272 STANDARD LUBRICATING OIL SYSTEM FOR GEARED TURBINES. 



(a) The oil companies advised us that the deterioration of oil in, pressure systems 

 was largely due to the small amount of oil in the system and to its being constantly circu- 

 lated and agitated without any opportunity for freeing itself from either air or water. These 

 difficulties could be easily overcome with a gravity system. 



(b) Lubricating oil of the correct grade and quality was not available in foreign ports, 

 so that it was advisable to have in the system, when the vessel was put in commission, a large 

 quantity of oil as well as provision for keeping that oil in good condition. A gravity sys- 

 tem takes care of this requirement to best advantage. 



(c) The gravity system with large tanks provided a margin of operating safety of 

 from three to five minutes for adjusting any parts of the system which might become in- 

 operative and switching over to spare apparatus without shutting down the propelling tur- 

 bine. By using the spare gravity tank and the storage tanks and wasting the excess of oil 

 to the bilges, it was possible to operate the main turbines from 20 to 30 minutes with all oil 

 pumps, etc., out of commission. 



(d) With a pressure system it is necessary to shut down the main propelling turbine, 

 either manually or by automatic devices, immediately on failure of the oil pumps. 



There were numerous instances during the war when the propelling machinery of ves- 

 sels had to operate in spite of all commercial considerations, even to the limit of destroying 

 machinery. A case in point occurred near the Azores. A twin-screw turbine-driven vessel 

 had operating trouble with the turbines due to an accumulation of water in the lubricating 

 oil. A submarine attack was imminent, and the engineer was ordered to operate the tur- 

 bines regardless of damage to them. This was done, and the submarine was escaped, al- 

 though the turbines were almost completely destroyed. 



The use of a protective device which automatically shuts down the main propelling 

 machinery endangers the vessel itself, because of the unreliability of its operating and per- 

 mitting the vessel to drift into a dock or on a lee-shore or when trying to escape a subma- 

 rine, and is generally condemned by operating men. For that reason an automatic stop-valve 

 operated by failure of the oil pressure was eliminated from the standard system. Further- 

 more, it was considered unsafe to depend absolutely on any automatic devices and, where 

 used, they were supplemented by facility for visual observation and manual operation. 



Mr. Smith raises the technical point that the title of the paper is too broad. It is rec- 

 ognized that the system is standard only for vessels of the Emergency Fleet Corporation, 

 and this limitation is clearly brought out in the paper itself. 



Mr. Smith also states that no instructions regarding the standard system were provided 

 for the operating force. The technical order promulgating the system contains rather com- 

 plete operating instructions. Copies of it were furnished not only to shipbuilders con- 

 cerned but to the Division of Operations, and it was expected that the shipbuilders would 

 provide the usual instructions furnished with vessels and that the Division of Operations 

 would take care of the instructions of the engineers through their superintending engineers 

 and schools. We believe that the expected action was generally taken, although no hand- 

 book for operators was ever prepared or published. 



The variations in the system causing no two vessels to be alike, mentioned by Mr. 

 Smith, must refer to very small details, because, as brought out in the paper, the only sub- 

 stantial change in the system was made after the armistice, and for the reason set forth in 

 the paper. The use of mechanical alarms and other automatic appliances as an alternate to 

 the electrical system was always permitted. 



