HISTORY: Why are tunnel boring machines named, and why are they named after women?

Yesterday, our tunnel boring machine Mackenzie—who has been disassembled for more than a month but keeps right on tweeting—received a great question from a follower:

Are all tunnel boring machines named after women? Why?@MomChungtheTBM @BerthaDigsSR99 @BigAlmatheTBM @LadyBirdTBM @MackenzieTBM
— Kimble McCraw (@kimblem) December 12, 2013

With a little help and a link shared by @HMMnews, we were able to find the answer. WNYC's Derek Wang reported earlier this year, covering Seattle's TBM Bertha, that "the tradition and practice of naming tunneling machines dates back to the earliest mining traditions" including devotions to patron saints of safety of underground workers.


Another source Gautrain says a TBM cannot start work until it has been given a name.

As for why they are most commonly female names, "a TBM is generally named after a lady as a sign of good luck for the project ahead," Gautrain reads.

Mackenzie finished her digging in August, but before she even started her work in 2012, she was named after the daughter of a McNally-Kiewit employee. McNally-Kiewit is the contractor for the Euclid Creek Tunnel project.