous statements of these officers. Primarily the objection has beén made to triple-screw ships that, 'were they introduced, it' would be necessary to give our officers special training in handling them if they had only been accustomed to handling twin-screw ships., This objection falls to the ground when we consider that we niow have ten battleships and nine large cruisers' with three 'screws, either completed or in process of construction, and that, in the near future, as far as can be seen, our first squadron will consist entirely of ships of this type. The good nautical 'qualities of the triple-screw system consists mainly in the excellent steering of the ship. With a judicious use of the helm, the ship is very steady, and the keeping of a given course presents no difficulties; ana it must be added that new -helmsmen learn to steer with exceptional ease and rapidity. The merit of. this good steering quality lies solely in the third screw, because, situated as it is just ahead of the rudder, it projects the water right on 'to it. Since twin-screw ships do not act so favorably in this respect, it may be stated as a fact that a great advantage of the triple-screw system 'consists in ability to steer well, and that with it steering is easily learned. ~' "Tt is well known that single-screw ships steer well when their engines 'dre.going ahead, and this is probably responsible for the opinion at first expressed, that a triple-screw ship in her entire behavior approximates the action of a single-screw ship; that like it, in all maneuvers, it is de- pendent upon its rudder alone. To this we offer decided objection. The 'Kaiser Friedrich III was always handled as a twin-screw ship, the center "serew always turning ahead, and thus exerting a favorable influence upon maneuvering, by its action upon the rudder. If, when lifting anchor, or casting off from a buoy the ships had to be turned, say sixteen points, to enter upon the course ordered, it was always found that the Kaiser Fried- rich III performed the evolution quicker and in less space than the Brandenburg class, and at least as well as the Sachsen 'class. On the other hand, it is true that the motion of the wing screws does not have 'such an immediate effect upon the turning of the ship as in a twin-screw ship. If it becomes necessary to make a sharp turn at the commence- ment of a run of greater or less duration, the stopping, or even the back- ing of the center screw, has no very noticeable effect upon the turning movement. On account of the otherwise excellent turning qualities of the three-screw ship, which answers the helm almost immediately,' this cir- cumstance has never appeared to cause annoyance when in squadron. Furthermore, the following evolution was executed: The ship lay 'at the south wharf of the fitting-out basin at Kiel dock yard, west of the 'passage to the building basin, heading east, and left the wharf without 'using the lines that: were got out. It is true there was no wind, but I doubt that a single screw ship of the same size could have performed this evolution under the same conditions. It should also be noted that the fitting-out basin:was not empty, but that there were two or three large vessels lying close to each other on its north and east sides. On the other hand, in backing, steering by means of the screws, especially under unfavorable conditions of wind, is exceedingly difficult. But in spite of this, it may be said that the Kaiser Friedrich III has left the wharf at Kiel backing under the most trying circumstances, and that they always succeeded in taking her to the desired place. However, as regards the lesser effect of the wing screws, it must be stated emphatically that this is only a consequence of the convergence of the wing-screw shafts, which approach so closely forward; and, therefore, it must not be assumed to -be an objection to the triple-screw system in general. This convergence of the: wing-screw shafts is due to the comparatively small beam of the ship, which necessitated this'construction. Where this is not required, as will be the case in our battleships, and when the wing shafts are parallel 'to the plane of the keel, the effect of their screws would be the same as in a twin-screw ship. With the increased engine power, I would suppose it more probable that, with three screws, the wing screws could be more easily arranged with parallel shafts than with the larger screws of only two engines. If this assumption is found to be correct, then the effect of the screws in the latter case would also be less. At any rate, as has been mentioned, the objection to their projection beyond the ship's side cannot be removed. The conclusion to be drawn from this is that the triple-screw ship with parallel shafts is superior to the twin-screw ship in ability to maneuver. ee THE MATTER OF CASUALTIES IN BATTLE. It only remains now to mention briefly the influence of casualties in battle, to either rudder or engine, in a triple-screw ship. In a twin-screw ship, if one engine is rendered inoperative, only one-half of the entire engine power remains for propulsion. The helm has to be put over from five to ten degrees towards the side of the injured engine in order to steer a straight course, by reason of which a part of the speed, even' though a small one, is lost; but the ability to maneuver suffers to a great extent. The three-screw ship, however, loses only one-third of her engine power, with a corresponding reduction in speed, when one wing screw is put out of action, The steering is hardly affected, because the central or steering screw remains intact. If the rudder gets out of order in a twin- screw ship it is necessary to steer with the screws, by which more or less speed is sacrificed, according to the evolution, If, however, the triple- screw ship becomes rudderless, she can be steered with the wing screws;° and even with the unfavorable arrangement of the wing shafts on the Kaiser Friedrich III this can be done without any special difficulty, But there the entire power of the center screw is available for the forward motion. Therefore, in these battle casualties, three screws are more advantageous than two. : If I were to condense all that has been said before, I should come' to the following conclusions: The three-screw system has: weighty argu- ments in its favor from a mechanical standpoint, but there are also some against it that should not be underestimated. It appears to me that' the advantages exceed the disadvantages, although I am fully aware that others hold a contrary opinion. However, from a nautical standpoint, the advantages are so great that I consider the use of three screws on large battleships absolutely correct. And this point of view must be the controlling one in the solution of the question. The majority of our technical officers would be of my opinion in this matter. But if it be asked how the other great navies stand in regard to the use of three screws, it must be said: The United States is again building only twin-screw ships; opinions there are, however, much divided. Russia is still wavering; in her new large ships we find two as well as three screws. In France, all new battleships and large cruisers are fitted with three engines. The British admiralty has vigorously opposed the triple-screw system, which is astonishing. ; Wee It would be manifestly wrong to form opinions against the triple- screw system from merely sentimental considerations; and yet there are officers who, without having had an opportunity of becoming familiar with three screws, and who, without being able to mention any special point against them, believe that the triple-screw system can not be good, because--the English have not yet adopted it. England' is inordinately conservative and holds on to old methods. It was only after the French had built ironclads and had successfully tried them that the English decided to change their "wooden walls" to iron ones; and they were many years behind other navies in adopting breech-loading 'rifles. Ad- miral Melville mentions in his paper the fact 'that no English warship has three screws, and seeks an explanation in the fact that English con- structors do not have to deal with light draught to the same extent that the American constructors do.' THREE-SCREW SHIPS SUITED TO KAISER WILHELM CANAL. _ But whatever reason may exist for the astonishing fact that. the triple-screw system has not yet been introduced in the British navy, there is a strategical reason for the use of three screws by us. It is this: A three-screw ship can pass through the Kaiser Wilhelm. canal with great ease. It is true that our other ships have passed through it, but. the demands upon their management were entirely different. Whoever, for instance, has passed through the canal, first in the Baden and shortly afterward in the Kaiser Friedrich III, must have been impressed with the immense advantage that the three-screw ship has over. the. two-serew one. On the Baden the best helmsmen were steering, and in spite of this the officer of the watch had repeatedly to help out with the engines in order to keep the ship on her course. He could not for a single moment -with- draw his attention from the steering of the ship, which fact made it nec- essary for the officers to be relieved every two hours during the. passage. The conditions on the Brandenburg class were similar, though. somewhat better. It must be added that these ships, and it is probably the case with all twin-screw ships, cannot exceed a certain number. of . revolutions, determined by experience, otherwise they have a tendency to run away from their rudders and thus cause damage to the banks of the canal by the increased stern wave. The passages through the canal with the Kaiser Friedrich III were entirely different. She was brought through the locks without any thought of damage to the wing screws. After leaving them,, the wing engines were stopped and the center engine proceeded with just as many turns as were necessary for the prescribed speed through the canal. In this way this ship of 11,000 tons went through the.canal as easily as a small boat. There was no intense attention by the officers of the watch, no anxious walking hither and thither of the navigator. The engine tele- graphs were not touched; quiet and peace prevailed on the bridge. The speed was low for a vessel of such large displacement, and might have been increased with safety without lessening the good steering qualities of the ship, and without injury to the banks of the canal, for there was hardly any stern wave. It is to be hoped that trials of this nature will soon be made. : os The Kaiser Wilhelm was built primarily for strategical reasons, and, as far as can be seen, it will play a great role in any naval war. with Ger- many. Is it not, then, self-evident that we should employ all aids that are given with the triple-screw system to make a quick passage, if neces- sary, without regard to the canal, and one that is safe under all circum- stances? If our new battleships had twin screws it is more than probable that they could never pass through the canal or the locks without injury. And what would be the conditions if such ships had just been commis- sioned and were without an experienced crew? : ee If the advantages of the triple-screw system from a nautical stand- point have caused me previously to declare in favor of them for general use, it follows from a consideration of these last conditions that, for the German navy, it is absolutely necessary to fit all the large ships of the home fleet with three screws. oes New train east via B. & O. R. R.--Leaves Cleveland 11:20 p. m. daily with through sleeper to Pittsburg and observation chair cars to Washington, Baltimore, Philadelphia and New York, giving daylight ride through the mountain scenery. June 30,