shoulder or ready to bring the hammer down if
you screw up.”
A lot of things need to happen all at once in order
to dig a tunnel.
The tunnel boring machine’s cutting head —
which looks a bit like a cheese grater attachment
on a food processor — will turn at 20 revolutions
per minute to tear up the earth, propelled by a
200-pound motor that uses repurposed car jacks
to push the machine along.
The dirt feeds through the holes in the cutting
head into a cavity in the machine, where it mixes
with water and is pumped through a swimming
pool tube back to the surface.
At the rear of the machine, what looks like a tarp
tunnel used for dog agility training will gradually
unfold like a massive accordion, lining and
supporting the tunnel so a remote-controlled car
can drive through it.
The entire digging process will only take a few
hours, but to make it happen, students have
been working anywhere from 30 to 70 hours a
week for more than a year to design and build
the tunnel boring machine. There are separate
subteams working on power, circuits, software,
propulsion, excavation, soil removal, structure
and tunnel support.
In late July, teams of students were working in
Wagner’s backyard and at a lab on campus.
Students worked at crimping connectors, wiring
motors and debugging computer software to
make sure all of the machine’s parts can talk to
each other and to the students.
Senior Toby Savage and sophomore Max
Balasubramaniam worked to create a filter for the