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
CPC-1424
Publication of 2024 AAR MSRP C-III (M-1002)
Issued: May 1, 2024
Effective: May 1, 2024
The AAR TCC has approved the release of the 2024 AAR MSRP C-III (M-1002). The manual will be available for purchase on May 3, 2024, using the link provided below.
Section C Part III – Specifications for Tank Cars M-1002 (2024) (aarpublications.com)
C-14354
Revisions to Figure 14-B: Steel Plate or Slab on 89 FT. or Less Flatcar – Section 2 of the AAR Open Top Loading Rules Manual (OTLR)
Issued: May 6, 2024
Effective: May 6, 2024
The AAR’s Open Top Loading Rules Committee (OTLRC) has approved the following revisions to Section 2 OTLR manual for Figure 14-B: Steel Plate or Slab on Flatcar. See circular for full details.
The implementation of these revisions to Section 2 is effective immediately and will be included in the next edition of the AAR’s OTLR manual. In the interim, please insert the circular attachment for Figure 14-B in your copy of Section 2 and be governed accordingly.
Carriers are asked to ensure that copies of this circular letter are distributed to all concerned shippers and railroad personnel for their attention and guidance.
C-14348
Revisions to MSRP F, Sensors, S-6101 –Detector Calibration & Validation Requirements / ABD Site Current Validations
Issued: May 6, 2024
Effective: May 6, 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. On April 1 and 9, 2024, the Equipment Health Monitoring Committee (EHMC) released comment circulars C-14331 and C-14334, respectively, seeking comment on the changes. No comments were received from the industry that proposed modifying the standard as presented.
AAR’s Equipment Health Monitoring Committee voted to progress the standard to implementation. The implemented standard is attached as reference. Modifications will be incorporated in the next issue of the Manual of Standards and Recommended Practices, Section F. Please update your library and be governed accordingly.
C-14357
Manual of Standards and Recommended Practices (MSRP), Section K-V Electronics Environmental Requirements and Systems Management, Standard S-9416.V1.0
Issued: May 7, 2024
Effective: May 7, 2024
S-9416.V1.0 describes the minimal set of behaviors that a Client must comply with for interfacing with ITC Systems Management. Any Client that communicates over bandwidth constrained channels with the back office should follow this pattern. This document also describes behavior requirements for the OPA and FTS client to be compliant with the PSA-2 security architecture. The PSA-2 security architecture is defined specifically for the bandwidth constrained remote applications.
Standard S-9416.V1.0 was adopted in 2024 and is attached in PDF format. S-9416.V1.0 will be incorporated into the next issue of the MSRP Section K-V Electronics Environmental Requirements and Systems Management. In the interim, please insert the Circular in your copy of the MSRP and be governed accordingly.
C-14358
Implementation of Revised MSRP Section H-II, ROLLER BEARING MANUAL, 2024
Issued: May 8, 2024
Effective: May 8, 2024
The Association of American Railroads Wheels, Axles, Bearings, and Lubrication Committee (WABL) is pleased to announce a new edition of the Manual of Standards and Recommended Practices, Section H-II, ROLLER BEARING MANUAL. The revised MSRP Section H-II is now available in both printed and electronic versions. Current pricing is available online at www.aarpublications.com where the manual can be purchased.
C-14373
Retirement and Archival of AAR MSRP Section M – Recommended Practice – RP-5209 BASIC BRAKE DESIGN DATA FOR FREIGHT LOCOMOTIVES
Issued: May 20, 2024
Effective: May 20, 2024
The purpose of this Circular is to notify the industry of the retirement and archival of Manual of Standards and Recommended Practices (MSRP) Section M, Recommended Practice – RP-5209 BASIC BRAKE DESIGN DATA FOR FREIGHT LOCOMOTIVES. Due to content redundancy addressed within Recommended Practice, RP-509 BRAKING RATIOS FOR LOCOMOTIVES, the Locomotive Committee voted to retire RP-5209 during their December 2023 monthly webinar.
Effective immediately, RP-5209 is hereby retired. Please remove RP-5209 from Section M and be governed accordingly.
C-14377
Implementation of two new Figures 840 and 840-A – Section 7 of the AAR Open Top Loading Rules Manual (OTLR)
Issued: May 30, 2024
Effective: May 30, 2024
The AAR’s Open Top Loading Rules Committee (OTLRC) has approved the addition of the following Figures 840 and 840-A to Section 7 of the AAR Open Top Loading Rules Manual (OTLR).
- LR 12.10.30: Section 7, Figure 840: Added this new figure, ‘CHASSIS, 53 FT LONG, FOUR HIGH ON DCLI CHASSIS SHIPPING UNIT (CSU),’ to Section 7 of the AAR OTLR Manual.
- LR 12.10.31: Section 7, Figure 840-A: Added this new figure, ‘DCLI CHASSIS SHIPPING UNIT (CSU) COLLAPSED AND STACKED, FOUR HIGH, FOR COFC AND TOFC,’ to Section 7 of the AAR OTLR Manual.
The implementation of this new additions to Section 7 is effective immediately and will be included in the next edition of the AAR’s OTLR manual. In the interim, please insert the circular attachment for Figures 840 and 840-A in your copy of Section 7 and be governed accordingly.
Carriers are asked to ensure that copies of this circular letter are distributed to all concerned shippers and railroad personnel for their attention and guidance.
C-14376
Implementation of a new Figure 200-D – Section 6 of the AAR Open Top Loading Rules Manual (OTLR)
Issued: May 30, 2024
Effective: May 30, 2024
The AAR’s Open Top Loading Rules Committee (OTLRC) has approved the addition of the following Figure 200-D to Section 6 of the AAR Open Top Loading Rules Manual (OTLR).
- LR 11.0.258: Section 6, Figure 200-D: Added this new figure, ‘SEMI-TRAILERS, M870A4, EMPTY (24,700 LB)-FLATCARS,’ to Section 6 of the AAR OTLR Manual.
The implementation of this new addition to Section 6 is effective immediately and will be included in the next edition of the AAR’s OTLR manual. In the interim, please insert the circular attachment for Figure 200-D in your copy of Section 6 and be governed accordingly.
Carriers are asked to ensure that copies of this circular letter are distributed to all concerned shippers and railroad personnel for their attention and guidance.
Call for Comment
C-14340
Proposal to Revise 500-byte File Layout and Eliminate Error Code 3 in Reference to Repair Facility Arrival Date
Issued: May 1, 2024
Effective: 30 days for comment.
IMPORTANT NOTE: It is recommended that this information be shared with all Car Repair Billing and IT personnel in your company that work with or are responsible for Car Repair Invoices submitted to and/or received from Railinc’s CRB Data Exchange.
At the March 2024 Car Repair Billing Committee meeting, the committee advanced a proposal to eliminate the use of “Repair Facility Arrival Date (YYMMDD)” field in the 500-byte file layout. This change will modify positions 283-288 in the 500-byte layout to a “Reserved for Future Use” field and will remove “Error Code 3: Repair Facility Arrival Date (YYMMDD)—If present, must not be greater than Repair Date.” Any data provided in positions 283-288 of the 500-byte file in the CRIP file will no longer be sent in the outbound CROP file.
See circular for full proposal.
C-14341
Revision to Proposal to Modify Car Repair Billing Data Exchange Run Dates
Issued: May 1, 2024
Effective: 30 days for comment.
IMPORTANT NOTE: It is recommended that this information be shared with all Car Repair Billing and IT personnel in your company that work with or are responsible for Car Repair Invoices submitted to and/or received from Railinc’s CRB Data Exchange.
This is a follow up to AAR Circular Letter C-14301 issued on January 22, 2024.
At the September 2023 Car Repair Billing Committee meeting, the committee advanced a proposal to modify the Car Repair Billing Data Exchange Run Dates. After reviewing comments received from a prior Circular Letter, a revision to the proposal was approved at the March 2024 Car Repair Billing Committee meeting.
The Car Repair Billing Data Exchange (CRBDX), maintained by Railinc, is a monthly exchange of repair bills for foreign freight equipment. Repairing entities submit bills of car repairs in a proprietary format. These bills are sorted and sent to the billed party for the equipment. The data serves as detail support for paper billing documents. Selected elements of the exchanged data are retained for use in equipment failure trend analysis.
See circular for full proposal.
C-14356
Revisions to MSRP Section B, FREIGHT CAR DRAFT COMPONENTS, Proposed new publications M-902 End-of-Car Energy Management Systems, and RP-903 Methodology: Multi-Car Drifting Simulations
Issued: May 6, 2024
Effective: 30 days for comment.
The purpose of this circular letter is to solicit comments for revisions proposed to Section B FREIGHT CAR DRAFT COMPONENTS. The AAR Equipment Engineering Committee (EEC) is proposing two new publications:
- Specification M-902 End-of-Car Energy Management Systems
- Recommended Practice RP-903 Methodology: Multi-Car Drifting Simulations.
M-902 is being proposed to allow interchange approval of new draft system types whose performance may be considered somewhere between a draft gear and a cushion unit.
RP-903 is being proposed to provide a method for predicting over-the-road performance of any draft system type. Use of RP-903 would be required upon implementation of M-902 to provide additional information for consideration by the EEC.
C-14355
Revisions to Field Manual, Rule 9 and Various Related Rules
Issued: May 6, 2024
Effective: 30 days for comment.
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 9 and to remove references to Job Code 4468 from associated Rules, was reviewed and approved.
See Circular for full proposal.
C-14353
Revisions to Field Manual, Rule 59, Cushioned Underframe Devices
Issued: May 6, 2024
Effective: 30 days for comment.
At the April 2024 meeting of the Arbitration and Rules Committee a proposal as advanced by the Equipment Engineering Committee to revise Field Manual Rule 59 was reviewed and approved.
See Circular for full proposal.
C-14352
Revisions to Field Manual, Rule 41 and Rule 83
Issued: May 6, 2024
Effective: 30 days for comment.
At the April 2024 meeting of the Arbitration and Rules Committee, a proposal as advanced by the Car Repair Billing Committee to revise Field Manual Rules 41 and 83 to add Why Made Codes to identify when a slid flat and a built-up tread are caused by the hand brake left applied, was reviewed and approved.
See Circular for full proposal.
C-14351
Revisions to Office Manual Rule 107.C.2
Issued: May 6, 2024
Effective: 30 days for comment.
At the April 2024 meeting of the Arbitration and Rules Committee, a proposal to revise Office Manual Rule 107.C.2, was reviewed and approved.
See Circular for full proposal.
C-14350
Revisions to Field Manual, Rule 62, Truck Side Bearings
Issued: May 6, 2024
Effective: 30 days for comment.
At the April 2024 meeting of the Arbitration and Rules Committee a proposal as advanced by the Equipment Engineering Committee to revise Field Manual Rule 62 was reviewed and approved.
See Circular for full proposal.
C-14349
Revisions to Field Manual, Rule 99 and Field and Office Manuals Rule 107
Issued: May 6, 2024
Effective: 30 days for comment.
At the April 2024 meeting of the Arbitration and Rules Committee, a proposal to revise Field Manual Rule 99 and Field and Office Manuals Rule 107, was reviewed and approved.
See Circular for full proposal.
C-14347
Revisions to Field Manual, Rule 47.A, Truck
Issued: May 6, 2024
Effective: 30 days for comment.
At the April 2024 meeting of the Arbitration and Rules Committee a proposal as advanced by the Coupling System and Truck Castings Committee to revise Field Manual Rule 47.A was reviewed and approved.
See Circular for full proposal.
C-14346
Revisions to Field Manual, Rule 16, Couplers, Type E and Parts
Issued: May 6, 2024
Effective: 30 days for comment.
At the April 2024 meeting of the Arbitration and Rules Committee a proposal as advanced by the Coupling System and Truck Castings Committee to revise Field Manual Rule 16 was reviewed and approved.
See Circular for full proposal.
C-14345
Revisions to Field Manual, Rule 13, Hand Brake Sheave Wheel
Issued: May 6, 2024
Effective: 30 days for comment.
At the April 2024 meeting of the Arbitration and Rules Committee, a proposal as advanced by the Car Repair Billing Committee to revise Field Manual Rule 13 to include a Job Code for Hand Brake Sheave Wheel, was reviewed and approved.
See Circular for full proposal.
C-14344
Revisions to Field Manual, Rule 13, Hand Brake Chain Wear Limits
Issued: May 6, 2024
Effective: 30 days for comment.
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 13 to address hand brake chain wear, was reviewed and approved.
See Circular for full proposal.
C-14360
Revisions to MSRP Section D, TRUCKS AND TRUCK DETAILS, Standard S-320, Side Frame – Column Wear Plate Application, and retirement of S-3003, Side Frame – Column Friction Wear Plate Application
Issued: May 9, 2024
Effective: 30 days for comment.
The purpose of this circular letter is to solicit comments for revisions proposed to Section D, Standard S-320, Side Frame – Column Wear Plate Application, and retirement of S-3003, Side Frame – Column Friction Wear Plate Application. This proposal consolidates information from both standards into S-320, which allows for retirement of S-3003.
See Circular for full proposal.
C-14361
Revisions to MSRP Section C CAR CONSTRUCTION FUNDAMENTALS AND DETAILS: Proposed new Standard “S-2057 Draft Arrangements, 24 5/8-in. Pocket”; retirement of S-239, S-243, and S-245; edits to S-236, S-238, S-270
Issued: May 13, 2024
Effective: 30 days for comment.
The purpose of this circular letter is to solicit comments for revisions proposed to Section C CAR CONSTRUCTION FUNDAMENTALS AND DETAILS. The AAR Equipment Engineering Committee’s (EEC) intent is to consolidate the following 24 5/8-in. pocket standards into one.
See Circular for full proposal.
C-14362
Revisions to MSRP Section S, CASTING DETAILS, Specification M-210, Side Frame and Bolsters AAR Approved – Purchase and Acceptance, regarding Audit Quality Task Force updates
Issued: May 16, 2024
Effective: 30 days for comment.
The purpose of this circular letter is to solicit comments for revisions proposed to Section S, Specification M-210, Side Frame and Bolsters AAR Approved – Purchase and Acceptance, regarding Audit Quality Task Force updates.
The AAR Coupling System and Truck Castings Committee (CSTCC) is proposing revisions to M-210 as part of a stepwise implementation of changes directed by the Mechanical Committee Audit Quality Task Force. Additionally, CSTCC is proposing changes to the welding and finishing requirements.
See Circular for full proposal.
C-14363
Revisions to MSRP Section S, CASTING DETAILS, Specification M-201, Castings Steel, regarding a change to the maximum aluminum content
Issued: May 16, 2024
Effective: 30 days for comment.
The purpose of this circular letter is to solicit comments for revisions proposed to Section S, Specification M-201, Castings Steel, regarding a change to the maximum aluminum (Al) content.
See Circular for full proposal.
C-14364
Revisions to MSRP Section S, CASTING DETAILS, Specification M-203, Truck Side Frames Cast Steel – Design and Testing, regarding load range and use of stabilizing vertical preloads
Issued: May 16, 2024
Effective: 30 days for comment.
The purpose of this circular letter is to solicit comments for revisions proposed to Section S, Specification M-203, Truck Side Frames Cast Steel – Design and Testing, regarding load range and use of stabilizing vertical preloads.
A non-zero preload is commonly used to stabilize the vertical loading of a side frame during M-203 fatigue testing. The Coupling System and Truck Castings Committee (CSTCC) is proposing changes to clarify that the maximum vertical load is adjusted by the amount of the preload to maintain the vertical load range.
See Circular for full proposal.
C-14375
Electric Vehicles Batteries for Auto Parts Shipments (DP&FC)
Issued: May 30, 2024
Effective: 30 days for comment.
The purpose of this circular letter is a request for information on electric vehicle batteries for auto parts (boxcar or intermodal) shipments from the electric vehicle battery industry. The Damage Prevention & Freight Claim Committee requested the formation of a technical advisory group (TAG) to research if electric vehicle batteries can be secured for rail transportation for auto parts shipments. Due to the characteristics of lithium batteries, the TAG is researching how battery packaging and load securement could respond during rail transportation.
See Circular for full details.
Notice of Circulars
C-14342
Save the Date – Announcing the 2025 AAR’s 37th Quality Assurance Industry Conference
Issued: May 6, 2024
Effective: May 6, 2024
The Association of American Railroads (AAR) Quality Assurance Committee (QAC) is pleased to announce the 37th Annual AAR Quality Assurance Industry Conference, February 25th – 27th, 2025, Phoenix, Arizona.
The AAR Quality Assurance Committee (QAC) seeks to continuously improve the conference based on recommendations from QAC members, AAR Auditors, and previous conference attendees. Based on positive feedback from this year’s conference, we are pleased to announce a return to Phoenix in 2025. A new series of topics, workshops and speakers is being complied. Visit the conference website regularly for updates:
C-14343
Informational Circular, 4-pressure Automated Single Car Air Brake Testing and Equipment Rules Clarified
Issued: May 6, 2024
Effective: May 6, 2024
AAR circular letters C-13546 (April 24, 2020) & C-13607 (June 30, 2020) were issued to implement an AAR Interchange Rules requirement to equip freight cars with 4-pressure Automated Single Car Air Brake Test capability by June 30, 2025. C-13984 (May 2022) was issued urging the equipping of freight cars with 4-pressure equipment. This circular is being issued to summarize the 4-pressure timeline and provide explanations on the related rules.
See Circular for full details.
C-14359
2024 AAR M-1003 Quality Assurance Auditor Training Class Schedule and Registrations – New Class Added
Issued: May 8, 2024
Effective: May 8, 2024
Due to high demand the Association of American Railroads (AAR) Quality Assurance Committee (QAC) has added a new class in Mexico that will be taught in Spanish. The new class is scheduled for October 8-10, 2024.
C-14371
Revisions to Office Manual, Appendix B General Rule 4
Issued: May 17, 2024
Effective: July 1, 2024
At the April 2024 meeting of the Arbitration and Rules Committee a proposal as advanced by the Specially Equipped Freight Car Committee to revise Office Manual Appendix B General Rule 4 to align with Field Manual Appendix B.C.5, was reviewed and approved. The entire text of the revision is identified in the circular.
This change will be included in the July 1, 2024 updates to the Office Manual.
C-14370
Revisions to Field and Office Manuals, Appendix A, Additions and Betterments
Issued: May 17, 2024
Effective: July 1, 2024
At the April 2024 meeting of the Arbitration and Rules Committee a proposal was advanced by to revise Field and Office Manuals Appendix A for clarification and to align with the Umler Data Specification Manual Appendix O was reviewed and approved. The entire text of the revision is identified in the circular.
This change will be included in the July 1, 2024 updates to the Office Manual.
C-14369
Revisions to Field Manual, Rule 82
Issued: May 17, 2024
Effective: July 1, 2024
At the April 2024 meeting of the Arbitration and Rules Committee a proposal as advanced by the Equipment Engineering Committee to revise Field Manual Rule 82 was reviewed and approved. The entire text of the revision is identified in the circular.
This change will be included in the July 1, 2024 updates to the Office Manual.
C-14368
Revisions to Field Manual, Rule 53, Running Boards, End Platforms, Brake Steps, and Supports
Issued: May 17, 2024
Effective: July 1, 2024
At the May 2024 meeting of the Arbitration and Rules Committee, a proposal as advanced by the Equipment Engineering Committee to revise Field Manual Rule 53 to add WM41, was reviewed and approved. The entire text of the revision is identified in the circular.
This change will be included in the July 1, 2024 updates to the Office Manual.
C-14367
Revisions to Field Manual, Rule 46
Issued: May 17, 2024
Effective: July 1, 2024
At the April 2024 meeting of the Arbitration and Rules Committee a proposal as advanced by the Equipment Engineering Committee to revise Field Manual Rule 46 was reviewed and approved. The entire text of the revision is identified in the circular.
This change will be included in the July 1, 2024 updates to the Office Manual.
C-14366
Revisions to Field Manual, Rule 36.E.13
Issued: May 17, 2024
Effective: July 1, 2024
At the April 2024 meeting of the Arbitration and Rules Committee a proposal as advanced by the WABL Committee to revise Field Manual Rule 36 was reviewed and approved. The entire text of the revision is identified in the circular.
This change will be included in the July 1, 2024 updates to the Office Manual.
C-14365
Revisions to Field Manual, Rule 21.B, Group S
Issued: May 17, 2024
Effective: July 1, 2024
At the April 2024 meeting of the Arbitration and Rules Committee a proposal as advanced by the Equipment Engineering Committee to revise Field Manual Rule 21.B.1 was reviewed and approved. The entire text of the revision is identified in the circular.
This change will be included in the July 1, 2024 updates to the Office Manual.
C-14372
Revision to AAR MSRP Specification for Quality Assurance, Section J, M-1003
Issued: May 17, 2024
Effective: May 17, 2024
The purpose of this circular letter is to inform the industry that the Association of American Railroads (AAR) Quality Assurance Committee (QAC) has made a revision in MSRP Section J, M-1003, Chapter 3 – Administrative Provisions. The revision addresses the requirements for proof of supply to the North American Railway Interchange Service, allowing M-1003 certified facilities a longer period where there may not be continuity of supply.
See Circular for full details.
C-14374
AAR OTLR Requirements for Containers on Flatcars or Articulated Flatcars in Manifest Train Service
Issued: May 20, 2024
Effective: May 20, 2024
The AAR Open Top Loading Rules (OTLR) Committee was requested to review new business opportunities to transport containers on flatcars or articulated flatcars in manifest train service.
In intermodal service these containers are permitted to ship secured with twist locks on flatcars or articulated flatcars; but not in manifest service, where railcars are likely to be handled in yards. Moving containers on flatcars in manifest/merchandise service places the shipments under the governance of the AAR Open Top Loading Rules.
To meet OTLR requirements a secondary securement method must be applied to the container(s), or the rail equipment itself must be re-engineered.
See Circular for full details.
Economic & Industry Update
The 14th edition of “Economic & Industry Update”, a short video produced by GBX’s marketing team, featuring Mallory Moran and Jay Carter.
Upcoming Event
Midwest Association of Rail Shippers (MARS) 2024 Summer Meeting
Lake Geneva, WI | July 8–9, 2024
Greenbrier is proud to sponsor the MARS conference.
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.
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- DOT Compliance Assessments (Corporate and Plant)
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- 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
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