LUBRICATION
1. Q. What produces friction, and what is the result of excessive friction?
A. Friction as considered in locomotive service is produced by one body being rubbed across the surface of another when they are held in contact by pressure, and the result of excessive friction is heat more or less intense and the destruction of the journal and its bearing or the roughening of the sliding surfaces.
2. Q. What is lubrication and its object?
A. The object of lubrication is to interpose a film of oil, grease or some lubricant between the two surfaces that will prevent these rubbing surfaces from coming into too intimate contact.
3. Q. What examinations should be made by the engineer to insure successful lubrication?
A. See that all oil holes are open, cups filled and in good working order, the packing in cellars evenly put in and in contact with the journal. That waste on top of driving or truck boxes is in proper shape, also that grease cups are filled, and the plugs and jam nuts in good shape, and that the grease cellars contain sufficient grease for the next trip.
4. Q. How should feeders of all oil cups be adjusted?
A. To feed as small a quantity of oil as possible and regularly to give perfect lubrication.
5. Q. Why is it bad practice to keep engine oil close to boiler in warm weather?
A. The oil is thinned to such a degree by the heat of the boiler that it runs off as soon as applied, and very often a hot bearing is the result.
6. Q. In what manner would you care for a hot bearing if discovered on the road?
A. Use as much time as available in cooling the same, making sure that all moving parts are free and carefully lubricated before proceeding.
7. Q. What kind of oil should be used on hot bearings?
A. Use engine oil unless the temperature of bearing consumes it, when a small quantity of valve oil may be used while the bearing is warm enough to make this oil flow. The valve oil must be removed as soon as the bearing cools to prevent reheating.
8. Q. At completion of trip what is necessary?
A. Close all adjustable feeds and examine all lubricated parts by contact with the hand to determine that they are not above running temperature.
9. Q. How would you determine what boxes to report examined? Why not report all boxes examined?
A. By placing the hand on driving box, on hub of engine truck wheel and on top of tender truck boxes nearest the brass, and would not report them examined unless the temperature of same was above running heat. It is not necessary to report all boxes examined, because they do not all give trouble at the same time. If this report was made, it would appear that a proper inspection had not been made and would result in unnecessary work and waste of material.
10. Q. Why is it bad practice to disturb the packing on top of driving and engine truck boxes with spout of oil can when oiling engine?
A. This packing is put on top of boxes to assist in keeping dirt and dust out of oil holes, also to aid in gradual lubrication from the top. If this packing is disturbed it will permit dirt and grit to work into oil holes and on the bearings as well as feed the oil away too rapidly.
11. Q. How do you adjust grease cups as applied to rods?
A. Screw down plug until you feel a slight resistance from the grease, stop when grease shows between brass and pin; this should be sufficient over the division.
12. Q. Is it usual for pins to run warm when using grease?
A. Yes; grease does not work properly until it gets warm enough to flow readily over the bearing.
13. Q. What effect does too much pressure produce?
A. Wastes grease and increases the friction until the surplus amount is worked out so the bearing runs free on its journal.
14. Q. Is it necessary to use oil with grease on crank pins?
A. No.
15. Q. When an engine is equipped with Elvin driving box lubricator, how can you tell whether a sufficient amount of lubricant is in the grease receptacle?
A. The indicator wire fastened to the bottom of the grease cellar indicates the amount of grease left in the cellar.
16. Q. Why should engine oil not be used on valves and cylinders?
A. Engine oil loses its lubricating qualities before it gets up to the temperature of the valves and cylinders when they are working steam.
17. Q. At what temperature does engine oil lose its lubricating qualities? At what temperature for valve oil?
A. Engine oil begins to separate and give off gas at 345 degrees F. The temperature of steam at 120 pounds is 350 degrees F., while valve oil has a flash test of 520 degrees F. The temperature of steam at 235 pounds is 431 degrees F., much lower than the flash test of valve oil.
18. Q. How and by what means are valves, cylinders and the steam end of air pumps lubricated?
A. By a sight-feed hydrostatic lubricator.
19. Q. What is the principle on which a lubricator operates. How does the oil get from the cup to the steam chest?
A. The lubricator is located in the cab so there is a gradual descent in the oil pipe from the lubricator to the steam chest. Above the oil reservoir is a condenser that is kept filled with water condensed from steam fed from the boiler. The pressure of this water comes on the oil in the oil tank below it, forcing oil through the sight-feed valves; it then passes up by the sight-feed glasses to the oil pipe and steam chest. The use of the glasses is to make the drop of oil visible as it leaves the sight-feed nipple so the amount of oil fed can be regulated. Steam from the boiler fed to the lubricator at boiler pressure through the equalizing tubes balances the pressure which comes from the steam chest when the engine is working steam.
20. Q. How should the lubricator be filled?
A. First close all valves connected with the lubricator, open drain plug and remove filling plug, allowing water to escape until oil appears with it. Drain plug should then be closed. Fill the oil tank in the usual way, being careful not to overflow it; then replace filling plug. If the supply of oil is insufficient to fill the lubricator, water can be used to finish it, as the lubricator will begin feeding sooner when filled full.
21. Q. After filling lubricator, what should be done?
A. Open the steam throttle to the lubricator wide, then carefully open the water valve, but do not open the feeds until sure the chamber in the glass is filled with water.
22. Q. How long before leaving terminal should the feed valves be opened? Why?
A. About fifteen minutes; this time is necessary to allow oil to feed through the oil pipe and reach the steam chests.
23. Q. How many drops should be fed per minute?
A. From one to seven, timed by the watch, depending on conditions. Cylinders of large size require more oil than smaller ones.
24. Q. If lubricator feeds regularly when working steam and too rapidly after shutting off, what is the trouble?
A. The opening in the choke plug at the lubricator or through the steam valves at the steam chest is too large and should be reduced to the proper size by applying new chokes or valves.
25. Q. When valves appear dry while using steam and the lubricator is working all right, what would you do to relieve these conditions?
A. Ease off throttle for a few seconds to reduce the steam chest pressure and drop the reverse lever a few notches to give the valve a longer travel; oil held in the pipes will then flow down.