Behold, DC Water's Lady Bird! Behold, DC Clean Rivers’ Lady Bird!

Last April, D.C.’s new tunnel boring machine, or TBM, was christened in the manner of a ship, albeit with tap water rather than champagne. The 442-foot-long beast, whose business end is 26 feet in diameter, is digging a tunnel to divert sewage from the Anacostia River. Despite this dirty job, the TBM was given an improbably dainty name: “Lady Bird,” after environmentalist and former first lady Claudia Alta Taylor Johnson.

It turns out, giving TBMs female names is a long-standing tradition in the tunneling world.

“It’s kind of murky how it started,” says Christopher Allen, construction manager for DC Clean Rivers, the entity in charge of Lady Bird. “It has the connotation, if you treat her well, she’ll be good to you and she’ll save you and keep you safe.”

Mining lore links the practice to diggers seeking favor with St. Barbara, their patron saint.

Most TBMs are still “female,” but that’s changing: Dogs, rivers and neighborhoods now have TBM namesakes. More-abstract monikers are chosen solely for cuteness’ sake. And these days, communities, rather than construction crews, often name their TBMs. The things even have Twitter accounts. Check out Lady Bird and some of her pals below.