THE TRAVELING ENGINEERS' ASSOCIATION
To Improve The Locomotive Engine Service of American Railroads
EXAMINATION QUESTIONS AND ANSWERS
For Firemen for Promotion and New Men for Employment :-:
Copyrighted by W. O. Thompson, March, 1911 Revised January, 1919
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It is the policy of railroads to employ firemen who will in time become competent locomotive engineers. This requires that a man should have at least a common school education, good habits and be in good physical condition. He should be alert, with good reasoning faculties and a man of sound judgment. Having these qualifications, advancement will come to those who are conscientious in discharging their duties and who devote some of their leisure hours to study.
As an aid to this end, and that the railroad companies may derive the highest efficiency from the man employed as a locomotive engineman, a code of questions is given him, and it is expected that the preparation necessary to correctly answer the questions will indicate how well he has progressed.
The list of questions is also intended as a guide to the matters on which he should be correctly informed, both during his term of service as a fireman and for future promotion to engineer.
When a man is first employed as a fireman he will be given a list of questions on which he will be examined at the end of the first year; having passed this examination successfully he will then be given the examination questions for the following year; having passed this examination satisfactorily, he will be given a third and final set of examination questions on which he will be examined before being promoted to engineer. All these examinations will be both written and oral. The third year examination for promotion will be before the General Board of Examiners. At any of these examinations, if he fails to pass 80 per cent. of the questions asked, another trial, not less than two months and not more than six months later, will be given him to pass the same examination; if he fails to pass by a percentage of 80 per cent. he shall be dropped from the service.
Where the examinations consist of both air brake and machinery, the candidate must pass 80 per cent. in each to be successful.
Firemen passing the third and final series of questions will be promoted in the order of their seniority as firemen, except that those who pass on the first trials shall rank, when promoted, above those who passed on the second trials.
Engineers employed who have had service on other roads, will be required to pass the third series of questions before entering the service.
It is not expected that the man will pass these examinations without assistance, and in order that he will understand the use of locomotive and air brake appliances properly, he is expected to go to the Master Mechanic, General Foreman, Road Foreman or Traveling Engineer, also Air Brake Inspector or Instructor, or any other official, and ask them for such information as may be required on any of the questions or on any points in connection with the work. He is not only invited, but also urged to do this, as the more knowledge of his business a man possesses, the better will be the results obtained. He will have ample time to study each set of questions; there is no doubt that with a reasonable amount of study each week, supplemented with close observation of the working of the locomotive, the information necessary to answer satisfactorily the entire list of questions can be easily mastered in the time given. In regard to breakdowns, it is advised that he carefully inspect each breakdown or disabled engine that comes to his notice, see where the parts have given way and in what manner the work of blocking up it done. It is not expected that all the breakdowns which may happen to a locomotive will occur on the engine that he is with; therefore it is good practice to observe how other men care for these breakdowns. In connection with these examinations the work done by the fireman during the year and how the work compares with that of other firemen in the same class of service will be carefully noted; his record as to the use of coal, supplies and attention to duty will be taken into consideration.
It is hoped that he will give everything in detail the consideration it merits and realize fully that it is by looking after the little things that a man succeeds. It should be borne in mind that by filling well the position he holds he becomes entitled to the confidence that makes better positions possible. It is understood that those who conduct the examination may ask any question or questions bearing on any subject of this examination, in order to determine how well the persons being examined understands the subject. A mere memorized answer will not be sufficient. The full meaning of each answer must be understood.
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?
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.
AIR BRAKE QUESTIONS
1. Q. What is an air brake?
A. A brake operated by compressed air.
2. Q. How is this air compressed?
A. By an air compressor on the locomotive.
3. Q. Name the different parts of the air brake as applied to the locomotive.
A. The air compressor, compressor governor, automatic and independent brake valves, distributing valve, triple valve, auxiliary reservoir, brake cylinders, main reservoir, air gauges, angle cocks, cut-out cocks and the necessary piping.
4. Q. What is the purpose of the main reservoir?
A. It is used for storing a large volume of air for the purpose of promptly charging and recharging the brakes. Where the engine is equipped with either the E. T. or L. T. type of brakes, main reservoir air is used to supply the air to the brake cylinders on the locomotive.
5. Q. What other appliances use main reservoir air?
A. It is used in the operation of the power reverse gear, sand blower, bell ringer, water scoop, air signal, fire door, water sprinkler and other devices.
6. Q. What does the red hand on each of the air gauges indicate?
A. The red hand on the large gauge indicates main reservoir pressure; on the small gauge, brake cylinder pressure.
7. Q. What does the black hand on each of the air gauges indicate?
A. The black hand on the large gauge indicates the equalizing reservoir pressure; on the small gauge, brake pipe pressure.
8. Q. What pressure is usually carried in the main reservoir?
A. Ninety pounds in freight and 130 pounds in passenger service. But where freight engines are equipped with duplex compressor governor, the low pressure top is adjusted to ninety pounds and the high pressure top to 130 pounds.
9. Q. What pressure is usually carried in the brake pipe?
A. Seventy pounds in freight and 110 pounds in passenger service.
10. Q. What must the air pass through in flowing from the main reservoir to the brake pipe?
A. Through the automatic brake valve.
11. Q. Name the different positions of the automatic brake valve.
A. Release, running, lap, service and emergency positions. The brake valve used with the E. T. and L. T. equipment has still another position known as holding position, which is located between running and lap positions.
12. Q. Name the different positions of the independent brake valve.
A. Release, running, lap, slow application and quick application positions.
13. Q. How many kinds of triple valves are there in use?
A. Two; plain and quick action.
14. Q. How is the automatic brake applied? How released?
A. The automatic brake is applied by a reduction of brake pipe pressure, and is released by restoring the brake pipe pressure.
15. Q. When the independent brake valve handle is placed in application position, are the train brakes affected?
A. No; only the brakes on the locomotive are applied.
16. Q. What controls the pressure in the main reservoir?
A. The compressor governor.
1. Q. What, in your opinion, is the best way to fire a locomotive?
A. To carry a nice, level fire on the grate, or it may be just a little heavier at the sides and front, so the air cannot come through it near the sheets as rapidly as in the center of the fire-box; always fire as light as consistent with the work required, endeavor to maintain a uniform steam pressure at all times, and avoid unnecessary black smoke and a waste of steam through the safety valves by the engine popping.
2. Q. What are the advantages of superheated steam over saturated steam in locomotive service?
A. Saving in water; saving in fuel; increased boiler capacity and a more powerful locomotive. Superheated steam does away entirely with all condensation in the cylinders, while saturated steam coming in contact with passages in cylinder saddle and walls of cylinders, is immediately cooled and in cooling, a part of it is changed back into water which affects the pressure and therefore its capacity to do work.
3. Q. How is the saving in water produced?
A. By the elimination of all cylinder condensation present in saturated steam locomotives and the increase in volume of a given weight of steam.
4. Q. How is the saving in coal accomplished?
A. Because there is less steam used to do the same amount of work, there is less water evaporated and consequently less coal required to evaporate the water.
5. Q. How is the increased boiler capacity obtained?
A. A boiler will evaporate a certain amount of water into steam and if part of the steam is lost by condensation, only that remaining is available for running the engine. Superheating eliminates the losses, thereby increasing the available useful steam. Further, superheating increases the volume of a given weight of steam, thereby reducing the consumption of steam required to develop a certain power and consequently increases the capacity.
6. Q. How is a more powerful engine obtained?
A. By reason of the increased boiler capacity an engine may be worked farther down before a steam failure occurs.
7. Q. What type of fire tube superheater is in most general use in locomotive service?
A. The top header fire tube type, known as the "Schmidt Superheater." A system of units located in large flues through which the steam passes on its way from the dry pipe to the steam pipes, and a damper mechanism which controls the flow of gases through the large flues.
8. Q. Describe the construction and location of the header.
A. The header is a simple casting, divided by partition walls into saturated and superheated steam passages. It is located between the dry pipe and the steam pipes, the same as the nigger head in a saturated locomotive. The dry pipe is in communication with the saturated steam passages and the steam pipes with the superheated steam passages and these are in communication with each other through the superheated units.
9. Q. Describe the construction of superheater units and their connection to the header.
A. The units are composed of four seamless steel pipes, connected by three return bends. Of the four pipes, two are straight and two are bent upward and connected to the header by means of a clamp and bolt; one end of the unit is in communication with the saturated steam passage and the other with the superheated steam passage in the header casting.
10. Q. Trace the flow of steam through the top header fire tube superheater.
A. When the engine throttle is open, saturated steam passes through the dry pipe into the saturated steam passage of the header casting. From this passage it enters one end of the unit, passing backward toward the fire-box, forward through one of the straight pipes and the front return bend, backward through the other straight pipe to the back return bend, and forward through the bent pipe and upward into the superheater steam passage of the header, from which it enters the steam pipes and is carried to the steam chest.
11. Q. What should be the position of throttle valve when running a superheater locomotive?
A. The engine should always be run with as wide open throttle as the conditions will permit, regulating the steam admission to the cylinders according to work to be performed.
12. Q. What should be the position of throttle while drifting?
A. The throttle valve should be kept slightly open while drifting, so as to admit a small quantity of steam in valve chamber and cylinder above atmospheric pressure, to prevent the inrush of hot air and gases which destroy lubrication, also to prevent excessive wear to valve, cylinder and piston rod packing.
13. Q. How should the water be carried in boiler of superheater locomotives?
A. As low as the conditions will permit, because this practice reduces the tendency to work water over into the dry pipe and units, as the superheater locomotive will use one-third less water than the saturated locomotive.
14. Q. What care should be exercised in lubricating a superheater locomotive?
A. The supply of oil to steam chest should be watched very closely by the engineer, he to know that lubricator is feeding constantly and evenly over entire division, and according to work performed.
15. Q. Describe the general form of a locomotive boiler.
A. A locomotive boiler is cylindrical in form, it usually has a rectangular shaped fire-box at one end and a smoke-box at the other, and flues extend through the cylindrical part, and, like the fire-box, are surrounded by water.
16. Q. How does the wide fire-box type of boiler differ from the ordinary boiler, and what are its advantages?
A. The wide fire-box type of boiler is built so the fire-box is above the frame and extends out over the driving wheels. The advantages of this are to obtain a larger grate area in the same length of fire-box and to give a slower rate of combustion per square foot of grate surface. The deep fire-box is limited in width to the distance between the frames, while the shallow fire-box sets on top of the frames and between the driving wheels.
17. Q. Why have two fire-box doors been placed in the large type of locomotive boilers?
A. For convenience of the fireman on account of the greater width of the fire-box, so that coal can easily be distributed to all parts of the fire-box.
18. Q. Describe a locomotive fire-box.
A. The modern form is a rectangular shaped structure located at the back end of the boiler. It has a door and is composed of two side sheets, a crown sheet, a back sheet and a flue sheet from which the flues extend to the smoke-box at the other end of the boiler.
19. Q. To what strains is a fire-box subjected?
A. To crushing strains and to those of unequal contraction and expansion.
20. Q. How are the sheets of a fire-box supported?
A. They are supported by staybolts screwed through the inside and outside sheets with their ends riveted over.
21. Q. In what manner is a crown sheet supported?
A. By crown bars or radial staybolts.
22. Q. What are the bad features about crown bars?
A. They are hard to keep clean and frequently cause crown sheets to become mud burned.
23. Q. What are the advantages of radial stayed crown sheets?
A. They are easier to keep clean and cheaper to repair.
24. Q. How are the inside and outside sheets of a fire-box secured at the bottom?
A. They are riveted to a wrought iron ring called a mud-ring.
25. Q. Describe the ash-pan and its use.
A. It is a receptacle secured to the fire-box and usually provided with dampers to regulate the flow of air to the fire. It collects the ashes that drop from the fire-box and prevents them from setting fire to bridges or other property along the track. Engine-men must know that ash-pan slide and hopper bottoms are closed before leaving enginehouse.
26. Q. What is a "wagon-top" boiler?
A. It is a boiler that has the fire-box end made larger than the cylindrical part to provide more steam space.
27. Q. Why are boilers provided with steam domes?
A. To furnish more steam space and to obtain dryer steam and to provide a place for the safety valves, steam pipes, throttle valve and whistle.
28. Q. What must be the condition of a boiler to give the best results?
A. It must have good circulation and be clean and free from mud or scale.
29. Q. What is meant by "circulation" in a boiler?
A. Free movement of the water, so that it may come in contact with the heating surface and after being converted into steam be immediately replaced by a fresh supply of water.
30. Q. What would be the effect if a "leg" of the fire-box became filled with mud?
A. There would be no water in contact with the fire-box sheets and they would quickly become overheated and mud-burned.
31. Q. What would be the result if the fire-box sheets became overheated?
A. They would be weakened and forced off the staybolts and an explosion would occur.
32. Q. Would it be advisable to put water into a boiler after the sheets had become bare and red hot?
A. No. The fire should be killed at once.
33. Q. What effect has the stoppage of a large number of flues?
A. The heating surface and draft are decreased by just that much area.
34. Q. Why are boiler checks placed so far away from the fire-box?
A. To introduce the water into the boiler at as great a distance from the fire-box as possible. This permits the water to become heated to a high temperature before it comes in contact with the fire-box and also improves circulation.
35. Q. What part of the boiler has the greatest pressure? Why?
A. The bottom, because it is subject to the weight of the water in addition to the steam pressure in the boiler.
36. Q. What are the advantages of the extension front end?
A. To provide room for suitable draft and spark appliances.
37. Q. What is the purpose of a netting in a smoke-box or front end?
A. To act as a crusher of all cinders and prevent large cinders from passing out of the front end to the atmosphere.
38. Q. What is the object of hollow staybolts?
A. To indicate when the staybolt is broken by the escape of steam through the small hole in the bolt.
39. Q. What will cause the engine to tear holes in the fire?
A. Working hard or slipping when the dampers are open and the door closed, or too thin a fire.
40. Q. Name the various adjustable appliances in the front end by which the draft may be regulated.
A. The exhaust nozzle, the diaphragm and the draft pipes or petticoat pipe.
41. Q. What object is there in having the exhaust steam go through the stack?
A. To create a draft through the tubes and fire-box.
42. Q. How does this affect the fire?
A. The exhaust steam escaping through the stack tends to empty the smoke-box of gases and produces a partial vacuum there, atmospheric pressure then forces air through the grates and tubes to refill the smoke-box, and in this way the draft through the fire is established and maintained.
43. Q. Explain what adjustments can be made and the effect of each adjustment on the fire.
A. Larger or smaller nozzle tips cause less or greater draft on the fire; raising or lowering the draft pipes and diaphragm causes the engine to burn the fire more at the rear or front end of the fire-box; the size and position of the draft pipes increase the draft through the top or bottom flues; the latter adjustments should always be attempted before reducing the nozzle.
44. Q. What does it indicate when the exhaust issues strongest from one side of the stack?
A. The stack, exhaust pipe or petticoat pipe are out of plumb.
45. Q. What is the effect of leaky steam pipe joints inside the smoke-box?
A. The engine will not steam freely.
46. Q. What causes "pull" on the fire-box door?
A. The partial vacuum in the front end; when excessive it indicates dampers closed, fire clinkered or insufficient opening for the admission of air under the fire.
47. Q. If upon opening the fire-box door you discover there what is commonly called a red fire, what might be the cause?
A. The grates may have become clogged with ashes or clinkers so that sufficient air could not pass through them to the fire.
48. Q. Is it not a waste of fuel to open the fire-box door to prevent pops from opening? How can this be prevented more economically?
A. Yes. This can usually be prevented by putting the heater into the tank, or putting on the injector, or by more careful firing.
49. Q. Describe the principle upon which the injector works.
A. The action of the injector is due first to the difference between "kinetic" or moving energy and "static" or standing energy; second, to the fact that steam at a pressure travels at a very high velocity and when placed in contact with a stream of water it is condensed into water, and at the same time it imparts enough velocity to the water to give it sufficient momentum to overcome a pressure even greater than the original pressure of the steam. By imparting this velocity to the water it gives it sufficient energy to throw open the check valves and enter the boiler against high pressure.
50. Q. What is the difference between a lifting and a non-lifting injector?
A. A lifting injector will create sufficient vacuum to raise the water from the level of the tank. The steam tubes in a non-lifting injector are different and it will not raise the water, but merely force it into the boiler. A non-lifting injector must be placed below the level of the water in the tank so the water will flow to it by gravity.
51. Q. Will an injector work with a leak between the injector and tank? Why? Will it prime?
A. A lifting injector will not work if the leak is bad. It will not prime because the air admitted through the leak destroys the vacuum necessary to raise the water to the injector level. A non-lifting injector will work, as the water will escape from the pipe instead of air being drawn into it as with the lifting injector.
52. Q. If it primes well, but breaks when the steam is turned on wide, where would you look for the trouble?
A. Insufficient water supply due to tank valve partly closed, strainer stopped up or tank hose kinked, injector tubes out of line, limed up, or delivery tube cut, or wet steam from the throttle.
53. Q. If it would not prime, where would you expect to find the trouble?
A. Insufficient water supply, priming valve out of order, or with the lifting injector the trouble might be caused by a leak between the injector and tank.
54. Q. Will an injector prime if the boiler check leaks badly or if it is stuck up? If the injector throttle leaks badly?
55. Q. If steam or water shows at the overflow pipe when the injector is not working, how can you tell whether it comes from the boiler check or the injector throttle?
A. Close the main steam valve at the boiler, that will stop the leak if it comes from the injector throttle.
56. Q. Will an injector prime if primer valve leaks? Will that prevent its working?
A. It will prime, but not as readily as with priming valve in good condition. This will not prevent its working, but it may waste some water from the overflow.
57. Q. Will an injector work if air cannot get into the tank as fast as the water is taken out?
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 cock 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 cock should be closed and the drip cock 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 quantity 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 passages?
A. No; the water should be worked out by opening the cylinder cocks 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 passing 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. Assuming 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. Assuming 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 passenger 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 glass or bulge or burst the lubricator.
82. Q. If a sight feed gets stopped up, how could you clean it out?
A. Close the water valve and the regulating valves to the other feeds. Open drain cock and draw out a small quantity of water so as to bring the oil in top part of lubricator below the top end of oil pipe leading to feed arm, then open wide the regulating valve to feed that is stopped up and the pressure from the equalizing tube will force the obstruction out of the feed nozzle and up into the body of the lubricator. Next, close this regulating valve until the feed glass fills with water, then open water valve and start feeds.
83. Q. How would you clean out chokes?
A. First, shut off boiler pressure and condenser valve; next, remove feed valve bonnet, then open main throttle valve, when the steam from steam chest will blow back through the choke plug, clearing it of any obstruction.
84. Q. What is superheated steam?
A. It is the saturated steam separated from the water from which it is generated with more heat added, increasing its temperature from 100 degrees to 250 degrees Fahrenheit above the saturated steam temperature.
85. Q. What is the advantage of superheating or increasing the temperature of the steam?
A. By increasing the temperature of the steam the volume of a given weight of steam is increased and all losses due to cylinder condensation are eliminated, which result in a reduced steam consumption, a saving in coal and water and increased boiler capacity.
86. Q. How is the increased temperature obtained by the use of the superheater?
A. By admitting the saturated steam into a partitioned receiver which has a number of 1-1/2-inch pipes attached to it. These are located in and extend nearly the full length of the large flues, the steam having to pass through these 1-1/2-inch pipes on its way back to the receiver, absorbs the heat from the gases passing through the large tubes, causing its temperature to rise, or in other words, become superheated.
87. Q. How much is the volume of steam increased by superheating?
A. For each 100 degrees of superheat added to saturated steam, at temperatures ordinarily used in locomotive practice, the volume of a given weight is increased roughly from sixteen to seventeen per cent.
88. Q. Why is the superheated steam so much more economical on coal and water than the saturated steam?
A. Because for a given amount of water evaporated you can increase the volume of steam 33 per cent. by superheating. It is readily seen that the coal does not have to be burned if the steam used has 33 per cent. more volume for filling space, or in other words, only so much steam can be admitted to the cylinders for every movement of the valve, and what can not be used must remain in the boiler, so if the engine can not use all of the steam that the boiler is capable of generating, the saving must show in coal and water. If you can not use all of the steam you do not have to burn coal to make it.
89. Q. Which is the better practice, to close the feed valves or water valve while waiting on sidings, etc.?
A. Close the feed valves; the water valve may leak.
90. Q. How can you tell if equalizer tubes become stopped up or broken?
A. If they were stopped up the equalization would be destroyed, and when the steam-chest pressure was less than the boiler pressure the feed would work too fast, the oil would enter the feed glass in a stream instead of forming into drops. If they were broken, the lubricator could not be used. The auxiliary oilers would have to be used to lubricate the cylinders.
AIR BRAKE QUESTIONS
1. Q. Explain how an air compressor should be started.
A. A compressor should be started slowly, with the drain cocks open to allow the water of condensation to escape; and as no provision is made in the steam end to cushion the pistons at the end of their stroke, it should be allowed to work slowly until a pressure of thirty or forty pounds has accumulated in the main reservoir; the piston, having to work against this pressure, will be cushioned at the end of each stroke. After the compressor is warm, the drain cocks should be closed and the throttle opened sufficiently to run the compressor at the proper speed. The lubricator should then be started and allowed to feed freely until eight or ten drops have passed, when the feed should be reduced to an amount sufficient for proper lubrication.
2. Q. What kind of oil should be used to lubricate both the steam and air cylinders of the compressor?
A. Valve oil.
3. Q. Where does the main reservoir pressure begin and end?
A. Begins at the discharge valves in the compressor and ends at the engineer's brake valve.
4. Q. Where does the brake pipe pressure begin and end?
A. The brake pipe pressure begins at the feed valve and ends at the brake pipe side of the triple piston, conductor's valve and at the rear angle cock.
5. Q. What is meant by excess pressure, and where is this pressure carried?
A. Excess pressure is carried in the main reservoir and is the pressure above that in the brake pipe.
6. Q. Why is excess pressure necessary?
A. To insure the prompt release of all brakes and quick recharge of the brake pipe and auxiliary reservoirs.
7. Q. How is the amount of excess pressure regulated?
A. By the compressor governor.
8. Q. Name the different parts of the air brake as applied to a car.
A. The triple valve, auxiliary reservoir, brake cylinder, brake pipe, angle cocks, cut-out cock, retaining valve, centrifugal dirt collector and strainer tee.
9. Q. What is the duty of the triple valve?
A. The triple valve has three duties to perform: Charge the auxiliary reservoir; apply the brake; and release the brake.
10. Q. What is the purpose of the auxiliary reservoir?
A. It is here that the air is stored that is admitted to the brake cylinder when the brake is applied; thus, each car carries its own brake power.
11. Q. What is the purpose of the brake cylinder?
A. It is here where the power of the compressed air is converted into work by forcing the brake piston out, moving the brake levers, rods and brake beams, forcing the brake shoes against the wheels, applying the brake.
12. Q. What is the purpose of the brake pipe and angle cocks?
A. It is through the brake pipe that all brakes in the train are placed into communication with the brake valve on the locomotive; and through the brake pipe, air from the main reservoir flows to the triple valves and auxiliary reservoirs on the different cars. The angle cocks are for the purpose of opening and closing the ends of the brake pipe.
13. Q. What is the purpose of the cut-out cock?
A. To cut out any brake that is not in operating condition.
14. Q. How is a brake cut out?
A. By closing the cut-out cock in the cross-over pipe and bleeding the auxiliary reservoir.
15. Q. How would you bleed an auxiliary reservoir?
A. By holding open the release valve on the reservoir until all air has escaped.
16. Q. How would you bleed off a stuck brake?
A. By holding open the auxiliary release valve until the brake piston starts to move toward release position.
OIL BURNING LOCOMOTIVES
1. Q. What are the fireman's duties on arrival at the enginehouse previous to going out on an oil burning locomotive?
A. In addition to the duties usually performed on any engine, the fireman should observe the condition of draft pans and arch, observe the condition of burner and dampers; try the oil regulating valve; see that the burner is properly delivering fuel oil to the fire; see that the oil heaters are in working order; that the fuel oil is heated to proper temperature; and see that proper supplies of fuel oil, sand and water have been provided as well as the necessary tools for handling an oil fire.
2. Q. How warm should the oil be at all times in the tank.
A. Warm enough to flow freely at all times, usually about 112 degrees. This temperature is about that which the hand can bear on the outside of the tank.
3. Q. If the oil is too warm, what happens?
A. Many of the good qualities of the oil may be lost by keeping it too warm, and the burner is more difficult to operate and does not work as well when the oil is kept at too high a temperature. Should the oil be too warm, it will give off too much gas which would be liable to cause an explosion in the oil tank.
4. Q. What tools are necessary for firing purposes on an oil burning locomotive?
A. The tools necessary for firing an oil burning engine include sand horn, brick hook, and a small iron bar to be used in cleaning carbon from the mouth of the burner.
5. Q. What is liable to happen if the heater valve is open too much?
A. If the heater valve is opened too much it would be liable to burst the heater hose as well as to heat the oil to a too high temperature and place an unnecessary strain on all the heater connections, causing them to leak.
6. Q. What should be done on approaching stations where additional supply of fuel oil is to be taken?
A. Shut off the fire, close safety and main oil valves, remove any lamps that are so close as to be unsafe when manhole cover is open.
7. Q. What care must be exercised in the use of lamps, torches or lanterns about oil tanks whether hot or cold?
A. Never permit oil lamps or oil torches to be carried within ten feet of the tank opening. Only incandescent lamps or pocket flash lights should be used around oil tank manhole when taking oil.
8. Q. How can oil in the tank be measured without taking a light to the manhole?
A. By inserting a measuring stick into oil in tank and taking stick to the light for reading.
9. Q. What precautions must be taken before entering tanks that have been used for oil to clean or make repairs?
A. Oil tanks, before being entered by workmen, should be thoroughly steamed and cooled before being entered. For safety they should be steamed from six to eight hours.
10. Q. How should the fire be lighted in an oil burning locomotive?
A. First see that no one is working under the engine, that there is the proper amount of water in the boiler and that it will flow through the gauge cocks, that there is no accumulation of oil in the ash-pan or fire-box or existing leaks throughout. If there is no steam in the boiler, the steam connections can be made to the three-way cock at the smoke-arch that will answer for blower and atomizer. If there are twenty pounds of steam in the boiler, it can be operated with its own blower. If oil in the tank is too cold to flow into the burner readily, it must be heated. Open the front damper and put on the blower strong enough to create the necessary draft, open the atomizer valve long enough to blow out any water that might be in the steam pipe to the burner, then close the valve and throw a piece of burning waste in front of the burner and open the atomizer valve enough to carry oil to the burning waste and open the regulating valve slowly until the oil is known to be ignited. Watch the ignition through the hole in the fire-box door, then regulate the steam and oil supply to suit. Be sure that no oil is wasting below the burner or an explosion may result that will prove disastrous.
11. Q. Should the fire go out and it is desired to rekindle it while bricks are hot, is it safe to depend on the hot bricks to ignite the oil without the use of lighted waste?
A. No; depending upon the heat from the firebricks to re-light the fire is dangerous and forbidden.
12. Q. What is termed an atomizer, and what does it perform?
A. The atomizer is a casting containing two long ports with an extension lip; the upper port is for oil and the lower one for steam. The lip aids the steam in atomizing and spreading the oil, which, when properly mingled with the air and ignited, will produce combustion. The atomizer is located just under the mud-ring and pointed a little upward, so the stream of oil and spray of steam would strike the opposite wall a few inches above the bottom if it would pass clear across the fire-box.
13. Q. In starting or closing the throttle of the locomotive, how should the fireman regulate the fire, in advance or after the action of the engineer?
A. In starting an oil burning engine the oil should gradually be brought up as the throttle is opened and the movement and amount of oil should be kept slightly in advance of the action of the engineer in order to prevent an inrush of cold air as the engine is working, which would result in injury to the fire-box and flues. When the throttle is to be closed, the fire should be reduced very slightly in advance of the closing of the throttle. This is to prevent the engine from popping off and black smoke drifting back over the train.
14. Q. Is it necessary that the engineer and fireman on an oil burning locomotive work in perfect harmony and advise each other of intended action at every change of conditions?
A. Yes; they should work in harmony with each other on any locomotive. The fireman should watch every move the engineer makes, and the engineer should advise the fireman of every intended change of the throttle, so he can operate his valves accordingly and save fuel and avoid black smoke.
15. Q. What is the effect of forcing the fire on an oil burning locomotive?
A. Forcing the fire is very hard on fire-box sheets and flues, and will cause them to leak. An even temperature should be maintained in the fire-box of any locomotive.
16. Q. Is a careful regulation of steam and oil valves and dampers necessary to obtain the most economical results?
A. Yes; the fireman's oil valve should be opened just wide enough to permit a sufficient amount of oil to be fed to produce a good fire, but not wide enough to waste oil or produce a volume of black smoke.
17. Q. How can you judge whether the combustion is good or bad, so the valve may be regulated accordingly?
A. By the color of the fire in the fire-box. When it is a dull red color, the temperature is below 1,000 degrees and combustion is incomplete, dense black smoke will issue from the stack. If it is a bright red, the temperature will be about 1,800 degrees and combustion very good, and no black smoke will appear from the stack.
18. Q. How should the flues be cleaned from soot when running, and about how often is this necessary?
A. By placing a small quantity of sand in an elbow shaped funnel or horn, and by inserting same in an opening provided in fire door while engine is working hard, allowing the exhaust to draw the sand through the flues, thus cutting soot and gum from them in its passage and discharging it from the stack. It is necessary that the flues be cleaned of soot on leaving terminals or sidings where the engine has been at rest for any length of time, and also as often as found necessary to aid the engine in steaming. This depends to a great extent upon the degree of perfection with which combustion is obtained. Attention should also be given flues just prior to entering points where engine is to be put in roundhouse or otherwise detained in order to leave the flues clean, as this will aid in putting engine under steam with little delay where the blower alone is to be relied on for draft.
19. Q. Is the injudicious use of the blower particularly injurious on an oil burning locomotive?
A. Yes; the injudicious use of a blower is injurious to any boiler. The cold air drawn through the fire-box is hard on the sheets and flues and will cause them to leak.
20. Q. Is the blower more injurious when a light smoke is emitting from the stack or when a dense black smoke is emitting?
A. It is most injurious when a light smoke is emitting.
21. Q. In drifting down long grades should the fire be shut off or burned lightly? Why?
A. The fire should be burned lightly and not permitted to get low enough to allow the fire-box to lose its temperature, as this will contract the flues and cause them to leak.
22. Q. How should the fire be handled when switching?
A. The fire must be regulated to meet the requirements of the work the engine is performing on each move and to protect against any possibility of the fire being drawn out by the exhaust.
23. Q. Would not some fuel be wasted in this way?
A. Not necessarily. A waste of fuel can be avoided by close attention on the part of the fireman when switching as well as when running.
24. Q. How should the fire be handled when leaving stations?
A. It should be burning brightly and strong enough to prevent the draft from putting it out when the throttle is opened. And a little smoke should show up at the stack, which would indicate that the fire was being forced just a little ahead of the working of the engine.
25. Q. Which is desirable, to use as much or as little steam jet atomizer as possible?
A. It is desirable to use as little atomizer as will make engine show perfect combustion and economy.
26. Q. What is the result of too little steam jet atomizer when standing at stations or when the engine is working light?
A. The result of too little atomizer when standing at station or when engine is working lightly, will result in the oil not being carried far enough into the fire-box or arch and not properly atomized and the fire is liable to go out. The oil will drop from the mouth of the burner into the draft pan to the ground where it is very liable to start a fire under the engine.
27. Q. If too much steam jet atomizer is used with a light fire?
A. It will create a disagreeable gas, which will cause the fire to burn with a succession of light explosions and kicks, also a waste of steam, and which would reduce the fire-box temperature.
28. Q. When the fire kicks and smokes, what should be done?
A. The atomizer should be adjusted. If this does not overcome the trouble, the heater should be put in service, for, possibly, the oil is too cold to flow freely. Another cause of the fire kicking and smoking results from water being mixed with the oil. If this is the case, it should be drained out of the oil tank immediately.
29. Q. How should the dampers be used on an oil burning locomotive?
A. They should be opened just enough to admit sufficient air to produce perfect combustion, but not enough to cool the fire-box. The dampers should be closed when the engine is drifting or when at rest and the fire is cut very low or is out entirely.
30. Q. About how much smoke do you consider an oil burning locomotive should make under adverse conditions, when the engine is steaming well, but is being crowded by the engineer?
A. Only a light smoke should show at the stack.
31. Q. What color is most desirable at peep holes in the fire-box?
A. A white color is most desirable.
32. Q. What will produce the bright red color?
A. Leaky steam pipes, side seams, flues and improper combustion will produce a ruddy color in the fire-box.
33. Q. How does water in the oil affect the fire?
A. Water in the oil will produce popping or kicking with the fire in the fire-box and at times the fire will die down entirely and then flash up as the water disappears and the oil reaches the burner. The most noticeable result of water in the oil is the fact that the fire will get very low. It will almost go out entirely and then will suddenly flash up again as the oil appears. Water in the oil produces a very dangerous condition and should be prevented immediately by draining the water from the fuel oil tank.
34. Q. Do you consider it advisable to keep the burners clean, and how often?
A. When equipped with steam blow-out pipes, they should be blown out before commencing trip so that burners will distribute oil evenly to each side of fire-box.
35. Q. What position should burner be with reference to level and in line with center of fire-box?
A. It is very essential that burners be level and throw flames just to clear floor of arch in order to derive full benefit of heating surface, as the draft has a great tendency to elevate flames, at opposite end of the fire-box.
36. Q. Are you aware that in course of time the atomizer port will become worn too large and will discharge too large a volume of steam to properly atomize, and the remedy?
A. Yes; the lip or bushing should be closed to proper opening so that steam will be restricted at the nozzle and escape with a bursting effect to properly atomize the oil instead of flowing out in quantities against flash walls before it has time to ignite.
37. Q. What is the real object of having the fire-box lined with bricks, and will engine steam without them?
A. Not so well as with the brick, the sheets being in contact with water are too cool to flash the oil readily and hence the use of what is called a "flash wall" built of fire brick and heated to a very high temperature aids combustion very materially.
38. Q. Do you consider it your duty to keep close inspection of brick work as to need of repairs, such as air entering between brick and side sheets?
A. Yes. To see that plaster is kept between the walls and sheets to keep cold air from being drawn in.
39. Q. Will engine steam if brick falls in front of burners or in path of flame and what may be done?
A. No. Remove them with the brick hook or rod by pulling them out through damper of draft pan.
40. Q. Where engine is equipped with an oil-reheater or oil line, do you consider it a help to engine's steaming qualities when used?
A. Yes; at all times this heater should be used.
41. Q. Why use second heater? Why not heat it to a high temperature in oil tank with oil heater?
A. Too much gas generating and boiling the oil continually destroys the higher qualities besides being hard to control the flow through regulation valve.
42. Q. Do you consider a vent hole in oil tank advisable, and why?
A. Yes; to allow any accumulation of gas to escape and to admit the air so that oil will flow freely.
43. Q. Do you inspect your oil pipes and report all leaks? What other bad effect has a pipe leak aside from waste of oil?
A. Yes. It will cause oil to feed irregularly.
44. Q. Are you aware that keeping the flues clean is the greatest one thing that you can do in regard to fuel economy, and how often should they be cleaned?
A. Yes. At least every ten miles.
45. Q. Do you know that the engine should be working hard and at a speed not less than twenty miles per hour when sanding flues to avoid the sand falling to floor of the fire-box and accumulating in front of them?
46. Q. Do you realize that on first closing throttle you should not adjust fire too low? Explain best method.
A. Yes. I would allow steam pressure to fall back some fifteen pounds before throttle is closed and on having closed same leave a good fire in box, allowing it to cool gradually to avoid leaky flues, broken staybolts, cracked sheets caused by sudden fall of temperature.
47. Q. How is the flow of oil controlled?
A. By the valves in tank and pipe connections.
48. Q. Name these valves, their location and purpose.
A. The safety valve controls the flow of oil from the fuel oil tank through an opening in bottom sheet of tank to the pipes leading to burner. This valve is forced to its seat by a heavy spring and is held off its seat by a key in the upright rod extending above the top of tank. To this key a rope or chain is attached and also attached to the cab to cause the pin in rod to be pulled in case of a separation between engine and tank and allow the valve to be seated by its spring and avoid a waste of oil. The second or main oil valve is located in oil pipe under deck leading to burner. It is usually of the plug-cock pattern connected by bell crank and this connected to some part of the engine by chain, in which case it also acts as a safety valve in case of separation between engine and tender. In other cases it is connected by an operating rod extending above deck of tender where it can be operated by hand in case of safety valves failure to shut off the flow of oil. The third or firing valve is usually located between heater box and burner, and is provided with an upright rod extending into cab where it is provided with a handle or lever in position to be conveniently handled by fireman while seated in cab. This valve regulates the flow of oil desired to reach the fire.
49. Q. When shutting out fire which valve should be closed first? Why?
A. The safety valve. To allow the oil in pipes to be consumed and to see that this valve is in working order.
50. Q. Should safety valve fail to shut off the flow of oil in such cases would it be safe to rely on the firing valve to shut off the fire?
A. No. The main valve should then be closed.
51. Q. Should the firing valve be depended upon to shut off the fire at any time? Why?
A. No. From constant use they are frequently leaking and the trouble is not detected while in use, and again there is always danger of the handle being moved by workmen or others about the cab.
52. Q. What is a heater box?
A. It is an apparatus having two passages, one for steam passing from boiler to heater pipes in tank and another passage for oil from tank before it is delivered to burner. In this manner the oil before reaching the burner is heated much higher than the temperature of that contained in tank.
53. Q. In the event of the heater pipes or connections becoming defective, how could the oil be heated in tank?
A. By closing the firing valve, closing the valve on heater pipe, and opening valve on heater box, the steam from heater throttle can be passed directly through the oil feed pipe to the fuel supply.
54. Q. In the event of an objectionable quantity of water in oil, how can it be removed?
A. In some instances the tanks are provided with drain pipes for this purpose, but in the absence of same, the feed hose or pipe between engine and tank can be disconnected and used as a drain to fuel oil tank.
55. Q. What effect has leaks between fuel tank and firing valve?
A. A waste of oil only.
56. Q. What effect has leaks between firing valve and burner?
A. In addition to a loss of oil while fire is burning low, and but little steam atomizer being used, it interferes very materially with the engine's steaming by admitting air when using considerable steam atomizer. This causes a very irregular oil feed.
57. Q. What action of the fire would indicate leaks in pipes between firing valve and burner?
A. The fire-box will give off sounds similar to slight explosions, and the smoke at stack will indicate irregular fuel feeding.
58. Q. What would you consider the proper adjustment of burner?
A. That which will provide for the delivery of the oil from burner to flash wall without striking arch, side walls, or floor brick while doing so.
59. Q. In case it becomes necessary to fire up an oil burning engine with wood, what parts should be given particular attention?
A. The brick work. To see that same is not damaged or displaced while placing the wood in fire-box, also to protect by placing brick over that portion of burner extending into fire-box ahead of mud ring, or by so arranging the wood in fire-box as to prevent any great amount of heat from reaching the burner and melting nozzle of same.
60. Q. In case of sudden drop in steam pressure, what might be the cause?
A. Loose brick perhaps fallen in front of burner and obstructed the flow of oil. The petticoat pipe may be loose and out of line or the dampers may have fallen shut.
61. Q. In case brick have fallen in front of burner, how can they be removed?
A. By a hook provided for that purpose. They can usually be forced out through the vent openings, but if this cannot be done, they should be thrown against the blast wall in order to get them as far as possible out of the course of the fuel feed.
62. Q. In case a petticoat pipe becomes deranged, what can be done?
A. In case it cannot be put back in proper position, it should be removed altogether. (Trips have been successfully completed in this manner.)
63. Q. Will a corroded burner mouth prevent the proper delivery of fuel to fire?
64. Q. What causes the mouth of burner to corrode?
A. The asphaltum and sand contained in the oil.
65. Q. How can this be removed on the road?
A. By having a hook or rod provided with a point that can be inserted into mouth of burner.
66. Q. Why should a fuel oil tank not be filled to its holding capacity?
A. Because when heater is applied the oil would expand and overflow.
67. Q. In case of derailment or other accident that might cause the fireman to desert his position in cab, what should he do?
A. Pull key out of safety valve rod, thereby allowing oil feed from tank to be shut off.
1. Q. What are the duties of an engineman before attaching a locomotive to the train?
A. He should make a complete inspection of the locomotive, observing all important nuts and bolts, look for any signs of hot bearings on previous trip, see that the engine is equipped with necessary tools and supplies, test both of the injectors and the air brake equipment to be sure they are in good working order, see that headlight and signal lamps are in place and ready for service, observe water conditions in boiler, inspect the interior of the fire-box and see that the locomotive is properly lubricated.
2. Q. What tools should there be on the locomotive?
A. Such as are necessary to properly operate the locomotive, care for the machinery, disconnect and block up in case of breakdown and the necessary firing tools.
3. Q. What examination should be made after any repair work has been done on valve, brasses, etc.?
A. See that brasses are properly fitted, keys fastened and nuts made tight. If any repairs have been made on valves or valve gear, would see that the reverse lever could be moved freely and that all movable parts had been properly replaced; would also give especial attention with reference to lubrication of these parts.
4. Q. What attention should be given to boiler attachments, such as gauge cocks, water glasses, etc.?
A. Would see that the gauge cocks can be opened to try the water and closed, so steam and water would not come out into cab. Observe the water glass and note if water is moving up and down in the glass, see that the steam valve at the top and water valve at bottom of glass could be opened and closed, and allow water and steam to circulate freely through the glass.
5. Q. What do you consider necessary to report on locomotive boilers?
A. Should report all defects on boiler and its attachments while engine is in engineer's charge.
6. Q. Trace the steam from the boiler through the cylinders to the atmosphere and explain how it transmits power.
A. Steam enters the throttle valve located in the highest part of the dome in order to get the driest steam, then passes through the standpipe and dry pipe out of the boiler to the steam pipe tee or nigger-head located in the front end, then through steam pipes to the steam chest. A steam valve in each steam chest distributes the steam so that it enters the cylinders at or just before the beginning of the stroke; pushing the piston to the end of its stroke; just before the piston reaches the end of the cylinder, the steam valve opens communication to the exhaust port through a cavity in its exhaust side, then through the exhaust pipes and tips up through the draft or petticoat pipe and stack to the atmosphere. When steam pushes the piston through the cylinder, its power is transmitted by the main rod to the main crank pin which causes the wheels to revolve, thus moving the engine and its train.
7. Q. Why is it important that there be no holes through the smoke-box door or front end and none in smoke-box seams or joints?
A. So as to maintain as good a vacuum as possible in the smoke-box and prevent small amounts of air coming in through leaks which tend to heat and warp the smoke-box and its door.
8. Q. How should the locomotive be started to avoid jerks, and what train and other signals should be looked out for at the time of starting?
A. Place the reverse lever in full gear, open the throttle valve gradually so as to start the train one car at a time and easily. Look for signals ahead to show that the track is clear and switch is in correct position, then look for signals from the rear end that the train is all coming.
9. Q. Will an engine equipped with superheat units move as quickly as a saturated steam locomotive when throttle valve is first opened?
10. Q. Why?
A. Because steam must first pass through superheat units before it enters the steam pipes leading to steam chest.
11. Q. In placing engine on the turntable, at water or stand pipes, or at other similar places, what must be done?
A. Close throttle valve sooner so that the steam confined in superheat units, pipes and steam chests, will have passed out to the atmosphere.
12. Q. After a locomotive has been started, how can it be run most economically?
A. By regulating the supply of steam to the steam chest with the throttle and the point of cut-off with the reverse lever; so that no more steam be used than necessary to maintain the proper speed, whenever possible working the engine at short cut-off so as to use steam expansively.
13. Q. What is meant by working steam expansively?
A. Hooking the reverse lever up toward the center gives the valve a shorter travel and closes the live steam port when the piston has made only a part of its stroke. This cuts off the supply of live steam coming from the steam chest. The expansion of the steam already in the cylinder pushes the piston to the end of its stroke without the use of a full cylinder of live steam.
14. Q. How rapidly should water be supplied to the boiler?
A. No faster than it is evaporated into steam, unless just before a hard pull; or when shutting off with a heavy bright fire in the fire-box to prevent waste of steam at the pops.
15. Q. What is the difference between priming and foaming of a locomotive boiler?
A. Priming is caused by carrying the water too high in the boiler so that when the throttle valve is opened some of it passes over with the steam in the form of a spray. Foaming is caused by the water becoming dirty from animal or alkaline matter, so that heat makes it foam like soap suds. Muddy water or certain vegetable matters will also make a boiler foam.
16. Q. What should you do in a case of foaming? What in a case of priming?
A. In a case of foaming, if possible, allow the boiler to cool off a little, increase the supply of feed water to prevent water getting too low, and whenever possible blow some of the dirty water out of the boiler, replacing it with clean water. In case of priming, shut off the supply of feed water until the water level drops to the proper height in the boiler.
17. Q. What danger is there when the water foams badly? When it primes badly?
A. There is danger of knocking out cylinder heads, cutting the valves, stalling on some grade or getting on some train's time because the engine cannot be worked to its proper power. When shutting off steam, the water is liable to drop below the crown sheet and thus risk burning the fire-box. When water primes badly, it is liable to break cylinder packing rings, knock out cylinder heads, break bolts in the steam chest and cut the valves. In such a case additional oil should be fed to the steam chest until the valves are properly lubricated.
18. Q. Suppose that with the water glass in good working order, immediately after closing the throttle the water disappeared from the water glass, what should be done?
A. Would open the throttle and endeavor to raise water until both injectors would put enough water into the boiler to make it entirely safe to close the throttle. If unable to raise the water level to the lower gauge cock would smother the fire or put it out entirely, if necessary, keeping both injectors working.
19. Q. What work about a locomotive should be done by the engineman?
A. Inspection of the engine both before and after the trip. The engineer should do any necessary work on the engine after starting out on the trip to avoid breakdowns and insure getting over the road promptly. This means tightening up any important bolts that work loose on the trip and keeping parts from working out of position, adjusting wedges and rod keys.
20. Q. How should the work of setting up the wedges be done?
A. Place the engine on the upper quarter on the side with the loose wedge. Do not set the brake if brake shoe will push the driving box against the defective wedge, but block engine truck wheels so the engine cannot move, push the boxes against the shoe or dead wedge with a little steam, set the wedge up until it is a snug fit, then pull it down about one-sixteenth of an inch and fasten. Provision should be made for expansion of the box when it gets warm.
21. Q. How should rod brasses be keyed?
A. If properly fitted they should be keyed brass to brass; if not so fitted, they should be keyed on the large part of the pin so they will be free enough to run without heating and snug enough to run without pounding. Do not key them so tight at either end as to prevent the lateral motion of the brass on the pins.
22. Q. How should an engine be placed for the purpose of keying the rod brasses?
A. For the main rod, place the engine on the quarter or the top forward eighth, whichever place gives the largest diameter of the pin to key the brass against. After keying up, test by moving the wheel to another position and see if brasses are free on the pin. For the side or parallel rods, always place the engine on the center for the side that is to be keyed.
23. Q. How should the side rods on a mogul or consolidation locomotive be keyed?
A. Place the engine on the center on that side, key up the brass on the main pin first, work each way toward the ends of the rods, being careful to keep them the proper length so they do not bind when passing either center. Be sure that wedges are properly set up before keying the side rods.
24. Q. What is the necessity for keeping the brasses keyed up properly?
A. If too tight, they will surely run hot; if too loose, they will pound and injure the brasses as well as endanger the safety of the straps and rod bolts. Very loose brasses can pound enough to get hot.
25. Q. What is meant by an engine out of tram? Out of quarter?
A. When corresponding wheels on opposite sides of the engine on different axes are not spaced equally apart; where the axle of any wheel is not at a right angle to the center line from front to rear of engine, so they do not run square on the rails, or where the space between the axle centers on opposite sides is not equal. This is sometimes indicated by unequal flange wear and should be reported at once. Wheels are out of quarter when the crank pin in one wheel is not exactly 90 degrees or one quarter of a turn from the pin in the wheels on the other end of the same axle. This is usually caused by slipping the engine with sand on one rail only and the condition of engine should be reported at once.
26. Q. Describe a piston valve.
A. A piston valve is a cylindrical spool-shaped valve constructed with packing rings much the same as the steam piston that moves through the cylinder, except that a piston valve is double or composed of two pistons connected by center rod or spool working in a bushing of equal diameter. Steam and exhaust ports are cut through this bushing; steam ports to the cylinder and exhaust port to the exhaust pipe. There is also a steam port for live steam from the boiler. As the pressure on this valve is equal in both directions it is practically balanced.
27. Q. What is a balanced slide valve? How is it balanced, and why? For what purpose is the hole drilled through the top of the valve?
A. One in which the steam pressure on the top and bottom of the valve is nearly equalized. This is done by protecting a portion of the top of the valve from the steam pressure. It is usually balanced by strips held against the pressure or balance plate by one or more springs. This is done to prevent live steam from getting on top of valve and thus relieve the valve from the top pressure which would cause excessive friction between the bottom of the valve and its seat. The hole through the top is to allow any steam which might leak by the strips to pass into the exhaust, so pressure could not accumulate on the top of the valve, also to equalize the exhaust pressure between the top of the valve and exhaust cavity as well as to assist in lubricating the balance plate.
28. Q. What is meant by inside and outside admission valves?
A. With an inside admission valve (usually a piston valve), the live steam comes between the piston valve heads, the outside end of the heads being connected with and exposed to exhaust pressure, it admits steam past the inside edges of the valves. An outside admission valve has the space between the ends connected to the exhaust and a space at the ends connected with the live steam. It admits steam past its outside edges. A piston valve can be either inside or outside admission, while a slide valve is always outside admission.
29. Q. What is the relative motion of the main piston and the steam valves for inside admission, and, on the other hand, for outside admission?
A. If the piston is in the front end of the cylinder, an inside admission valve must move forward in order to connect the inside of the valve with the front live steam port to admit steam against the piston. The outside end of the valve opens the exhaust port for the back end of the cylinder. In the same position of the piston an outside admission valve must move backwards to open the steam port or in the same direction as the steam piston when commencing its stroke.
30. Q. What is an Allen ported valve, and what is its object?
A. An Allen ported valve is an outside admission slide valve having an extra port from one end of the valve to the other, above the exhaust cavity and through the body of the valve. This extra port is calculated to admit steam through the valve at the same time that steam passes by the end of the valve into the same steam port, thus doubling the area of opening for live steam when the port is first opened.
31. Q. What is the difference in the valve motion for outside admission valves and for inside admission valves?
A. An outside admission valve must be moved in the opposite direction to an inside admission valve in relation to the movement of the steam piston when beginning its stroke; therefore either the position of the eccentric or the position of the rocker arms in relation to the rocker shaft must be opposite for a change in these valves.
32. Q. What is a direct motion valve gear? What is an indirect motion valve gear?
A. A direct motion valve gear is one in which the valve moves in the same direction as the eccentric rod, that is doing the work, in many cases no rocker arm is used. In case a rocker arm is used, both arms point in the same direction like the letter U. An indirect motion valve gear is one in which the valve moves in an opposite direction to the eccentric rod doing the work. A rocker is used in which the arms point in opposite directions from the shaft connecting them. Owing to the design and construction of the Walschaert valve gear, it is a direct motion gear when the engine is running in one direction with the link block in the bottom of the link, an indirect motion when the engine is running in an opposite direction with the link block in the top of the link; usually direct motion when running forward.
33. Q. How can you detect the difference between a blow in valve or piston packing?
A. A blow from the valve is more constant and has a somewhat different sound, while a blow from cylinder or piston packing will blow stronger at the beginning of the stroke and gradually decrease as the stroke is completed.
34. Q. How would you place engine to locate broken admission steam ring in piston valve?
A. Would place engine on quarter, reverse lever in center so as to cover ports, then open throttle; and the steam will blow out of cylinder cock at the end of cylinder where broken valve ring is located.
35. Q. How would you locate broken exhaust ring in piston valve?
A. Watch the cross-head when engine is working steam. As there will be three normal and one light exhausts, you can determine on which side of the engine the light exhaust takes place.
36. Q. What is meant by lead? What by line and line?
A. Lead is the amount of port opening for live steam to cylinder ahead or back of piston when the piston is on the dead center. If the steam edge of the valve is in line with the edge of the steam port when the piston is on the center, it is said to be line and line.
37. Q. What is meant by steam lap?
A. The distance that the valve overlaps the live steam edges of the steam ports when it is in the center of its travel over the seat. This distance is measured at one end only, although the valve laps equally at both ends.
38. Q. What is meant by exhaust lap? What by exhaust clearance?
A. Exhaust lap is the distance that the exhaust edge of the valve overlaps the exhaust edge of the steam port when the valve is in central position. Exhaust clearance is the opening between the exhaust edge of the valve and the exhaust edge of the steam port with valve in central position. If the valve has neither exhaust lap or clearance it is said to be line and line.
39. Q. What is meant by release? What by compression?
A. Release is the point in the travel of the piston when the port is opened. Compression is the distance the piston travels after exhaust port closes before the live steam port opens. During this travel of the piston the exhaust port is closed so the moving piston compresses the steam left in the cylinder.
40. Q. With an indirect valve motion and outside admission valve, what would be the position of the eccentric relative to the crank pin on that side? What with a direct valve gear? What difference between outside admission valve and inside admission valve as to this position?
A. With an indirect valve motion and an outside admission valve, the go-ahead eccentric follows the crank pin with engine running ahead. Without any lap or lead it would be a quarter of a turn or 90 degrees behind the pin, but as all valves have lap and lead, the eccentric is advanced or placed toward the pin enough to move the valve the amount of the lap and lead. With a direct valve gear and an outside admission valve, the eccentric will be a quarter of a turn or 90 degrees ahead of the crank pin and advanced enough to move the valve the amount of the lap and lead. With an inside admission valve and an indirect valve motion, the eccentric will come the same as for an outside admission valve and direct motion, or more than a quarter of a turn ahead of the pin. With an inside admission valve and direct motion, as piston valves are usually put up, the eccentric will follow the pin less than a quarter of a turn.