The Union Pacific Big Boy No. 4014 the world’s largest operating steam locomotive. Only 25 were made and out of the eight remaining "Big Boys" the No. 4014 is the only one still in operation
The Union Pacific Big Boy is an absolute behemoth. From coupler to coupler, it measures about 133 feet in length and stands roughly 16 feet tall. In full working order, it tips the scales at a staggering 1.2 million pounds (600 tons)
