In a factory yard north of Moscow, among the scrapyard of rusted and decrepit machines of Soviet times, a piece of Cold War history sits frozen in time. Its nose juts upward, sleek as a fighter jet.

In 1966, the New York Central Railroad built the M-497 “Black Beetle,” a jet-powered train using surplus B-58 Hustler bomber engines. Designed to prove that high-speed rail could work on existing ...