66 PROGRESS IN TURBINE SHIP PROPULSION. 



NOTE A. 



U. S. S. Neptune. — This ship was equipped with two sets (twin screws) single reduction gears and tur- 

 bines, the turbines having been largely experimental and were not successful. The gears, however, operated 

 splendidly. The turbine machinery was then replaced, and inasmuch as a higher turbine speed was con- 

 sidered desirable, new gears involving a greater speed reduction were also installed at this time. The 

 designed constants of the new gears were very high and are still much in advance of our present practice. 



Considerable trouble was experienced due to the teeth abrading, which was only overcome by the use 

 of lard oil. Since that time, however, in November, 1915, no further trouble has been recorded, and the 

 teeth at the last inspection were in good condition without any indication of wear. 



NOTE B. 



S. S. Maul. — This vessel was built by the Union Iron Works. Inasmuch as we were late in delivering 

 the machinery, we were unable to carry out any tests on the gears in the works, and inasmuch as great store 

 was set by the owners that nothing should go wrong on the maiden voyage, and as there was some un- 

 certainty as to the excellence of the tooth surfaces, lard oil was employed as a lubricant for the first two 

 voyages, after which mineral oil was substituted for the lard oil. 



The operation of the machinery was all that could be desired for eight voyages, at which time there 

 was abrasion of the gears due to failure of the lubrication. This was discovered in Honolulu and the 

 ship returned to San Francisco with nothing being done to the machinery except an attempt to clean the 

 oiling system. The tooth surfaces smoothed up considerably during the voyage. 



The gears were then transposed from one side to the other so as to make what had been the astern 

 surfaces the ahead surfaces, so as to use uninjured tooth surfaces for ahead operation. 



Again because of some uncertainty of the tooth surfaces lard oil was employed as a lubricant and 

 the vessel entered in government service, going to Chile for cargo and proceeding to Baltimore. During 

 the voyage there was an accident to an oil cooler, admitting salt water to the system. The shipbuilder 

 having provided no means of removing any water, the effect of the salt water on the lard oil was to turn 

 it violently acid which necessitated a complete overhauling of the machinery on its arrival in Baltimore. 



On this being completed and on the trip from Baltimore to New York trouble was experienced with 

 abrasion of the tooth surfaces due, it was believed, to an inferior quality of oil, together with further 

 failure of the oil cooler, admitting enough water to the system to make an emulsion of approximately 30 

 per cent. A better oil was substituted and nothing was done to the tooth surfaces, the vessel having made 

 one voyage to Europe and back with no trouble so far as the gears are concerned. 



During this voyage trouble was experienced with one of the turbines, causing quite an extensive re- 

 pair because of an obstruction in one of the oil passages to the thrust bearing of the turbine, causing the 

 thrust bearing to fail; the turbine rotor, moving endwise, completely wrecking the labyrinth packing be- 

 tween the ahead and astern elements and buckling the rotor. 



NOTE C. 



S. S. Golaa.— Norwegian oil tanker built by Chester Shipbuilding Company and chartered by British 

 Admiralty. Put in service July 6, 1917. Made three round trips to English ports. At present in coastwise 

 trade between Port Arthur, Texas, and Philadelphia or Bayonne. Towards end of last trip from Europe 

 (February, 1918) some teeth on starboard high-speed pinion broke out. This gear was disconnected and 

 ship made port, using low-pressure turbine only. Inspection showed break occurred on one helix, 3 

 inches from end of tooth face. There was no evidence of ^ear on any of the tooth faces, the undamaged 

 portion of broken tooth face indicating uniform distribution of load. This fact and the position of frac- 

 ture make certain accident was due to defective material. 



In August of this year the high-pressure turbine suffered injury as a result of improper setting of the 

 turbine thrust bearing. Shortly thereafter an accident occurred to the pinion which replaced the one originally 

 defective. The character of the broken tooth was similar to the previous one. The broken parts have not 

 yet been received to enable a careful examination of the material to be made. 



NOTE D. 



S. S. Sudbury.— An American freighter built by the Chester Shipbuilding Company for the Shawmut 

 Steamship Company. It is at present being operated by the U. S. Naval Overseas Transportation Service. 

 A few days after leaving France on return half of maiden voyage, some teeth broke out of starboard high- 

 speed pinion. This gear was disconnected and ship returned to New York, using low-pressure turbine only, 

 with which 9 knots was attained, the designed full speed being lOyi knots. 



On arrival at port, inspection showed no wear, the tooth load having been well distributed on all tooth 



