Examination Questions First Series

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, ashpan, flues and firebox. Put fire in proper shape; see that a proper supply of firing tools, water, coal, oil and waste are provided, that all lamps and markers are filled, cleaned and in proper condition; and to perform such other duties as may be required by the engineer to assist him in getting the engine in readiness.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

10. Q. At what temperature does water boil?

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

11. Q. What is carbon?

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

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

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

13. Q. What is combustion?

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

14. Q. Is air necessary for combustion?

A. Yes.

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

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

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

A. Air, like coal and its gases, must be heated before they will unite to form what is known as combustion and so as not to reduce the temperature of the firebox 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 firebox 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 firebox it is most required.

A. The center is the hottest part of the firebox. There is a much lower temperature in the firebox at the sides and end sheets, due to the water on the opposite sides of the sheets being of a lower temperature than the firebox; 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.