The following text may have been generated by Optical Character Recognition, with varying degrees of accuracy. Reader beware!

494 horsepower, that the data on which this paper is based can be considered absolute in any sense of the word We know what happens, as practical men, when you make a bold leap and start from an insufficient basis--you generally land in a mess. Internal Combustion Engine. Personally, I have been trying to adopt the electric drive for a very peculiar cause--the limits of the ves- sel being fixed in size, we have to get increased capacity by decreased machinery weight, and also fuel weight, and I think one great advan- tage of the electric propulsion scheme will ibe this--that you will be able by it to introduce very simple internal combustion engines for ship propul- sion, that is, absolutely linked to this electrical arrangement, but I do not think the internal combustion engine can be introduced without the intro--- duction of electricity for reversing or changing the speed. We have tried it the' other way, not to the extent of including the engine, but we found we could get no satisfactory means for reversing the engine or grading the speed, no satisfactory means of gearing would get rid of the difficulty of the gas engine, or running at one speed for the best results. Mr. Emmet has passed rather light- ly over the question of the propel- lers. I believe the propeller will de- termine the success ot his system. I - quite agree with him that a new pro- peller will probably 'be evolved to suit the new conditions, and it. will not be a propeller for the present reciprocating machinery, nor a pro- peller for the turbine, 'but one in be- tween, but I think in a high speed boat the best results can be got by using this electric arrangement to gear down from a small propeller to 'a large diameter' propeller. witha slow speed of revolution. I do not want to put Mr. Ander- son right, because he knows more about Mr. Parsons than I know, but I will say this method has the back- ing of Mr. Parsons, and is receiving his consideration, and he is still in- terested in it. It has come before the British admiralty, and has also 'been investigated by the United States navy, so that I hope something prac- tical will ibe heard about it. President Taylor: Mr. Dobson, do you care to say anything about the subject under consideration? Mr. William A. Dobson. William A. Dobson: I should be glad to discuss the paper, but I do . myself. |. based them. on TARE MarRINE REVIEW not really feel qualified to do so. The subject is one of great interest. It is of great interest to me, and I have been especially interested in the ta- bles of velocity given for the 'electric drive, and I have no doubt that the statement on page seven has a good deal to do with that, the form of re- sistance has tbeen developed by ex- periment, and I think we will be glad to learn something about that. There are so many others better qualified to speak on the subject, that I pre- fer they should speak rather than President Taylor: Mr. Magoun, will you discuss the subject? Henry A. Magoun: I should be glad to say something,' 'but unfor- tunately I have not been able to look into the matter. President Taylor: These battleship builders are' very modest. Mr. Ed- wards? Mr. Charles B. Edwards. Charles' B. 'Edwards: "i, do: 'not think I can' add very 'much, gentle- men, to the remarks that have been madé. [here are 'one. or two state- ments brought out I should like to correct, one in relation to the (brake horsepower developed on the trial of the North Dakota, to which reference was made. That amounted to a little over 41,000°H. P. at 21.6 knots, which I ibelieve has been. variously quoted as high as 35,000 H. P. In regard to the reversing of the turbines while cold, we have never experienced any trouble from that cause. The reversing portion of the turbine is running, of course, under low vacuum, perhaps 28 inches, and no difficulty has been with the blading in admitting live steam suddenly to the reversing tur- bine. That has been done repeatedly. While in the early stages of the de- velopment we had some fear. that there might be trouble yet practical experience shows there has been no difficulty in that respect. Mr. Em- met's paper is certainly very inter- esting and indicates a great step in advance in marine propulsion. I do not think there is anything more I can add. Mr. Ernest H. B. Anderson. Ernest H. B. 'Anderson;* > In the figures I gave for the North Dakota, the published re- ports, which gave 33,800 shaft horse- power for a speed of 21.8 knots, and which, for a corrésponding speed of 21 knots, would be approximately 30,- 000 shaft horsepower, tor: the experienced. December; 1909 As to the other point, about putting steam into the astern turbines when cold. In this combination drive, the case is quite different, because the ahead turbine has not been used at all, it is shut down, so that the whole thing is under vacuum at a tempera- ture between 90 and 100 degrees, and it is bound to get cold, even into the other shaft, and that is where I think there would be danger in doing that to the astern turbine. Of course, if the ahead turbine had ibeen working right along all the time, then the astern turbine has a good chance of keeping warm, but in this case it is quite different. One other point I forgot to men- tion--when using the one generator, with the turbines shut off, at 12 or 13. knots, you are carrying about with you 330 tons all the time in your engine room, doing no work, but always, to my mind in some danger of damage happening, if for any rea- son they put steam into the reverse nozzles and the other way would be to make the motors reversible so that there is no need to use 'the tur- bine. Mr. Emmet: I would like to ask Mr. Anderson a question. He asked about cost. I. will give him some idea of the cost of my. device, if he will give me some ideas of the cost of 'his.. I do not. know the-cost. of the Parsons turbine equipment, and will be interested in knowing \some- thing about it. ' Mr. Anderson: I am sorry that I do not have any idea of the cost, for the reason it is not up to me, but up contractors who make _ the turbines,--my work is more in giving the estimates of weight and that sort of thing, and working up the design. But as to the actual cost of building, I know nothing about it. Electric Drive Promises Much. Capt.. W. Hoveaard: electri¢é drive seems great deal for us in our warships, especially in battleships, and there is one point, which has already been touched on, which I desire further to bring to your notice, and that is the direct control from the 'bridge. That is a point which I think is very im- portant,- and in several other ways we are working in the direction of controlling everything in the battle- ship in one central station, from the conning tower. There has been taken out a patent by an English engineer for controlling the turbines from the bridge, and [I suppose the electric motors would lend themselves still I think the to promise a Si Se Niet a giles ahi ao as i bse aa 9 Poe