Part 10

64. Q. How would you proceed to locate the point of trouble with a short circuit?

A. Would remove (1) one of the lead wires from the binding post at dynamo; if trouble was in dynamo you would not note any difference in action of speed. (2) Would disconnect one of the cab wires; if the trouble is in cab circuit, speed would increase and lamp would burn. (3) If trouble is not in cab circuit, would go to lamp, disconnect one of the main wires from binding post; if short circuit is in the wires between dynamo and lamp, there would be no change in speed of dynamo, but if the wires are O. K. the speed of engine would increase and your trouble would be in the lamp.

=DUPLEX LOCOMOTIVE STOKER=

1. Q. Of what does the driving mechanism of a Duplex Locomotive Stoker consist?

A. It consists of a steam cylinder with reverse head and valve arrangement similar to the steam end of an eleven inch Westinghouse air pump.

2. Q. How is the power controlled?

A. The speed is variable, and by turning the valve controlling the engine steam inlet, can be made greater or less according to the amount of coal needed.

3. Q. For ordinary operation, how much steam pressure is required?

A. About fifteen pounds, with piston strokes varying from 10 to 15 per minute.

4. Q. How can the duplex stoker driving engine be started, stopped, or reversed?

A. By means of operating and reversing rod, fastened to the back head and connected with the valve on reverse head of engine cylinder.

5. Q. How can the conveying screws be started, stopped, or reversed separately or together?

A. By ratchet and pawl arrangement controlling each.

6. Q. What practice should be followed in building up the fire before leaving a terminal?

A. Build up a light even fire by hand and do not bring stoker into use until the locomotive is working steam.

7. Q. How should the stoker be oiled and operated?

A. It should be thoroughly oiled before leaving the terminal, then see that operating rod on back head is in center or running position, open main jet line so they register about fifteen pounds on the jet steam gauge if coal is coarse, or ten pounds if coal is small. Next, the driving engine steam valve should be opened wide and the throttle valve opened just enough to supply the proper amount of coal to the fire-box.

8. Q. How is the distribution of coal over the grate area accomplished?

A. By means of a low-pressure constant steam jet located in the back and bottom portion of each distributor elbow, as indicated by its individual pointer on steam gauge.

9. Q. By increasing the jet pressure, will more coal be carried to forward end of fire-box and against the flue-sheet?

A. Yes, it will, and by decreasing the jet pressure more coal will be fed at middle and back end of fire-box.

10. Q. Can the fireman direct the even distribution of coal in the fire-box?

A. Yes; by changing position of the dividing rib located in the transfer hopper, and by moving the regulating lever to either side.

11. Q. Should the sliding plates at the bottom of the tank be closed before coal is put on tank?

A. Yes, so that screw conveyor will not become clogged and inoperative. Only one slide should be opened at a time and coal fed from tank as required.

12. Q. In case the stoker becomes clogged or it is desired to reverse it for any reason, what must be done?

A. The operating rod located on the back-head of the locomotive boiler--if the piston is making a power stroke--should be moved to its lower position, and if the piston is making a return stroke, it should be moved to its upper position. This moves a small valve in the auxiliary head, bolted to reverse head, and steam is admitted to opposite head of cylinder, causing the piston to change its direction. The return of the operating rod handle to a central position causes the driving engine to resume its normal operation.

13. Q. How can the fireman observe the condition of fire in fire-box?

A. The elbows are provided with peep valves with swinging covers through which the coal supply and condition of fire may be seen.

14. Q. Why are two gauges necessary?

A. The driving engine gauge on the left indicates the pressure of steam used by the driving engine. The one on the right has two indicators, the red indicator showing the steam pressure on the jet in left elbow, and the black indicator showing the pressure on the jet in the right elbow.

15. Q. When train is standing on siding for a short period, what should be done?

A. Shut stoker off by throwing operating rod on back head of locomotive boiler out of running position.

16. Q. When train is to stand for a long time or engine is left at terminal, what should be done?

A. The driving engine should be cut out entirely by closing main steam line inlet and main lubricator connection, and in winter time all drain cocks should be opened.

17. Q. If sufficient coal can not be supplied over front grates, what may be the cause?

A. Distributors may be warped and point too low, or steam jets may be plugged with pipe scale and not blowing freely.

18. Q. How would you start and operate stoker?

A. First open main valve No. 1 at steam turret. Valve 2 is then opened; this is the main valve in stoker steam line. Next open valve 3, which allows the steam to flow to the distributor jet line; open valves 4 and 5, which govern the pressure on the jets until ten pound pressure shows on the right-hand gauge. See valve 8 to the exhaust line is open, and valve 9 to the transfer hopper is closed.

19. Q. How would you start the stoker engine?

A. Place operating lever 10 in horizontal or running position. Place conveyor reversing lever 12 in forward position. Open valve 6, which allows the steam to pass to the operating valve and starts stoker running. Valve 7 is to be used as an emergency valve only in case of clogging. Stoker should be run slowly at first. Do not feed too much coal and carry a light fire.

20. Q. How would you reverse conveyor screw in tank?

A. Lower handle 10 on operation rod on boiler head to bottom position. Move screw conveyor, reverse lever 12 back to rear or reverse position, raise handle 10 on operating rod to center position.

21. Q. How would you stop conveyor screw in tank?

A. Place conveyor reversing lever 12 in center position.

22. Q. How would you reverse right or left elevator screw?

A. Raise elevator pawl shifter 26 on top of the vertical shaft to upper position.

23. Q. How would you stop right or left elevator screw?

A. Raise elevator pawl shifter 26 on top of the elevator to middle position.

24. Q. How would you locate clogs in case the stoker stalls?

A. First, shut off pressure to stoker engine cylinder by closing valve 6. Second, move operating valve lever 10 to its lowest position. Third, place tender conveyor reverse lever 12 in center. Fourth, place right elevator pawl shifter 26 in neutral position. Fifth, raise operating valve lever 10 to center position. Sixth, open valve 6 sufficiently to run left elevator to ascertain if it operates freely. Cut in right elevator by lowering pawl shifter 26, and if stoker stops, the obstruction is in the right elevator. If it continues to operate, then the obstruction is in the tank conveyor.

25. Q. How would you remove clogs?

A. Clogs in upright elevators usually occur at the bottom. Raise the door in the engine deck and remove the obstruction if in the elevator, reverse the elevator screw forcing the obstruction back down in transfer hopper. It may be a small mine spike lodged above this point, and by removing the nut at top of elevator casing and removing the door the obstruction can be easily removed.

26. Q. If the clog is in the tank conveyor, how would it be removed?

A. The clog will usually be found in the crushing zone. Reverse the tank conveyor screw, forcing the obstruction back, when it can be removed from the trough.

27. Q. How far should the conveyor screw be run backwards?

A. Not more than three revolutions.

PARTS OF DUPLEX LOCOMOTIVE STOKER 1. Conveyor Trough. 2. Conveyor Screw. 3. Angle Ring. 4. Crusher. 5. Operating Head. 6. Driving Engine Cylinder. 7. Reverse Valve. 8. Piston Rod. 9. Transfer Hopper. 10. Left Elevator Casing. 11. Left Elevator Screw. 12. End of Elevator Screw Shaft. 13. Elevator Pawl Shifter. 14. Elevator Pawl Casing. 15. Distributors. 16. Left Distributor Elbow. 17. Right Distributor Elbow. 18. Dividing Rib. 19. Right Elevator Casing. 20. Oil Box. 21. Conveyor Reverse Lever. 22. Conveyor Oil Cups. 23. Rack Housing. 24. Rack. 25. Conveyor Pawl Casing. 26. Conveyor Screw Flexible Connection Sleeve. 27. Conveyor Screw Flexible Connection. 28. Conveyor Slide Support Roller. 29. Conveyor Slide Support. 30. Conveyor End Bearing and Gear Case. 31. Conveyor Screw Gear. 32. Conveyor Screw Driving Gear.

=AIR BRAKE QUESTIONS=

COMPRESSOR GOVERNOR

1. Q. When steam is first turned on, what must it pass through before entering the compressor?

A. The compressor governor.

2. Q. What does Fig. 1 represent?

A. This shows a sectional view of the SF compressor governor in open position.

3. Q. What is the duty of the compressor governor?

A. To automatically regulate the main reservoir pressure by controlling the steam to the compressor.

4. Q. How are the regulating portions of the governor designated?

A. The one having two pipe connections and a light regulating spring is known as the excess pressure head; the other, with a single pipe connection and heavy regulating spring, as the maximum pressure head.

5. Q. When does the excess pressure head control the flow of steam to the compressor?

A. When the automatic brake valve is in any one of its first three positions; namely, release, running and holding positions.

6. Q. With the automatic brake valve in release, running or holding position, what pressure is in chamber "f" above the diaphragm? In chamber "d" below the diaphragm?

A. Air, at feed valve pipe pressure, enters at the connection marked "FVP" and flows to chamber "f" above the diaphragm; this pressure acts in conjunction with the regulating spring 27 in creating the total pressure on the diaphragm. Air at main reservoir pressure flows through the automatic brake valve to the connection marked "ABV" to chamber "d" under the diaphragm.

7. Q. At what pressure is the regulating spring in the excess pressure head adjusted?

A. Usually twenty pounds.

8. Q. With the spring adjusted at twenty pounds, what will be the total pressure on the upper side of the diaphragm?

A. Twenty pounds, plus the pressure in the feed valve pipe.

9. Q. With the feed valve adjusted at seventy pounds, and the regulating spring at twenty pounds, what pressure will be had in the main reservoir when the governor stops the compressor?

A. Ninety pounds.

10. Q. Explain the operation of the governor in controlling the compressor when a main reservoir pressure of ninety pounds is reached.

A. When the main reservoir pressure in chamber "d" slightly exceeds the pressure on top of the diaphragm it will move upward, carrying the pin valve with it. The air in chamber "d" passes by the unseated pin valve through port "b" into chamber "b" above the governor piston, forcing it downward, seating the steam valve 5, thus shutting off the steam to the compressor.

11. Q. How long will the governor remain in this position?

A. Until the main reservoir pressure falls below ninety pounds, when the combined spring and air pressure in chamber "f" will force the diaphragm 28 down, seating the pin valve. This shuts off the supply of air from chamber "d", and the air confined in chamber "b" will escape to the atmosphere through the vent port "c". The pressure now being removed from above the governor piston, the spring 9 aided by the steam pressure under the valve 5, will force the piston upward, unseating the steam valve 5, allowing steam to pass through the governor to the compressor.

12. Q. When the steam valve is seated, is steam entirely shut off from the compressor?

A. No; there is a small port drilled through the valve; its purpose is to maintain a circulation in the steam pipe and keep the compressor working slowly; thereby preventing condensation when the steam valve is closed.

13. Q. With the automatic brake valve in release, running, or holding position, does the maximum pressure head operate?

A. No; as during this time the main reservoir pressure is not sufficiently high to actuate its diaphragm.

14. Q. Where does the air come from that operates the maximum pressure head?

A. From the main reservoir direct. (See Fig. 1.)

15. Q. When does the maximum pressure head control the compressor?

A. When the automatic brake valve is in either lap, service or emergency position, also when the main reservoir cut-out cock is closed.

16. Q. How is the pressure created on top of the diaphragm in the maximum pressure head?

A. By the regulating spring 19.

17. Q. What is the adjustment of this spring?

A. Spring 19 is adjusted to the maximum pressure desired in the main reservoir usually 130 pounds.

18. Q. Explain the operation of the governor when the main reservoir pressure exceeds the tension of the regulating spring 19.

A. When the pressure in chamber "a" exceeds the tension of the regulating spring 19, the diaphragm 20 is forced upward, unseating the pin valve, allowing air to flow from chamber "a" to chamber "b" above the governor piston, forcing it down, shutting off steam and stopping the compressor.

19. Q. How long will the governor remain in this position?

A. Until the main reservoir pressure in chamber "a" under the diaphragm becomes slightly less than the adjustment of the regulating spring 19, when the diaphragm 20 will move down, seating the pin valve, shutting off the flow of air from chamber "a" to chamber "b". The air entrapped above the governor piston will escape to the atmosphere through the relief port "c"; this will allow the governor piston to raise, unseating the steam valve 5, again allowing steam to pass through the governor to the compressor.

20. Q. Is the maximum pressure head cut out in any position of the automatic brake valve?

A. No; as the air that operates this head comes direct from the main reservoir, therefore is not controlled by the brake valve.

21. Q. Is the excess pressure head cut out in any position of the brake valve?

A. Yes; as the air that operates this head comes through the automatic brake valve, and when the handle is moved beyond holding position, the port in the rotary valve seat, through which the air flows to chamber "d" is closed, thereby cutting out this head, leaving the compressor under the control of the maximum pressure head.

22. Q. What is the object of the duplex or double head governor?

A. By use of the duplex governor the main reservoir pressure may be controlled at two different predetermined pressures; as when running along the excess or low pressure head controls the compressor, at the low pressure--usually ninety pounds--this being sufficient to keep the brakes released and fully charged; whereas, in lap position, as following a brake application, the maximum or high pressure head controls the compressor at the maximum pressure used--generally 130 pounds--this for a prompt release and quick recharge of the brakes. From this it will be seen that the compressor has to work against the high pressure only during the time the brake is applied.

23. Q. In what position should the automatic brake valve handle be placed when adjusting the excess pressure head? The maximum pressure head?

A. Running position for the excess pressure head; lap position for the maximum pressure head.

24. Q. If, with the automatic brake valve handle in running position, the brake pipe and main reservoir do not stand twenty pounds apart, where would you look for the trouble?

A. Would first learn if the maximum pressure head was properly adjusted, and if it were, would then look for the trouble in the adjustment of the regulating spring in the excess pressure head.

25. Q. What should be done?

A. The regulating spring should be properly adjusted.

26. Q. How should the adjustment of the regulating spring in either pressure head be made?

A. By removing the cap nut 25 or 17 and screwing the regulating nut 26 or 18 up or down as may be required.

DEFECTS OF THE GOVERNOR

27. Q. What would be the effect if one or both of the pin valves leaked?

A. Would cause a delay in opening of the steam valve after the pin valve had seated; and if air leaks by faster than it can escape through the relief port "c", pressure will accumulate in chamber "b" and force the governor piston downward, so as to partially or wholly close the steam valve 5.

28. Q. How can you tell if the pin valves leak?

A. Leakage past the pin valve in the maximum pressure head will cause a constant blow at the relief port in all positions of the brake valve; leakage past the pin valve in the excess pressure head will cause a blow in the first three positions of the brake valve only.

29. Q. What would be the effect if the relief port "c" stopped up?

A. The compressor will not start promptly after the pin valve seats.

30. Q. What would be the effect if the drain port "W" were stopped up?

A. Steam leaking into the chamber under the governor piston will form a pressure and prevent the piston being forced downward to close the steam valve; the compressor will therefore continue to work until the main reservoir pressure is about equal to boiler pressure.

31. Q. If the pipe leading from the feed valve pipe to the excess pressure head of the governor breaks, what effect will it have on the compressor?

A. The compressor will stop when the main reservoir pressure reaches about forty-five pounds.

32. Q. If the pipe breaks, what should be done?

A. Plug the end toward the feed valve and put a blind gasket in the pipe leading from the automatic brake valve to the governor, at the connection marked ABV.

33. Q. If the pipe leading from the automatic brake valve to the governor breaks, what should be done?

A. Plug the pipe toward the brake valve; the compressor will now be controlled by the maximum pressure head.

34. Q. If the pipe leading from the main reservoir to the maximum head of the governor breaks, what should be done?

A. Plug the main reservoir end of the pipe. The excess pressure head will now control the compressor in the first three positions of the automatic brake valve handle, but will have no control after the handle is moved as far as lap position.

=PARASITE GOVERNOR=

35. Q. What is the purpose of the parasite governor, and where is this governor located?

A. This governor is located in the pipe connection between the main reservoir and parasite reservoir, and its purpose is to control the flow of air from the main to the parasite reservoir.

36. Q. What is the purpose of the parasite reservoir?

A. It is here that air is stored for use in all air operated devices on the locomotive, except the brake.

37. Q. Explain the operation of the parasite governor.

A. The operation of this governor is much the same as the compressor governor, and differs only in that the supply valve is open when it is in its lower position.

38. Q. At what pressure is the regulating spring adjusted?

A. About fifteen pounds.

39. Q. What pressure is required in the main reservoir before air is admitted to the parasite reservoir?

A. At least fifteen pounds above that in the brake pipe.

40. Q. What pressure is obtained in the parasite reservoir?

A. The same as that in the main reservoir, when the main reservoir pressure is fifteen pounds greater than that in the brake pipe.

41. Q. What will prevent the charging of the parasite reservoir, and what should be done?

A. This may be caused by the feed valve being improperly adjusted, sticking in open position or leakage of main reservoir air past the valve to the feed valve pipe and governor top.

=WESTINGHOUSE 9-1/2 OR 11-INCH COMPRESSOR=

42. Q. What is the duty of the air compressor?

A. To furnish the compressed air used in the operation of the brakes, and all other air operated appliances on both locomotive and cars.

43. Q. Explain the operation of the steam end of the compressor.

A. When steam is turned on at the boiler it flows through the steam pipe and governor, entering the compressor at the steam enlet, then through the steam passage "a" to the reversing valve chamber "C" also to the main valve chamber "A" between the differential pistons 77 and 79. The area of the piston at the right being greater than the one at the left, the main valve is moved to the right, (See Fig. 2) admitting steam to port "b" which leads to the lower end of the steam cylinder; steam is now free to flow under the main piston, forcing it upward. When the piston has almost completed its upward stroke, the reversing plate 69 on top of the piston 65 engages a shoulder on the reversing rod 71, moving the rod and reversing valve 72 upward (See Fig. 3). The upward movement of the reversing valve closes the ports "f" and "h" and opens port "g"; thus permitting steam to enter the chamber at the right of the large piston 77, balancing the pressure on this piston, and the pressure acting on the right side of the small piston 79--the chamber at the left being open to the exhaust--will force the main valve to the left.

When the main valve moves to the left, steam is admitted through port "c" to the upper end of the cylinder on top of the piston 65, forcing it downward. At the same time the lower end of the cylinder is connected through exhaust cavity "b" of the main valve to the exhaust port "d", allowing the steam below the piston to escape to the atmosphere.

44. Q. When the piston has about completed its downward stroke, what takes place?

A. The reversing plate 69 engages the button "k" on the end of the reversing rod 71 pulling the rod and the reversing valve down. This movement of the reversing valve closes port "g" and the cavity in the face of the valve connects ports "f" and "h", which allows the steam in chamber "D" at the right of the large differential piston to escape to the exhaust, thus allowing the main valve to move to the right, exhausting the steam from the top end of the cylinder, and at the same time admitting steam to the lower end, causing an upward stroke of the piston.

45. Q. Explain the operation of the air end of the compressor.

A. The movement of the steam piston 65 is imparted to the air piston 66 by means of the piston rod. When the air piston moves up, a partial vacuum is formed below it, and air from the atmosphere will enter through passage "F" thence through passage "n" to the under side of receiving valve 86b (see Fig. 2), lifting this valve from its seat, and will fill the cylinder with air at about atmosphere pressure.

In the meantime the air above the piston, being compressed, will hold the upper receiving valve 86a to its seat, and when the pressure is slightly greater than that in the main reservoir, this pressure acting under the upper discharge valve 86c, will lift this valve from its seat and now the air will be free to flow through passage "G" to the main reservoir connection. On the down stroke the action is similar, air is taken in through the upper receiving valve 86a, while the air below the piston is being compressed and forced past the lower discharge valve 86d, to the main reservoir. (See Fig. 3.)

46. Q. What lift should the air valves have?

A. All valves should have a lift of three thirty-second of an inch.

47. Q. At what speed should the compressor be run to obtain the best results?

A. At 100 to 120 single strokes per minute.