The world’s largest operating steam locomotive has several Louisiana whistle-stops and overnight stays in two cities as part of a 10-state tour. Big Boy No. 4014 will be on display Saturday in New Orleans, where it will arrive Friday night and leave Sunday morning on its way back to Cheyenne, Wyoming. Before leaving Louisiana it also will spend a night in Shreveport. “This is the biggest steam locomotive Union Pacific ever built and it’s the only one in operation today,” Union Pacific Railroad spokesman Mike Jaixen told The American Press. At more than 130 feet (nearly 40 meters) long — longer than two city buses — and 560 tons (508 metric tonnes) in weight, the Big Boy locomotives are generally accepted as the largest steam locomotives ever built anywhere, according to the Guinness Book of World Records. The most powerful, though, was a tank engine built by Baldwin Locomotive Works in 1916 for the Virginian Railway, according to Guinness. The American Locomotive Co. built 25 Big Boys for Union Pacific in the 1940s to haul freight over Utah’s Wasatch Mountains on a route between Wyoming and Utah. Eight remain. The others all are in museums, Jaixen said. No. 4014 was retired in 1961. It underwent a five-year renovation for a yearlong tour in 2019 to mark the 150th anniversary of the transcontinental railroad’s completion.