GP9-1- 154                                                   DESCRIPTION

SECTION 2

OPERATION

The successful and dependable operation of the locomotive is dependent upon the quality of inspection and repair at regular maintenance periods, as well as the proficiency of the operating crews. As a supplement to the regular terminal maintenance, a "pre-service check" should be made by the engine crew upon boarding the locomotive.

BASIC INFORMATION

200 When Boarding the Locomotive

201 Precautions Before Starting Engine

The following items should be performed when an engine is to be started after a layover.

202 To Start Engine After completing the items mentioned in Art. 201, the engine is started by performing the following steps:

203 Placing An Engine On The Line Before the engineman can control the speed of the engine with the throttle lever, the engine must be placed "on the line," and the "Engine Run" circuit breaker must be in the "ON" position.

  • 1. After the oil pressure has built up, the engine is placed "on the line", by merely placing the isolation switch in the RUN position, Fig. 2-4.
  • 2. If an engine has been taken off the line for any reason, DO NOT place it "on the line" if the locomotive is being operated in dynamic braking.

Starting Engine - Fig. 2-3


Placing Engine On-the-Line - Fig. 2-4

204 To Stop Engine There are three ways of stopping engine; these can be designated as (1) normal (2) under power and (3) emergency.

  • 1. Normally stopping an engine applies when the locomotive is standing still. In this case place the isolation switch in the Start position and press in on the Stop button, in the electrical cabinet, until engine stops, Fig. 2-5.
  • 2. Under power, in dynamic braking, or whenever necessary, an engine can be taken "off the line" by pulling the engine manual Layshaft closed until the engine stops, Fig. 2-6. After stopping the engine, place the isolation switch in the Start position.
  • 3. In an emergency all engines "on the line" are simultaneously stopped by pulling the throttle lever away from the controller, Fig. 2-7, and pushing the throttle lever as far forward as possible to the right to Stop position.

Stopping Engine Fig. 2-5


To Stop Engine Fig. 2-6

When engines are shut down in this manner, the "Blue" alternator failure light will light up and the alarm bells will ring. The isolation switch must be placed in "Start" on each unit to silence the bells and extinguish the lights.

205 Securing Locomotive for Layover


To Stop Engine - Fig. 2-7
  • 4. Place all the circuit breakers at the engineman's control panel in the OFF position (down).
  • 5. Open all the knife STOP switches and circuit breakers in the electrical cabinet.
  • 6. Apply hand brake and block the wheels, if necessary.
  • 7. Cover the exhaust stacks, if there is danger of a severe rain.
  • 8. Take the proper precautions against the freezing of the cooling system water in cold weather, see Art. 221.

HANDLING LOCOMOTIVE

206 Precautions Before Moving Locomotive

207 Handling Light Locomotive With the engines placed "on the line" and cab preparations completed the locomotive is handled as follows:

208 Coupling To Train and Pumping Up Air After coupling to a train, stretch coupling to make sure it is properly made. If main reservoir pressure falls below feed valve setting when brakes are cut in, proceed as follows:

209 Starting a Train Starting a train depends not only on the kind of locomotive being used, but also on the type, length, weight, grade, weather conditions and the amount of slack in the train. Because of the locomotive's very HIGH STARTING TRACTIVE EFFORT is important that the air brakes be COMPLETELY released before attempting to start the train. Actual tests have shown that a 100 car train, having the average uniformly distributed leakage, may require 9 minutes to completely release the brakes. It requires aproximately 30 minutes (with 130 pound main reservoir ressure) to completely charge a depleted air system on similar 100 car train.

The Load indicating meter, Fig. 2-8, can be used s a PULL METER to judge the tractive effort of the locomotive. Merely looking at the ground and listening the engine exhaust may give a false indication of the locomotive's draw bar pull.

The GP9 locomotive is designed to have about the ame rapid yet smooth power build-up characteristics (previous Model GP7 and other EMD locomotives having governors set for a modified maximum field start.

As the throttle is open to the first notch, a definite over build up will be noted. Any further advancement of the throttle is accompanied by an almost immediate additional increase in power. This may be seen by observing the speed with which the Load indicating meter responds to throttle advance.

Load Indicating Meter Fig. 2-8

With a power control of this type the rate and extent of power build-up is left largely to the desire of the engineman yet is still controlled by the load regulator V and engine governor.

When ready to start, the following general procedure is recommended:

NOTE: If the wheel slip indicator flashes continuously, reduce the throttle one notch. Apply sand as needed to prevent further slipping and reopen the throttle when rail conditions improve. See Art. 210 - Automatic Sanding In Power.

Although it will generally be unnecessary to take slack in starting, there will be cases where it is wise to do so, after making sure that all brakes are released. The throttle should be opened one notch at a time, in starting the train. A TONNAGE TRAIN SHOULD BE STARTED IN AS LOW A THROTTLE POSITION AS POSSIBLE, BEARING IN MIND THAT THE SPEED OF THE LOCOMOTIVE MUST BE KEPT AT A MINIMUM UNTIL THE TRAIN HAS BEEN STRETCHED. Sometimes it is advisable to reduce the throttle a notch or two the moment the locomotive begins to move, in order to prevent stretching the slack too quickly. The engineman must be the judge of the acceleration and the conditions under which the train is being started.

When the locomotive has moved far enough to completely stretch the train, the throttle may be advanced as quickly as desired, but should not be advanced so quickly that slipping results. Smooth acceleration is obtained by opening the throttle one notch each time the pointer of the load meter begins moving to the left.

210 Automatic Sanding in Power GP9 locomotives are equipped with automatic sanding in power to assist in controlling wheel slip. When operating in transition one (1) (as in starting a train) sanding automatically takes place while slip is in its "creep' or initial stage. In this manner a wheel slip is "anticipated" and prevented before any appreciable loss of tractive effort occurs.

In transition 2, 3, and 4 (and on some occasions in transition 1) automatic sanding, caused by wheel slip, is ccompanled by a reduction in main generator output.

Duration of sanding, after the wheel slip or creep has stopped, is controlled by the setting of a time delay sanding (TDS) relay. An off-on circuit breaker switch on the engineman`s control panel cuts in or out this sanding-in-power feature.

With the automatic sanding feature "cut-in" (Auto Sanding circuit breaker in ON position) throttle reduction to avoid repeated wheel slip will rarely be necessary. Also, manual operation of the sanders by the engineman at points on the road where slippage is likely to occur can be eliminated.

211 Acceleration of a Train After the throttle is in the 8th notch and the train begins to accelerate, the indicating meter pointer will move slowly to the left. Forward and backward transition will automatically take place without any attention on the part of the engineman, other than necessary throttle reductions to keep under any speed restriction.

212 Slowing Down Because of a Grade As the train slows down on a grade the pointer on the indicating meter will move slowly toward the right. Backward transition will take place automatically.

213 Locomotive Operation At Very Slow Speeds The operation of a GP9 locomotive, regardless of gear ratio, is not governed by any specific short time ratings.

In most cases, the locomotive may be operated up to the limit of the adhesion attainable.

GP9 locomotives pulling tonnage trains at very slow speeds should be operated with the throttle in Run 8 position. In the event of a wheel slip indication (wheel slip light flashes on), the locomotive wheel slip control system will automatically apply sand to the rails (Auto Sanding circuit breaker in ON position) and reduce power to a point where slipping stops. If continuous wheel slipping on sand occurs, due to unusual rail operating conditions, the throttle can be reduced for short periods. Under these circumstances, the GP9 locomotive can operate at reduced throttle, provided it is not necessary to reduce below the 5th throttle notch to correct for a continuous wheel slip. If slipping persists, tonnage should be reduced.

If there are any questions about an unusual operation of the locomotive, such as a passenger locomotive operating in freight service, Electro-Motive will, upon request, analyze the actual operation and make specific recommendations.

BRAKING

214 Air Braking With Power The method of handling the air brake equipment is left to the discretion of the individual railroad. However, when braking with power it must be remembered that for any given throttle position the draw bar pull rapidly increases as the train speed decreases. This pull might become great enough to part the train unless the throttle is reduced as the train speed drops. Since the pull of the locomotive is indicated by the amperage on the load meter, the engineman can maintain a constant pull on the train during a slow down, by keeping a steady amperage on the load meter. This is accomplished by reducing the throttle a notch whenever the amperage starts to increase. It is recommended that the hidependent brakes be kept fully released during power braking. The throttle MUST be in Idle before the locomotive comes to a stop.

MISCELLANEOUS OPERATING

INSTRUCTIONS

215 Multiple Unit Operation In operating GP9 units in multiple with each other or with GP7 units, the operating controls of the locomotive are set up as outLined in Art. 217. When setup for multiple unit operation, the following operating precautions should be observed.

If the units of the consist are of different gear ratios, the locomotive should not be operated at speeds in excess of that recommended for the unit having the lowest maximum permissible speed.

If some of the units in the consist have an overload short time rating, the locomotive operation should be governed by the overload short time rating of the unit having the highest minimum speed.

216 Uncoupling and Coupling Units in Locomotive

217 Changing Operating Ends When the consist of the locomotive includes two or more units with operating controls, the following procedure should be followed in changing from one operating end to the opposite end.

NOTE: When the 6BL brake is equipped with safety control foot pedal or automatic train control, the N-1-A brake application valve is used. The three-position brake valve cut-out cock (double heading cock) is mounted on this N-1-A brake application valve instead of on the automatic brake valve. This cut-out cock is accessible through a small trap door in the cab floor.

218 Handling Locomotive Dead-In-Train A dead locomotive unit that is physically and electrically connected to the locomotive units pulling the train requires no special handling to move it over the road. In such cases the engine is shut down, the unit isolated and the controller handles removed as they should be in all but the lead unit.

In cases where a dead locomotive unit is placed in a train for movement from one location to another, it will be necessary to make some adjustments to the air brake system which will allow the air brakes on the dead locomotive unit to function like that of the cars in the train. In addition to this, attention should be given to certain items in the electrical system prior to moving locomotive unit dead in a train. All of these preparations are outlined below.

Double Heading Cock Positions - Fig. 2-9

219 Doubleheading Prior to double heading behind another locomotive, make a full service brake pipe reduction with the automatic brake valve and close the double heading cock. On Locomotives equipped with 24RL brake, leave the Rotair valve in FRGT. or PASS. position depending upon the service required. Return the automatic brake valve handle to the running position and place the independent brake valve in release position. The operation of the throttle is normal, but the brakes are controlled from the lead locomotive. The engineman on the second locomotive may make an emergency application of the brakes with automatic brake valve, and/or may release his locomotive brakes by depressing the independent brake valve handle, in the release position.

220 Operation In Helper Service Basically, there is no difference in the instructions for operating the GP9 locomotive as a helper or with a helper. In most cases the GP9 locomotive can be operated in either service up to the limit of the adhesion attainable. The throttle can be reduced to prevent excessive wheel slip, [or short periods, but the locomotive should not be operated below the 5th throttle position.

If other Diesel Locomotives having overload short Lime ratings are used with the GP9 Locomotive in helper service, their operation will be governed by the permissible length of time the locomotives can operate at the short time ratings.

To obtain a maximum tonnage rating for any single application, Electro-Motive will, upon request, analyze the actual operation and make specific tonnage rating recommendations.

221 Freezing Weather Precautions In freezing weather, precautions must be taken to see that water in the locomotive does not freeze when the engine is shut down for any reason. If trainline steam is not available, the entire system will have to be drained.

222 Operation Over Railroad Crossings When crossing railroad crossings, reduce throttle to the 5th notch before reaching crossing and Leave reduced until all locomotive units are over crossing. This will reduce arcing from the brushes to the motor commutator.

223 Running Through Water Under ABSOLUTELY NO circumstances should the locomotive pass through water which is deep enough to touch the bottom of the traction motor frames. When passing through water, always go at a very slow speed (2 to 3 miles per hour). Water any deeper than three inches above the top the of rails is likely to cause damage to the traction motors.

224 Resetting PC Switch After Safety Control Application

225 Ground Relay Action When this protective device is tripped the engine will not speed up when throttle is opened and no power will be developed; the alarm bell will ring and the ground relay light (White) on the engineman`s control panel will be on. If the ground relay trips, while the throttle is in Run 5 or 6, the engine will stop. To reset: isolate engine, depress relay reset button and put engine "on the line." If relay continues to trip isolate unit.

226 Wheel Sup Indication The wheel slip light will flash on immediately when a pair of wheels has slipped. The detection of wheel slip action automatically reduces the application of power to stop the slipping; the power will be reapplied after slipping has stopped.

It will generally be unnecessary to reduce the throttle because of momentary wheel slip action. Sand may be applied to prevent repeated wheel slipping which may occur under extremely poor rail conditions.

227 Indication of a Pair of Wheels Sliding If one pair of wheels should slide when starting a train, the wheel slip light will flash on and off intermittently. As the train speed increases, the light will stay on more or less continuously and will not go out when the throttle is reduced. The light will go out when throttle is closed to idle.

If sliding is suspected, the engine crew should make an immediate investigation to determine the cause. The wheels may be sliding due to a locked brake, a broken gear tooth wedged between the pinion and ring gear, etc.

Repeated ground relay action, accompanied with unusual noises such as continuous thumping or squealing, may also be an indication of serious traction motor trouble that should be investigated at once.

IF AN ENGINE MUST BE ISOLATED BECAUSE OF REPEATED WHEEL SLIP OR GROUND RELAY ACTION, DO NOT ALLOW THAT UNIT TO REMAIN IN THE LOCOMOTIVE CONSIST UNLESS IT IS CERTAIN THAT ALL OF ITS WHEELS ROTATE FREELY.

228 Air Box Drains The engine air box accumulation settles in two drain tanks incorporated in the engine oil pan near the generator end, one on each side. Two air box drain valves, Fig. 2-10, permit draining of these tanks. The tanks should be drained periodically when the locomotive is standing still. With the air box drain valves open, observe the drain pipe discharge under the locomotive to determine if there is any water or an excessive oil accumulation in the air box. If a discharge Is observed from the drain pipes under the locomotive with the air box drain valves closed (accumulation flowing through overflow pipe), the air box accumulation should be investigated.
Air Box Drain Valve
Fig. 2-10

OPERATION OF LOCOMOTIVE "EXTRAS"

GP9 locomotives can on special order be equipped with dynamic brakes, hump speed control, motor lockout switches and dual cab controls.

229 Dynamic Brake Operation Dynamic braking is an electrical hookup used to change some of the power developed by the momentum of a moving locomotive into an effective holding brake. The traction motor armatures, being geared to the axles, are rotating whenever the train is moving. When using dynamic brake, electrical circuits are set up which change the traction motors into generators. Since it takes power to rotate a generator, this action retards the speed of the train. The dynamic brake is, in effect, very similar to an independent brake, and the load indicating meter serves the purpose of a "brake cylinder pressure gauge."

In descending a grade, with throttle in Idle position, drawbar "push" of the trailing train tonnage moves the locomotive forward. If no resistance other than the locomotive and the wheel friction is exerted against this "push," the momentum of the train on the descending grade would soon reach a speed where the train brakes would have to be applied. In dynamic brake, a resistance to this drawbar push is set up which in effect "holds back" the speed of the train as would the application of the locomotive independent brake. The effect of the resistance is to slow down the traction motor armatures being driven by the "push" of the train.

The resistance set up in each traction motor is a magnetic field through which the traction motor armature must rotate. Increasing the strength of the magnetic field will effect a "slow down" of the traction motor armature, thus holding back the train. The magnetic field is produced by connecting the traction motor fields of each unit in series with the main generator, and passing a current through these fields. The strength of the magnetic field is varied by varying the main generator current to the traction motor fields in each unit.

The main generator battery field of each unit in the locomotive consist is connected in series to the low voltage supply of the lead unit. This is called the "field loop" circuit. Movement of the selector lever in the lead unit into the "B" braking position, sets up the controller for the throttle lever to control the position of the load regulator which in turn regulates the main generator battery field current for dynamic braking. The throttle moves a 499 ohm rheostat which acts through a micropositioner relay (LRP), Fig. 2-11, to position the load regulator. Moving the throtUe lever toward the 8th notch and away from idle increases the effectiveness of the "holding brake." Thus, In effect, the strength of the traction motor field in which the traction motor armature must rotate is controlled by the throttle lever.

In dynamic braking, the traction motor armatures are connected to grids located in the top of the carbody. Rotation of the armature through the magnetic field generates power (braking current) and this current flows through the grids to be dissipated as heat. The current generated increases as the armature rotation increases (momentum of train increases the drawbar push) or as the strength of the magnetic field is increased. The maximum braking current that can flow through the grids is automatically limited to 700 amperes regardless of locomotive speed or throttle lever position.

To operate the dynamic brake on locomotives so equipped, proceed as follows:

NOTE: The most effective use of the dynamic brake is between 15 and 25 miles per hour depending on the gear ratio. Speed on grades should not be allowed to creep up" by careless handling of the brake, as this is a holding brake and is not too effective in slowing down heavy trains on steep grades.

GP9 locomotives can be operated in dynamic braking coupled to older units that are not equipped with brake current limiting regulators. If all the units are of the same gear ratio, the unit having the lowest maximum brake current rating should be placed as the lead unit in the consist. The engineman can then operate and control the braking effort up to the limit of the unit having the lowest brake current rating, without overloading the dynamic brake system of a trailing unit. The locomotive consist MUST always be operated so as not to exceed the braking current of the unit having the lowest maximum brake current rating.

Units equipped with dynamic brake current limiting regulators can be operated in multiple with GP9 locomotives in dynamic braking regardless of the gear ratio, or difference in the maximum brake current ratings.

Units not equipped with dynamic brake current limiting regulators and of different gear ratios will require special operating instructions when used in multiple with a GP9 locomotive in dynamic braking.


Unit Selector Switch -- Fig.2-12


Dynamic Brake Grid Blower -- Fig. 2-13

230 Dynamic Brake Selector Switch The dynamic brake unit selector switch, Fig. 2-12, located at the engineman`s control station, has four positions (1, 2, 3 and 4) and should be set to correspond with the number of units in the locomotive consist. This switch should be set before leaving the terminal and must not be changed even if an engine is isolated enroute. This switch is changed only if number of units in the locomotive consist is changed.

231 Dynamic Brake Warning Light In dynamic braking, the wheel slip light on engineman's Control panel is also used to indicate an excessive braking current. Generally, the over-current is only temporary, and the dynamic brake current limiting regulator will automatically reduce the braking current to a maximum 700 amperes.

232 Dynamic Brake Grid Blower The grids are cooled by a motor driven fan, Fig. 2-13. The grids and fan are located in the top of the carbody directly above the center of the engine. Power generated by the No. 1 and 3 traction motors drives the grid blower motor.

233 Dynamic Brake Wheel Speed Control The relays used to correct a wheel slip while under power are also used to correct the tendency of one pair of wheels to rotate slower while in dynamic braking due to an unusual rail condition.

When a pair of wheels is detected tending to rotate at slower speed, the retarding effort of the traction motors in the unit affected is reduced (main generator battery field excitation is reduced in the unit affected) and sand is automatically applied to the rails ("Automatic Sanding" circuit breaker on engineman's control panel must be in "ON" position). When the retarding effort of the traction motors in the unit is reduced, the tendency of the wheel set to rotate at a slower speed is overcome. After the wheel set resumes normal rotation, the retardlng effort of the traction motors returns (increases) to its former value. Automatic sanding continues for Approxlmately 10 seconds after wheel speed is corrected.

234 Hump Speed Control When used, the electrical hump speed control circuit controls the positioning of the load regulator in order to maintain constant loconotive speed regardless of the number of cars in the train. The hump speed controls are shown in Fig. 2-14.

Hump Speed Control -- Fig. 2-14

To set the hump control circuit into operation, bring the throttle out as far as possible, consistent with desired train speed and adequate cooling air to the traction motors. Leave it in that position for the remainder of the hump operation. Turn the hump control toggle switch to its ON position and adjust the rheostat knob, Fig. 2-14, to give the exact desired speed. Once the desired train speed is reached, there should be no need to move the knob again. If an extremely long train is to be handled, it may be necessary to trim the amount of battery field excitation to reduce speed after a substantial number of cars have been released. This can be accomplished by turning the hump control rheostat slightly toward decrease until the desired train speed is regained.

As shown in Fig. 2-15, the hump control circuit is a bridge type, between the two ends of the hump control rheostat on one side and the load regulator and battery field on the other side. The diesel engine governor pilot valve tries to force the load regulator toward maximum field in an effort to load the engine by increasing main generator excitation. This is especially true after the number of cars in the train is substantially reduced. The minute the load regulator moves toward maximum, the circuit, Fig. 2-15, becomes unbalanced and a current begins to flow in the hump control relay (HCR) from 1 to 3. This action closes the 8-6 contact of the relay which completes a circuit to the ORS solenoid in the governor. ORS forces the pilot valve back to its original position and restores the balanced circuit. A constant locomotive speed is maintained in the face of a constant reduction in horsepower requirement.

In order that full load regulator effectiveness can be utilized, a hump relay (HR) becomes energized when the hump control toggle switch is turned to its ON position. The A-B interlocks of HR complete a circuit to the load regulator control relay (LRC). The E-F interlocks of LRC in turn open to remove the resistance from around the load regulator.

Schematic Hump Control Circuit
Fig. 2-15

235 Motor Lock-Out Switches Traction motor lockout switches, Fig. 2-16, permit cutting out of a W grounded traction motor. Locomotive operation could then continue on the remaining three motors. These switches are applied to each reversing contactor, RVF1, RVF2, RVR3 and RVR4. The switch mechanically positions the reversing contactor in mid-position to disconnect the traction motor from its circuit. Through interlocks, the switch establishes the necessary circuits for operation on the remaining motors. Never cut out more than one motor at any time and always make sure all motors are free to rotate. Always isolate unit before moving the lock-out switch.
Motor Lock-Out Switch -- Fig. 2-16

236 Dual Cab Control Operation Dual cab controls permit locomotive operation from either control station, allowing the engineman to choose his station depending on the direction which locomotive is operated.

Two identical control and brake stands are provided. Both are equipped with load indicating meters but only one control stand is equipped with a speed recorder; the other stand has a speed indicator. This allows the engineman to observe his speed at either control stand. If the locomotive is equipped with overspeed control, the speed recorder will govern the maximum speed regardless of locomotive direction.

The circuit breakers on the two engineman s control panels in the cab of these locomotives are connected in series; the proper circuit breakers at both control stations must be in the "ON" position in order to operate the locomotive.

To facilitate the operation of the various circuit breakers in the two control panels it is recommended that ALL circuit breakers at the NON-OPERATING control station be placed in the "ON" position. The engineman may then turn on ONLY those circuit breakers at the OPERATING control station that are necessary for the operation of the locomotive. In this manner the engineman will be able to instantly turn "ON" or "OFF" any item from the operating control station where he is located.

When changing operation from one control station to the other the procedure for handling the throttle, selector and reverse levers and the brake equipment is the same as that given for changing ends (Art. 217) with the following exceptions:

When changing ends in multiple unit operation, the procedure outlined in Art. 217 must be followed completely, with the understanding that all circuit breakers at the dual control stations are to be placed in the "OFF" position in the unit that is being made inoperative.

237 Brake Pipe Flow Indicator A brake pipe flow indicator is a very useful supplement to locomotive air brake equipment. The indicator provides the engineman with the following desirable indications:

The flow indicator consists of a duplex gauge case and bezel with a special movement, and employs bourdon tubes with enough sensitivity to indicate differentials encountered during the various brake operating conditions. This is accomplished by measurement of differential pressures across the feed valve, which would indicate the degree of work the feed valve was required to do in order to supply the demand of the brake pipe.

Figs. 2-17 through 2-22 explain the use of the indicator by illustrating the position assumed by the gauge under various conditions.

Uncharged Train Or Dead Brake Pipe
Fig. 2-17 		Partially Charged Train, Or Reduction Made From Rear End Of Train
Fig. 2-18
Brakes Released And Train Charged, Ready For The Initila Brake Test
Fig. 2-19 		Continuous Leakage In A Charged Train
Fig. 2-20
Charged Brake Pipe With No Leakage
Fig. 2-21 		After An Emergency Application
Fig. 2-22