In 2019, the Class I kicked off the program to rebuild its line-of-road units, and has, to date, completed 120 with “more on the horizon,” it said.
Each SD-70 rebuild takes 12 weeks—from the replacement of rotating equipment (engine, main, trucks) to paint, according to Bryon Keim, Assistant Plant Superintendent, Huntington Heavy Repair at CSX, who in the video offers a closer look at the process on No. 4770, the first unit to be rebuilt in 2025 (watch below).
The project is a collaborative effort, Keim noted in the video, with the Mechanical team crafts working together.
“Since we’ve been doing this project for so long, we have a pretty good rhythm,” he reported. “We have the same group of people that work on these locomotives every day. They know the timeframe in each phase, and they hit it each time.”
“This program is a testament to the teamwork and expertise of our Mechanical team,” CSX Vice President of Mechanical Operations Arthur Mayo said in the announcement of the video’s release. “These rebuilds set a higher standard for performance and ensure our train crews have reliable, high-quality equipment to operate.”
CSX is also continuing an AC4400 modernization program (see photograph of a completed unit below). It selected Wabtec for the project in 2021, and in 2024 extended the work to the remaining 200-plus AC4400 units in its 460-plus fleet to improve fuel efficiency, reliability, utilization and tractive effort. The program includes a suite of Wabtec hardware, such as the FDL Advantage (FDLA) engine upgrade, and digital solutions like LOCOTROL® Expanded Architecture (LXA).
Separately, CSX in 2023 partnered with Canadian Pacific Kansas City to develop hydrogen fuel cell (HFC)-powered locomotives. The first unit was unveiled last year, demonstrating what CSX called a “pioneering achievement marking a significant milestone in sustainable freight transportation” that “demonstrates the company’s commitment to innovation and environmental stewardship.”




