As part of the BAR’s planned retirement of its most worn DL17s, some of them had all the existing components stripped to keep the rest of the fleet going, then had the frames & trucks shipped up to ILW for remanufacturing into a modern drop-in replacement machine.

The eco-435m (aka the “rs-38”) was the result; a 3300HP locomotive with a Tier 4 Cummins QSK78 – a 3500 HP engine, but it loses a couple of hundred HP to the exhaust scrubbing system – coupled to an AC drivetrain, all wrapped in a very alco-like superstructure on the existing GP38 frame.

The prototype (BAR #1211) was delivered in 2013, and was rebuilt with radial trucks after a rollover wreck in 2021.

In 2023, ILW started producing a second version of the rs-38 which came with vista cabs, tweaks to the electrical system, and ballasted frames. They are otherwise mechanically identical to the first generation eco-435m’s

At roughly the same time in 2023, the BAR’s Derby shops started doing their own rebuilds of GP38 carcasses into second generation rs-38s, using the existing EMD cab & short hood, and after the 2025 abolition of EMD power on the system is now doing these rebuilds on the once again huge pile of retired and (officially) scrapped geeps that are piling up in the Derby storage yard.