Locomotives Steam until

Locomotives

Steam until

Steam until

mid 1950’s

Types of Locomotives

Types of Locomotives

• Steam
• Diesel-Electric
• Electric
• Hybrid

Two Factors Determine the Ability of a Locomotive to

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

Adhesion Control

Adhesion Control

• Grip Rail without Slipping
• Dependent on weather, rail conditions
• Controlled automatically in modern locomotive
• Sanding

Different Horsepower Ratings

• Not all engine power pulls train
• On average, 82% of power is left to pull train

Diesel–Electric Locomotive

• Diesel Engine – Prime Mover
• Turbocharger / Electronic Fuel Injection
• Alternator / Generator / Fans / Batteries
• AC/DC Traction Motors

Locomotive Principal Components

Radial Trucks

Radial Trucks

Locomotive Controls

Locomotive Controls

• Minimum Levers, but Connected to Circuitry
• “Microprocessor” Control
• Display Screens
• Interfaces with Primary Operator

Six Axle, approx. 390,000 pounds

Six Axle, approx. 390,000 pounds

vs.

Four Axle, approx. 260,000 pounds

Slugs and Mates

No Prime Mover

Store Excess Power

Provide Weight for Tractive Effort

Maintenance and Life Span

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

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