1. CHAPTER 4 The Locomotive

2. Steam until mid 1950’s

3. Types of Locomotives Steam Diesel-Electric Electric Hybrid

4. Two Factors Determine the Ability of a Locomotive to Start, Accelerate, and Obtain Top Speed Tractive Effort The Ability to Overcome Resistance -Starting, Grade, Wind, Curve, Rolling Tractive Force = Weight of Drivers x Coefficient of Adhesion Horse Power (mainly 1,500 to 5,000 hp) Rate of Doing Work Drawbar Horsepower: horsepower available to haul

5. Adhesion Control Grip Rail without Slipping Dependent on weather, rail conditions Controlled automatically in modern locomotive Sanding

6. Tractive Force vs. Tonnage and Grade

7. Performance Curve of the Locomotive (with train resistance for 420 tons trailing load of passenger stock)

8. Different Horsepower Ratings Not all engine power pulls train On average, 82% of power is left to pull train

9. Power Required vs. Speed and Grade

11. Diesel–Electric Locomotive Diesel Engine – Prime Mover Turbocharger / Electronic Fuel Injection Alternator / Generator / Fans / Batteries AC/DC Traction Motors

12. Locomotive Principal Components

13. Radial Trucks

14. Locomotive Controls Minimum Levers, but Connected to Circuitry “Microprocessor” Control Display Screens Interfaces with Primary Operator

15. Six Axle, approx. 390,000 pounds vs. Four Axle, approx. 260,000 pounds

16. Multiple Unit Arrangements Distributive Power / ECP Mid-Train or Rear End

17. Slugs and Mates No Prime Mover Store Excess Power Provide Weight for Tractive Effort

18. Maintenance and Life Span Most New Locomotives can Self-Diagnose Problems Different Inspections Mandatory at Daily, 92-days, Annual, and Biennial Periods Remote Diagnostics Average Locomotive Service is 20-25 Years Used to be Returned to Manufacturer, but Now Sold to Smaller Railroads

19. Genset and Hybrid Locomotives (Mainly for Switching) Genset – Multiple engine-generators per vehicle Hybrid – Operates on batteries that are charged overnight