About AAR Circular Letters
Circular letter summaries are produced monthly by Greenbrier Management Services Group.
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
C-14383
Revisions to MSRP F, Sensors, S-6101 –Detector Calibration & Validation Requirements / ABD Site Current Validations
Issued: June 13, 2024
Effective: June 13, 2024
This implementation circular is being released to the industry for revisions to the AAR’s Manual of Standards & Recommended Practices (MSRP) Section F – Sensors / Detector Calibration & Validation Requirements / ABD Site Current Validations.
AAR’s Equipment Health Monitoring Committee (EHMC) voted to progress the standard to implementation upon WABL Committee’s recommendation. The implemented standard is attached to the circular.
C-14384
Implementation of Revisions to General Rule 37 and Appendix F – Section 1 of the AAR Open Top Loading Rules Manual (OTLR)
Issued: June 18, 2024
Effective: June 18, 2024
The AAR’s Open Top Loading Rules Committee (OTLRC) has approved revisions to Section 1 OTLR manual for General Rule 37 and Appendix F. See circular for details.
The implementation of these revisions is effective immediately and will be included in the next edition of the OTLR manual. In the interim, please insert the circular attachments for General Rule 37 and Appendix F in your Section 1 copy and be governed accordingly.
C-14385
Implementation of Revisions to General Rule 21: Chain, Binders, and Assemblies – Section 1 of the AAR Open Top Loading Rules Manual (OTLR)
Issued: June 18, 2024
Effective: June 18, 2024
The AAR’s Open Top Loading Rules Committee (OTLRC) has approved revisions to Section 1 OTLR manual for General Rule 21: Chain, Binders, and Assemblies. See circular for details.
The implementation of these revisions is effective immediately and will be included in the next edition of the OTLR manual. In the interim, please insert the circular attachment for General Rule 21 in your Section 1 copy and be governed accordingly.
C-14386
Implementation of Revisions to General Rules 1, 11, 19, and 20 – Section 1 of the AAR Open Top Loading Rules Manual (OTLR)
Issued: June 18, 2024
Effective: June 18, 2024
The AAR’s Open Top Loading Rules Committee (OTLRC) has approved the following revisions to Section 1 OTLR manual for General Rules 1, 11, 19, and 20. See circular for details.
The implementation of these revisions is effective immediately and will be included in the next edition of the OTLR manual. In the interim, please insert the circular attachments for General Rules 1, 11, 19, and 20 in your Section 1 copy and be governed accordingly.
C-14390
AAR Manual of Standards and Recommended Practices (MSRP), Section K-VI Railway Data Management and Communications, Standard S-9501 Appendix A.V1.0
Issued: June 24, 2024
Effective: June 24, 2024
S-9501 Appendix A V1.0 – Positive Train Control Data Model Definition – Data Model Bundle is external content to the requirements of AAR Standard S-9501, “Positive Train Control Data Model Definition”. Appendix A is a multi-page document consisting of four Entity Relationship (ER) Diagrams that illustrate how the PTC concepts, entities and attributes relate to each other.
The update frequency to the AAR document and the content of this appendix is not the same, therefore, the information in the appendix is stored separately from the document. Nevertheless, this information shall be considered part of Standard S-9501.
Standard S-9501 Appendix A V1.0 is attached to this Circular in PDF format. S-9501’s latest version and all external content will be incorporated into the next issue of the MSRP Section K-VI Railway Data Management and Communications. In the interim, please insert the circular in your copy of the MSRP Section K-VI and be governed accordingly.
C-14389
AAR Manual of Standards and Recommended Practices (MSRP), Section K-VI Railway Data Management and Communications, Standard S-9501.V4.0
Issued: June 24, 2024
Effective: June 24, 2024
S-9501.V4.0 – Positive Train Control Data Model Definition is to establish a common data format between the various railroad databases to facilitate the conversation of track data for use by positive train control applications.
The data tables described in this specification contain all the data elements necessary to produce a PTC Track Data File (as defined in AAR S-9503) structured in a relational model form. Although S-9503 defines the Track Data File format for an individual subdivision, a relational database created per the relational model defined in this specification is suitable to maintain data for multiple subdivisions from one or more railroads.
S-9501.V4.0 was Adopted in 2013 and Last Revised in 2024 and is attached to this circular in PDF format. S-9501.V4.0 will be incorporated into the next issue of the MSRP Section K-VI Railway Data Management and Communications, in the interim, please insert the Circular in your copy of the MSRP Section K-VI and be governed accordingly.
C-14388
Manual of Standards and Recommended Practices (MSRP). Section K-I Railway Electronics Architecture and Concepts of Operations. Standard S-9080.V5.0
Issued: June 24, 2024
Effective: June 24, 2024
S-9080.V5.0 – Positive Train Control Interoperability Committee Policy defines the policy-related items related to or required for PTC interoperability and document standard(s) associated with each.
Standard S-9080.V5.0 was Adopted in 2020 and Last Revised in 2024 and is attached to this Circular in PDF format. S-9080.V5.0 will be incorporated into the next issue of the MSRP Section K-I Railway Electronics Architecture and Concepts of Operations. In the interim, please insert the Circular in your copy of the MSRP Section K-I and be governed accordingly.
Call for Comment
C-14382
DRAFT S-9506.V1.0 ITC Data Exchange Business Processes, in support of AAR’s MSRP – Section K-VI, Railway Data Management and Communications
Issued: June 10, 2024
Effective: 15 days for comment.
The Positive Train Control Interoperability Committee (PTCIC) of the Association of American Railroads (AAR) is publishing DRAFT S-9506.V1.0 ITC Data Exchange Business Processes for review and comment. This document captures the business processes for exchanging PTC data between roads. This process will ensure the continued interoperability at interconnections, interlockings, rail crossings at grade, and locations where the role of operations and maintenance are split between railroads requiring coordination to maintain the relevance of PTC track data. The purpose of the ITC Data Exchange Business Process is to facilitate the exchange of data between roads, specifically data that a railroad needs from another in order to produce and maintain interoperable track data files.
See circular for more information.
C-14392
Solicitation of Comments for Revisions to MSRP Section C, CAR CONSTRUCTION FUNDAMENTALS AND DETAILS, Standard S-2060, Design Requirements for Rigid Open-Top Freight Car Covers, implementation of new standard
Issued: June 25, 2024
Effective: 30 days for comment.
The purpose of this circular letter is to solicit comments for revisions proposed to Section C by addition of new Standard S-2060, Design Requirements for Rigid Open-Top Freight Car Covers. The standard defines the minimum requirements for rigid covers applied to open-top freight cars by a new car builder or as a retrofit. A draft of the standard is attached to the circular.
Notice of Circulars
Informational Circular, Revisions to Field Manual, Rule 5.B Correct Repair Chart for End Hoses
Issued: June 3, 2024
Effective: July 1, 2024
At the April 2024 meeting of the Arbitration and Rules Committee a proposal as advanced by the Brake Systems Committee to revise Field Manual Rule 5.B Correct Repair Chart for End Hoses was reviewed and approved. The revision is being made to provide clarification related to S-4032 and the increased usage of 33″ end hoses. See circular for entire text of revision.
This change will be included in the July 1, 2024 update to the Field Manual.
C-14378
Informational Circular, Revisions to Field Manual, Rule 4.E.27
Issued: June 3, 2024
Effective: July 1, 2024
At the April 2024 meeting of the Arbitration and Rules Committee a proposal as advanced by the Brake Systems Committee to revise Field Manual Rule 4.E.27, was reviewed and approved. This change was also included in the informational circular C-14343 with 4-pressure clarifications published on May 6, 2024. See circular for entire text of revision.
This change will be included in the July 1, 2024 update to the Field Manual.
C-14380
Informational Circular, Car Repair Facility Labor Rate – Effective July 1, 2024
Issued: June 4, 2024
Effective: July 1, 2024
The Car Repair Facility Labor Rate, effective July 1, 2024 is $166.52, an increase of $4.85 (or 3.0%) from the labor rate estimated on April 1, 2024. The increase is from general wage increases for most railroads. Primarily, railroads included in national negotiations received a 4.5 percent general wage increase effective July 1, 2024. The higher wages also affect Railroad Retirement contributions, but Health & Welfare is unchanged.
This will be reflected in the July 1, 2024 release of the AAR Office Manual.
C-14381
Informational Circular, Canadian Car Repair Facility Labor Rate – Effective July 1, 2024
Issued: June 4, 2024
Effective: July 1, 2024
The Canadian Car Repair Billing Labor Rate calculation for July 1, 2024 is $242.60 CAD (Two hundred and forty‐two Canadian dollars and sixty cents), an increase of fifty-one cents from the calculation for April 1. For comparison purposes, this converts to about $177.35 in U.S. dollars. The currency conversion factor used to calculate the Health & Welfare portions of the April 1 Canadian Labor Rate is 1.3478. The currency conversion factor used to calculate the Health & Welfare portions of the July 1 Canadian Labor Rate is 1.3679. This caused the increase in the Canadian Labor Rate.
The change will be reflected in the July 1, 2024 release of the Canadian Price Master.
C-14391
July 2024 Field and Office Manuals, Summary of Comments and Implementation Details
Issued: June 25, 2024
Effective: July 1, 2024
In May 2024, several Circular Letters soliciting comments on the proposed rule changes were issued. In addition, several letters were issued that advised of approved changes that would become effective on July 1, 2024. See circular for a recap of those letters seeking industry comment, an indication of comments received (if any), consideration and implementation details. Unless otherwise noted, the rule changes are for the Field Manual.
Upcoming Event
38th North American Rail Mechanical Operations (NARMO) Seminar
Nashville, TN | August 12–15
See Circular C-14387 for full agenda and registration information.
Fall 2024 AAR Technical Committee Meetings
AAR meetings that have been planned for the second half of 2024 are listed on Circular C-14393. AAR Meeting Announcements can also be found online on the MxV Rail Technical Services web page: http://www.aar.com/standards/AARMeetingAnnouncements.html
Midwest Association of Rail Shippers (MARS) 2024 Summer Meeting
Lake Geneva, WI | July 8–9, 2024
Greenbrier is proud to sponsor the MARS conference.
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- Expert Witness Services in Rail-Related Litigation
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- Nondestructive Testing Programs
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- 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
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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.
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