BATTLESHIPS. EXPERIENCE GAINED ON THE JUPITER. 199 



pany, put a clause in that contract relating to electric propulsion, that is, Mr. Curtis re- 

 served the right to use his turbines for marine propulsion, but Mr. Rice wrote into the con- 

 tract the words "except when through the medium of electric motors" or some words to that 

 effect, showing that he considered electricity a possibility wherever power transmission had 

 to be done in a compact, simple and reliable way. 



The strength of the case of electric propulsion has steadily gained ever since I first 

 discussed the subject before this Society, because high-speed turbines have become steadily 

 better, and as they have become better they have become lighter and higher in speed, makmg 

 more necessary suitable means of reducing the speed in any desired ratio. My first propo- 

 sition to apply electric propulsion was in connection with a battleship, as I have always 

 made it a practice in engineering to figure the best case first. I try to select the things on which 

 to exert my energies which will bear the most fruit in a single operation rather than to take 

 something in which the possible result is only a little better. I realized that the great merit 

 of electric propulsion lay in its application to a battleship where there was necessity for high 

 speed with a minimum of boilers, and where the desire for good economy at low cruising 

 speed was very great. 



When the question of equipping the Jupiter came up I rather protested against putting 

 an electric plant into the Jupiter, because she was a ship of one speed, and while I knew I 

 could make an enormous gain over any other propelling system in existence, I knew that the 

 relative gain would be nothing like so great as if I could install the system on a battleship. 

 The Jupiter requires about 7,000 horse-power, and is a very large, low-speed vessel. She 

 runs practically at one speed, and there is no particular occasion for changing the ratio of 

 speed in such a ship. The demonstration which has been made on the Jupiter is a very im- 

 portant one in marine engineering, and in spite of the fact that T did not consider it a de- 

 sirable case, and hesitated to take it up lest we should not make a sufficienth' striking dem- 

 onstration, this paper reports the Jupiter as about 25 per cent better than her sister ships. 

 The sister ships are as good as any ships afloat, with very good engines in them. The trials 

 of the Cyclops showed what was considered a phenomenal performance, but the gain in the 

 Jupiter is in reality, I think, more than is indicated by test, since her auxiliary arrangements 

 are very imperfect and involve a great waste of steam. In the trials of the Jupiter the steam 

 consumption for auxiliary purposes was reported as about 20 per cent. The reason for that 

 was that in order to hold a good vacuum on the main unit they had to hold the pressure above 

 the atmosphere on the auxiliaries, and were exhausting the auxiliaries into the main conden- 

 ser. The auxiliary economies ruiming with back pressure were extremely bad — turbine units, 

 some of them — and the steam consumption was outrageous. 



There are one or two things in Mr. Robinson's paper relating to the Jupiter I think I 

 might explain. The breaking of a bolt in the first stages of the Jupiter when she was on 

 her trial was probably due to the fact, as he mentions in another part of the paper, namely, 

 that there was an immense amount of water passed through the turbine by violent priming. 

 There was so large an amount of boiler compound in the boiler that the outside of the tur- 

 bine was encrusted with solids from the boiler compounds which primed over into the tur- 

 bine and was forced out at the valve stem. The shock from this water undoubtedly broke 

 the head off one of three bolts that held the stationary buckets. The ship came in under her 

 own steam with the bolt broken. That illustrates a great advantage of a turbine of this 

 type, which is practically nine separate turbines in separate cases. If anything happens to one 

 of them, you can lift off the top and clear that element so that it will rtm, and the remainder 



