End of Car Systems for Heavy Haul Operations John DeppenAmsted Rail
RRIX18PENN STATE ALTOONA RAILROAD INDUSTRY EXCHANGE
PERFORMANCE-DRIVEN SOLUTIONS FOR TOMORROW’S HEAVY HAUL WORLD
RAILROAD INDUSTRY EXCHANGE CONFERENCE
John DeppenDirector EngineeringOctober 15, 2018
Amsted Ra i l : G loba l l eader in heavy hau l ra i l
• Largest manufacturer of freight car systems and components in the world
• Multi-billion dollar company• Over a century of innovation
Amsted Ra i l : Expand ing a round the g lobe
• Expansion in major markets migratingto heavy haul
• 38 locations in 10 countries, spanningover 6 continents
• Serving the world’s most challengingrailroad markets
Amsted Ra i l : V i r tua l l y every th ing under the wagon
Fu l ly in tegra ted sys tems: End-o f -ca r sys tems
• Durable protection can take all the hits• Stress tests strengthen performance • Designed to lower maintenance
cost, reduce downtime andextend service life
Systems ApproachReduce Total System / Life Cycle Costs
End of Car SystemsEnergy Management
Under Car SystemsPerformance M anagem ent
End-of-Car Product Offering
AbstractIt is typical for railcars to be assembled into a train by coupling individual cars in a marshalling or hump yard. These yards often use impact ramps or flat switching to accelerate the railcar to a velocity sufficient to roll through a series of switches and tracks to the designation train. Rail operations attempt to keep these velocities to a minimum, but unfortunately, at times impact velocities can be higher than desirable. Depending on the type of coupling system (i.e. draft gear or end-of-car cushion unit), damage to the railcar, lading or both can occur at these velocities.
Another source of damage can occur in-train, where relative velocities between railcars can become large. Train length, gross rail load, terrain and the locomotive inputs are sources for these in-train shocks along with automatic couplers and their inherent free slack. Coupling components must be designed to account for these various inputs to reduce in-train shocks to acceptable levels. Computer simulations validated through over-the-road testing is one of the tools that used to predict the performance of various end-of-car products.
As trains become longer and heavier, it is critical that coupling component manufactures understand railcar dynamics and focus their efforts on products that can reduce in-train shocks. Products such as active draft cushioning along with improvements to A.A.R. specifications will be instrumental to support global heavy haul operations.
It’s all about Energy Management…
Work = ½ MV²
Kinetic energy of moving car = Work done by End-of-Car Device½MV² = Coupler Force x Travel (Longer the Travel; Lower the Force)
lading protection from Yard Impactslading protection from In-Train
Events“Slack is the Enemy”
Lading Damage Not Limited to Yard Impacts
Where does the Energy Come From?
Coupling ImpactsProtect freight car structure Protect sensitive lading
Train OperationProtect sensitive ladingImprove train handlingPrevent high forces v. Managing high forces
Energy Management Objectives…
If not Properly Managed…
How the force is applied is important…
How the force is applied is important…
Hydraulic Cushion Unit Standard Draft Gear
6 mph Impact…Active Draft v. Draft Gear
Hydraulic Cushion Unit Standard Draft Gear
M ovem ent @ im pact: .75” M ovem ent @ im pact: 3.6”
6 mph Impact… Active Draft v. Draft Gear
162 lb. Steel Block Lading Damage Demonstration…
Cushion Unit vs. Draft Gear Application
40
M-921BM-921DM-921CRule 59
M-901EM-901GM-901BRule 21
~20% Fleet Equipped with End-of-Car Hydraulic CushioningLading Protection (automotive, paper, building materials)
Vs.
End of Car Cushion Unit v. Draft Gear
Draft Gear Basics
42
Friction Elements compress and absorb energy.Mechanical or Elastomer Springs ‘return’ unit back to neutral position.
Elastomer Elements compress and absorb energy via. Hystersis…and act as ‘return spring’
How the EOC’s work…
Inner Cylinder filled with hydraulic fluid
Piston forces oil thru special valving Nitrogen gas pushes
piston/rod back to
neutral position
AAR Specifications
M-901E Drop Hammer Required, But…must still evaluate impact performance
Unit Trains Are Exposed to Impacts…Run In/Out
Low Yard Impact Forces with Active Draft Cushion Unit
Impact Performance…Loaded Car
Heavy Haul Considerations…• Axle Load• Train Length• Terrain• General Manifest Application
• Marshalling Yard• Unit Train
• Slack is the Enemy…consider drawbars• Lading & Unloading Mechanism
• Rotary Dumper• Continuous Bottom Dump
• ECP vs. Air vs. Dynamic Braking
One Size Doesn’t Fit All…
Computer Simulations…Dumper/Startup/Braking
0
50
100
150
200
250
300
350
Force
s (klb
s)
0 10 20 30 40 50 60 70 80 90 100 110 120 Time (s)
Con. 2 Con. 52 Con. 102 Con. 152Con. 202 Con. 250 Total tractive force
2 Loco at 396 klbs, 125 Draw-Barred Pairs of Freight Cars 2x286 klbs. SL-76,Stuck at 2" of Travel with 1.25" of Travel Left, Inside and Between the Pairs.Free Slack in Coupler Connections - 6.5 in/con. Free Slack in Draw-BarredConnections - 4 in/con. Start Up. Tractive Force and Coupler Forces in SelectedConnections vs. Time
Tractive forces increase gradually, in 3 steps
This particular application, the Dum per Operation is the problem ; free slack
associated with train length created high force condition.
Solution: Reduce Coupling System Slack
Summary
‘One size fits all’ may not always be appropriate.
• Unit train v. manifest train v. ‘mini-unit train’
• Specific car performance expectations / requirements
• Autoracks, Container flats, ISO Tank Containers, Boxcars
Critical to working with RR’s, Asset Owners, Shippers…
Understand ‘energy inputs’, lading, car body sensitivity and then
recommend appropriate equipment.
Prevent High Forces vs. Managing High Forces
T h a n k Yo u
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