@BigAlmatheTBM: I’m the farthest from starting to tunnel, so I’m very anxious to begin and curious about what it’ll be like. The others give me tips and tell me about their experiences. Online, it’s much the same—a lot of encouragement, and we share one another’s accomplishments with our followers.

@LadyBirdTBM: We talked about having a reunion, but I don’t think it’s going to happen. We’ve all got plans for the summer. We’ve traded skincare secrets, too, like how to dig 24,000 feet and keep that youthful glow…not really; I made that up. But I am a little worried this arduous journey is going to prematurely age me.

Mom and Alma, since the two of you are on the same project, is there any kind of rivalry going on?

@MomChungtheTBM: We’ve made a few friendly wagers. Big Alma talks a lot of dirt about how she thinks she’ll be faster than me. We’ll see what happens when the boring starts. There’s a lot of bedrock between here and there.

@BigAlmatheTBM: When we finish the job, the loser owes the winner a dinner of her favorite volcanic rock. Mom Chung: I’ll take mine slightly molten.

Anything else you’d like to share with ENR’s readers?

@BerthaDigsSR99: Just that I’m committed to finishing this job on time and on budget, and that I’ll have lots of help. I’m part of a project that combines the best of local and global expertise. The people in charge of me have had success building major projects, including large-diameter tunnels, all over the world. These people know what they’re doing. I hope folks will keep watching and rooting for us. We’re doing our best to make Washington proud.

@MackenzieTBM: Like I said, I don't share much myself, but I love how Twitter makes projects and personalities so accessible. Every one of us, especially the TBMs, has our own voice and experiences, and what we’re doing impacts the people living hundreds of feet above us. Why not be accessible to help them know more about it?

@LadyBirdTBM: I hope they will follow me. It’s going to be an exciting trip through the Potomac Clay 100 feet below ground, and I’m really looking forward to sharing updates and photos of my progress. That’s why I’m on Twitter—I’m a sharer by nature. Okay, more of a digger, but I like to share, too.

@MomChungtheTBM: Just that we’re excited to get digging! Our tunnels will travel beneath some of San Francisco’s busiest areas. Once the tunnels and are done, trains will travel quickly underground, improving transit for thousands of Muni customers every day. Big Alma and I are honored to be a part of this important project. To us, our job is the opposite of boring.