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H.L. Hunley Assessment Expedition Fieldwork
Completed
By Christopher F. Amer,
Steven D. Smith and Jonathan M. Leader
The South Carolina
Hunley Commission and the U.S. Navy/Naval Historical Center initiated on 29
April a jointly funded assessment survey of the remains of the submarine H.L.
Hunley. The survey was conducted during a five-and-one-half-week period.
The principal goals of this survey were to confirm the identity of the object
at the site as the Hunley, document the site to the extent conditions
would permit, ascertain condition of the hull, and to evaluate the feasibility
of a future recovery project. The principal parties tasked to carry out this
expedition were the National Park Service-Submerged Cultural Resource Unit
(NPS-SCRU), South Carolina Institute
of Archaeology and Anthropology-Underwater
Archaeology Division (SCIAA), Naval Historical Center-Underwater Archaeology
Program (NHC), and the South Carolina Department of Natural Resources (DNR).
 Mr. Daniel Lenihan
(NPS-SCRU) and Mr. Christopher Amer (SCIAA) were Co-Principal
Investigators for
the project and Mr. Larry Murphy (NPS-SCRU) was Field Director. The
U.S. Coast
Guard, the Naval Weapons Station, and Naval Criminal Investigative
Service
provided site security. A South Carolina Educational Television
crew lived
with the archaeology crew and documented all phases of the
project. Several
private companies and not-for-profit groups donated their unique
expertise and
an array of state of the art technology for remote sensing, geology,
marine
biology, sedimentology, and corrosion engineering. These groups
include Marine
Sonic Technology, Inc., Edgetech Corporation, Oceaneering Inc.,
Geometrics
Inc., Sandia Research Associates, Inc., Jim Graham and Associates, and
the Institute of Nautical Archaeology.
Phase
One of the H.L. Hunley Expedition was carried out from 29 April through
6 May (Figure 2). This Phase consisted of non-invasive, remote sensing using a
marine proton magnetometer, a RoxAnn bottom classification unit, a side-scan
sonar, and a digital sub-bottom profiler. This sophisticated magnetic and
acoustic sensing equipment relocated the site of the Hunley, defined the
limits of this archaeological site, discovered other areas possibly associated
with the site, and profiled the depth of the submarine below the sediments.
Additionally, information from cores taken around the site provided
environmental contextual information to assist in the assessment.
After several
“down days” due to a series of weather fronts passing through the region Phase
Two began on 9 May. This phase was designed to uncover and positively identify
the Hunley by discovering and recording several of the hull attributes
unique to the submarine. Attributes included the forward and aft hatches with
portholes and cutwaters forward of the hatches (Figure 3), torpedo spar, diving
planes, air box and snorkel, propeller, rudder, and external iron keel
ballast. On 17 May, the identity of the Hunley was confirmed with the
identification of five of the seven attributes unique to the vessel. While
areas of the hull were exposed and being recorded, Mr. Dan Polly, a corrosion
engineer from Jim Graham and Associates, conducted studies of the corrosion
levels of the metal. Both phases were hindered by high winds and heavy seas.
Once Phase
Two was completed the submarine was reburied under protective sediments. The
site of this significant find is currently protected by physical barriers,
electronic surveillance and sensing device to provide continuous security. The
analysis of the data gathered during this expedition will take many months to
evaluate. However, some preliminary results include the following: The Hunley
is completely buried in the harbor sediments, lying 45 degrees on starboard
side, bow facing the shore, dive planes elevated. The evidence suggests that,
after the initial sinking, the hull became buried within 10 to 15 years in a
single event. The hull still contains much metal, however there is active
corrosion taking place throughout the vessel. There is little apparent damage
to the hull in the areas investigated (less than one-quarter of the vessel).
However, the forward face of forward hatch combing is fractured, possibly where
a port hole once existed.
The
construction of the submarine, H. L. Hunley, at the Park and Lyons
machine shop in Mobile, Alabama in 1863 was overseen by one Lieutenant William
Alexander. Some 40 years later, Lieutenant Alexander published a description
and sketch of the vessel in the New Orleans Picayune. Architecturally,
the Hunley differs in a number of ways from Alexander's description and bears
much more similarity to Conrad Wise Chapman's painting of the vessel done
shortly after it was built. The hull investigated has a hydrodynamic shape
with smooth lines converging at bow and stern. The hull is 39 feet, 5 inches
long, and approximately 3 feet, 10 inches in diameter. A 4-3/4-inch external
keel runs along the bottom of the hull. Both hatches are present, each located
approximately 9 feet from either end of the hull. Each hatch coaming contains
a small view port on its port (left) side, while the forward hatch coaming
apparently contained one facing forward but which is broken. The dimensions
and configuration of the hatches approximate those noted by Alexander. A
cutwater, formed from a single plate of iron, angles forward from the forward
hatch toward the bow. The air box/snorkel is located directly aft of the
forward hatch, although only stubs of the snorkel tubes remain. Between the
air box and the aft hatch, evenly spaced along the hull, and to either side of
the centerline, are 5 pairs of flat-glass deadlights, presumably to facilitate
illumination of the interior of the vessel. The port dive plane, located below
the air box is 6 feet, 10 inches long (longer than the 5 feet noted by
Alexander), 8-1/2 inches wide, and pivoted on a 3-inch pivot pin. No evidence
for a spar was found during the assessment.
When all of
the studies have been completed a final report of the expedition and
recommendations for the preservation and recovery of H.L. Hunley will be
delivered to the South Carolina Hunley Commission and U.S. Navy.
Maritime Research Division, South Carolina Institute
of Archaeology and Anthropology, USC
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