82 PROGRESS IN TURBINE SHIP PROPULSION. 



Mr. Howard C. Higgins, Member of Coimcil: — The author makes a statement regard- 

 ing the feed water heating which is misleading. He says : "With the advent of turbine-driven 

 auxiliaries and electrically operated winches, etc.,theauxiliary exhaust may be uncontaminated 

 with oil, permitting the employment of an open heater for shipboard use, and a more com- 

 plete separation of air from the feed water," and refers to this open heater as being similar 

 to the jet condenser. I think heaters of that kind, the jet condenser style, were in use in 

 marine practice before the tube heater which we now use. The Weir heater is an open 

 heater; the steam comes in contact with the feed water. He says further, with regard to 

 the economy of the open heater, that there is no advance in economy in operation beyond 

 the economy secured by the use of the closed heater. That is probably true, but you save 

 money in the cost of the heater, and it necessitates no pump. He further says : — "Such a 

 type of feed heater eliminates need of a separate feed tank and must be located some feet 

 above the feed pumps to preclude the latter being vapor bound because of pumping water 

 near the temperature of evaporation." Of course we can appreciate that some feet may 

 be considered a few feet. The Weir heater is located about 20 feet above the pump, which 

 necessitates additional piping and additional expense. The open heater may not give as 

 much temperature, in some cases, as the closed heater. The greatest temperature I have 

 ever seen on an open heater is about 220' degrees, while 240 degrees can be obtained with 

 a closed heater used with the exhaust steam on board ship. You can also obtain within 

 about 12 or 15 degrees the temperature of the feed water of the actual temperature in the 

 steam, which is not a great loss to pay for the advantages of the closed heater. 



The President : — Professor Sadler, have you anything to say ? 



Professor Herbert C. Sadler, Member of Council: — I regret, Mr. President, I have 

 not had an opportunity of reading the paper. It just came into my hands this morning, and 

 I would like to have permission to communicate some comments on the paper later. 



I would like, however, to draw attention to one fact, and that is that we are facing 

 somewhat of a serious situation in connection with geared turbines. I think the general 

 opinion to-day is that we ought to be a little careful before adopting geared turbines for 

 cargo vessels. I for one am always anxious to see advances made in engineering, and I 

 have the feeling that we, all of us, have got to do whatever we can to make the geared units 

 we have on board our ships a success. They may not be the final solution of the problem, 

 but we have taken a step in advance by adopting the geared turbine to a large extent in our 

 modem cargo vessels and although we may have had some failures, I sincerely hope that we 

 can, and I think we can, find out the cause of these failures. Certainly every one connected 

 with this Society should take an interest in this matter and do what he can to make this in- 

 stallation a success. 



Mr. N. W. Akimoff, Visitor: — It would be of great interest to all present to know 

 Mr. Emmet's opinion on the subject oi torsional vibration. It is a well-known fact that a 

 shaft, bearing on both ends heavy objects, such as, say, a propeller on one end and a large 

 reduction gear on the other, will possess a rather low period of torsional oscillation, the am- 

 plitude of which may be quite considerable. I remember in my own experience in a high 

 grade motor car, built in this country, it had a seven-bearing shaft and had all the parts bal- 

 anced, and yet there was a tremendous vibration, which apparently came from the priming 



