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Examination Questions and Answers
Examination Questions and Answers
E-T Locomotive-Brake Equipment
No. 5 and No. 6
Q. 1.-What differences are there in handle positions, and general operation, between the Engineer's Brake-Valves—Automatic, and Independent,-of the No. 5 and No. 6 styles, E-T locomotive-brake equipment?
A.—No difference ordinarily. On secondary engines in double heading, there is a difference in the positions in which the different automatic brake-valve handles should be carried.
Q. 2.–Name the Positions of the Handle of the Automatic Brake-Valve used in the E-T equipment.
A.—Beginning with the leftward, the positions are Release, Running, Holding, Lap, Service-Application, and Emergency-Application.
Q. 3.-What is the effect of the Release Position ?
A.-In Release Position, main-reservoir pressure flows directly to the brake pipe, and, after an application,
releases the train brakes, but the locomotive brakes remain applied. It does not affect the normal action of the pump governor. The warning port blows.
Q. 4.-What changes occur when the handle is moved to Running Position ?
A.-The locomotive brake releases. The direct flow of main-reservoir pressure to the brake pipe is stopped; but its air, reduced by the feed valve to 70 pounds, is then supplied to the brake pipe, to the pressure chamber of the distributing valve, and the auxiliary reservoirs of the cars in the train. The pump governor remains unaffected.
Q. 5.-If the brake-valve handle had been brought from Release Position to Holding Position at once, what would have been the effect ?
A.—The effect would have been the same as in Running Position, except that in Holding Position the locomotive brake would not release.
Q. 6.-After an automatic application of the brakes on the locomotive and cars of a short train, if the brakevalve handle is placed in Running Position, what will result? If placed in Holding Position ?
A.-If the handle is placed in Running Position, the brakes on locomotive and cars will release; if in Holding Position, the car brakes only will release. In neither case will more than 70 pounds pressure flow into the brake pipe.
Handle Positions, Automatic Brake-Valve
Q. 7.—What are the maximum main-reservoir and brake-pipe pressures possible in the first three brakevalve-handle positions just referred to, as commonly used?
A.--If the brake-valve handle had been left in Release Position long enough, main-reservoir and brakepipe pressures would have equalized at 90 pounds; in Running and Holding Positions, main-reservoir pressure 90 pounds, and brake-pipe pressure 70 pounds.
Q. 8.—What results when the handle is placed in the Lap Position ?
A.—All supply of air pressure to the brake pipe is cut off. The (90-pound) excess-pressure head of the pump governor is cut out of service, and the main-reservoir pressure will be increased to 110 pounds. This condition of pump-governor action, and pressure of mainreservoir air, is maintained, also, in both application positions.
Q. 9.—What is the effect when the brake-valve handle is placed in the Service-Application Position ?
A.-Brake-pipe pressure is reduced: rapidly enough to cause the brakes of the locomotive and a train of any length to apply with service action, but not fast enough to cause quick action of any of the triple valves; the number of pounds-pressure reduction being indicated by the black hand on the large duplex gauge that registers equalizing-reservoir pressure”; after
the gauge has shown the desired amount of reduction, the handle should be returned to Lap Position.
Q. 10.-After such a graduated service reduction as alluded to, when the handle has been returned to Lap Position, will the discharge of brake-pipe pressure cease at once ?
A.-Not necessarily. With a brake-pipe air volume no greater than that of the locomotive and one or two cars, the pressure discharge will cease as soon as the brake-valve handle is brought to the Lap Position; with more than that number of cars, the discharge of brakepipe pressure will continue for a time after the brake valve has been lapped—the longer the train line, the longer will be the duration of the pressure discharge.
Q. 11. -What results when the brake-valve handle is placed quickly in the Emergency-Application Position ?
A.-In the Emergency-Application Position the brake-pipe air is heavily discharged and its pressure quickly reduced, through a large port in the rotary valve, resulting in the almost instantaneous application of every cut-in brake in the train, the triple valves operating with quick action.
Q. 12.--What differences are there as between the Air Gauges of No. 5 and No. 6 E-T Locomotive- Brake Equipments ?
A.—There are 2 air gauges in all styles of the E-T equipment; the larger is always a duplex gauge,
Handle Positions, Independent Brake-Valve
which shows main-reservoir pressure by the Red Hand, and Equalizing-Reservoir Pressure by the Black Hand; in the No. 5 equipment, the dial of this gauge reads “Red Hand Main-Reservoir Pressure,” and “Black Hand Train-Line Pressure"; while the No. 6 gauge reads the same as to the Red Hand, but states more correctly—“Black Hand Equalizing-Reservoir Pressure.” The smaller gauge is of the single-pointer style in the No. 5 equipment, the hand is Black, and indicates “Locomotive Brake-Cylinder Pressure”; in the No. 6 equipment, it is of the duplex style, and the dial is changed to read—“Red Hand Brake-Cylinder Pressure,” and “Black Hand Brake-Pipe Pressure.”
Q. 13.–Name the Positions of the Handle of the Independent Brake-Valve.
A. From the left, the Handle Positions are Release, Running, Lap, Slow-Application, and Quick-Application.
Q. 14.—Why would it be impossible to leave the handle of the independent brake-valve in Release, or Quick-Application, Positions ?
A.-Because the return spring within the valve body will automatically rotate the rotary valve from Release to Running Position, and, in the No. 6 equipment, from Quick-Application Position to Slow-Application Position.
Q. 15.-What is the result when the independent brake-valve handle is put into the Release Position ?