Why tunnel boring machines are named after women

Why are the eight tunnel boring machines (TBMs) used in London's mega Crossrail project all named after women (Phyllis, Ada, Elizabeth, Victoria, Jessica, Ellie, Sophia and Mary)? Why is the infamous TBM stuck underneath Seattle for the last two years called (Big) Bertha and why is Alice tunneling Vancouver's new Evergreen Line?

Gizmodo's Factually picks up on a Los Angeles Times article, about a competition to name the new machine digging the city's new Crenshaw rail line to explain why these diggers are named after famous women or have female names.

It's a tradition dating back to the 1500s when miners - and anyone working with explosives such as armourers and military engineers - prayed to Saint Barbara to protect them from the dangers underground.

The Great Martyr Barbara lived in present day Turkey or Lebanon during the the third century and was locked up in a tower and executed by her father Dioscorus because she secretly converted to Christianity.

According to Catholic lore God struck her father with a blast of lightning as punishment, hence the association with explosives and flashes of light in underground darkness.

Image of shrine to Barbara in Germany's Schacht Konrad mine by Wusel007