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ELECTRONICALLY CONTROLLED PNEUMATIC BRAKE REVENUE SERVICE TESTS Office of Research and
Development
Washington, D.C. 20590
DOT/FRA/ORD-99/07
January 1999
Final Report
This document is available to the
U.S. public through the National
Technical Information Service
Springfield, Virginia 22161
Federal Railroad
Administration
U.S. Department
of Transportation
ELECTRONICALLY CONTROLLED
PNEUMATIC BRAKE REVENUE SERVICE
TESTS Disclaimer: 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 the contents or use thereof.
The United States Government does not endorse products or manufacturers.
Trade or manufacturers' names appear herein solely because they are
considered essential to the object of this report. 1. Report No.

FRA/ORD-99/07
2. Government Accession No.
3. Recipients Catalog No.
5. Report Date
January 1999
4. Title and Subtitle

Electronically Controlled Pneumatic Train Brake
Revenue Service Tests
6. Performing Organization Code
7. Authors

Fred Carlson
8. Performing Organization Report No.
10. Work Unit N o. (TRAIS
)
9. Performing Organization Name and Address

Association of American Railroads
Transportation Technology Center, Inc.
P.O. Box 11130
Pueblo, CO 81001
11. Contract or Grant No.

DTFR53-93-C-00058
13. Type of Report or Period Covered
12. Sponsoring Agency Name and Address

U.S. Department of Transportation
Federal Railroad Administration
Office of Research and Development
1120 Vermont Avenue, NW
Washington, DC 20590
14. Sponsoring Agency Code
15. Supplemental Notes
16. Abstract
This letter report, prepared by the Transportation Technology Center, Inc. (TTCI), Pueblo, Colorado, a
subsidiary of the Association of American Railroads (AAR), summarizes the findings of the service testing
of Electronically Controlled Pneumatic (ECP) Brakes, carried out between the spring of 1996 and the
summer of 1997. This report focuses on the Conrail Revenue Service Test, which is one of the two tests
specifically featured in Task Order Number 1 Advanced Braking System Safety Evaluation. In addition,
selected results from the other revenue service tests, conducted during the same time, are included for
comparison purposes. Also, the actions taken by the AAR in the specification development process, as a
result of the findings of the revenue service tests, are discussed.
The primary focus of the AAR's ongoing work is to establish a non-overlay ECP test train, assure
that the system is safe for revenue service, and then compare its operation to an identical standard train.
Once a pure ECP test train is established, it will not be capable of operating in a conventional mode, and
the data from such a test will be a true indication of the economic benefits possible through the use of ECP
brake systems.
Additional plans are to complete the development of the draft AAR ECP Performance Specifications
and submit them to AAR Safety and Operations technical committees.
17. Key Words

electronically controlled pneumatic (ECP) brakes, overlay ECP brake
system, manifold, Head End Unit (HEU), car brake systems, car
control device (CCD)
18. Distribution Statement

This document is available through
National Technical Information Service
Springfield, VA 22161
19. Security Classification

(of the report)
20. Security Classification
(
of this page)
21. No of Pages
51
22. Price
Form DOT F 1700.7 (8-72)
i
EXECUTIVE SUMMARY
This letter report, prepared by the Transportation Technology Center, Inc. (TTCI),
Pueblo, Colorado, a subsidiary of the Association of American Railroads (AAR),
summarizes the findings of the service testing of Electronically Controlled Pneumatic
(ECP) Brakes, carried out between the spring of 1996 and the summer of 1997. This
report focuses on the Conrail Revenue Service Test, which is one of the two tests
specifically featured in Task Order Number 1 Advanced Braking System Safety
Evaluation. In addition, selected results from the other revenue service tests, conducted
during the same time, are included for comparison purposes. Also, the actions taken
by the AAR in the specification development process, as a result of the findings of the
revenue service tests, are discussed.
The primary focus of the AAR's ongoing work is to establish a non-overlay ECP test
train, assure that the system is safe for revenue service, and then compare its operation
to an identical standard train. Once a pure ECP test train is established, it will not be
capable of operating in a conventional mode, and the data from such a test will be a true
indication of the economic benefits possible through the use of ECP brake systems.
Additional plans are to complete the development of the draft AAR ECP
Performance Specifications and submit them to AAR Safety and Operations technical
committees. ii iii
Table of Contents
1.0 Introduction ................................................................................................................1
1.1 Background..........................................................................................................1
2.0
Test Objectives .........................................................................................................3
3.0 Description of Technical Services and Marketing Inc. ECP Brake System ....4
4.0 Discussion of the Results Presented in the Conrail Report................................ 6
4.1 Energy Consumption and Coupler Force Data......................................... 7
4.2 CCD Reliability...............................................................................................8
4.3 Percentage of Operability Under ECP Brake Control............................10
4.4 Sticking Brakes in the Overlay Mode .......................................................11
4.5
Repair Data ..................................................................................................12
4.6
BNSF Test Results......................................................................................13
5.0
Conclusions ............................................................................................................14
6.0 Future Plans ............................................................................................................15
Appendix A: Conrail Test Report .....................................................................................17
Appendix B: Technology Digest 97-022 .........................................................................45
Appendix C: Technology Digest 97-008 .........................................................................51
List of Figures
Figure 1. CCD Mounting on Conrail Coal Hopper..........................................................9
Figure 2. Failed Connector on Conrail ..........................................................................10
Figure 3. Connector Design adopted by the AAR........................................................11
List of Tables
Table 1. Conrail Test Repair Data Summary..................................................................13
Table 2. BNSF Taconite Train Maintenance Data .........................................................14 1
1.0 INTRODUCTION
This letter report, prepared by the Transportation Technology Center, Inc.
(TTCI), Pueblo, Colorado, a subsidiary of the Association of American Railroads
(AAR), summarizes the findings of the service testing of Electronically
Controlled Pneumatic (ECP) Brakes, carried out between the spring of 1996 and
the summer of 1997. This report focuses on the Conrail Revenue Service Test,
which is one of the two tests specifically featured in Task Order Number 1
Advanced Braking System Safety Evaluation. In addition, selected results from
the other revenue service tests, conducted during the same time, are included
for comparison purposes. Also, the actions taken by the AAR in the specification
development process, as a result of the findings of the revenue service tests, are
discussed.
1.1 Background
An AAR Working Group was established in 1993 to evaluate the use of ECP
brakes on heavy haul freight trains in North America. TTCI was tasked, under
the AAR funded research program, to coordinate the Working Group activities
and to develop a performance specification for ECP brake systems for eventual
incorporation into the AAR Manual of Standards and Recommended Practices. The
specification development process, which culminated in the acceptance of the
new specification, S-4200, relied heavily on information gathered from
engineering analysis performed on behalf of the AAR Working Group, on
laboratory and full-scale testing performed by the ECP brake developers and
TTCI, and on service testing by individual member railroads. Of all of these, it
was the service testing experience that provided the most vital information on
system safety and reliability. 2
During 1993-95, numerous successful revenue service tes