A Multidisciplinary Collaborative Effort to Rotate the H.L. Hunley

A Multidisciplinary Collaborative Effort to Rotate the H.L. Hunley Submarine
Christopher Watters1, Paul Mardikian2, and Vincent Blouin3
1
Newco, Inc.
2811 W. Palmetto St.
Florence, SC 29451
(previously with Warren Lasch
Conservation Center)
2
Warren Lasch Conservation Center
Clemson University Restoration Institute
1250 Supply St., Bldg.255
North Charleston, SC 29405 USA
3
Department of
Materials Science and Engineering
Clemson University
Clemson, SC 29634 USA
Abstract
The H.L. Hunley became the first submarine to sink an enemy ship in battle on February 17, 1864 during the
American Civil War. After sinking the USS Housatonic, the 40-foot long hand cranked submarine disappeared with
its eight crewmembers. In 2000, a multidisciplinary team of archaeologists, conservators and engineers successfully
raised the submarine from the ocean floor maintaining its exact resting position at a 45 degree tilt towards
starboard using 30 slings attached to a lifting truss. Immediately after recovery the submarine was transported to
the Warren Lasch Conservation Center to be excavated and conserved. After several years of excavation and
removal of approximately ten tons of sediment, conservators decided to rotate the H.L. Hunley to remove the
supporting slings and truss to facilitate the conservation of the 7-ton hull.
The rotation was the most technical procedure in the project’s history, since the recovery. The 45-degree rotation of
the submarine about its longitudinal axis was initially thought to be simple. If the structural loads remained
uniformly distributed along the hull and smoothly controlled during the entire rotation process, risks would be
minimal. A complete set of motorized hoists and load cells would have provided sufficient flexibility and reliability
to safely rotate the submarine. However, the cost of such a system was prohibitive and a manually controlled
system had to be considered based on budget limitations. At the same time, the complex structure and unknown
degree of deterioration of the H.L. Hunley posed elevated risk factors. Examining different solutions along with
ways to mitigate possible risk required detailed and time-consuming preparation. The main cost reduction came
from reducing the number of slings used to support the
submarine, which increased the structural loads on each sling.
Recognizing the scope of this procedure, conservators worked
with engineers to develop a numerical simulation to determine
the safe minimum number of slings for the rotation. To refine
the rotation protocol finite element analysis and computer
modeling was used in tandem with a full scale mockup, 3-D
imaging, and real-time monitoring to assess the rotation. The
project rapidly became a collaborative effort of experts in
engineering, rigging, industrial measurement, and ship building.
Further cost reductions were achieved by mobilizing corporate
and private donations from professionals that had a personal
interest in the project.
Despite the worst economic crisis in recent memory, the H.L.
Hunley submarine was successfully rotated to an upright
position in 2011. As the vessel came to rest on its keel for the
first time in nearly 150 years, preparation for the final phase of
conservation was completed. The project moved forward
through careful planning and community support. This paper
presents an overview of how the rotation was implemented,
including the materials and techniques used in the rotation and
the collaborative planning needed for its successful completion.
Figure 1. The H.L. Hunley was recovered from
the ocean floor on August 8, 2000.
© Friends of the Hunley
Figure 2. The H.L. Hunley in its recovery position, supported by the slings attached to the recovery truss.
© Friends of the Hunley
INTRODUCTION
The H.L. Hunley was constructed in 1863 at the
Park and Lyons machine shop in Mobile, Alabama.
Primarily made of cast and wrought iron, the
submarine was on the forefront of mid-19th century
industrial technology. Shortly after construction, it
was shipped to Charleston, SC and put into military
service in the hopes of breaking the naval blockade
off the coast of Charleston. Although the H.L. Hunley
sank twice and killed thirteen crewmembers during
practice tests, on February 17, 1864 it succeeded in
sinking the 210-foot USS Housatonic. After
becoming the first successful submarine used in
battle, the H.L. Hunley sank for a third time, along
with its eight crew members into the Atlantic Ocean.
In 2000, the H.L Hunley was raised from the
seabed and brought back to a purpose built facility
at the Warren Lasch Conservation Center (see Figure
1). During recovery, the original burial orientation of
the submarine [45 degrees on its starboard side] was
maintained. From the recovery until 2011, the H.L.
Hunley remained supported by slings that attach to
an overhead truss (see Figure 2). During the
excavation of the interior of the submarine the 45
degree angle ensured that the archaeological layers
remained intact for excavation of the interior. From
the beginning of the project, the possibility of
rotating the H.L. Hunley to be placed upright on its
keel had been incorporated into the conservation
treatment plan. From the conservation and
archaeological standpoints, returning the submarine
to its original position offered the following benefits:
2

Shorten the desalinization treatment time and
enhance the overall efficacy of the treatment.
Removing the sling and bag system would
expose a greater hull surface area, thereby
enhancing the diffusion of chloride ions into the
caustic treatment solution.

Removal of the truss and slings would facilitate
access to the surface of the submarine during
archaeological and conservation work.
Necessary for a full hull 3D imaging
reconstruction and analysis, the rotation would
permit the documentation and scanning of a
currently inaccessible longitudinal strip along
exterior starboard side of hull and keel blocks.
For conservation work, these areas needed to be
accessible for deconcretion of the hull and
inspection during treatment.

The hull was originally designed to rest on its
keel blocks, providing a low center of gravity and
stability to the structure. Compared to the
original 45 degree angle, a twelve o’clock
position will provide a symmetric side-to-side
load distribution, reducing uneven stresses.

Health and safety conditions for staff during the
caustic immersion treatment would be improved
by removing the truss and slings.
engineering study, acknowledging that their
expertise alone was not sufficient to fully assess the
impact the rotation may have on the complex
structure of the H.L. Hunley. Potential risks included:
a structural failure of the H.L. Hunley’s hull,
especially, the separation of either or both of the
end caps; creation or propagation of cracks in the
metal; and the possibility of a partial rotation that
leaves the H.L. Hunley in a less stable position due to
unforeseen difficulties. Fortunately, in 2007 an
opportunity for a solution was presented when the
Warren Lasch Conservation Center became affiliated
with the Clemson University Restoration Institute
(CURI).
ENGINEERING STUDY THROUGH ADVERSITY
The new affiliation with CURI in 2007 led to
a close collaboration between conservators working
on the H.L. Hunley and Dr. Vincent Blouin along with
his students at Clemson’s Department of Materials
Science and Engineering. Even though in 2008
Clemson University, along with all other state
institutions, suffered large budget cuts, this
collaboration continued. Although an engineering
study by a private company may have provided quick
results, it would have never matched the depth and
detail of involvement gained in the collaboration
with the Department of Materials Science and
Engineering faculty. Results and studies from the
collaboration were crucial in every step of the
rotation process, as the role of the Clemson
engineers evolved throughout the process.
Using finite element analysis (FEA) and
computer simulation, theoretical models were
While the benefits of an upright were always clear,
conservators recognized the magnitude of this task
in the planning stages. An engineering study was
requested in 2006 to assess the feasibility of rotation
and the potential risk it posed to the structural
integrity of the submarine. A number of factors
contributed to this risk including: the unknown
degree of corrosion of structural components; the
size and weight of the H.L. Hunley , and the
structural components that had been removed for
excavation. Estimates for the engineering study
were gathered by private engineering firms, but
funding was not available. However, conservators
remained adamant about the need for an
Figure 3. Finite element analysis and computer
modeling were used as risk assessment tools by
conservators and engineers.
Figure 4. Computer modeling illustrates potential applied
forces that could cause structural failure or damage to the
H.L. Hunley.
3
developed into predictive tools aiding to assess
potential risks to the submarine (see Figure 3).
Three critical conclusions were drawn from the
analysis: firstly, the submarine would be under less
stress in an upright position; secondly, the
submarine could be rotated without damage, and
finally, that the submarine could be severely
damaged in the rotation. These findings meant that
depending on how the rotation proceeded structural
failure could be induced by torsional or bending
forces (see Figure 4). Structural failure was narrowly
defined as anything altering the archaeological
record of the structure including permanent
deformation and crack propagation.
Unfortunately, the exact amount of force
allowable before failure was unknown. After more
than 140 years of corrosion acting on the submarine,
its exact mechanical properties, including thickness,
density, and stiffness of the structural components
could not be accurately determined for use in the
FEA. Parametric studies were conducted with
estimated mechanical property ranges to reduce
error, but it was decided that the goal of the rotation
should be to reduce the maximum global stress as
much as possible. It was found that this can be
accomplished by maintaining a consistent load
distribution from bow to stern. Conservators and
engineers then focused on practical ways to achieve
this and continued to consult the computer model
throughout the development of the rotation
procedure. FEA was used to predict stress levels in a
number of different scenarios, making it a very
practical tool.
devices are connected to a computer, the tension
measurements of each sling can be displayed as realtime data. However, tension is not a direct
measurement of load. The angle of the sling also
must be taken into account. Angles of the slings
supporting the H.L. Hunley varied from about 20° to
60°, and thus had to be factored into the equation.
Another factor that had to be accounted for was the
uneven load distribution from starboard to port,
since the submarine rested on its side in the slings.
Therefore by measuring the angle of the sling on
both sides and measuring the tension of the sling on
both sides with a load cell, the actual load on each
sling could be determined mathematically. With
load cells on all slings, the load distribution across
the entire submarine could then be measured. This
load cell system ultimately guided the rotation, but
first it had to be tested.
TESTING ASSUMPTIONS
Throughout the rotation procedure the
computer model continued to evolve. In order to
refine the computer model, simulations needed to
be compared to the results obtained from an actual
rotation. Since the H.L. Hunley itself could not be
used for testing, a test-rig was constructed by
Detyen’s Shipyard, Inc. to allow these experiments to
be conducted. The test-rig that was constructed is
shown in Figure 5. Two slings suspend a model that
LOAD VISUALIZATION
Since Clemson engineers identified the load
distribution as the key factor in the rotation, a
system had to be developed to measure loading on
the submarine at each sling position. After
consulting with J.A. King, Inc., a solution utilizing load
cells was developed. A load cell is a device that
precisely measures force and by installing the device
at the connection point between the slings and truss,
tension in the sling is measured. When multiple
Figure 5. The Test-Rig, a segmented scale model of the H.L.
Hunley, helped test and refine the computer model.
4
represents two different bottom profiles of the
submarine’s hull and can be loaded with ballast to
approximate the actual weight per sling. The hull
segments are a scale representation, based on 3D
scanning data from the H.L Hunley. The geometry of
the slings and truss support in the test-rig are also to
scale and based on measurement. Load cells at each
sling connection point provided valuable data
measuring the load distribution in the test-rig during
mock rotation experiments.
The experiments with the test-rig gave a
better understanding of how the H.L. Hunley’s
support system would behave during the rotation.
Some assumptions made while building the
computer model were challenged. One example is
that the first FEA assumed a fixed axis of rotation;
however, experiments with the test-rig showed that
the axis of rotation changed as the rotation
progressed. The computer model was corrected and
this led to a more accurate assessment. Perhaps the
most important thing learned from the test-rig was
the degree of interaction with the submarine’s
support system. Loads are readily transferred
between slings and adjustments to one sling can
affect the tension of another sling. The idea of a
dynamic support system where loads are transferred
from one part of the system to another informed
many of the decisions made during the rotation.
COMPLICATIONS
Working with engineers gave conservators a
theoretical framework and basic understanding of
how this dynamic support system interacted. Yet,
there remained a number of practical issues still to
be addressed. Limiting factors and complications
that restricted rotation options included: constantly
maintaining an even load distribution on the
submarine; limiting the submarine’s exposure to air;
having to work around the complex truss structure;
the confines of tank area layout; configuration of the
overhead cranes.
Many different scenarios were considered
and professionals from the rigging and shipbuilding
industries helped evaluate the different scenarios.
Figure 6. Chris Watters, front, helps CURI staff get acquainted with their ratcheted chain hoists, which
controlled the rotation and are connected to the truss via an S-beam load cell. © Friends of the Hunley
5
Another variation on this idea was a ‘release only’
system, where only the port side slings would be
lengthened. Both would accomplish the same goal.
Several factors made it challenging to
control the load distribution during the rotation with
these models. The first factor was the dynamic
nature of the support system, which meant
controlling the overall load distribution could not be
done one sling at a time. In order to maintain a
specific load distribution, length adjustments of the
slings would have to be done simultaneously.
The other factors dealt with the structural
properties of the submarine including the uneven
distribution of mass and flexibility of the structure
and the non-uniform shape of the submarine’s
bottom hull. This meant that if two slings in
different positions on the submarine were released
the exact same amount at the same rate, the
resulting rotation rate for each position would be
different and internal stresses would increase. The
sling positions in the wide middle sections required
more length of the sling to be released at a faster
rate to keep up with the more narrow bow and stern
sections. Therefore, it was determined that the
rotation must occur simultaneously and at a variable
rate according to sling position.
Figure 7. Dr. Blouin analyzes load cell during the
rotation. © Friends of the Hunley
These professionals donated their expertise because
of their interest and dedication to the H.L. Hunley,
which is widely accepted as an integral part of the
South Carolina community and culture. Each
alternative was evaluated in terms of safety to the
submarine and practicality of the solution. One
example of an option strongly considered was
attaching all port side slings and all starboard side
slings to separate single beams and raising/lowering
the beams simultaneously to rotate the submarine.
However, the geometry of the truss and spatial
limitations of the tank would not accommodate this
sort of rigging. Other ideas like rotating the
submarine underwater with an air bladder or
creating a wheel-like superstructure to rotate the
submarine were deemed infeasible because of risk
to the submarine.
THE IDEAL SOLUTION
Through computer models and test-rig
experiments, engineers gained a thorough
understanding of how the rotation needed to
proceed in order to minimize the maximum global
stress within the submarine. Based on the FEA and
computer model, actual ratios of sling length pull
and release adjustments were calculated. This
would allow engineers to control the load
distribution during the rotation by modifying these
ratios. Having this ability, it was easy to imagine the
optimal system for rotation.
The ideal solution would be to attach each
sling via a load cell to an electric cable winch that
would be attached to the truss. Having all the slings
connected to an electric winch, the pull and release
of each sling could be controlled through a computer
OUTLINING THE ROTATION
A clear picture of the best way to rotate the
submarine emerged after collaborative discussions
involving conservators, engineers, archeologists,
riggers, shipbuilders, and others. The basic idea was
to use the slings that had been supporting the
submarine for years to rotate the submarine by
gradually making the slings longer on the port side
and shorter on the starboard side. This would return
it in a slow and controlled manner to an upright
position. This is called a ‘pull and release’ system.
6
program automatically and precisely. Each winch
could be synchronized and adjustments would be
exactly simultaneous, based on real-time load cell
data. With the right programming, the rotation could
be fully automated. The technology for such a
system existed at the time, but cost was prohibitive
and other solutions were pursued.
COMPROMISE AND COST SAVINGS
Incorporating the same principles as a fully
automated rotation, conservators and engineers
compromised on a solution that reduced cost, while
minimizing risk to the submarine. A simultaneous
and variable rate rotation was accomplished using of
trained personnel (see Figure 6).
The costly idea of writing a custom software
program that would automatically interpret the load
cell data, calculate, and control the pull/release was
eliminated. Instead, Dr. Blouin manually transferred
the load cell data between computer programs to
calculate the load profile throughout the rotation
(see Figure 7). From this calculation, the exact
pull/release length for each sling position was
determined and then relayed to trained personnel in
the tank. The trained personnel, which included
CURI staff and professionals that worked with CURI,
synchronized the manual adjustments to allow the
submarine to rotate one degree at a time.
Instead of electric wenches, ratcheted chain
hoist were identified as a readily available and
economical hardware to drive the rotation. Since the
cost of chain hoists increases with the load rating
and the rotation slings varied in load from about 400
lbs. to as much as 2000 lbs., different make/model
chain hoists were used in the rotation. Trained
personnel operated the chain hoists according to Dr.
Blouin’s calculations.
The number of slings to be used for the
rotation was also carefully considered. Thirty-two
slings were used in the recovery, but a number of
these slings had to be removed to allow the upright
support system to be put in place. Even so, up to
eighteen slings could have been used in rotation;
however, each individual sling added cost and
Figure 8. Paul Mardikian visually inspects the submarine during
the rotation, which was one of several safety measures taken.
(view from under the submarine during the rotation, looking
forward) © Friends of the Hunley
complication to the process. Using the computer
model, fifteen slings were determined to be the
optimal number of slings for rotation.
SAFETY MEASURES
In addition to the load monitoring system,
two 3-D measurement tools were used to monitor
the rotation. One tool was extremely sophisticated
and the other was quite simple. A photogrammetric
survey, which precisely measures distance using
triangulation, was performed before, during, and
after rotation. Results were compared and no
significant movement in the hull was observed. The
other tool used was a laser beam attached to the
stern of the submarine that projected onto an
affixed target in the bow. This simple 3-D tool
proved extremely effective in visualizing movement
of the hull. Conservators expected some movement
in the hull structure, but could not precisely calculate
how much movement would be dangerous.
Engineers used the computer model to determine
that if the hull moved more than 5 mm, the rotation
process would need to be stopped and reversed.
Using the laser projection, the maximum movement
was measured at 3.5 mm off target. It is interesting
7
to note that at the end of the rotation the off-target
movement actually self-corrected. While the
deviation of the laser projection from its original
position was measured at 3.5 mm at one point
during the rotation, when the submarine was set
into its upright position the deviation was <1mm.
Along with frequent visual checks (see Figure 8),
these tools added another layer of safety to the load
visualization system.
inserts conformed to the hull’s profile and evenly
distributed the pressure around areas of the hull
with irregular-shaped concretion to prevent pointloading. This was identified by engineers as a major
concern. The fitted inserts also prevented the slings
from exerting pressure on the dive planes and the
cushioning effect of the foam absorbed some of the
momentum during the rotation.
As each sling was detached, the old recovery
bags were replaced by the Ethafoam© fitted inserts.
Before reattachment, an S-beam load cell was fitted
to the attachment point on both the port and
starboard side. On the starboard side new
turnbuckles were installed, to allow minor pull
adjustments. On the port side a ratcheted chain
hoist was added and provided a tool to drive the
rotation.
PREPARING FOR THE ROTATION
The first step in preparing for the rotation
was to elevate the support truss to provide sufficient
clearance during the rotation. The truss rigging
hardware from the recovery was reused and
attached to the truss holding the submarine. On
June 15, 2011 the same crane operator from Parker
Rigging Company, Inc. that originally placed the
submarine in the tank after recovery, lifted the truss
and submarine about 40” off the tank floor via the
overhead cranes. The four corner supports for the
truss were supported with stacked wooden blocks
fastened with cross beams. This measurement was
determined by engineers using the computer model.
It needed to be accurate so once the rotation was
completed and the submarine was upright, it would
be at the correct height above the tank floor to meet
the supports. Rigging cables were left attached to
the truss and overhead cranes as a safety
precaution. Scaffolding was erected along the port
and starboard side of the submarine for better
access to the sling attachment points.
The next step was to replace the hard foam
bags, which were used for the recovery with more
compliant foam. The recovery bags were designed
specifically to conform to the shape of the hull and
be rigid enough to lock the H.L. Hunley in position
during the recovery. However, the rotation required
a different material, one that adapts to different
profiles and does not create concentrated areas of
stress, also called point-loads. Strips were cut from
4’ x 8’ planks of 2” Ethafoam© 220 and custom
shapes were built up by laminating stacked lengths
together with heat. In this way, the fitted foam
ROTATION
From June 22-24, 2011, the rotation
proceeded. Two models of how to best proceed with
the rotation were put forth in the Proposal to Rotate
the H.L. Hunley, these were a ‘pull and release’
model and a ‘release only’ model. The rotation was
actually a combination of these two models, perhaps
best called a ‘mostly release’ model. Ratcheted
chain hoists were used to simultaneously lengthen
the slings on the port side, controlling most of the
rotation. Turnbuckles on the starboard side were
used only to adjust the load profile.
Release of the fifteen chain hoists were
performed by fifteen trained personnel and at one
degree of rotation at a time. The release of each
chain hoist was controlled by a friction brake and the
release of each hoist varied by the applied weight
and make/model of the chain hoists. Before the
rotation, each make/model was empirically tested to
determine a nominal release length for eighth,
quarter, half, and full turns. This allowed control of
the chain hoist release within a +/- 2mm error.
Trained personnel practiced chain hoist operation
before the rotation and engineers relayed each
volunteer’s assignment as an eighth, quarter, half, or
full turn.
8
During the rotation, the data from the load
cells were analyzed to determine the appropriate
pull/release. For each sling, the vertical load was
calculated from the load cell data and sling angle
measurements. At the outset of the rotation, this
was done after every adjustment. As the rotation
progressed this was done less often. Vertical and
horizontal translation of both the bow and stern
were also closely monitored. Theoretic calculations
guided the rotation, but adjustments were made in
response to the data collected.
During the rotation, the H.L. Hunley
responded well to the simultaneous release and the
rotation proceeded mostly as predicted. At one
point the rotation was stopped because the vertical
translation was proceeding faster at the bow than
the stern, causing the submarine to tilt towards the
bow. This was caused by a 1° tilt, present in the
submarine’s positioning since recovery, which was
amplified during rotation. By adjusting the release
rates during rotation this tilt was gradually corrected
and the rotation proceeded as planned. One of the
most important calculations was where the
submarine would by at its upright position, vertically
and horizontally in relation to the tank. After
rotation, the H.L. Hunley finished well within the
required +/- 2” vertical height needed to properly
transition to its upright supports. It was also
centered in the tank. A backup plan to move the
truss with the submarine suspended upright was
fortunately not needed.
This allows the supports not only to be moved
around, but also to make fine load adjustments after
rotation. Another design issue was ensuring
adequate lateral stability to support the submarine.
This was addressed with the addition of three sets of
folding lateral supports that form a self-supporting
triangle with the submarine at the top point. These
can be clearly seen in Figure 10.
After three days of rotation, the H.L. Hunley
approached upright and on June 24, 2011 the
transition to its upright supports began. The first
step was to activate the load cells on the upright
support system. The load cell system for the slings
and the load cell system for the upright supports
shared connection ports, so as one load cell was
disconnected from the sling system it was hooked to
a support load cell. The first supports to be
connected and raised were the middle supports.
Each support was raised until the adjacent slings
were at half load. Once all the supports were raised
enough to carry half the load, the slings were
released and the submarine rested on its keel for the
first time in over 140 years (see Figure 10).
Fifteen supports in total currently support
the H.L. Hunley, twelve are instrumented with load
cells and three do not carry enough load to require
visualization. The twelve instrumented supports
allow very sensitive load visualization. Since these
load cells are directly below the submarine, unlike
the load cells on the slings, they provide a direct
reading of the load across the hull with no data
TRANSITION TO UPRIGHT SUPPORTS
Detyen’s Shipyard, Inc. was largely
responsible for the design and fabrication of the final
upright support system. The system consists of
fifteen individual supports with integrated load cells
installed within a track on the tank floor (see Figure
9). The support system was designed with the ability
to raise and lower the supports so their position
could be alternated once the desalinization
treatment began. The supports were constructed of
opposable wedges connected with a threaded rod
controlling the height adjustment of the supports.
Figure 9. Schematic for an individual component of the
upright support system.
9
interpretation. The high sensitivity of this system
allowed an unanticipated phenomenon to be
observed. After filling the tank with water, the
precisely adjusted loads changed in an erratic
manner. This was caused by a slight deformation in
the steel I-beams supporting the tank floor because
the poured concrete lab floor was not perfectly level.
This issue was easily corrected by several carefully
placed shims; however, having gone undetected this
problem would have caused unnecessary, repeated
stress on the hull. In the future, the load cell system
will ensure against other unforeseen problems.
CONCLUSION
Amidst tough economic conditions, the
rotation was successfully completed. Professionals
from the local community and the collaboration with
Clemson University’s Department of Materials
Science and Engineering were instrumental in the
rotation. This was only possible because of the
significance of the H.L. Hunley to the South Carolina
community and the project’s public outreach efforts
that encouraged collaboration.
Designed to be a minimal risk procedure,
the rotation blurred the lines between the
engineering and conservation disciplines. A mutual
appreciation of each field was needed to understand
and overcome practical problems encountered
throughout the process. Although every problem
was not anticipated and adjustments were
constantly made during the procedure, preparation
with the computer model and the scale model testrig informed a decision making process that
ultimately led to a safe, successful rotation. Major
engineering challenges lay ahead for the project
including implementing the desalinization treatment,
deconcreting the iron hull surface, and transporting
the submarine from the lab to its final home. The
knowledge, experience, and equipment gained
through this collaboration will surely aid in these
future endeavors.
Figure 10. The H.L. Hunley after rotation in its upright support
system. © Friends of the Hunley
Special thanks to our industry partners, who donated their time, expertise, and equipment:
John King, president
J.A. King & Company, Inc
Greensboro, NC
Tim Parker, president
Parker Rigging, Inc.
North Charleston, SC
10
Loy Stewart, president
Detyens Shipyards, Inc. (DSI)
North Charleston, SC
BIBLIOGRAPHY
Blouin, V. and A. Choragudi, ‘Predicting Structural Failure of the H.L.Hunley Submarine’, Poster presented at South
Carolina Computing Consortium- SC3 (2008).
Choragudi, A. ‘Finite Element Analysis Prediction of Stresses in H.L. Hunley Submarine By Global-to-Local Model
Coordination’ Thesis for Master of Science in Mechanical Engineering, Graduate School of Clemson University,
(May 2011).
Blouin, V., P. Mardikian, and C. Watters, ‘Finite Element Analysis of the H.L. Hunley Submarine: A Turning Point in
the Project’s History’ in Metal 2010, Interim Meeting of the ICOM Committee for Conservation, Charleston, South
Carolina, USA, 11-15 October 2010, ed. P. Mardikian, C. Chemello, C. Watters, P. Hull, Clemson University (2010).
Mardikian, P., ‘Conservation and Management Strategies Applied to Post-Recovery Analysis of the American Civil
War Submarine H.L. Hunley (1864)’, The International Journal of Nautical Archaeology (2004) 33.1.137-148.
Mardikian, P., M. Drews, N. Gonzalez, and P. deVivies, ‘H.L. Hunley conservation plan’, ed. J. Hunter III., Submitted
to the US Naval Historical Center for approval after peer review, (internal document Friends of the Hunley Inc.,
Clemson University) Charleston, (2006).
Watters, C. and V. Blouin, ‘Proposal to Rotate the H.L. Hunley’ internal document, Clemson University Restoration
Institute submitted to the South Carolina Hunley Commission (March 2011).
AUTHORS
Christopher Watters currently works with Newco Inc. managing their digital radiography products and
southeastern region. Newco, Inc. is a company that provides products, consulting, and design services for the nondestructive testing (NDT) industry. The NDT industry includes X-ray imaging, ultrasonic analysis, eddy current
testing, boroscope inspection, and other industrial inspection techniques. From 2008-2012, Chris held the position
of conservator at the Warren Lasch Conservation Center, where he worked on stabilization treatments for the
H.L. Hunley submarine, its associated artifacts, and other collections. He was the lead conservator on the June
2011 rotation of the H.L. Hunley, which merged engineering and industrial practices with the conservation
field. He holds an M.A./advanced certificate in conservation from Buffalo State College and has also worked at the
National Gallery of Art, the Brooklyn Museum, and the Kaman- Kalehöyük excavation in Turkey.
Vincent Y. Blouin is Assistant Professor at Clemson University with a joint appointment in the School of
Architecture and the School of Materials Science and Engineering. He graduated from Ecole Centrale Nantes,
France, in 1993. He then received dual master degrees in Mechanical Engineering and Naval Architecture and
Marine Engineering from the University of Michigan in 1999 and a PhD in Naval Architecture and Marine
Engineering from the University of Michigan in 2001. His research activities include multi-physics numerical
modeling and experimental characterization of materials degradation processes.
Paul Mardikian is senior conservator for the H.L. Hunley Project at Clemson University in South Carolina, USA, a
position that he has held since 1999. Prior to joining the Hunley Project, he worked on the conservation of artifacts
from the RMS Titanic (1912) and the CSS Alabama (1863). He has graduate degrees in archaeology, art history, and
conservation from the school of the Louvre and the Paris I Pantheon-Sorbonne University respectively, specializing
in the conservation of underwater cultural heritage. He has provided conservation for numerous maritime
excavations in the Mediterranean, Australia, Canada, and the United States. Paul’s primary interests are the
conservation of large-scale maritime archaeological and industrial artifacts, particularly metals and composite
artifacts. He is a professional associate member of the American Institute for Conservation and assistant
coordinator for the ICOM-CC Metal Working Group (MWG). More recently, Paul served as program chair and coeditor for the MWG interim meeting, METAL2010.
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