ELECTRIC PROPULSION OF SHIPS. 149 



The analysis in the table does not include fuel. Taking the fuel consumption roughly 

 at 0.55 pound i^er effective shaft horse-power hour for the Diesel and Diesel electric (which 

 is very conservative), and twice this amount per shaft horse-power hour for the geared tur- 

 bine (which is likewise conservative), and 5 per cent more for the turbine electric than for 

 the geared turbine, and allowing sufficient fuel for a round trip of 3,300 miles each way, 

 for a 3,000 S. H. P. ship, operating at 11 knots, the total fuel consumption would be as 

 follows : 



1,648,000 pounds for the geared turbine. 

 1,730,000 pounds for the turbine electric. 



874,000 pounds for the direct Diesel. 



874,000 pounds for the Diesel electric. 



Adding these figures to the total weights in the table, we have : 



3,500,000 pounds for the geared turbine drive. 

 3,221,500 pounds for the turbine electric. 

 2,533,200 pounds for the direct-drive Diesel. 

 2,242,200 pounds for the Diesel electric. 



The corresponding ratios as compared with the geared turbine would then be: 



Geared turbine 1 



Turbine electric 1.07 



Direct-drive Diesel 845 



Diesel electric 747 



The above results agree with the general statements in the writer's paper, but are at 

 variance with the figures given by Mr. Bailey and Mr. Smith, particularly the latter. I am 

 quite sure that if these gentlemen would have used the same engine for their Diesel electric 

 drives, their figures would have been substantially in agreement with the table, provided all 

 related items as listed were included. 



The tables given by Mr. Bailey and Mr. Smith also show considerably higher cost figures 

 for the Diesel electric than seem justifiable in the light of my experience. I feel quite cer- 

 tain that the price of Diesel engines is still higher than it should be. This is particularly 

 true in the case of engines for Diesel electric drive. I have no figures on the installation of 

 the machinery, shafting, propellers, etc., but I am sure that the engines, generators, exciters, 

 motors and control can be bought today for $130 to $140 per shaft horse-power, provided 

 the proper Diesel electric units are used. Previous quotations might run at variance with 

 this statement, but until recently electrical manufacturers have been forced to quote relatively 

 low-speed Diesels. My remarks on cost referred to future developments, except in a few 

 present cases. 



Rather than point out the detailed differences of the comparisons in the tables prepared 

 by Mr. Bailey and the table given above in this reply, the reader is requested to review the 

 tables for himself. I have stated the basis on which my table has been compiled, and, pre- 

 suming that Mr. Bailey's table has been compiled in much the same manner, the largest dis- 

 crepancy appears in the cases of the Diesel direct and Diesel electric. The probable reasons 

 for this have been stated above. Mr. Bailey's analysis shows that, in the case of the single- 

 screw Diesel electric, the space favors this type of drive slightly, and it is safe to say that with 



