Railroad Design
The Second Kuwait Metro and
Rail Conference & Exhibition
April 17, 2012
Understanding Railroads HDR, Inc. © Copyright March, 2012
Outline of Presentation
•Railroad Design –Understanding Railroads
–Rail Infrastructure Types
–Yards and Facility Design
–AREMA and UIC Standards
Understanding Railroads HDR, Inc. © Copyright March, 2012
What Is Special About Railroading?
• Trains covey a lot of freight and passengers quickly
and efficiently
– Trains - 18,000+ tons and over 2 miles long.
– Rail is a “GREEN” - 1 ton / 500 miles / 1 gallon or
1 metric ton / 833 KM / 4 liters.
• IEA estimates global averages for carbon intensity, by
those estimates:
– Passenger rail has 4 to 6 times lower carbon emissions
then air transportation.
– Freight rail has 7 to 13 times lower carbon emissions then
long distance trucking.
HDR Railroad Design
Understanding Railroads
Understanding Railroads HDR, Inc. © Copyright March, 2012
USA Rail Design Standards
AREMA
Means
American Railway Engineering & Maintenance
Association.
AREMA has committees with representative of all
North American Railways to offer guidance on the
design specification of railways and operational
components
Understanding Railroads HDR, Inc. © Copyright March, 2012
Europe Standards
UIC International Union of Railways, is an
international rail transport industry body
(French: Union Internationale des
Chemins de fer)
Understanding Railroads HDR, Inc. © Copyright March, 2012
AREMA and UIC Standards
• AREMA
– American Railway Engineering and Maintenance-of-Way
Association
– merger of three engineering support associations
• UIC
– (French: Union Internationale des Chemins de fer), or
International Union of Railways, is an international rail
transport industry body.
• North American rail system is one of the premier freight
hauling systems, the cost to move a ton of freight are
the lowest in the world.
HDR Railroad Design
Rail Infrastructure Types
Understanding Railroads HDR, Inc. © Copyright March, 2012
Design Elements UIC and AREMA
• Track Roadbed and bridges
• Track Work, Spirals and Curves
• Clearances for the width and height of the train
• Locomotives
• Freight Cars (Wagons)
• Train Lengths, Trailing Tonnage and Train
Dynamics
• Construction Costs and Operating Cost
Understanding Railroads HDR, Inc. © Copyright March, 2012
Main Line Track
Understanding Railroads HDR, Inc. © Copyright March, 2012
Infrastructure Track Design Types Requires Different Design Standards
• Main line (differing traffic densities)
• Branch line or side tracks
• Yard lead
• Yard body tracks
• Industry lead tracks
• Industry spur tracks
• Shop tracks
Understanding Railroads HDR, Inc. © Copyright March, 2012
Multiple Main Line Track & Siding Track
Understanding Railroads HDR, Inc. © Copyright March, 2012
Types of Yards
• Classification yards
– Flat switching
– Hump or mini-hump
• Receiving yards
• Departure yards
• Storage or staging yards (coal, grain, other unit trains)
• Intermodal yards (COFC, TOFC, autos)
• Shop or maintenance yards
Understanding Railroads HDR, Inc. © Copyright March, 2012
Yard Tracks
HDR Railroad Design
Yards and Facility Design
Understanding Railroads HDR, Inc. © Copyright March, 2012
The Yard - Definition
• A system of tracks other than the main tracks and
sidings used for storing cars and assembling, sorting,
classifying and forwarding trains.
Understanding Railroads HDR, Inc. © Copyright March, 2012
Storage or “SIT” Yard
• Store excess equipment
• “Storage-in-Transit” for product awaiting sale or distribution
Understanding Railroads HDR, Inc. © Copyright March, 2012
Local Yards
• Small yard used to sort and hold cars for nearby customers served by a “local” switching run
Understanding Railroads HDR, Inc. © Copyright March, 2012
Branch Line Track
Understanding Railroads HDR, Inc. © Copyright March, 2012
Terminal or Division Yard
• “A facility for separating trains or cuts of cars via prearranged plans for distributing the cars in blocks according to destinations, routes or commodities.”
• Where most non-unit trains start and end their runs
Understanding Railroads HDR, Inc. © Copyright March, 2012
Mini-hump Classification Yard
• Similar track arrangement to flat switching yard
•Mini-hump
•Dowty piston retarders
•-0.5% •Crest
Understanding Railroads HDR, Inc. © Copyright March, 2012
Major Retarder Hump Classification
• Tracks spread from hump in a “fan”
•Major retarder hump
•Master
•retarder
•Group
•retarders
•Crest
•Tangent point
•retarders
Understanding Railroads HDR, Inc. © Copyright March, 2012
Standard Ladder
• Standard ladders
Understanding Railroads HDR, Inc. © Copyright March, 2012
Typical Track Section
Understanding Railroads HDR, Inc. © Copyright March, 2012
Track Roadbed and Bridges
Basic Design Criteria:
Track consists of two steel rails that are 56 ½ inches apart, supported by timber or concrete crossties, resting on rock ballast and sub-ballast, which, in turn, rests on sub-grade or embankment of the land.
The track structure must support loads generated by modern heavy-haul freight trains, which can weigh 17,000 tons or more and each wheel which carries 36,000 pounds or 18 tons
Understanding Railroads HDR, Inc. © Copyright March, 2012
AREMA Design Limits
Track Structure Stresses •Wheel-Rail Contact Stress ~ 100,000 PSI
• Rail Bending Stress < 25,000 PSI
• Tie Bearing Stress < 200 PSI
• Ballast Bearing Stress < 85 PSI
• Sub-grade Bearing Stress < 20 PSI
Understanding Railroads HDR, Inc. © Copyright March, 2012
AREMA Design Limits Cont
Track Loading Range •Lateral Loads up to 15,000 lbs (side load against inside of rail)
•Vertical Loads up to 36,000 lbs per wheel (Dynamic impact ~ 3X)
•Longitudinal forces up to 20,000 lbs per rail (along the rail traveling direction of the train)
Bridge Loading Rating –
Cooper E 80 (design for two 4 axle driving engines weighing 284 tons each and pull a 8,000 lb per linear foot loaded train
HDR Railroad Design
UIC versus AREMA
Design Standards
Understanding Railroads HDR, Inc. © Copyright March, 2012
UIC verses AREMA Design Standards
• How to compare
– Track Roadbed and Bridges
– Track Work, Spirals and Curves
– Clearances for the width and height of the
train
– Locomotives
– Freight Cars (Wagons)
– Train Lengths, trailing tonnage and train
dynamics
Understanding Railroads HDR, Inc. © Copyright March, 2012
AREMA - UIC
PARAMETERS UIC AREMA
Axel Loading 22-25 TPA
(Metric)
35.7TPA (English)
32.4 TA (Metric)
Bridge Rating 25 TPA Cooper E-80 Exceeds TPA
requirements
Width Clearance W 3150 mm (10’-4”) W3251mm (10’-8”)
Height Clearance 3175 mm (10’-4”)
rising to 4280mm
14’-1/2” at track Center above
top of rail
Plate H
6147mm
Provide 20’-2” Min. above top of
rail
Curvature 750 m curve radius 2 degree, 19
min Maximum curvature
267 m curve radius 6 degree Max
curvature
Cant 120 mm Max. (4.72 in) 76.2 mm max (3 inches)
Design Speed /Low Freight 120 kph Design speed
80 kph Operating Speed
120 kph Design Speed
120kph Operating Speed
Recommend Specific Curve
Speed in Mountain Grade
Draft Gear Tensile Strength 224,800 pounds(lbs)
191,080 for screw type
350,000 lbs standard
650,000 lbs Heavy Duty
Understanding Railroads HDR, Inc. © Copyright March, 2012
Railway Design Standards
AREMA Standards will: • Provide for Railway that can handle the heavier axle loads
• Provide Freight Car equipment that can carry the most freight per
car (both in tonnage and in cubic capacity)
• Provide for the longest size of trains and reduce daily operating
costs
• Provides for an open international market for suppliers of
locomotives and freight cars to bid and compete in pricing to
supply the highest quality and lowest cost equipment to the
Middle Eastern countries.
• Provides the flexibility to operate Double Stacked rail transport
versus single stacked trailer on flatcar (TOFC) or container on
flatcar (COFC).
Understanding Railroads HDR, Inc. © Copyright March, 2012
North American Double Stack train
Understanding Railroads HDR, Inc. © Copyright March, 2012
North American Auto Train
Provides for the loading of up to 15 automobiles or 10 trucks or SUV into a single fright car
Railroad Design
Questions