Читать книгу The Traveling Engineers' Association to Improve the Locomotive Engine Service of American Railroads - Traveling Engineers' Association - Страница 4

Table of Contents

1. Q. What do you consider essential for your success in regard to the use of fuel?

A. I deem it essential to my success to be as economical in the use of fuel and supplies as is consistent with the work to be performed, exercising good judgment in my work, harmonious co-operation with my engineer, and showing a willingness to learn and practice the best methods in my work.

2. Q. What are the fireman's duties on arrival at enginehouse previous to going out on a locomotive?

A. He is required to examine the bulletin board, guards on water and lubricator glasses; try gauge cocks to find true water level; then examine grates, ash-pan, flues and fire-box. Put fire in proper shape; see that a proper supply of firing tools, water, coal, oil and waste are provided, that all lamps and markers are filled, cleaned and in proper condition; and to perform such other duties as may be required by the engineer to assist him in getting the engine in readiness.

3. Q. What pressure is indicated by the steam gauge? What is meant by atmospheric pressure?

A. The pressure per square inch inside of the boiler. Atmospheric pressure is the pressure represented by the density of the atmosphere in pounds per square inch, which is at sea level 14.7 pounds.

4. Q. On what principle does a steam gauge work?

A. The steam gauge pointer is actuated by a flattened or bent round tube to straighten itself under the pressure of steam against the water inside of tube. The gauge pointer receives movement from suitable mechanism connected with the tube.

5. Q. What is the source of power in a steam locomotive?

A. Heat is the source of power in all steam engines. It is necessary to have fuel and water. When fuel is burned, the water coming in contact with the hot sheets evaporates and becomes steam, which is then used in the cylinders to force the pistons back and forth.

6. Q. About what quantity of water should be evaporated in a locomotive boiler to the pound of coal?

A. From five to seven pounds of water. For example, one gallon of water weighs eight and one-third pounds, therefore 100 pounds of coal should evaporate from sixty to eighty-four gallons of water.

7. Q. What is steam, and how is it generated?

A. Steam is water in the condition of a vapor and is generated by heating the water above the boiling point.

8. Q. What is the purpose of the water gauge glass and gauge cocks?

A. To indicate the level of water in the boiler.

9. Q. What would indicate to you that the boiler connections of water gauge glasses were becoming clogged?

A. The up and down movement of the water in the glass would become slow and inactive, or it would not register correctly with the gauge cocks.

10. Q. At what temperature does water boil?

A. At atmospheric pressure, which is 14.7 pounds at sea level, water boils at 212 degrees Fahrenheit; the temperature, however, increases as the pressure under which the water is boiled increases. At 200 pounds boiler pressure the temperature would be 388 degrees Fahrenheit.

11. Q. What is carbon?

A. Carbon forms the greatest part of all kinds of coal; the higher the per cent. of carbon, the higher the grade of coal.

12. Q. What is the composition of bituminous coal?

A. It is composed of carbon about 75 per cent. and many gaseous substances, as is shown by its burning with a large flame and much smoke. Anthracite, on the contrary, is nearly pure carbon and burns with a small flame.

13. Q. What is combustion?

A. Combustion or burning is a chemical process, it is the action of fire on inflammable substances and is the union of the oxygen in the air with the carbon in the fuel; this is called rapid combustion. Slow combustion is the decaying of wood or iron by the elements.

14. Q. Is air necessary for combustion?

A. Yes.

15. Q. About how many cubic feet of air is necessary for the combustion of a pound of coal in a locomotive fire-box?

A. About 300 cubic feet of air must pass through the grates and fire for complete combustion of one pound of coal.

16. Q. Why must air be heated before combining with coal?

A. Air, like coal and its gases, must be heated before they will unite to form what is known as combustion and so as not to reduce the temperature of the fire-box below the igniting point of the gases.

17. Q. Why is it necessary to provide for combustion a supply of air through the fuel in the furnace?

A. In order to supply the oxygen necessary for combustion.

18. Q. What is the effect upon combustion if too little air is supplied? If too much air is supplied?

A. If too little air is supplied, combustion is not complete, and only one-third as much heat is obtained. If too much air is supplied, combustion is complete; but the excess air must be heated, resulting in a lower temperature. If twice the amount of air required for complete combustion be supplied, the temperature of the fire-box will be about one-half as high.

19. Q. Give a practical definition of the igniting temperature.

A. In all ordinary combustion there is a definite temperature, called the ignition or kindling temperature, to which combustible substance must be heated in order that it may unite with the gas in supporting the combustion. The burning substance must not only be heated up to the kindling temperature, but it must be kept as high as this temperature, or combustion will cease.

20. Q. State why such temperature is necessary and at what place in the fire-box it is most required.

A. The center is the hottest part of the fire-box. There is a much lower temperature in the fire-box at the sides and end sheets, due to the water on the opposite sides of the sheets being of a lower temperature than the fire-box; therefore if we get as high a temperature as possible at the side and end sheets, we will increase the steam-making efficiency of the boiler. The gases which are liberated from the coal as soon as it becomes heated must attain a temperature of about 1,800 degrees Fahrenheit, known as the "temperature of ignition," before they will unite with air which must also be heated up to that point.

21. Q. How is draft created through the fire?

A. Exhaust steam escaping through the stack reduces the pressure in the smoke-box below the pressure of the atmosphere outside, therefore the air tends to force itself into the smoke-box through all openings; with everything in good condition, the easiest and largest passage for it is through the grates and other openings into the fire-box and from it through the tubes into the smoke-box and up the stack.

22. Q. Is smokeless firing practicable?

A. Yes, but it is necessary in order to obtain good results that boiler and fire-box be in good condition, coal broken to the proper firing size; then, with the hearty and intelligent co-operation of both engineer and fireman, smokeless firing is both economical and practicable.

23. Q. In what condition should the fire be in order that the best results may be obtained from the combustion of the coal?

A. The fire should be as light as the work being done by the engine will permit, evenly distributed over the grates and free from clinkers.

24. Q. How should the blower be used?

A. A blower should be used very lightly, being careful not to draw too much air into the fire-box and through the flues, especially when fire is being cleaned or thin on grates.

25. Q. What is the result of opening the fire-door when the engine is working steam?

A. It will cause a cooling effect in the fire-box and is liable to start the flues leaking.

26. Q. What is the effect of putting too many scoops of coal on a bright fire? Is this a waste of fuel?

A. It has the effect of temporarily deadening and cooling the fire, causes emission of quantities of black smoke, as only a limited amount of gas can be burned in a fire-box at a time; all in excess of that amount escapes from the stack and is a waste of fuel.

27. Q. What effect has the fire upon a scoopful of coal when it is placed in the fire-box?

A. The heat from the fire drives the gases from the coal and they are ignited by the hot flame as they pass over the bright fire; the coke which is left burns where it is.

28. Q. In what condition should the fire be to consume these gases?

A. A bright white coke fire, almost incandescent.

29. Q. What is the temperature of the fire when in this condition?

A. It must not be less than 1,800 degrees Fahrenheit to consume the gases liberated from the coal, and it only requires from 750 to 900 degrees Fahrenheit to burn the coke that remains on the grate; as coke burns from the outside, less heat is required to consume it.

30. Q. How can the fire be maintained in this condition?

A. By adding coal to the fire in small quantities, spreading it over the grate surface and no faster than it is burned.

31. Q. What is black smoke? Is it combustible?

A. Black smoke consists of small particles of carbon suspended in the gases of combustion and indicates incomplete combustion. Black smoke is not combustible, it is like lampblack and cannot be burned after having been produced. The production of it can be prevented by suitable arrangements and manipulation.

32. Q. Should the gas not burn in the fire-box, will it burn after it enters the flues? Why?

A. Gas will not burn only a short distance in the flues of a boiler, as the water absorbs the heat so quickly that the temperature of gas is lowered below the igniting point.

33. Q. What is the effect on the flow of air through the fire from opening the door? What on the burning of the gases? What on the flues and sheets of the fire-box?

A. When the furnace door is opened, the flow of air through the grate is stopped in proportion to the amount that passes through the door. The vacuum will be filled from the quickest source and the door is closer than some parts of the grate. The gases mix with the air from the door and pass out through the flues; no combustion takes place, as the air is not hot enough to unite with the gas. The flues and sheets of the box will be caused to leak on account of the rapid contraction.

34. Q. Can the firing be done more effectively if the water level is observed closely?

A. Yes, in order to know how much water there is in the boiler and whether it is necessary to hurry the fire; if the boiler is full, it is possible to prevent the pops opening by delaying the fire.

35. Q. How should the fire and water be handled in starting from a terminal or other station?

A. The steam pressure should be near the maximum and there should be sufficient water in the boiler to last until such time as the fire is burning well so that the pressure will not be reduced when water is put into the boiler. There should be a moderately heavy bed of fire well burned and distributed evenly over the grates. After the fire is burning well, the injector should be started lightly; the feed being gradually increased so as not to cause any decrease of steam pressure.

36. Q. What is the purpose of a safety valve on a locomotive boiler? Why are more than one used?

A. A safety valve is used to limit the maximum pressure in the boiler by opening and allowing steam to escape. More than one safety valve are used as additional protection against excessive pressure; one is set at the maximum pressure and the others are set at two or three pounds above the maximum pressure.

37. Q. What is usually the reason for steam being wasted from the safety valve? What can be done to prevent this waste?

A. Careless firing, careless running. Both engineer and fireman work in harmony to obtain the best results.

38. Q. What is the estimated waste of coal for each minute the safety valve is open?

A. About fifteen pounds. The estimated waste of steam when an engine pops equals every second all the heat obtained from a quarter pound of coal. Safety valves usually remain open about half a minute, resulting in the loss of about eight pounds of coal.

39. Q. What should be the condition of the fire on arriving at a station where a stop is to be made?

A. On approaching the station where a stop is to be made, firing should be stopped far enough back to allow the carbon gases to be consumed before the throttle is closed, so there will be little or no black smoke from the stack and yet have sufficient fire that it will not be necessary to feed the fire again if a short stop is to be made until the train is started and the engine cut back or nearly to the running cut-off.

40. Q. How should you build up the fire when at stations in order to avoid black smoke?

A. Put in small quantities of coal at a time, have the door slightly open and have the blower on lightly; good judgment must be exercised by the fireman.

41. Q. Why is it that if there is a thin fire with a hole in it the steam pressure will fall at once?

A. Because too much cold air is drawn into the fire-box and through the tubes, retarding combustion and cooling the fire-box and tubes.

42. Q. If the injector is to be used after throttle is shut off, how should the fire be maintained?

A. A sufficient quantity of coal should be placed on the grates to maintain the maximum steam pressure and the blower used to keep the fire burning brightly.

43. Q. What would be the result of starting a heavy train or allowing drivers to slip with the fire too thin on the grates?

A. The fire would be pulled off the grates and into the tubes, leaving the fire bed full of holes and some of the fire remaining on the grates turned over. Large quantities of cold air would be drawn in, resulting in a rapid decrease of temperature and pressure. The tubes would possibly start leaking and the fire would be in such condition that it could not be built up properly in a long distance. Possibly the grates would become clogged up with green coal—an excellent opportunity for forming clinkers. In this condition, the engine would fail to make steam for the entire trip.

44. Q. Where should the coal, as a rule, be placed in the fire-box?

A. As a rule, more coal is burned along the sides and in the corners than in the middle of the grates; the fire should consequently be kept somewhat heavier along the sides and corners than in the middle.

45. Q. How is the fire affected by and what causes clinkers?

A. A clinker shuts off area of grate surface according to its size, and thereby shutting off that much of the air supply and interfering with proper combustion. Clinkers are caused by firing too heavy in spots, which prevents sufficient air passing up through these spots and allows the coal to run together, melting the ash, and sand; running a hoe or slash bar through the fire will bring the points of melted sand together, thereby causing a clinker.

46. Q. How can you best avoid their formation and dispose of them?

A. Light firing and occasionally moving the grates lightly is the best preventive. When once formed, they should be removed if possible by firing around and burning them out.

47. Q. How can you explain the slower burning of the coke and how understand the proper manner of supplying fresh coal?

A. The gases of coal are lighter than air and will pass away whether consumed or not. The slow burning of the coke is due to the fact that it burns from the outside only. When a fire reaches a white or incandescent heat it indicates that the gases are burned and a fresh supply of coal should be added; this is to be done as light as the service performed by the engine will permit.

48. Q. When and for what purpose is the use of a rake on the fire bed allowable?

A. The rake should be used on the fire very seldom, because raking the fire bed tends to form clinkers, especially when the rake is plunged down through the fire to the grate. It may be used when necessary to rake the fire lightly when on the road for the purpose of breaking the crust, which may be found as a consequence of too heavy firing.

49. Q. Within what limits may steam pressure be allowed to vary, and why?

A. Pressure should not be allowed to vary more than five pounds from the maximum for the reason that too much expansion and contraction will take place, which many times is the cause of flues leaking, cracked or broken side sheets and stay bolts.

50. Q. Has improper firing any tendency to cause the tubes to leak? How?

A. Yes; if the pressure is not regularly maintained, the fluctuations of temperature cause constant contraction and expansion to take place. If the fire is not carried level, but is carried heavy in some parts of the fire-box and light in others, holes will be worked in, cold air drawn through, lowering the temperature, chilling the tubes and causing leaks. Carrying the fire too heavy in some places, causes clinkers to form. If the door is open too long, too much cold air is drawn over the fire, causing the tubes to leak.

51. Q. What do you consider abuse of a boiler?

A. Careless or improperly supplying water to the boiler, improper firing or allowing steam to vary from high to low pressure, causing unnecessary expansion and contraction.

52. Q. Does the stopping up of flues affect the steaming capacity of the engine?

A. Yes; obstructed flues reduce the heating surface, reduce the steaming capacity of the engine, and, as a rule, result in causing the flues to leak. They also cause an increase of speed of the gases through the remaining flues and a poor steaming engine.

53. Q. What causes honeycomb over the flues?

A. Honeycomb on flues is usually caused by the draft through the fire picking up the sulphur and molten clay which is in a molten and sticky condition in the fire; as it passes on its way to the stack, some of it strikes the flue-sheet and sticks or passes through the flues, clogging up the netting in the front end.

54. Q. How would you take care of a boiler with leaky tubes or fire-box, and why?

A. Keep a bright, clean fire, especially up next to the flue-sheet, and as even a pressure of steam as possible and not use the blower any stronger than is absolutely necessary.

55. Q. Why is it very important that coal should be broken so that it will not be larger than an ordinary sized apple before being put into the fire-box?

A. In order to get rapid and complete combustion, coal should be broken into small pieces; this aids combustion by exposing a larger surface to the flame and can be fired more economically and better results are obtained.

56. Q. Should rapid firing be practiced?

A. No; it should not be practiced for the same reason that heavy firing is wrong. A few moments should intervene between each shovelful to allow the fresh coal to get to burning and to maintain the high temperature in the fire-box.

57. Q. When and why should you wet the coal on the tender?

A. Coal should be wet for the purpose of cleanliness to keep dust from flying and because moderately wet coal gives out more heat for the reason that there is not so much fine coal drawn through the tubes. It should be wet as often as necessary to accomplish these purposes.

58. Q. What are the advantages of a large grate surface?

A. Greater heating surface, lighter fire and more complete combustion are possible with the larger grate surface, because a larger amount is burning at one time at a slower rate of combustion.

59. Q. Why are grates made to shake, and how, when and where should they be shaken?

A. For the purpose of breaking any clinkers that might form and to shake out all refuse from the grates. The best time to shake grates is when throttle is closed, as there is no exhaust to carry the unconsumed gases and sulphur through the flues into the front end, which is liable to choke or clog up netting and cause a steam failure. Grates should not be shaken while passing over bridges, near lumber or hay yards or through prohibited territory.

60. Q. Do you understand that coal furnished represents money invested, and should be fired economically and not allowed to fall out of the gangway?

A. The fuel of locomotives is property and represents money invested the same as do buildings, rolling stock, etc.; careless or inefficient firemen who waste fuel destroy property as certainly as though cars or engines were smashed up. The coal should be carefully raked off the deck and in from the gangways; it should not be allowed to fall, as it is wasted and dangerous to people near the track. The deck should be kept clean for greater comfort and convenience.

61. Q. Is is objectionable to fill the tanks too full of coal or overflow tank at standpipes or water tanks?

A. It is. Tanks filled too full of coal are dangerous and a great waste of coal, as the jar when running will cause a part of it to fall off; water overflowing from tanks results in washing away the ballast and in cold weather freezes over the tracks.

62. Q. What are the duties of a fireman on arrival at the terminal?

A. Different roads have different assigned duties for the firemen to perform. They should leave the cab, boiler head, oil cans and deck in a clean condition, boiler full of water, enough fire and steam, so that the hostler will not be required to put in fuel while the engine is in his charge; should know that throttle valve is securely closed, reverse lever in center of quadrant, cylinder cocks open, and if equipped with independent brake, it to be applied; in fact, it is an excellent opportunity for a mechanical officer to judge the ability of the fireman and future engineer.

63. Q. Is the engineer responsible for the fireman's conduct while on duty and for the manner in which the fireman's duties are performed?

A. He is. The fireman is under the direction of the engineer, and the fireman's duties are to be performed in accordance with the engineer's instructions.

64. Q. What is the duty of the superheater damper, and how does it operate?

A. The duty of the damper is to control the flow of gases through the large flues, thereby protecting the units which are contained therein from being overheated after throttle is closed. The position of damper when the engine is not working steam, is closed.

65. Q. What will be the effect on the steaming of the engine if the damper does not open properly?

A. Engine will steam poorly for the reason that there will be no draft through the large flues. The steam will not be superheated because heated gases cannot come in contact with superheated units contained in the large flues.

66. Q. How may steam failure be avoided in case the damper fails to operate?

A. The counterweight may be tied up, thereby opening the damper.