The world's largest operating steam locomotive, Big Boy No. 4014, is currently traveling across the United States. Crowds are gathering to watch the historic train pass through their towns.
The locomotive is 133 feet long and weighs 1.2 million pounds. It recently went through Valley Forge National Historical Park in Pennsylvania, with its bells ringing and whistle blaring. Spectators described the whistle's sound as powerful.
A Cross-Country Journey
Big Boy is on a cross-country tour to celebrate America's 250th birthday. After stopping in Philadelphia for July 4 and 5, it continued through Ohio, Indiana, Illinois, Missouri, Kansas, and Colorado. The train will return to Wyoming at the end of the month. You can track its journey online.
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Ed Dickens, senior manager of Union Pacific's heritage operations and a train engineer, noted that the train is entirely manually operated. Every sound and movement is controlled by human hands, using 1940s technology.
Inside the cab, the crew wears earplugs and eye protection due to the loud noise and heat from the furnace. They drink water regularly and use hand signals to communicate.
The History of Big Boy Locomotives
Big Boy No. 4014 is one of 25 Big Boys built by the American Locomotive Company between 1941 and 1944. Union Pacific designed them to haul supplies through the Wasatch Mountains between Utah and Wyoming.
These locomotives were known for their power, size, and weight. They had extra wheels and larger cylinders, allowing them to pull 120-car freight trains weighing 3,800 tons at 40 miles per hour.
Only eight Big Boys still exist today. Most are in museums, but No. 4014 is the only operational one. It retired from freight duty in December 1961 after traveling over one million miles.
In 2013, Union Pacific reacquired No. 4014 from the RailGiants Train Museum in California and began restoring it. Austin Barker, a lead journeyman machinist, called it "the holy grail of all steam locomotive restorations."
Big Boy No. 4014 returned to service in 2019 for the 150th anniversary of the first transcontinental railroad. This current journey is its first-ever coast-to-coast trip. Union Pacific CEO Jim Vena described it as a "trip of a lifetime." Engineer Ed Dickens noted the millions of people turning out to see the locomotive, calling it a "heartwarming emotion."
Deep Dive & References
Big Boy No. 4014 - Union Pacific Big Boy Locomotive Steam - NPR, 2026 America’s 250th Anniversary - Smithsonian Magazine Union Pacific Press Release - Union Pacific Big Boy Schedule - Union Pacific Track Big Boy - Union Pacific Ed Dickens Profile - Union Pacific Big Boy Infographic - Union Pacific Inside Big Boy - Pittsburgh Tribune-Review History of the Union Pacific Big Boy No. 4012 - National Park Service RailGiants Train Museum Transcontinental Railroad's 150th Anniversary - Union Pacific Big Boy in Western Pennsylvania - CBS Pittsburgh
