Expanding Certain Locomotive Wheel Set Diameter Variations

DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Railroad Administration</SUBAGY> <CFR>49 CFR Part 229</CFR> <DEPDOC>[Docket No. FRA-2025-0126]</DEPDOC> <RIN>RIN 2130-AD50</RIN> <SUBJECT>Expanding Certain Locomotive Wheel Set Diameter Variations</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Railroad Administration (FRA), Department of Transportation (DOT). <HD SOURCE="HED">ACTION:</HD> Notice of proposed rulemaking (NPRM). <SUM> <HD SOURCE="HED">SUMMARY:</HD> FRA proposes to amend its locomotive safety regulations to expand the maximum permitted variation in diameter for locomotive wheel sets using alternating current technology, in response to a Class I railroad's May 2019 petition for rulemaking and innovations in traction motor control. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> Comments on the proposed rule must be received by September 2, 2025. FRA may consider comments received after that date, but only to the extent practicable. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> <E T="03">Comments:</E> Comments related to Docket No. FRA-2025-0126 may be submitted by going to <E T="03">https://www.regulations.gov</E> and following the online instructions for submitting comments. <E T="03">Instructions:</E> All submissions must include the agency name, docket number (FRA-2025-0126), and Regulatory Identification Number (RIN) for this rulemaking (2130-AD50). All comments received will be posted without change to <E T="03">https://www.regulations.gov;</E> this includes any personal information. Please see the Privacy Act heading in the <E T="02">SUPPLEMENTARY INFORMATION</E> section of this document for Privacy Act information related to any submitted comments or materials. <E T="03">Docket:</E> For access to the docket to read background documents or comments received, go to <E T="03">https://www.regulations.gov</E> and follow the online instructions for accessing the docket. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Gary Fairbanks, Staff Director, Motive Power & Equipment Division, Federal Railroad Administration, telephone: (202) 230-9594, email: <E T="03">gary.fairbanks@dot.gov;</E> or Michael Masci, Attorney Adviser, Federal Railroad Administration, telephone: (202) 302-7177, email: <E T="03">michael.masci@dot.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">I. Background</HD> Consistent with the deregulatory agenda of President Donald J. Trump and Secretary of Transportation Sean P. Duffy, which seeks to unleash America's economic prosperity without compromising transportation safety, FRA is reviewing its regulatory requirements in parts 200 through 299 of title 49, Code of Federal Regulations (CFR). Under 49 CFR part 229, <E T="03">Railroad Locomotive Safety Standards,</E> FRA prescribes minimum Federal safety standards for all locomotives except those propelled by steam power. Some of the requirements contained in part 229 could be updated to reduce burdens, make technical or conforming changes, or otherwise adjust to advancing technology without any adverse effect on railroad safety. Please review the Section-by-Section Analysis below for the relevant information related to each proposed change. <HD SOURCE="HD1">II. Section-by-Section Analysis</HD> <HD SOURCE="HD2">Section 229.73 Wheel Sets</HD> FRA proposes to amend paragraph (b) of this section to expand the maximum permitted variation in diameter for locomotive wheel sets using alternating current (AC) technology. In May 2019, Union Pacific Railroad submitted a petition for rulemaking under 49 CFR part 209 on the basis that “[n]ew technology with individual axle control developed and placed in service after 1980 provides the basis for change which will result in better customer service through a reduction of locomotive out of service time and increased wheel life without impacting safety.”  <SU>1</SU> <FTREF/> <FTNT> <SU>1</SU>  UP's petition for rulemaking is available in Docket No. FRA-2025-0126 on <E T="03">https://www.regulations.gov.</E> </FTNT> Generally, excessive wheel size variation is a safety concern due to the potential impact on wheel slip and truck dynamics. For older locomotives equipped with direct current (DC) traction motors, excessive wheel size variation causes current imbalance and triggers wheel slip corrections, including unnecessary sanding, removing tractive effort, and removing power. These corrections can have adverse effects on the equipment and efficiency of operations but are necessary to prevent more serious safety hazards like damage to the rail. Newer locomotives equipped with AC traction motors utilize single axle control technology to apply voltage and control current more precisely to each wheel set based on operating conditions. As such, the AC traction motors function as an independent wheel slip correction system that do not use wheel size variation as a trigger for correction. Despite the improvements to prevent wheel slip, wheel sets on locomotives equipped with AC traction motors still need to minimize wheel size variation to help maintain proper truck dynamics. Excessive wheel size variation can decrease the effectiveness of weight distribution from corresponding trucks, and the trucks' inability to help absorb the impact of a shifting load could lead to a derailment. Existing paragraph (b) of § 229.73 specifies that the maximum variation in the diameter between any two wheel sets on different trucks on a locomotive that has three-powered-axle trucks may not exceed 1 <FR>1/4</FR> inches. FRA proposes to separate the existing requirement in current paragraph (b) into new paragraphs (b)(1)(i) and (b)(1)(ii), generally continuing the current 1 <FR>1/4</FR> inch maximum variation for wheel sets on older locomotives equipped with DC traction motors. FRA proposes to add a new paragraph (b)(2)(i), generally allowing a 1 <FR>1/2</FR> inch maximum variation for wheel sets on newer locomotives equipped with AC traction motors that utilize single axle control. Proposed new paragraph (b)(2)(ii) would eliminate the wheel set variation requirement of this section for wheel sets on non-powered axles on locomotives equipped with AC traction motors that utilize single axle control because FRA does not expect wheel variation to have a significant impact on truck dynamics in that case. FRA expects this proposal would better accommodate new technology and maintain current levels of safety. <HD SOURCE="HD1">III. Regulatory Impact and Notices</HD> <HD SOURCE="HD2">A. Executive Order (E.O.) 12866 (Regulatory Planning and Review) and DOT Regulatory Policies and Procedures</HD> FRA has considered the impact of this proposed rule under E.O. 12866, Regulatory Planning and Review (58 FR 51735, Oct. 4, 1993), and DOT Order 2100.6B, Policies and Procedures for Rulemaking (Mar. 10, 2025). The Office of Information and Regulatory Affairs within the Office of Management and Budget (OMB) determined that this NPRM is not a significant regulatory action under section 3(f) of E.O. 12866. This proposed rule would amend FRA's locomotive safety regulations to expand the maximum permitted variation in diameter for wheel sets using alternating current technology. FRA expects that this proposed rule would result in cost savings to the industry as it would increase a maximum threshold for certain locomotives under 49 CFR 229.73(b) due to innovations in traction motor control. This would, in turn, result in a reduction of locomotive out-of-service time and increased wheel life without impacting safety. The increased allowable variation would help reduce the regulatory burden on the railroad industry while maintaining proper truck dynamics. <HD SOURCE="HD2">B. E.O. 14192 (Unleashing Prosperity Through Deregulation)</HD> E.O. 14192, Unleashing Prosperity Through Deregulation (90 FR 9065, Jan. 31, 2025), requires that for “each new [E.O. 14192 regulatory action] issued, at least ten prior regulations be identified for elimination.”  <SU>2</SU> <FTREF/> Implementation guidance for E.O. 14192 issued by OMB (Memorandum M-25-20, Mar. 26, 2025) defines two different types of E.O. 14192 actions: an E.O. 14192 deregulatory action, and an E.O. 14192 regulatory action. <SU>3</SU> <FTREF/> <FTNT> <SU>2</SU>  Executive Office of the President. <E T="03">Executive Order 14192 of January 31, 2025. Unleashing Prosperity Through Deregulation.</E> 90 FR 9065-9067 (Feb. 6, 2025). </FTNT> <FTNT> <SU>3</SU>  Executive Office of the President. Office of Management and Budget. Guidance Implementing Section 3 of Executive Order 14192, Titled “Unleashing Prosperity Through Deregulation.” Memorandum M-25-20. Mar. 26, 2025. </FTNT> An E.O. 14192 deregulatory action is defined as “an action that has been finalized and has total costs less than zero.” This proposed rulemaking is expected to have total costs less than zero, and therefore it would be considered an E.O. 14192 deregulatory action upon issuance of a final rule. While FRA affirms that each amendment proposed in this NPRM has a cost that is negligible or “less than zero” consistent with E.O. 14192, FRA requests comment on the extent of the cost savings for the changes proposed in this NPRM. <HD SOURCE="HD2">C. Regulatory Flexibility Act and E.O. 13272</HD> The Regulatory Flexibility Act (5 U.S.C. 601 <E T="03">et seq.</E> ), as amended by the Small Business Regulatory Enforcement Fairness Act of 1996, <SU>4</SU> <FTREF/> requires Federal agencies to consider the effects of the regulatory action on small business and other small entities and to minimize any significant economic impact. Accordingly, DOT policy requires an analysis of the impact of all regulations on small entities, and mandates that agencies strive to lessen any adverse effects on these businesses. The term <E T= ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 19k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━