CE 515 Railroad Engineering
Rolling Stock: Locomotive
Source: Armstrong Ch 4
AREMA Ch. 2.6
“Transportation exists to conquer space and time -”
What is a Locomotive?
• A Vehicle which Provides the Motive Power to
the Train
• Almost All Trains Use One or More
Types of Locomotives
•
•
•
•
•
Steam
Diesel-Electric
Electric
Hybrid
This Discussion will
Focus on Diesel-Electric
http://www.brookvilleequipment.com/forum/viewtopic.php?t=80
Tractive Effort
• The ability to Overcome Resistance
– Starting
– Grade
– Wind
– Curve
– Rolling
• Is Discussed Further in REES #3
Tractive Effort
Adhesion Control
• Grip Rail without
Slipping
• Dependant on weather,
rail conditions
• Controlled
automatically in
modern locomotive
• Sanding
http://science.howstuffworks.com/diesel-locomotive3.htm
Power to Pull Train
• Not all Engine Power
Pulls Train
• Powering Auxiliary
Devices, Efficiency
Losses, Pulling
Locomotive Itself
• On Average, 82% of
Power Left to Pull Train
Locomotives Today
• Used Today on Class I
– Endcab Switcher (5%)
– Four-Axle Road Switcher
(20%)
– Six Axle Medium
Horsepower Road
Switcher (15%)
– High Horsepower SixAxle Road Switcher
(55%)
Prime Mover (Engine)
• V-8 to V-20 Diesel
Engine
• Idle at 300 rpm, Full
Power 900-1050 rpm
• Alternator Converts into
Electrical Energy for
Traction
– AC produced, converted
to DC (and converted
back for AC)
http://www.vistacorpofva.com/images/engine1.jpg
What Locomotive Carries
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•
•
•
Engine Cooling Water: 325 gallons
Engine Lube Oil: 450 gallons
Diesel Fuel: 5000 gallons
Sand: 1.5 tons
Traction Power System
•
•
•
•
DC is used for 80% of Fleet
What Actually Drives the Wheels
Since 1990’s AC is Gaining Ground
AC Offers Greater Power
– However, Most Have Gone Back to Regular Power
– Used Mainly in Heavy Haul
Emissions
• 1998-EPA Issues Final
Emission Standards
– Applies to Newly
Manufactured and
Remanufactured
Locomotives After
January 1, 1973
• Tier Based on
Manufacture Date
• Plus Tiers for
Remanufacture
http://www.epa.gov/oms/regs/nonroad/locomotv/420f09025.pdf
Locomotive Controls
• Minimum Levers, but
Connected to Circuitry
• “Microprocessor”
Control
• Display Screens
• Interfaces with Primary
Operator
Four vs. Six Axles
• Why Have 6 Axles when
4 can Haul More
Tonnage?
– Adhesion at Higher
Speeds and Grades
– Starting up?
Maintenance and Life Span
• Most New Locomotives can Self-Diagnose
Problems
• Different Inspections Mandatory at Daily, 92days, 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
Videos / Websites
• How Diesel-Electric Locomotive Works:
http://www.youtube.com/watch?v=L8MxASJoC4M
• Modern Marvels: Freight Trains (go to 5:00 for Sand
Operations) (Evan Vencil):
http://www.youtube.com/watch?v=h6ozfxDeXII&feature=rela
ted
• http://science.howstuffworks.com/diesel-locomotive3.htm
(Nicole Oneyear)
• http://www.thedieselshop.us/DS.html (Ben Hucker)
• http://www.nrm.org.uk/OurCollection/LocomotivesAndRollin
gStock.aspx?ipp=12&cat=All&comp=All (Na Ning)