The Santa Fe Was DPU Before DPU Was Cool

Before Distributed Power locomotives (DPU’s) became commonplace, the Santa Fe and the Southern Pacific used unmanned helper locomotives with an early version of DPU technology.

The Santa Fe installed Locotrol II equipment in its re-built U36C fleet in the mid 1980’s. This  allowed remote control operation of mid-train helper engines. Even numbered units were masters, and would be used as the lead unit. Odd numbered units were the remotes, receiving radio commands from the lead unit.

Here we see a 785 train (Rustler Springs, NM – Galveston, TX sulfur unit train) approaching Wallis, Texas on May 5, 1990, with SF30C 9550  leading a SD45-2B and an SD45 on the head end.

The remote locomotive consist  is B40-8 7414 MU’d to  remote receiver SF30C 9519.

In a page straight out of the Southern Pacific playbook, a Santa Fe yardmaster has added a fill of loaded grain to what typically always ran a solid train of molten sulfur tankcars.