Smithsonian_03_2020

40 SMITHSONIAN | March 2020

eff ect from the bomb fi rst. As I searched for information on
the Hunley’s explosive charge, one image in particular kept
appearing: a yellowed, faded scan of a cylinder, with hand-
drawn lines and circles detailing its shape. “Singer’s torpedo,”
proclaimed the large, old-fashioned calligraphy at the top
of the image, with the more crucial information in a slightly
smaller font below: “used for blowing up the Housatonic.”
According to this drawing, the Hunley’s charge contained
135 pounds of black powder. That is a lot of powder. It’s a lot of
any kind of explosive.
The spar, attached to the bottom corner of the Hunley’s
bow, had recently been conserved. What had initially seemed
to be voluminous concretion, the accumulated crud of 13 de-
cades underwater, had turned out to contain the peeled-back
shards of the torpedo casing itself. I sat staring at photos of the
beautiful, shiny copper ribbons. The bomb had to have been
fi rmly attached to the end of the spar for those strips to be
peeled back so cleanly. The spar was 16 feet long—which had
to be the distance between the boat and the bomb.
At some point, the sun had set, and I realized I was destroy-
ing my potato-chip cache because I was starving. I closed my
laptop, leaving open the browser windows so I could contin-
ue to stare at the pictures and articles later from home, over a
burrito. I made my way out of the building, past the doors of
open offi ces fi lled with other students still working into the
night. As I swung my leg over my motorcycle, parked on the
sidewalk outside the lab, I decided I could spare a few weeks
to calculate the crew’s oxygen supply and determine whether
suff ocation was a realistic theory.
I have never so drastically underestimated the time it would
take to solve a problem.

The next day I had the browser windows still open on my lap-

top, ready and waiting for Dale’s inevitable appearance in my

offi ce. “Well?” he asked. I angled the laptop screen toward him.

“This is the charge. One hundred thirty-fi ve pounds of black

powder.” I fl ipped to a second window. “This is the end of the

spar. The charge was made of copper. It was still attached. The

spar was 16 feet long.”

A third browser window. “These are the remains.” The im-

age showed a neat, color-coded row of skeletons inside the

hull of the submarine. Each color represented the remains of

one individual, and each individual’s remains were crumpled

in place at his battle station inside the boat.

“Nobody tried to escape. They died where they sat.” A grin

spread slowly across Dale’s face.

BEFORE I COULD BEGIN to fi gure out whether the crew had

somehow been killed or injured by their own massive bomb, I

had to evaluate other theories that could explain their deaths.

Had the men, for instance, suff ocated inside the closed hull?

I was reasonably certain that suff ocation, a term that spe-

cifi cally describes lack of oxygen or cessation of breathing,

would not have caused the deaths of the Hunley crew. They

could have asphyxiated, a more general term that would in-

clude the eff ects of carbon dioxide. But their bodies’ painful

symptoms would have warned them that their demise was im-

minent, giving them time to try to escape.

Carbon dioxide is normally a tiny 0.04 percent of each

breath that we inhale. As the percentage starts to climb, more

and more CO 2 is driven into the bloodstream. At around 5

percent, a person starts to notice what underwater divers in

one experiment politely labeled “distracting discomfort.” The

pain and discomfort escalate as the CO 2 levels rise because

the blood itself becomes increasingly acidic. Receptors in

the brain sense the increase in acidity and try to counteract

it. The blood vessels on the surface of the brain dilate in an

attempt to transport the acidity away from the sensitive neu-

rons; this dilation causes a headache. The brain increases the

BYLINES

Rachel Lance is a biomedical engineer and blast-injury

specialist who lives in Durham, North Carolina.

Smithsonian previously featured Christopher Wilson’s

portraits of the Hadza, Barabaig and Masai of Tanzania.

Matthew Twombly, a freelance illustrator and graphics

editor, created infographics for our “America at War” issue.

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CSS Hunley

Propeller

Rudder

Rear hatch Crew

Stern

A schematic diagram shows the HL
Hunley and its crew shortly before the
torpedo attack on the USS Housatonic.
Seven men, sitting in a row, powered the
submarine by turning a crank, which
set the propeller in motion. With the
exception of the captain, the crew sat on
the port side to off set the weight of the
crank, which was on the starboard side.
The torpedo, positioned about eight feet
below the water’s surface, was attached
to the end of a rigid spar that was set
at about 45 degrees from the sub; the
angle was meant to keep the vessel from
getting stuck in the hole the blast created
in the ship’s side. Engineers also believed
that the explosion’s recoil would push the
Hunley out of the range of danger. But
they failed to account for the eff ects a
shock wave could have on a human body.

THE WEAPON