216 STEAM ENGINES 



Water may be, used on a moderately hot bearing without doing 

 very much harm. It is quite common in practice, when 

 sprinklers are fitted to an engine, to run a light spray of water 

 on the crankpins when they show a tendency to heat, with very 

 beneficial results. 



Dangerous Heating. Should a bearing become so hot as 

 to scorch the hand or to burn oil before it is discovered or 

 because of the necessity of keeping the engine running from 

 some cause, it is imperative that the engine should be stopped, 

 at least long enough to loosen up the brasses, even though it 

 is necessary to start up again immediately; otherwise the 

 brasses will be damaged beyond repair and deep grooves 

 will be cut into the journals. If the brasses are babbitted, 

 the white metal will melt out of the bearing at this stage. 

 The engine will then be disabled, and if there is not a spare 

 set of brasses on hand, it will be inoperative until the old 

 brasses are rebabbitted or until a new set is made and 

 fitted. 



Running Engine With Hot Bearing. If it is absolutely 

 necessary in an emergency to keep the engine running while 

 a bearing is very hot, the engineer must exercise his best 

 judgment as to how he shall proceed. After slacking off the 

 brasses, about the best he can do is deluge the inside of the 

 bearing with a mixture of oil and graphite, sulphur, soap- 

 stone, etc., and the outside with cold water from buckets, 

 sprinklers, or hose, taking the chances of ruining the brasses 

 and cutting the journal. 



Refitting Cut Bearing. The wearing surfaces of the brasses 

 and journal must be smoothed off as well as circumstances 

 will permit; but if the grooves are very deeply cut, it will 

 be useless to attempt to work them out entirely, and if the 

 brasses are very much warped or badly cracked, it will be best 

 to put in spare ones, if any are on hand. If not, the old ones 

 must be refitted and used until a new set can be procured. 

 As for the journal, it is permanently damaged. Temporary 

 repairs can be made by smoothing down the journal and 

 brasses; but at the first opportunity the journal should be 

 turned in a lathe and the brasses properly refitted or replaced 

 with new ones. 



