Battery electric locomotives started becoming more popular in the early 2000s as switchers, but as the ongoing climate catastrophe intensified most of the class 1s in North America started showing interest in “what about a battery electric road locomotive” (cheaper than electrification if you’re primarily interested in them for PR purposes.)

Caterpillar subsidiary Progress Rail introduced one, Wabtec introduced one, so ILW’s board sighed heavily and directed the company to also build some demonstrator units.

The eco-646fb was what came out of this process in the middle of 2023; An (ILW-built) eco p-series sled on radial trucks, with a Derby-built battery compartment (& suitably large halon fire suppression system)

This unit demonstrated (as LT&L #1493) on the LT&L’s international line in the last 6 months of 2023, was not purchased by the Parsons Vale, but eventually found a home as part of an order by the BNSF in the United States.