Army sizes its first new locomotives in over a decade to the track each one runs on

Blue Grass Army Depot in Kentucky runs its trains on older track with lower weight limits. Its new switcher, USAX 1699, accepted in October 2025, was built by SpecSys to the physical dimensions of a vintage General Electric 80-ton locomotive so it could work that track ^[6]. At Crane Army Ammunition Activity in Indiana the limit is geometry. USAX 4673, a 120-ton unit from Knoxville Locomotive Works accepted in February 2026, has special couplers and restricted exterior dimensions to get through tight curves and limited clearances ^[5].

The program is pitched as replacing locomotives past a 65-year expected life ^[1]. What the crews actually received is a pair of machines built around the track they already have. We think the Army chose correctly. A standard locomotive that cannot clear a curve, or that is too heavy for the rails, does nothing for the people who move ammunition on that line ^[4].

Whether the program reaches its target is harder to judge. TACOM wants the over-age share below 20 percent, down from more than a third, a drop of more than 13 percentage points ^[17]. If each new locomotive retires one over-age unit, two deliveries close that gap only on an active fleet of fewer than 15 locomotives ^[16]. The Army's October 2026 announcement, as reported, does not give the fleet size or a date for the target ^[12].

Better visibility into equipment readiness was already on the agenda at the Army Rail Summit in 2026. Officials there discussed the strain decades of demand have put on locomotives, railcars and installation track, and the need for better visibility into equipment and track readiness ^[11]. The work is routine. Rail moves "much of the service's equipment from home or mobilization stations to training areas and ports of embarkation," according to the Army's Transportation Corps ^[13].

Custom fitting has a price. The three deliveries total about $5.73 million ^[14]. In nominal dollars, before any adjustment for a decade of inflation, the Crane locomotive cost about 58 percent more than the 2015 Fort Cavazos unit while weighing 20 tons less ^[15].

For any team replacing an aging fleet against a share target, two checks sort the decision. The first is a count: over-age units that must retire to hit the target, set against units arriving each year. The second is the receiving site, and whether its track weight, curves or clearances rule out a standard unit. Crossing the two gives four cases. In our view, over-age and site-constrained means a custom build priced like Crane's. Over-age and unconstrained means the cheapest standard unit that does the job. Within service life but constrained is where track maintenance money goes further, and Fort Drum's ballast regulator is spending of that kind ^[8]. Within life and unconstrained can wait.