AAR Circular Letter Summary – July 2022



About AAR Circular Letters

Circular letter summaries are produced monthly by Greenbrier’s Regulatory Management team, a division of Greenbrier Management Services Group.

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AAR circular letters provide information of general applicability to the railroad industry, including proposed and final rules, revisions, standards and recommended practices, and calls for comments. These summaries provide the main points of circular letters issued in the prior month, as well as important implementation deadlines.

For access to the complete circular letter, please go to my.aar.org/circulars. Circular letters are a fee-based service provided by the AAR’s Transportation Technology Center Incorporated (TTCI). You may subscribe online at publications@aar.com or call 719.584.0538.

Implementation Circulars

Implementation: Revisions to MSRP F, Sensors, S-920, Component Identification Bar Code Standard – Section 10 Wheel Set CID Labels
Issued: June 30, 2022
Effective: June 30, 2022

This implementation circular is being released to the industry as notice of revisions to MSRP F, Sensors, S-920. The changes pertain to the wheelset component identification (CID) label. The standard is attached to the circular as reference and the updates to the Component Registry will be announced to the user community via a Railinc release notice.


IMPLEMENTED, AAR Manual of Standards and Recommended Practices (MSRP), Section K-1 Railway Electronics Systems Architecture and Concepts of Operations, Standard S-9075.V1.0
Issued: July 19, 2022
Effective: July 19, 2022

S-9075.V.1.0 – ISMP Design Considerations, contains common and interoperable requirements for; the creation of ISMP messages, the signing of ISMP messages, the encryption of the fields in ISMP messages, establishing sessions between a back-office application and the domestic ITCSM gateway, and ISMP Message response codes. Insert the Circular into your copy of the MSRP Section K-I and be governed accordingly.


Implementation of Revisions to MSRP Section C, CAR CONSTRUCTION FUNDAMENTALS AND DETAILS, Standard S-2045 Remote Monitoring Equipment, Installation.  Revision of requirements
Issued: July 19, 2022
Effective: July 19, 2022

Revised Standard S-2045, attached to the circular, is now implemented and effective immediately. Updates include the following:

  • Approval will be given only to car owners.
  • The quantity of cars must be included with each application but may be increased upon request.
  • An effective date of January 1, 2024, was added to the intrinsically safe requirement.
  • Devices exposed to flammable liquid/gas or oxidizing material must comply with Section C-III Specification for Tank Cars.

This modification will be incorporated in the next issue of the Manual of Standards and Recommended Practices, Section C. Please update your library and be governed accordingly.


Implementation of Revisions to MSRP Section C-III, Specification for Tank Cars (M-1002), Appendix B
Issued: July 29, 2022
Effective: July 29, 2022

This implementation circular is being released to the industry as notice of revisions to MSRP Section C-III, Appendix B, Certification of Tank Car Facilities. All revisions are identified by change bars in the margins of the Appendix B document (attached to the circular). Please update your library and be governed accordingly.


Call for Comment

Solicitation of Comments for Revisions to Circular 43, Rules Governing the Loading, Blocking, and Bracing of Freight in Closed Containers and Trailers in Intermodal Service (DP&FC)
Issued: July 11, 2022
Effective: 30 days for comment.

The purpose of the circular letter is to solicit comments for revisions proposed to Circular 43, Rules Governing the Loading, Blocking, and Bracing of Freight in Closed Containers and Trailers in Intermodal Service (DP&FC). Circular 43 (attached to the circular) contains the proposal and replaces Circular 42-G.


Solicitation of Comments: Revisions to MSRP F, Sensors, S-6103 Wheel Profile Detector – Section 5.0 Measurement Standards (Flange Thickness)
Issued: July 15, 2022
Effective: 30 days for comment.

The proposed changes include modification to the subject section as it relates to the measurement determination for flange thickness (FT) and impact section 5.2.2 and Appendix B, Figure B.1 of this section and are being made to conform to the measurement described in AAR Field Manual Rule 41 A.1.a, in which a wheel can show cause for attention at any time for thin flange (Why Made Code 60). The proposed document is attached to the circular.


DRAFT S-9101 – APPENDIX F – VERSION 1.2 – Locomotive Interface Gateway (LIG) Segment and Locomotive Application (LAPP) Segment Subsystems Addresses is available for review and comment, in support of AAR’s MSRP – Section K-II
Issued: July 19, 2022
Effective: 30 days for comment.

This document is the appendix to the requirements in AAR Standard S-9101, “Locomotive Electronics System Architecture.”

SharePoint access can be found at www.railinc.com.


Solicitation of Comments, Revisions to Field Manual, Rule 3
Issued: July 26, 2022
Effective: 30 days for comment.

The revision to Field Manual Rule 3 allows the capture of more data to the causation of brake related repairs. The entire text of the revision is included in the circular. The targeted implementation date is January 1, 2023.


Solicitation of Comments for Revisions to MSRP Section M, Specification, M-1005 LOCOMOTIVE ELECTRONICS SAFETY ASSESSMENTS AND ANALYSES
Issued: July 29, 2022
Effective: 30 days for comment.

The proposal provides a comprehensive response and standard protocol to demonstrate compliance with 49 Code of Federal Regulations (CFR) Part 229, Subpart E – Locomotive Electronics. Specification M-1005 defines a methodology and the responsibilities for both railroads and suppliers to comply with the regulatory requirements. The proposal is attached to the circular.


Notice of Circulars

Recommended Railroad Operating Practices for Transportation of Hazardous Materials
Issued: July 22, 2022
Effective: July 1, 2022

AAR’s Safety and Operations department has amended Appendix A: and B: of OT-55-R by adding HMRC 4927002 / TOXIC BY INHALATION LIQUID, FLAMMABLE, CORROSIVE, N.O.S. / UN3489 / PG 1 / Hazard Zone B / Hazard Class 6.1. These are the only changes from OT-55-R Dated April 30, 2021. AAR Circular No. OT-55-R Dated July 1, 2022 (attached to the circular) becomes effective July 1, 2022, and supersedes all previous versions.


Fall 2022 AAR Technical Committee Meetings
Issued: July 29, 2022
Effective: July 29, 2022

Tank Car Committee meetings will be held October 18-20 in Addison, TX. The hotel has not yet been announced. The full list of technical committees and dates are included in the circular.

AAR In-person committee meetings are open only to those fully vaccinated for COVID, at least two weeks past final vaccination. AAR-hosted meetings will abide by CDC, State, and local guidelines, which call for masks to be worn in public indoor settings in areas of substantial or high transmission.


Upcoming Event

NEARS Conference
September 20 – 22

Join us at the next NEARS Conference in Pittsburgh, PA. Be sure to check out the The Railcar Revolution Has Begun session on Wednesday, September 21 at 3:45 pm ET. Panel featuring United States Steel, Norfolk Southern and Greenbrier.


Greenbrier’s Regulatory Services Group

Peace of mind for your business.

The Regulatory Management Group, led by James Rader, provides regulatory, engineering, process consulting and advocacy support to the railcar repair industry and the petrochemical rail shipper community.

  • ASNT Level III Subscription Services
  • DOT Compliance Assessments (Corporate and Plant)
  • DOT Hazardous Materials Training (Corporate and Plant)
  • Expert Witness Services in Rail-Related Litigation
  • Federal Government Claims Mitigation (e.g. FRA and PHMSA)
  • Nondestructive Testing Programs
  • Quality Assurance Program Development
  • Regulatory Counsel and Policy Advocacy
  • Railcar Repair Management (Design Review, Drawings, Engineering and AAR Approval Administration)
  • Tank Car Reliability and Maintenance Programs (49 CFR Subpart F of Part 180)
  • Tank Car Maintenance Data Collection and Reliability Performance Analysis
  • Welding Program Development

For inquiries about these summaries or any of our services, please reach out to: regulatoryservices@gbrx.com


About Greenbrier Management Services (GMS)

Greenbrier Management Services (GMS) is North America’s most comprehensive railcar management solutions provider. GMS manages nearly 400,000 railcars and has invested over 20 years in developing technology, processes, and people to provide the best railcar management products and services in the industry. GMS is powered by proprietary software and the best subject matter experts in the railcar business.



Combined, these two vitally important capabilities are able to deliver world-class solutions to every type of customer, from Class I railroads, lessors and industrial shippers to financial investors. GMS brings broad expertise to cover nearly any railcar management need that customers may have and its integrated solutions and reporting can be customized for any customer function or management need.