The first batch (414-435) of these C420s were purchased as part of the post-merger dieselisation of the TdM & LT&L. The second batch (469-482) were acquired second-hand when the PV&T bought the D&H in 1984, and a third batch started trickling in as various Alco-powered shortlines started retiring their no-​longer-​even-​close-​to-​EPA-​conformant historic locomotives.

In the 2020s, they started to be rebuilt at ILW with modern internals and a Tier 4f prime mover (a Cummins QSK60 diesel). This program was slowed by the China Tunnel Project, but by the mid 2020s most of them had been remanufactured.

All of these units, whether remanufactured or not, remain in service.