8o 



ENGINEERING PROGRESS IN THE U. S. NAVY. 



just as essential to have naval machinery free from any possible chance of ma- 

 chinery breakdown. Blading troubles with the main turbines are very rare. When 

 they do occur it is usually after opening up the turbines for inspection. The men 

 who do this overhaul work do not realize the absolute necessity for taking proper 

 precautions to see that no foreign materials are left within the casings. 



Rotor Corrosion simply means a question of personal supervision down in the 

 engine-room, and if instructions are faithfully carried out this will not happen. 

 In the turbines of a battleship, rotor corrosion means neglect; for the interior of 

 every rotor can be thoroughly examined by removing manholes on the casings and 

 internal examinations should be made periodically. There have been one or two 

 bad cases of rotor corrosion in the Navy, which have been largely due to neglect. 

 On the other hand, there are many turbine-driven ships in the Navy which have 

 had absolutely no trouble in this respect. 



As regards reliability, take the engines of the scout cruisers, and recall the full 

 speed trials of these ships when they were practically new. 



. The Birmingham made 24 knots, but it was found advisable to shut down at 

 the end of 12 hours, and this ship returned to the navy yard for repairs. 



The Chester made 25.08 knots for 24 hours. 



The Salem made 24.32 knots for 24 hours. 



Dealing with the somewhat vexed question of comparative machinery weights 

 and engine-room spaces, I have extended the author's list and carried the com- 

 parison on to the latest battleships jnow under construction. In each case, I 

 have first of all given the designed figures, or the basis of all calculation. Note that 

 the displacement of each class of ship has steadily increased. 



The weights included above were as follows : — 



Designed displacement . . 

 Contract speed, knots . . . 

 Type of engine 



I. H. P. design 



S. H. P. design 



Engine-room length 



Mean width 



Total area in square feet 

 Shop weights, gross tons 



Delaware. 



20,000 



21 .00 



Recipro- 

 cating. 



25,000 



23,000 



44 ft. 

 50.50 ft. 



2,222 

 654.50 



Utah and 

 Florida. 



2I,»25 



20.75 



Parsons 

 turbines. 



28,000 

 60 ft. 

 51 ft. 

 3,060 



659.01 



Arkansas 

 Wyoming. 



26,000 



20.50 



Parsons 

 turbines. 



28,000 



60 ft. 



52.50 ft. 



3.150 

 648 . 23 



Texas and 



and 

 New York. 



27,000 



21 .00 



Recipro- 

 cating. 



60 ft. 



53 50 ft. 



3.210 



Oklahoma. 



27.500 



20.50 



Recipro- 

 cating. 



24,800 



60 ft. 

 58 ft. 

 3.480 



