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-656fb was what came out of this process in the middle of 2023; An eco p-series sled on radial trucks (with a Derby-built battery compartment) that can supply a constant 5600 HP for about a hour (in actual service regenerative braking and not needing that sort of horsepower all the time stretches it out to about 6 hours; At the press conference for the unveiling of this unit ILW said that the 656fb’s could be ordered with pantographs for charging from overhead wire or MU power connectors so they can be charged by other locomotives in a consist.)

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.