Clemson conservator Johanna Rivera-Diaz works to remove a
century’s worth of hardened sand and sediment from the interior of the
Civil War-era submarine H.L. Hunley. If there are any last remaining secrets onboard the Hunley, they will be out soon.
Scientists at Clemson University’s Warren Lasch Conservation Center
are beginning their final scrub of the Civil War submarine’s interior — a
painstaking and slow process of removing all the hardened layer of
sand, sediment and shell that coats nearly everything in it. This is the last remaining big job before restoration can be
completed, one last chance to dig into every nook and cranny of the 19th
Conservators and archaeologists expect there are more artifacts to
find in the crew compartment, including buttons, tools and anything else
the eight-man crew might have carried since parts of the interior
remain heavily encrusted.
The work will reveal more details about the surprisingly sophisticated
machinery of the 1863 sub, but it is looking less and less likely that
there will be anything approaching a smoking gun that says definitively
why the Hunley disappeared in 1864.
“We are hoping to find more significant clues, but mostly this will
tell us more about how they operated the sub,” said Clemson
archaeologist Michael Scafuri. “This will be more akin to an excavation
than simply removing concretion.”
Last year, conservators spent months removing concretion from the
sub’s exterior as one of the final steps in the Hunley’s restoration.
Perhaps the most intriguing discovery found then was a crack in the
sub’s bow cap. Scafuri said it may be evidence of the Hunley’s collision with the USS
Housatonic, the Union Navy ship the sub sank on Feb. 17, 1864, just
before it disappeared for more than a century.
The exterior work revealed no major surprises; it looks exactly like
Conrad Wise Chapman’s contemporary painting of the sub. The interior
work will be completely different, as there are no historical records
that detail the inner-workings of the Hunley or its crew compartment. There is no timetable on the interior de-concretion/excavation, but
odds are it will be much slower than work on the sub’s exterior. The
Hunley is being soaked in sodium hydroxide to remove salt from the metal
and stabilize it to prevent further deterioration. Even when the tank
is drained, some of those chemicals remain, making it even harder to
climb around in the cramped confines of the 40-foot sub, which is only
3½ feet wide. Conservator Johanna Rivera-Diaz said the trade-off is that those
chemicals are softening up the concretion. “Some of it is falling off,”
Still, the team will be working in cramped quarters, chipping away at
concrete-hard mud in the tricky corners of the submarine. Anytime an
artifact is found, the scientists will have to stop scraping to map its
location on a 3-D grid. Scafuri said that all these clues are probably all scientists will
have to piece together the final moments of the first attack sub. Every
piece of evidence suggests one thing and eventually that research will
point to an answer for the biggest lingering question: why didn’t the
Hunley return after sinking the Housatonic.
Between work on the interior, conservators are busy restoring pieces
of the sub that were removed — rubber gaskets and glass deadlights, for
instance. All those pieces will be replaced when the caustics treatment
ends and the sub is ready for dry display. That’s still several years away. But the last answers anyone are going to get from the sub are just around the corner.
Text and Image Source: Post and Courier