One of the World's Largest Steam Locomotives Is About to Make a Triumphant Return

Union Pacific’s No. 4019, pictured here in Weber Canyon, Utah. COURTESY OF UNION PACIFIC

Hold onto your engineer caps, railroad history lovers.
BY JUSTIN FRANZ JUNE 12, 2018

SEVENTY YEARS AFTER THE FIRST Transcontinental Railroad was completed in 1869, the steep Rocky Mountains of Wyoming and Utah were still giving the Union Pacific Railroad trouble.

Despite having massive steam engines, the Union Pacific, one of the biggest railroads in America, still struggled to move heavy freight trains over the mountains and would often have to use multiple locomotives to get trains to their destination. This practice required more workers and more fuel. In 1940, the Union Pacific’s mechanical engineers teamed up with the American Locomotive Company to build one of the world’s largest steam locomotives, a class of engine simply known as “Big Boy.”

Now, six decades after the last Big Boy was taken off the rails, the Union Pacific is rebuilding one of the famous locomotives in honor of the upcoming sesquicentennial celebration of the first Transcontinental Railroad. It’s a project so ambitious that Ed Dickens Jr, a Union Pacific steam locomotive engineer and the man leading the rebuild, has likened it to resurrecting a Tyrannosaurus rex.

FULL story: https://www.atlasobscura.com/articles/where-can-i-see-big-boy-steam-locomotive