@PopularMechanics _ April 2019 25How to Tunnel
Across the
United States
IN THIS MONTH’S The Hummingbird Project,
two cousins, played by Jesse Eisenberg and
Alexander Skarsgård, quit their jobs at a high-
frequency trading firm in pursuit of a grand
idea: They’re going to build a tunnel for fiber-
optic cable on a straight line from the servers
of the New York Stock Exchange (actually
in New Jersey) to a communications hub in
Kansas. High-frequency traders make money
by executing trades milliseconds faster than
competitors, so they think their straight-line
route, faster than meandering existing cables,
will make them rich. Here are some of the
challenges they’ll face.
A Very Warm Sleeping Bag
for the Great Outdoors
WHEN I HEARD that Therm-a-Rest’s new Hyperion 20 sleeping bag was rated for 20 degrees
Fahrenheit—even at an impossibly light weight of one pound four ounces—I needed
to know if it could actually handle the cold. But the perfect testing conditions are not
conditions in which I typically plan camping trips, and the idea of sleeping in my 22-degree
backyard in Vermont, next to my truck and trash cans, wasn’t thrilling. Watching Dan
Aykroyd and John Candy in The Great Outdoors on my porch, though? That I could do.
I wrapped up in the bag and settled into my porch couch. As I watched, I had the weird
experience of forgetting I was outside. Clever distribution and baffling minimizes
compression, so the bag’s down captures lots of warm air—I had to pull my torso out
when I got toasty. And the 900-fill down is hydrophobic, so no big deal when I moved my
legs straight into the snow on the porch edge. Quick review of the movie: mediocre; not
about the outdoors; mostly rich-jerk/lovable-regular-guy one-liners. Quick review of the
bag: It’s ready for trips much farther than the front porch, though that’s where I was again
the next week. Figured I’d give Nothing But Trouble a chance. —James Lynch1 / KANSAS CITY, KANSAS
Most of the upper
Midwest was once
under glaciers, and its
soil is soft sediment
left behind as they
melted—theoretically,
easy to tunnel through.
But here the bedrock is
tilted, rather than flat,
meaning layers of hard
rock can be closer to
the surface than would
be ideal.
3 / ILLINOIS/INDIANA
Crossing under a major
municipality means
identifying utilities,
subbasements, and
the like, and rout-
ing around them. But
to dig straight, you’d
have no choice but to
go deep—probably
too deep for HDD.2 / MISSISSIPPI RIVER
The cousins use
horizontal directional
drilling (HDD), a com-
mon technique for small
tunnels, like for utilities.
Its drilling fluid poses
environmental risks,
which may make it hard
to get a permit from the
Army Corps of Engi-
neers—required to go
under the Mississippi.5 / NEW JERSEY
While much of the
Appalachian section
is relatively soft rock,
the earth trends
harder approaching
the Eastern seaboard.
The super-hard
bedrock that makes
great foundations for
skyscrapers in New
York and New Jersey is
hell on drills.4 / CENTRAL PA
HDD can only go
about two miles before
the machine has to
resurface—so in the
Appalachians the crew
would have to dig
deep shafts through
mountains to get it out.
Or switch to a proper
tunneling machine, which
is bigger and slower, but
doesn’t have to surface.ILLINOIS2PENNSYLVANIAMISSOURIINDIANA15
4KANSASOHIONEW
JERSEY3
Electronic Kansas^
ExchangeMississippi RiverThe cousins drilling a
straight line through
the eastern third of
the U.S.—before the
going gets tough.