57. Q. Will an injector work if air cannot get into the tank as fast as the water is taken out?
A. No.
58. Q. If you had to take down a tank hose, how would you stop the water from flowing out of the tank that has the syphon connections instead of the old-style tank valves?
A. Open the pet c.o.c.k at the top of the syphon before taking the hose down.
59. Q. Is any more water used when the engine foams than when the water is solid?
A. Yes, very much more.
60. Q. How would you prevent injector feed pipes or tank hose from freezing in winter when not in use?
A. The steam valve should be slightly open to permit a slight circulation of steam through the feed and branch pipes. The heater c.o.c.k should be closed and the drip c.o.c.k under the boiler check or on the branch pipe should be opened to insure a circulation of steam through the branch pipe.
61. Q. How would you prevent the overflow pipe from freezing with a lifting injector?
A. The overflow valve should be opened just enough to permit a little steam to escape through the overflow pipe to prevent it from freezing.
62. Q. Name the various parts of the injector.
A. The injector consists of a body supplied with a steam valve, a steam nozzle, a primer, a combining tube, a delivery tube, a line check valve, an overflow valve, a water valve, and a lifting injector has a lifting tube.
63. Q. What may be done if a combining tube is obstructed?
A. The steam valve bonnet may be removed and the obstruction forced out with a piece of stiff wire, or uncouple the delivery pipe from the injector and unscrew and remove the tubes; the obstruction can then be removed and the tubes replaced.
64. Q. How is the greatest injury done to a boiler when cleaning or knocking the fire?
A. By excessive use of the blower drawing cold air through the fire-box and flues.
65. Q. Why does putting a large quant.i.ty of cold water into a boiler when the throttle is closed cause the flues to leak? When is this most serious?
A. When steam is not being used there is not much circulation of water in the boiler, and the water entering the boiler at about 150 degrees temperature is heavier than the water in the boiler. The cooler water will go to the bottom and reduce the temperature in that part of the boiler and causing the flues to contract in length as well as in diameter and this has a tendency to pull them out of the sheet. This will loosen them and cause them to leak. After the fire has been knocked this tendency is much greater, and for that reason cold water should not be put into a boiler after the fire has been knocked out. Always fill the boiler before the fire is knocked out.
66. Q. Is warm water in the tank of any advantage in making steam rapidly?
A. Yes; careful experiments have shown that a locomotive will generate one per cent. more steam for every eleven degrees that the tank water is heated; thus by heating the feed water in the tank from 39 degrees to 94 would effect a saving of five per cent.
67. Q. Then why not heat the feed water to the boiling point (212 degrees)?
A. If the feed water is heated much above 100 degrees it will not condense enough steam in the injector to cause it to work properly. Some injectors will work hotter water than others. It would also spoil the paint on the tank if heated to a much higher temperature.
68. Q. At 200 pounds pressure per square inch, what is the pressure per square foot on the sheets of a boiler?
A. About fifteen tons.
69. Q. What is the total pressure on the fire-box of a large locomotive?
A. Over 3,000 tons.
70. Q. Give a practical definition of heating surface.
A. The heating surface of a boiler includes all parts of the boiler and tubes that are directly exposed to fire or heat from the fire and are surrounded by water.
71. Q. Should an engine be slipped to get water out of the cylinders or steam pa.s.sages?
A. No; the water should be worked out by opening the cylinder c.o.c.ks and starting the engine slowly.
72. Q. What does it indicate when the smoke trails back over the train and into the coaches after shutting off?
A. It indicates poor firing or a lack of understanding between the engineer and fireman in regard to where the engine was to be shut off.
73. Q. Before shaking grates or dumping the ash-pan, what should be observed?
A. That the engine is not pa.s.sing over bridges or cattle guards, crossings, switches, interlocking fixtures, or in yards. Fire on the track should be extinguished promptly at places where ash-pans are cleaned.
74. Q. Which is easier and more satisfactory on a long run, to stop and clean the fire if necessary or to continue to the end of a long, hard trip with a dirty fire?
A. Stop and clean the fire if necessary. It will save fuel and labor during the remainder of the trip and may also save an engine failure.
75. Q. Should you examine the flues to see if they are stopped up and leaking, and inspect the grate and grate rigging carefully before leaving the engine at a terminal?
A. Yes, so they can be reported if necessary. Clean flues and grates working well make a vast difference in the success of a fireman, and a great many engine failures could be avoided by keeping the flues and grates in proper condition.
76. Q. How should cab lamps, signal lamps, oil cans and lanterns be cared for?
A. They should be kept clean, free from leaks and always filled and ready for service before leaving terminals.
77. Q. About how many drops in a pint of valve oil when fed through a lubricator?
A. About 4,500 drops.
78. Q. a.s.suming that five drops per minute are fed to each of two valves and one drop per minute to the air pump, how many hours would be required to feed one pint of valve oil?
A. About eight hours.
79. Q. a.s.suming that the engine is running twenty-miles per hour, how many miles per pint would be run?
A. About 160 miles per pint.
80. Q. How many drops per minute should ordinarily be fed?
A. This will vary with the size of the locomotive and the work to be performed. On small yard engines one drop per minute for each cylinder is usually sufficient and one drop for the air pump every two or three minutes. This depends on the condition of the pump and the service being performed. For large engines in slow freight service four to five drops per minute, and for large engines in heavy fast pa.s.senger service from five to seven drops per minute should be fed. Air pumps in freight service where the brake pipe is in moderately good condition can usually be run with one or two drops per minute when handling long trains of cars equipped with air brakes.
81. Q. Will any bad results ensue from filling the lubricator full of cold oil?
A. Yes; when the oil gets hot it will expand and may break the gla.s.s or bulge or burst the lubricator.