80 PROGRESS IN TURBINE SHIP PROPULSION. 



gears, but I wish to mention that I read a paper before this Society two or three years ago 

 on the Alquist type of gearing, and we have put on the sea a great number of ships contain- 

 ing that type of gearing. We have had an unconscionable amount of trouble with than, so 

 much so that there is a general state of very serious alarm as to the matter. 



However, there is always a reason for everything in engineering; the thing to do is to 

 look for the reason, and that is what we are endeavoring to do. In this connection, there 

 are some interesting effects of the relation of gear pressures, and in Mr. Hodgkinson's paper 

 there is a curve showing the legitimate tooth pressures and pinion diameters. I will 

 not take up much time with that. The point I have in mind is this — we have run these 

 Alquist gears for some time. We have one particular case in Schenectady of a laminated 

 gear which we have run for 1,500 hours at a pressure considerably more than double that 

 shown by the diagram in Mr. Hodgkinson's paper, for such a pinion diameter, without the 

 formation of a single pit, burr or abrasion of any kind, absolutely perfect glassy engagement 

 of the tooth surfaces, showing that if you can make a thing like that and take some means 

 by which the pressure will be equally distributed and divided, you. get the result. 



This Macalpine gear, of course, does that to a very great extent, and its records, I 

 believe, are very good, as shown by Mr. Hodgkinson's paper, and also judging from what 

 I have heard in various ways. What I have been engaged upon is another way of doing 

 the same thing and, when it is properly applied, it works. The reason why it probably has 

 not worked in many cases of service — although it has worked very well in some particular 

 instances — is that it is an elastic thing, and elastic things are always liable to be subject to 

 periodic action ; that is, a thing which tends to run by a succession of bounces, in some way, 

 due to oscillations, causes terrible strains. We have evidence of such action, and it is prob- 

 ably the secret of the trouble which has occurred with this type of gearing. 



There are ways of restraining such movements, and these are being applied. We know 

 that very heavy duty has been and is being done with such gears, and I simply want, as 

 far as the present situation goes, for everybody to be patient and seek the reason for the 

 troubles encountered. 



When any troubles occur in connection with machinery, the last thing to do is to start 

 over again. What you must do, if you have trouble with machinery, is to seek the reason. 

 In Mr. Hodgkinson's list there is only one ship which shows more than 125,000 miles of 

 service, but we had many ships with an equal distance to their credit before we ever knew 

 that we were in trouble. We have a much larger number of ships on ' the ocean with our 

 equipment, and they have been on the ocean a much longer period and were on the ocean 

 long before the ships with the other classes of equipment began to appear in any large num- 

 bers. We have been turning out generators for four years driven by this type of gearing, 

 and in a large number of cases the pressures were very heavy. We have a 100 per cent record. 

 We never have made a renewal and never have had a broken tooth, which is a significant fact. 



I am taking up your time with something a little apart from Mr. Hodgkinson's paper, 

 because there is a very serious situation confronting the country, maybe due to the fact of 

 the failure of these gears for which I have been responsible, and I want to say that the story 

 is not all told. Some of them are working, and I think they are all going to work. I am 

 not certain of it, but I think so. 



The President: — Mr. Riley, will you add something to the discussion, founded on 

 your recent experience? 



