SD-40 Operator Manual Cover

SD-40 Operator Manual Title Page





The data appearing in this manual is intended as a guide and as an aid in explaining the locomotive equipment used during operation. It is generally applicable to the basic locomotive, that is, a locomotive without optional extra equipment. Some data is also included for a number of the more frequently used extras. When special extra equipment is involved, consult specific drawings or instructions as provided by the railroad.

The information contained in this manual is based on data available when released for printing.

Minor differences encountered in equipment are due to changes made after the manual was sent to press. These changes will be covered in subsequent editions of this manual.


his manual has been prepared to serve as a guide to railroad personnel engaged in the operation of the 3000 horsepower General Motors Model SD40 turbocharged diesel-electric locomotive.

The contents are divided into four sections as follows:

A block of page numbers is allocated to each section, Section 1 starting with page 101, Section 2 with 201 and the others following in this manner. Figures are identified by section and sequence. For example: Fig. 2-3 is the third figure used in Section 2.

To obtain the most benefit from this manual, it is recommended that the sections be read in the sequence in which they appear.

Information pertaining to maintenance, adjustment, and testing is contained in the SD40 Locomotive Manual. Instructions for testing and maintenance of dividual locomotive components will remain a part of the standard EMD Maintenance Instruction bulletin series.


Model Designation SD40
Locomotive Type (C-C) 0660
Locomotive Horsepower 3000
Diesel Engine Model 645E3
- - Type Turbocharged
- - Number Of Cylinders 16 Cylinder
- - Arrangement 45 "V"
- - Cylinder Bore And Stroke 9-1/16" x 10"
- - Operating Principle 2 Stroke Cycle, Turbocharged, Unit Injection, Water Cooled
- - Full Speed 900 RPM
- - Idle Speed 315 RPM
Main Generator Model AR10-D14
- Traction Alternator (Rectified Output) AR10
- - Number Of Poles 10
- - Nominal Voltage (DC) 600
- - Frequency (at 900 RPM) 75cps
- Companion Alternator D14
- - Nominal Voltage (AC) 180
- - Number Of Poles 16
- - Frequency (At 900 RPM) 120 cps
Auxiliary Generator Voltage (DC) 74
- Rating - 10KW
Traction Motors
- Model D77
- Number 6
- Type DC, Series Wound Axle Hung
Driving Wheels
- Number 6 Pair
- Diameter 40"
Tread Tapered


Maximum Speed Options With Gear Ratio

Gear Ratio Top Speed*
62:15 65
61:16 70
60:17 76
59:18 82
58:19 88

*Based on rated RPM of traction motors.

Weight On Drivers
Air Compressor
- - Type 2 Stage
- - Number Of Cylinders 3
- - Capacity (At 900 RPM) 254 Cu. Ft./Min.
- - Air Compressor Cooling Water
- - Lube Oil Capacity 10-1/2 Gal.
Storage Battery
- - Number Of Cells 32
- - Voltage 64
- - Rating (8 Hour) 420 Amp Hr.
- - Lubricating Oil Capacity 243 Gal.
- - With Deep Sump Oil Pan 395 Gal.
- - Cooling Water Capacity 254 Gal.
- - Fuel Capacity (Basic) 3200 Gal.
- - - - With Extra Capacity 4000 Gal.
- - Sand 56 Cu. Ft.
Air Brakes Type 26L
Approximate Weight On Rails 368,000 lbs.
Major Dimensions
- - Length Between Coupler Faces 65' 9-1/2"
- - Width Over Underframe 10'
- - Overall Height - Top Of Rail To Top Of Cooling Fan 15' 7-3/16"
Minimum Curve
- - Radius Single Unit 30 degrees or 193'
- - Coupled to Standard 50' Car 17 degrees or 338'
- - Two Units Coupled 23 degrees or 250'



Introduction 101

How The Locomotive Operates 104


Introduction 201

Engine Starting Controls 201

Switch And Fuse Panel 203

AC Circuit Breaker Panel 208

Circuit Breaker Panel 208

Engine Control Panel 210

Locomotive Controller 218

Mechanical Interlocks On The Controller 228

Air Brake Equipment 230

Brake Equipment Positions 234


Introduction 301

Preparation For Service 301

Starting The Diesel Engine 306

Trailing Unit Cab Inspection 308

Starting Trailing Unit Diesel Engines 310

Placing Units On The Line 310

Precautions Before Moving Locomotive 311

Handling Light Locomotive 311

Draining Of Air Reservoirs And Strainers 312

Engine Air Box Drain 314

Remote Traction Motor Cutout Switch 315

Coupling Locomotive Units Together 315

Coupling Locomotive Units Together For
Dynamic Braking In Mixed Consists

Coupling Locomotive To Train 317

Pumping Up Air 318

Brake Pipe Leakage Test 318

Starting A Train 319

Accelerating A Train 322

Air Braking With Power 323

Operating Over Rail Crossing 323

Running Through Water 324

Wheel Slip Correction 324

Wheel Slip Light 325

Locomotive Speed Limit 325

Mixed Gear Ratio Operation 326

Dynamic Braking 327

Dynamic Brake Wheel Slide Control 330

Double Heading 330

Operation In Helper Service 331

Isolating A Unit 331

Changing Operating Ends 331

Stopping Engine 334

Securing Locomotive For Layover 335

Towing Locomotive In Train 336

Freezing Weather Precautions 337

- - Introduction 401

1. Sand Box 11. Engine Cranking Motors
2. Battery 12. Engine 16-645E3
3. Control Stand 13. Dynamic Brake Fans
4. No. 1 Electrical Cabinet 14. Equipment Rack
5. Inertial Air Filter 15. Air Compressor
6. Traction Motor Blower 16. Radiators
7. Generator Blower 17. Radiator Cooling Fans
8. Auxiliary Generator 18. Trucks
9. Turbocharger 19. Fuel Tank
10. Main Generator 20. Electrical Cabinet Air Filter

Fig. 1-1 - General Arrangement - SD40 Locomotive




The General Motors Model SD40 locomotive, illustrated in Fig. 1-1, is equipped with a turbocharged diesel engine that delivers 3000 horsepower to the main generator for tractive purposes. This power is then distributed to six traction motors, each of which is directly geared to a pair of driving wheels.

The basic locomotive is arranged and equipped so that short hood or cab end is considered the front or forward part of the unit. However, the locomotive operates equally well in either direction, and on special order controls may be arranged so that the long hood end is forward, or dual controls may be provided.

The locomotive may consist of one or more individual units, each of which is a completely functional power plant. When coupled together for multiple unit operatIon, all can be simultaneously controlled from a single set of controls located in the cab of the lead unit. This is accomplished through jumper cables connected between the units.

The general arrangement of equipment used on the SD40 locomotive is shown in Fig. 1-1. Each of the more important equipment components is numbered and identified in this illustration.

On special order, an SD locomotive can be equipped with a steam generator for use in passenger service. The fuel tank is divided into a combination fuel tank and water tank and the gear ratio at the traction motor pinion will generally be suitable for high speed operation. Operating instructions for the SD and SDP models are the same, except for those operations relating to the steam generator. Instructions for operatIon of the steam generator are provided by the manufacturer of that equipment.


The locomotive can be operated in dynamic braking U when 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 operator 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 it. 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 other 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 an SD40 locomotive in dynamic braking.


Electrical relays in a bridge circuit with traction motors are used to correct the tendency of one pair of wheels to rotate slower due to an unusual rail condition while in dynamic braking.

When a pair of wheels is detected tending to rotate at a slower speed, the retarding effort of the traction motors in the unit affected is reduced (traction alternator field excitation is reduced in the unit affected) and sand is automatically applied to the rails. 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 retarding effort of the traction motors returns (increases) to its former value. 1 Automatic sanding continues for approximately seconds after the wheel slide tendency is corrected.


Prior to double heading behind another locomotive, make a full service brake pipe reduction with the automatic brake valve, and place the cutoff valve in CUTOUT position. Return the automatic brake valve handle to the release position and place the independent brake valve in release position. On 26L equipment place the MU valve in LEAD position.

The operation of the throttle is normal, but the brakes are controlled from the lead locomotive. An emergency air brake application may be made, however, from the automatic brake valve of the second unit. Also, the brakes on this unit may be released by depressing the independent brake valve handle while it is in the release position.


Basically, there is no difference in the instructions for operating the locomotive as a helper or with a helper. In most instances it is desirable to get over a grade in the shortest possible time. Thus, wherever possible, operation on the grades should be in the full throttle position. The throttle can be reduced, however, where wheel slips cause lurching that may threaten to break the train.


When the occasion arises where it becomes advisable to isolate a locomotive unit, observe the following:

1. When operating under power, a unit may be isolated at any time, but discretion as to timing and necessity should be used.

2. When operating in dynamic braking, it is important to get out of dynamic braking before attempting to isolate the unit. This is done by reducing the braking lever (throttle) to IDLE. The isolation switch can then be moved to START position to eliminate the braking on that unit. If the braking is resumed, other units will function normally. If field loop control of dynamic brakes is being used, do not change position of the unit selector switch.


When the locomotive consist includes two or more units with operating controls, the following procedure recommended in changing from one operating end to the opposite end on locomotives equipped with 26L brakes.


1. Move the automatic brake valve handle to service position and make a 20-pound reduction.

2. After brake pipe exhaust stops, place cutoff valve in CUT OUT position by pushing dial indicator handle in and turning to the desired position.

3. Place independent brake in fully released position.

4. Place MU valve in the desired TRAIL position, depending on brake equipment on trailing units. (MU valve is located in the left hand side of the air pedestal. Push dial indicator inward and turn to desired position.)

5. Position automatic brake valve in handle off position. (Handle may be removed if so equipped.)

6. Place selector lever in OFF position.

7. Place reverse lever in neutral position and remove to lock controller.

8. At the controller, place all switches in the OFF position. Be absolutely certain that the control and fuel pump switch, generator field switch, and engine run switch are in the OFF position.

9. At the engine control panel, place headlight control switch in proper position for trailing unit U operation. Place other switches ON as needed.

10. At the circuit breaker panel, the control circuit breaker and the local control circuit breaker remain in the ON position.

NOTE: If the local control circuit breaker is inad vertently placed OFF at this time, the engine will shut down when the trainlined control circuit is re-established. However, the engine may be re-started in the normal manner after placing the local control circuit breaker ON.

11. After completing the operations outlined in the preceding steps, move to the cab of the new lead unit.



There are six ways to stop the engine.



When a locomotive unit equipped with 26L air brakes is placed within a train consist to be towed, its control and air brake equipment should be set as follows: