Meet the Secret Locomotive that was Used to Move Serious Cargo

Built by General Electric in 1954, this diesel locomotive had no name, no number or even an official year designation. Yet it was based and used only at one of the most sensitive facilities operated by the U.S. Government for 30 years.

Despite only being 45 feet in length, the locomotive weighed a monstrous 215 tons and could only produce 400 horsepower. So, as you can guess, it was not a particularly fast engine, but that was intentional. Most of its weight came from the several inches of lead and water placed around the engineer’s cab in a semi-circular shell, which gives it its unusual shape.

Unique Features of the Locomotive

It only had two windows, both of which were 4 feet thick and used an oil mixture between the layers of glass. One of these windows could actually open but was intended to be an emergency exit. Crews would board the locomotive via a trap door that was under the locomotive and would have to use a special tunnel that the locomotive would park over when not in use. But just what was this train used to move?

Well, this Engine with no name was posted at the Idaho National Laboratory, where a number of tests using nuclear materials were conducted, and there was a need to move heavy pieces of equipment across the test site. Mainly at the TAN, or Test Area North, at the north end of the laboratory. So I guess you can call it the “TAN Locomotive.”

The Role of the TAN Locomotive

Either way, the TAN Locomotive would push custom-made rail cars that used four rails to move their heavy cargo across the laboratory. These cargoes could weigh up to several hundred tons at a time.

Today, you can still visit this most unusual locomotive at the Experimental Breeder Reactor No. 1 (EBR-1) Atomic Museum near Arco, Idaho, where it sits as one of the more interesting pieces of the Cold War. ~NC