The following text may have been generated by Optical Character Recognition, with varying degrees of accuracy. Reader beware!

Electric Motors, Generators on Ships How to Keep them in Good Condition HERE is probably no greater T tex on shipboard from an engineer’s point of view than that of making periodic inspections; say, making the rounds of certain apparatus on Mondays, Wednesdays, and Fridays, and others on Tuesdays, Thursdays and Saturdays, and then reporting to the captain in this wise, “The anchor windlass has been in- spected and is secure, sir.” When machinery is furnished for shipboard use, it is generally accom- panied by a long list of instructions telling just what to inspect, weekly, monthly, semi-annually, and annual- ly. It is something like the instruc- tion book one gets with his automo- bile, saying that this gadget should be oiled every 500 miles, another every 1000 miles and still another every 2500, and then finding yourself on a long trip with all of the mile- ages passed without a thought. Set times and set mileages look good en paper and show much profundity of thought, but an engineer can get into a lot of trouble if he follows them blindly and rests during the in- between periods. What an engineer is really inter- ested in is if the equipment under his care is gradually building up a condition that will eventually spell for trouble;—in this regard nothing will take the place of common sense, good eyesight, good hearing, and a good sense of smell. If the engineer has all these, and most engineers have, the thing he wants to know is, if he makes an inspection and finds things getting a little off color, just how he can bring an equipment back te its original condition so that it will be as good as new. That is, he wants to scent trouble before it happens, and never allow an equip- ment to run down at the heel to the point that it is a shore job to fix it. Using Too Much Grease Most troubles on electrical equip- ment are caused by conditions that are cumulative. A few years ago, ball bearing motors began to replace the sleeve bearing type with oil rings. The manufacturers in order’ to simplify things put alemite fittings on the bearings so that they could be filled with a pressure gun. The result was that in many cases, Oover- zealous oilers who wanted to make The author, Frank V. Smith, is a member of the staff of the Federal and Marine Department, General Electric Co., Schenectady, N. Y. By Frank V. Smith their job a real job, used the gun once a watch and in a few weeks time had piled up enough grease on the floor plates to last a dozen motors for a year. Then there is the other extreme, that of a chief telling an oiler not to dare oil that motor (after 3-years running) as it was oiled when it left the factory. These conditions point out one thing and that is, some engineers need more knowledge and that others should exercise more vigilance. Now the facts about ball bearings are: that the ball races want to be packed only about 1/3 to % full for if they are packed too tight, they will run hot; another thing is that good grease ought to last from. six months to a” year. When grease has been in this long, it is likely to contain some of the wearings, and the ball race should, therefore, be cleaned and properly packed with new grease, being sure that in the process of cleaning and packing no foreign substances get mixed with the grease—this means erit off the hands or pieces of waste. Many ill results take place from too much grease; first, with a pres- sure gun it is possible to force grease out of the bearings along the shaft, and on to the commutator if it happens to be the commutator end bearing. A dirty, greasy commutator does not help the electrical end of the motor; and second, the grease may deposit on the windings and form the first sticky mess to caten dust and start building up accumula- tions on the insulation. Care in Lubrication From this point on, a lot of things can happen. The dielectric strength of the insulation may be affected, or the motor may run hot because the windings are blanketed and cannot get rid of their heat. These cumula- tive ills are generally what cavse serious trouble in the end. It is per- fectly obvious, however, that if the chief gave the oiler a good bawling out, the first time he saw grease on the floor plates or creeping along the shaft, all of the troubles to come could be averted. Sleeve bearings too have caused their troubles, and more motors have been ruined by too much oil than with too little. Other troubles have resulted from not using care when drawing the oil and allowing gritty substance to get into it before ap- plied. MARINE REvIEw—September, 1933 If one takes the common sense view of a motor on shipboard, there is not a great deal to do in their upkeep if they are given a fair chance. Cleanliness, a smooth run- ning commutator and freedom from long sustained overloads that might cause Overheating, are about all they ask. The life of a motor depends upon its insulation. Overheating causes certain elements in the in- sulating varnish to evaporate and this in turn makes it porous, allow- ing the absorption of moisture dur- ing periods of idleness. This is the reason for saying many times that a motor in idleness deteriorates more rapidly than one in use. If one keeps a motor clean and the insulation intact, no one ean tell its life. Records are on file where motors have run for thirty years and are still to all visual appear- ances, running as good today as they were when new. Importance of Cleanliness Cleanliness and good insulation being the main factors in the life of a motor or generator, let’s see what tools the engineer has at his dis- posal to check these items. Cleanli- ness, he can detect with his eyes— insulation resistance, with a megger. Assuming that he wants to get right on the job, let’s consider what might be considered good advice, rather than the presentation of a _ stereo- typed list of instructions. First, one might say it is a good idea, when on a trip, to keep one’s eyes open to what is going on so as to prevent any troubles arising as denoted in the first part of the article; and second, when the ship arrives in port, to look things over to see that no oil, moisture nor dirt is collecting. This makes it doubly sure that the engineer not only knows what is going on but that he has a check on his observations, and if things are not as they should be, lhe can do something about it next trip. Once, he finds that the crew has fallen in line with the finer points of operation, and that trip after trip everything appears as bright and clean as it was the first day the equipment went into service, he can afford to let down slightly and make his inspections a little less often. When a ship is new, a daily in- spection might not be too often. After a crew has fallen into. a routine, and the routine has been 1