Railway titan Union Pacific recently announced a new partnership with ZTR Control Systems, which specializes in green technology for trains, to build new hybrid-electric locomotives, which are to be constructed at the Union Pacific facility in North Little Rock.
Much like a hybrid car, the locomotives will be capable of swapping between multiple modes, and will feature several ways to charge the batteries, including wayside and onboard charging. The first prototype is expected to be delivered in late 2023, with another five arriving in 2024.
“Adding hybrid-electric locomotives to our fleet is another important step for Union Pacific as we work to explore ‘drop-in’ technologies that modify current systems and reduce our carbon footprint,” said Union Pacific’s Senior Vice President of Engineering and Mechanical Shane Keller. “This pilot will help make our fleet more fuel efficient and further advance our commitment to reaching our sustainability goals, while testing the technology’s capability for expanded use across our locomotive fleet.”
Rather than having two locomotives, this prototype will use a “mother-slug” system, with one diesel locomotive connected to a “slug” that will be equipped with batteries, power electronics and controls supplied by ZTR. This will allow the train to shift between single engine, battery charging or electric only modes. The slugs will also improve traction, which is vital for the yard operations the Union Pacific plans to use them for.
“ZTR is proud of our long-standing relationship with Union Pacific and excited to partner with them on this hybrid-electric locomotive development,” said ZTR Control Systems President Derek Shipley. “This investment aligns well with our ongoing goal to leverage ZTR’s technical expertise to support railways in their decarbonization and efficiency improvement efforts. This initial hybrid-electric mother-slug application will be the basis of our design for future hybrid-electric, long-haul and fully electric solutions.”
Similar “mother-slug” sets have been in use by Union Pacific since 2017, and new developments from this project could reduce fuel usage and greenhouse gas emissions by as much as 80% on what is already one of the most fuel-efficient forms of transportation. To further reduce waste, the new locomotives will be made out of refurbished old locomotives.
This project is in line with Union Pacific’s 2021 Climate Action Plan to reduce absolute Scope 1 and 2 GHG emissions 26% by 2030 and achieve net zero greenhouse gas emissions by 2050.