U.S. Department of 

Transportation

Federal Railroad 

Administration

HIGHER SPEED FREIGHT TRUCK DESIGN

PERFORMANCE REQUIREMENTS

Office of Research

and Development

Washington, DC 20590

DOT/FRA/ORD-13/41 Final Report

October 2013
NOTICE

This document is disseminated under the sponsorship of the 

Department of Transportation in the interest of information 

exchange. The United States Government assumes no liability for 

its contents or use thereof. Any opinions, findings and 

conclusions, or recommendations expressed in this material do not 

necessarily reflect the views or policies of the United States 

Government, nor does mention of trade names, commercial 

products, or organizations imply endorsement by the United States 

Government. The United States Government assumes no liability 

for the content or use of the material contained in this document.

NOTICE

The United States Government does not endorse products or 

manufacturers. Trade or manufacturers’ names appear herein 

solely because they are considered essential to the objective of this 

report.
i

REPORT DOCUMENTATION PAGE Form Approved

OMB No. 0704-0188

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503.

1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE

October 2013

3. REPORT TYPE AND DATES COVERED

Technical Report

4. TITLE AND SUBTITLE

PERFORMANCE REQUIREMENTS: FOR A 70-TON HIGHER SPEED FREIGHT 

TRUCK DESIGN FOR OPERATIONS OF UP TO 125 MPH

5. FUNDING NUMBERS

BAA-2010-1

DTFR53-11-C-00009

6. AUTHOR(S)

Sharma & Associates, Inc.

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

Sharma & Associates, Inc.

5810 S. Grant Street

Hinsdale, Illinois 60521

8. PERFORMING ORGANIZATION 

REPORT NUMBER

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

U.S. Department of Transportation 

Federal Railroad Administration

Office of Railroad Policy and Development

Office of Research and Development

Washington, DC 20590

10. SPONSORING/MONITORING

AGENCY REPORT NUMBER

DOT/FRA/ORD-13/41

11. SUPPLEMENTARY NOTES

COTR: S. K. Punwani

12a. DISTRIBUTION/AVAILABILITY STATEMENT

This document is available to the public through the FRA Web site at http://www.fra.dot.gov.

12b. DISTRIBUTION CODE

13. ABSTRACT (Maximum 200 words)

This proposed requirements document combines a set of requirements for high-speed freight car truck design and performance 

from the generally accepted standards in the U.S. Code of Federal Regulation (CFR), the Association of American Railroads 

(AAR) Manual of Standards and Recommended Practices (MSRP), and the American Public Transportation Association 

Standards (APTA). The proposal will ideally establish a set of design and performance requirements specifically for freight car 

trucks intended to operate at speeds of up to 125 mph.

This proposed requirements document covers the design and performance requirements for freight car trucks applied to freight 

cars that are intended for use in rail service at speeds of up to 125 mph, the Track Class 7 maximum allowable operating speed. 

Accordingly, only elements essential to track worthiness, basic equipment, and strength are addressed. Special component and 

braking requirements are not addressed in this document.

In addition to design and strength, safety performance requirements based on lateral wheel load, vertical wheel unloading, L/V 

ratio, and lateral and vertical car body accelerations are addressed in this report.

14. SUBJECT TERMS

AAR, APTA, Carbody, Code of Federal Regulations, Coefficient of Friction, Flange Angle, 

Higher Speed Truck, L/V Ratio, Lateral Load, Minimally Compliant Analytical Track

Minimum Vertical Wheel Load, Revenue Service Track, Track Class, Vehicle-Track Interaction 

Safety Limit, Wheel Unloading

15. NUMBER OF PAGES

16

16. PRICE CODE

17. SECURITY CLASSIFICATION

OF REPORT

Unclassified

18. SECURITY CLASSIFICATION

OF THIS PAGE

Unclassified

19. SECURITY CLASSIFICATION

OF ABSTRACT

Unclassified

20. LIMITATION OF ABSTRACT

NSN 7540-01-280-5500 Standard Form 298 (Rev. 2-89)

Prescribed by ANSI Std. 239-18

298-102
ii

METRIC/ENGLISH CONVERSION FACTORS

ENGLISH TO METRIC METRIC TO ENGLISH

LENGTH (APPROXIMATE) LENGTH (APPROXIMATE)

1 inch (in) = 2.5 centimeters (cm) 1 millimeter (mm) = 0.04 inch (in)

1 foot (ft) = 30 centimeters (cm) 1 centimeter (cm) = 0.4 inch (in)

1 yard (yd) = 0.9 meter (m) 1 meter (m) = 3.3 feet (ft)

1 mile (mi) = 1.6 kilometers (km) 1 meter (m) = 1.1 yards (yd)

1 kilometer (km) = 0.6 mile (mi)

AREA (APPROXIMATE) AREA (APPROXIMATE)

1 square inch (sq in, in2) = 6.5 square centimeters (cm2) 1 square centimeter (cm2) = 0.16 square inch (sq in, in2)

1 square foot (sq ft, ft2) = 0.09 square meter (m2) 1 square meter (m2) = 1.2 square yards (sq yd, yd2)

1 square yard (sq yd, yd2) = 0.8 square meter (m2) 1 square kilometer (km2) = 0.4 square mile (sq mi, mi2)

1 square mile (sq mi, mi2) = 2.6 square kilometers (km2) 10,000 square meters (m2) = 1 hectare (ha) = 2.5 acres

1 acre = 0.4 hectare (he) = 4,000 square meters (m2)

MASS - WEIGHT (APPROXIMATE) MASS - WEIGHT (APPROXIMATE)

1 ounce (oz) = 28 grams (gm) 1 gram (gm) = 0.036 ounce (oz)

1 pound (lb) = 0.45 kilogram (kg) 1 kilogram (kg) = 2.2 pounds (lb)

1 short ton = 2,000 pounds 

(lb)

= 0.9 tonne (t) 1 tonne (t) =

=

1,000 kilograms (kg)

1.1 short tons

VOLUME (APPROXIMATE) VOLUME (APPROXIMATE)

1 teaspoon (tsp) = 5 milliliters (ml) 1 milliliter (ml) = 0.03 fluid ounce (fl oz)

1 tablespoon (tbsp) = 15 milliliters (ml) 1 liter (l) = 2.1 pints (pt)

1 fluid ounce (fl oz) = 30 milliliters (ml) 1 liter (l) = 1.06 quarts (qt)

1 cup (c) = 0.24 liter (l) 1 liter (l) = 0.26 gallon (gal)

1 pint (pt) = 0.47 liter (l)

1 quart (qt) = 0.96 liter (l)

1 gallon (gal) = 3.8 liters (l)

1 cubic foot (cu ft, ft3) = 0.03 cubic meter (m3) 1 cubic meter (m3) = 36 cubic feet (cu ft, ft3)

1 cubic yard (cu yd, yd3) = 0.76 cubic meter (m3) 1 cubic meter (m3) = 1.3 cubic yards (cu yd, yd3)

TEMPERATURE (EXACT) TEMPERATURE (EXACT)

[(x-32)(5/9)] °F = y °C [(9/5) y + 32] °C = x °F

QUICK INCH - CENTIMETER LENGTH CONVERSION

0 1 2 3 4 5

Inches

Centimeters 0 1 2 3 4 5 6 7 8 9 10 11 12 13

QUICK FAHRENHEIT - CELSIUS TEMPERATURE CONVERSIO

 -40° -22° -4° 14° 32° 50° 68° 86° 104° 122° 140° 158° 176° 194° 212°

 

°F

 °C -40° -30° -20° -10° 0° 10° 20° 30° 40° 50° 60° 70° 80° 90° 100°

For more exact and or other conversion factors, see NIST Miscellaneous Publication 286, Units of Weights and 

Measures. Price $2.50 SD Catalog No. C13 10286 Updated 6/17/98
iii

Contents

1. Proposed Requirements—General .............................................................................. 5

2. Scope ........................................................................................................................... 6

3. Design and Clearance .................................................................................................. 7

3.1 Material ....................................................................................................................... 7

3.2 Construction ................................................................................................................ 7

3.3 Limiting Profile ........................................................................................................... 7

3.4 Components................................................................................................................. 7

4. Strength and Endurance............................................................................................... 9

4.1 Test Requirements....................................................................................................... 9

5. Safety and Performance............................................................................................. 10

5.1 Wheel Load Limits.................................................................................................... 10

5.2 Acceleration Limits................................................................................................... 11

5.3 Performance Limits Summary Tables....................................................................... 12

6. References ................................................................................................................. 13

Abbreviations and Acronyms ....................................................................................................... 14
iv

Tables

Table 1. Wheel Rail Forces........................................................................................................... 12

Table 2. Carbody Acceleration ..................................................................................................... 12
5

1. Proposed Requirements—General

This proposed requirements document combines a set of requirements for high-speed freight car 

truck design and performance from the generally accepted standards in the U.S. Code of Federal 

Regulation (CFR), the Association of American Railroads (AAR) Manual of Standards and 

Recommended Practices (MSRP), and the American Public Transportation Association 

Standards (APTA). The purpose of this standard is to establish a set of design and performance 

requirements specifically for freight car trucks that are intended to operate at speeds of up to 125 

mph.
6

2. Scope

This proposed requirements report covers the design and performance requirements for freight 

car trucks intended for use in rail service at speeds of up to 125 mph, the track Class 7 maximum 

allowable operating speed. Accordingly, only elements essential to track worthiness, basic 

equipment, and strength are addressed. Special component and braking requirements are not 

addressed in this document.
7

3. Design and Clearance

3.1 Material

3.1.1 Frames, Bolsters, and Other Structural Components

The material of structural truck components, including frames, bolsters, and any other primarily 

load bearing member, shall meet the minimum requirements of AAR M-201 for castings and 

AAR M-213 for fabricated components [1].

3.1.2 Steel Coil Springs

The material and processing of steel coil springs shall conform to the requirements of AAR M114 [2].

3.2 Construction

Fabricated frames shall be constructed according to the requirements of AAR M-1001 Chapter 5 

[3].

3.3 Limiting Profile

Trucks shall meet the dimensional requirements of 49 CFR 229.71 [4] and AAR S-2026-88 

Plate B limiting profile [5], and AAR S-301, S-302, and S-303 [6] truck design dimensions.

3.4 Components

3.4.1 Wheels

Wheels shall meet the requirements of AAR M-107/208 Class B Wheels [7].

3.4.2 Axles

Axles shall meet the requirements of AAR M-101 [7].

3.4.3 Roller Bearings

Roller bearings shall meet the requirements of AAR M-924 [8].

3.4.4 Side Bearings

Side bearings, if used, shall meet the requirements of AAR M-948 [2].
8

3.4.5 Steel Center Plate Liners

Steel center plate liners, if used, shall meet the requirements of AAR S-305, S-306, S-307, and 

S-308 [2].
9

4. Strength and Endurance

4.1 Test Requirements

Frames and bolsters shall meet the strength and endurance requirements of AAR M-202, M-203, 

M-203-A, M-204, and M-213 [3] depending on their cast or fabricated construction.
10

5. Safety and Performance

The safety and performance requirements listed below are intended for revenue service track. 

These requirements can also be used to assess truck performance through analytical simulations 

where track defects are represented by the Minimally Compliant Analytical Track (MCAT) 

methodology described in 49 CFR Parts 213 and 238 [9]. Each referenced specification covers 

all aspects of testing, including data collection and signal conditioning. For minimum and 

maximum vertical wheel loads, the Federal Railroad Administration and CFR data collection and 

signal conditioning standards may be substituted for the APTA and EN standards to enable more 

uniform test and analysis operations.

5.1 Wheel Load Limits

5.1.1 Minimum Vertical Wheel Load

For safety against derailment on track twist (warped track) in the form of curve spirals and track 

level deviations, trucks shall meet the static and dynamic requirements of:

Static – APTA SS-M-014-06 – 4.0 Wheel Load Equalization Requirements – 4.2 Class R

Passenger Equipment [10]

> 35 percent of static vertical wheel load at 2-inch single wheel vertical displacement, 

and

> 0 percent of static vertical wheel load at 2.5-inch single wheel vertical displacement

Dynamic – 49 CFR 213.345 – Vehicle/Track Interaction Safety Limits (VTISL) – Single Wheel 

Vertical Load [8].

≥ 15 percent of static vertical wheel load; not to be less than this value for 5 foot or more 

length along the track 

5.1.2 Maximum Wheel L/V

For safety against wheel climb derailment in curves, spirals, track twist, and track level 

deviations, trucks shall meet the dynamic requirements of 49 CFR 213.345 – VTISL – Single 

Wheel L/V Ratio [8].

≤ (Tan(δ)-μ)/ (1+μ∙Tan(δ)); not to exceed this value for 5 feet or more; where

δ = Flange Angle, 

μ = Coefficient of Friction, 0.5 shall be used as per 49 CFR 213.345 Proposed Rule

5.1.3 Net Axle Lateral L/V Ratio

For safety against track panel shift, trucks shall meet the requirements of 49 CFR 213.345 

Proposed Rule – VTISL – Net Axle Lateral L/V Ratio [8].

≤ 0.4+5.0/Va; not to exceed this value for 5 feet or more; where 
11

Va = Static Vertical Axle Load (kips)

5.1.4 Truck Side L/V

For safety against track rail roll over, trucks shall meet the requirements of 49 CFR 213.345 –

VTISL – Truck Side L/V Ratio [8].

≤ 0.6; not to exceed this value for 5 feet or more 

5.2 Acceleration Limits

5.2.1 Car body Lateral Sustained

For safety against derailment, and track damage prevention, trucks shall meet the requirements 

of 49 CFR 213.345 Proposed Rule – VTISL – Car body Lateral (Sustained Oscillatory) – Other 

Vehicles [9].

≤ 0.12g rms, 4-second window, 4 seconds sustained

5.2.2 Car body Vertical Maximum

For vehicle track interaction safety, trucks shall meet the requirements of AAR Chapter XI.

≤ 1g dynamic augment, loaded car only
12

5.3 Performance Limits Summary Tables

Table 1. Wheel Rail Forces

Safety Limit Window

Min Vertical Wheel Load ≥ 15% Static Vertical Wheel Load 5 ft

Max Wheel L/V ≤ (Tan(δ)-μ)/(1+μ∙tan(δ)); where

δ = Flange Angle,

μ = Coefficient of Friction, 0.5 shall be used 

as per 49 CFR 213.345 Proposed Rule

5 ft

Net Axle Lateral L/V ≤ 0.4 + 5.0/Va; where 

Va = Static Vertical Axle Load (kips)

5 ft

Max Truck Side L/V ≤ 0.6 5 ft

Static Twist Load Equalization - test only

Min Wheel Vertical Load 

(Truck Twist – Static)

≥ 35% Static at 2-inch wheel lift

≥ 0% Static at 2.5-inch wheel lift

Min Wheel Vertical Load 

(Truck Twist – Static)

Table 2. Carbody Acceleration

Safety Limit Window/Condition

Carbody Lateral Sustained ≤ 0.12g rms 4-second window, 4 second 

sustained

Carbody Vertical Transient ≤ 1.0 g dynamic augment instantaneous
13

6. References

1. Association of American Railroads (AAR) – Manual of Standards and Recommended 

Practices (MSRP) – Section S - Casting Details.

2. AAR – MSRP – Section D - Truck and Truck Details. 

3. AAR – MSRP – Section C – Part II – Design Fabrication and Construction of Freight 

Cars. 

4. U.S. Code of Federal Regulation – 49 CFR 229.71 – Clearance Above Top of Rail 

5. AAR – MSRP – Section C – Car Construction Fundamentals and Details. 

6. AAR – MSRP – Section S-II - Truck Details and Casting Codes. 

7. AAR – MSRP – Section G - Wheels and Axles. 

8. AAR – MSRP – Section H - Journal Bearings and Lubrication. 

9. U.S. Code of Federal Regulation – 49 CFR 213.345 – Vehicle/Track System 

Qualification and Appendix D. 

10. American Public Transportation Association Standards – 14. APTA SS-M-014-06 

Standard for Wheel Load Equalization of Passenger Railroad Rolling Stock.
14

Abbreviations and Acronyms

AAR Association of American Railroads

APTA American Public Transportation Association

CFR Code of Federal Regulations

FRA Federal Railroad Administration

MSRP Manual of Standards and Recommended Practices