The Big Boy locomotives were built to conquer mountains, massive articulated steam engines designed to haul heavy freight over some of the steepest grades in the American West. This episode looks at the scale and engineering of the largest steam locomotives ever built.

Few trains carry as much legend as the Orient Express. Linking Paris to Istanbul in luxury and mystery, it became a symbol of adventure and elegance across Europe. This episode traces its storied route and the world it once connected.

Somewhere in India, a steam locomotive built in 1855 still runs today, believed to be the oldest of its kind still operating in the world. This episode follows the Fairy Queen's long life, from its earliest days hauling freight to its place now as a living piece of railway history.

Built to mark a century of the American railroad, the Union Pacific 6900 was among the most powerful diesel locomotives ever constructed. This episode explores the scale of its engineering and what it took to build a machine strong enough to carry Union Pacific's centennial ambitions across the country.

In 1964, as Tokyo prepared to host the Olympics, Japan unveiled a train unlike anything the world had seen. The 0 Series Shinkansen redefined what speed on rails could mean, carrying passengers between cities faster than anyone thought possible. This episode traces the engineering and ambition behind the birth of the bullet train.