The Locomotive So POWERFUL It Ripped Apart Its Own Tracks

Everyone knows the Union Pacific Big Boy — the legendary steam locomotive celebrated in museums and history books.
But almost no one remembers the Pennsylvania Railroad S1.

And that’s strange… because by raw power alone, the S1 may have been the most powerful steam locomotive ever built in North America.

Designed to prove that steam could outperform diesel, the S1 was longer, faster, and more powerful than anything that came before it. But that power came at a cost. The locomotive generated so much force that it damaged the very infrastructure it ran on — twisting rails, breaking joints, and pushing 1930s railroad engineering beyond its limits.

Unveiled at the 1939 New York World’s Fair to crowds of over 100,000 people, the S1 was meant to be the future of railroading. Instead, it became one of the most spectacular engineering overreaches in transportation history.

In this documentary, we explore:

Why the Pennsylvania Railroad built the S1

How its extreme power caused track damage and operational failures

Why it was quietly retired and erased from public memory

What the S1 reveals about the true limits of steam locomotive technology

The S1 wasn’t defeated by weakness.
It was defeated by excess.

This is the forgotten story of the steam giant that proved power alone is never enough.