DEVELOPMENT
OF FIELD
AND CONSERVATION
PROCEDURES FOR THE MAPLE LEAF SITE
By Lee B. Manley
Historical Background
The Maple Leaf sank in 20 feet of water
in the middle of the main river channel 12 miles upriver from
During the next 19 years, the Maple Leaf was primarily a nuisance to river traffic. In 1883, the U.S. Army Corps of Engineers signed a contract to have the remainder of the wreck and its cargo removed from the channel. But from the relatively low bid price made by the contractor and the information in existing documents, it is doubtful this actually occurred. More likely, by removing the upper decks and the vertical walking beam the only thing accomplished was to provide an 18 foot clearance between the wreck and the surface of the river. By this time there was probably already three feet of mud accumulated on the main deck of the Maple Leaf. For better than a century, this mud would protect the wreck of the Maple Leaf and its cargo.
Wreck site: Location and Condition
The Maple Leaf is 12 miles south of downtown
At the wreck site, the
The Maple Leaf is encased in the river bottom,
which consists of a top layer of fine, suspended silt some 12 to 18 inches
thick. Below the silt there is a layer of moderately packed mud at least 20 feet
deep. The river water contains a large amount of tannin, an acid that discolors
the river and creates a dark water environment that restricts the penetration
of light. Visibility on the bottom of the river is further reduced to a few
inches because of the layer of silt.
In 1981, the approximate location of the Maple Leaf wreck
was determined with the use of intense historical research from the existing
documentary evidence as well as a systematic search of the supposed location of
the steamer. With the formation of St. Johns Archaeological Expeditions, Inc.,
the company subsequently secured the legal rights to excavate the ship and her
cargo through the
In April 1985, the first survey of the site was produced with remote sensing and magnetometer equipment. These magnetometer surveys showed large deposits of metal in the immediate vicinity of the wreck site. In June of 1985, preliminary survey dives were begun at the site using scuba gear, a task continuing for a period of two years. Initially, it was ascertained that the remaining portions of the Maple Leaf above the mud consisted of only a few pieces of timber and pieces of the steamship's propulsion system. A number of crab traps, shrimp nets and fishing lines were entangled on the wooden and metal parts of the ship. Working in zero visibility and without surface support, these early survey reports lacked continuity, and the safety of the divers was always in question.
By the end of the dive season in June of 1985, several things had been determined about the wreck site. First, the main deck of the steamship was buried under three to seven feet of mud. Second, there was no safe way to excavate the cargo using scuba gear. And third, it was apparent the excavation of the Maple Leaf's cargo was going to be a demanding task.
1986 - 1987: Initial Site Procedures
In January of 1986, two major decisions were reached
about future work on the ship. First, it was recognized the overburden of mud
needed to be removed in order to access the main cargo hold. To accomplish this
task, environmental and land use permits to remove a limited amount of mud from
the wreck of the Maple Leaf were sought from federal and state agencies
(a process that would eventually take 18 months). The second decision was that
surface supplied dive equipment would be used to work the site.
In the first months of 1986 the equipment was being
assembled that would finally allow the excavation of the ship's cargo hold. The
heart of the system was the surface supplied diving equipment. This equipment
allowed direct and continuous communications between the surface support crew
and the divers. The divers could talk to one another while in total darkness at
the bottom of the
The second component for this system would be the dredge equipment necessary to remove the overburden of mud. For this purpose a four inch venturi dredge was used. The third component of the system was the diving platform. The Mud Puppy, a 28 foot pontoon boat, was completely redesigned to accommodate the specialized diving equipment, as well as a support barge, measuring eight feet by 12 feet, to hold the dredge pump and the air cylinders.
The last and the most important element was the group of individuals who would operate the diving system. In addition to the divers, a topside support team was a primary concern but there were others; recorders, lab technicians, a ship design specialist and experts from various other disciplines and crafts. The various experts were needed to handle artifacts and assimilate the data.
In June of 1986, there was a limited amount of diving at the site to test the equipment and make preliminary site surveys. In the spring of 1987, SJAEI returned to the wreck site to continue site work. Since the dredging permits had not yet been received it was not possible to remove any mud and find the access to the aft cargo hold, but there were many tasks to perform even without being able to enter the cargo hold. Not the least of these were the continued training of divers and support personnel, the establishment of operational procedures, further site surveys, and the clearing away of all modem debris that might entangle or trap the divers. This training and clearing took the entire spring and summer of 1987.
1988: First Excavation
Early in 1988, all of the environmental and land use
permits necessary for dredging operations had been secured from the proper
federal and state agencies. The permits approved the removal of up to 660 cubic
yards of mud over a five year period. Although this amount would be sufficient
to uncover the entire deck of the Maple Leaf, this was never the
intention. After studying several modern shipwreck excavations (Bertrand,
The primary objective of this first excavation was deliberately to recover a small cross sectional sample of material from within the cargo hold while minimally affecting the wreck's environment. The recovery of this small sample was necessary to determine the preservation quality of the cargo and the conservation demands. More important, by recovering material SJAEI hoped to prove the historical significance of the Maple Leaf. In order to accomplish this goal it was decided the aft cargo hold was probably in better condition than the forward hold, which was damaged by the Confederate mine.
At this point, the divers started looking for the aft cargo hatch. To assist in locating the hatch, a base line was secured from the rudder post at the stern of the Maple Leaf to the paddle wheel shaft amidships. This base line was a quarter inch cable marked off in ten foot increments to assist in quadrant identification. The search began at the shaft and continued toward the rudder post. The divers used a seven foot rod to probe though the mud at ten foot increments on both sides of the base line all the way to the rudder post. The survey process continued for a period of two months, but the hatch was never located. Nonetheless, it was determined that the main deck was intact and solid, and there was very little structural debris to be found in the layer of mud over the deck. Although the hatch eluded the divers, an area was found that seemed to be a very small opening in the deck.
In the middle of June, the decision was made to remove the mud at the small opening in the deck to determine the actual condition of the deck. The initial penetration through the five feet of mud produced a hole in the mud six feet in diameter. When the deck was reached, it was discovered that two of the deck planks had broken and were parting from the deck beams. The rest of the deck was still solid and intact. It was decided to enter the aft cargo hold at the point where the deck planks had parted. First it was necessary to enlarge the excavation in the mud to 15 feet in diameter to provide a more manageable working space. The first plank was removed, creating an opening into the hold measuring six inches by four feet.
This created a place to start sawing the deck planks with
a hand saw. After prying up the deck planks an access hole was produced
measuring four by three feet, with a deck beam five and one half inches wide
running from port to starboard down the center of the hole.
The initial entry into the cargo hold was made in July of
1988. Upon entry into the cargo hold it was discovered that it was full of mud.
After removal of the first three to six inches of mud, hard objects began to take
form: crates, barrels, trunks, and tent poles. During this initial excavation
three separate boxes were selected to excavate. Out of these boxes over 100
artifacts were recovered, providing what was hoped to be a cross section of the
total cargo in the hold, and proving conclusively that the shipwreck was a
Civil War site. The artifacts also provided an opportunity for a preliminary
investigation of the condition of the waterlogged cargo.
By the end of July 1988, this first field operation was
nearly completed. For future security, before leaving the site a piece of four
by eight foot plywood was placed over the access hole and nailed in place, and
the area of the deck that had been excavated was back filled with mud to
protect the site.
Conservation Challenges
With artifacts successfully retrieved, a new and
extensive challenge had to be met. Each item needed to be carefully stored,
catalogued, analyzed, and properly preserved. Working closely with Herb Bump,
the conservator with the Florida Division of Historical Resources, this task
had begun. After making sure all artifacts were in proper storage the next task
would be to develop conservation procedures, based on accepted standards in the
industry, for each of the five major groups of materials identified. These
major groups were: metal, wood, leather, textiles and glass/ceramics.
The first step in the conservation process was to number,
identify, and photograph each item. This would be a basic requirement for all
artifacts, regardless of the type of material. With the small amount of
material recovered in 1988 there was no need for a large conservation facility.
But with plans for a larger scale test excavation for the summer of 1989, it
was realized that a larger permanent laboratory would be necessary.
Metals
Metal artifacts recovered in this first excavation
included both ferrous and nonferrous items. Ferrous metals are those containing
iron in some form, such as cast iron, wrought iron, tin iron, etc. Nonferrous
metals include copper, brass, bronze, lead, pewter, silver, and gold.
Electrolysis is being used to treat all types of metal. Electrolysis is a
process of forcing the corrosive salts out of the metals with the use of
electrical currents.
Woods
The wooden artifacts recovered from the Maple Leaf have
proven to be the most difficult to conserve and the most numerous of the
artifacts recovered so far. There was a great degree of variation in the
condition of the different pieces of wood. To a degree, this can be attributed
to the different species of wood encountered. Initial procedures set up for
wood began with bulking up the wood using Poly ethylene glycol (PEG) and then
drying it slowly. It was apparent that a freeze dryer would shorten the time
needed to treat these items and would increase the success of the treatment for
some items.
With a great deal of research completed on the treatment
of waterlogged wood, the consensus remains that there is much to be learned
about different bulking agents, how different species react to certain
treatments, and how the different drying treatment affect the items.
Leather
Leather goods are a very large portion of the material
recovered from the cargo of the Maple Leaf The physical condition of the
leather items is very good. At present, Lexol is used to treat the leather.
Textiles
At present very few textiles have been recovered. It is
not known whether this is because textiles have not survived in the waterlogged
environment, or if there was no large collection of textiles in the area
excavated. The types of textiles that have been found and remain in relatively
good condition are wool sashes and pieces of silk. There are several different
conservatories presently working with these textiles to determine the best
conservation method.
Glass and Ceramics
Because of the relatively freshwater environment in
which the cargo of the Maple Leaf lies, the current conservation of
glass and ceramic artifacts is less complicated than for other items. The
process begins with mechanical cleaning, if needed. It then goes through a wash
with deionized detergent and a freshwater rinse. If the artifacts have been
stained by mud or iron, they go through a prolonged soaking in hydrogen
peroxide or citric acid. After the stains are removed they again go through the
wash process.
Excavation Methods Improved
Following the 1988 field season, it was obvious that
there were several procedural areas requiring improvement. The first was the
need for a second mooring point on the wreck in the vicinity of the bow of the Maple
Leaf. Also, there was an obvious need for a center line that would run the
entire length of the ship, one that would assure better continuity in mapping
the entire main deck. In order to accomplish both of these tasks, it would
first be necessary to locate the stem post and secure a clamp on it that would
be strong enough to hold the weight of the Mud Puppy.
A second clamp would be placed on the rudder post for
the stern mooring. With these moorings in place, it was then possible to move
the Mud Puppy over any portion of the Maple Leaf. Also, these
clamps were used to secure the base line along the center of the steamship.
It was decided that during the limited amount of time being spent removing artifacts from the aft cargo hold (during the 1989 field season), the divers would use the deck planking and transverse deck beams to mark the location of the item to be excavated. To ensure that the artifacts recovered from a particular location were recorded at that specific point, a recovery system was established. Since a diver is working in zero visibility while recovering artifacts, the only workable system is the direct communication system that exists between the diver and the Mud Puppy crew.
By using this two-way communication system, the diver simply relayed the location and the data was recorded on the surface even before the recovery was made from the hold. The information the diver passed on to the top side crew included the location of the item, and, with feeling each object, its condition, size and type. It was left to the judgment of the diver whether he would attempt to recover an intact box of artifacts, or remove each artifact separately from the box.
The entry hole into the aft cargo hold was enlarged by removing four more linear feet of decking. The reason for this was two fold, first to provide a safer environment for the divers who were entering and leaving the cargo hold and, secondly, to facilitate the safe removal of the cargo from the hold.
It was recognized that new diving safety regulations would have to be established and implemented in the next year's excavation of the ship. The new safety procedures themselves prompted other changes. To ensure the use of the new safety measures, new training courses had to be designed, one for the divers themselves and another for the support crew on the Mud Puppy. These courses covered topside procedures, diving and recovery procedures, boat operation. on-site artifact conservation and storage procedures. An operational procedure manual containing all of the information taught in the classes was produced.
1989: New Discoveries
In the spring of 1989, work was begun again at the site.
First the clamps were secured on the rudder post and the main shaft. With this
accomplished the divers set out to find the stem of the Maple Leaf. The
divers started at the main shaft and started probing toward the bow to locate
the stem post. After three weekends of work, the stem post was located about
one foot under the mud. The divers jetted down at the stem post and evaluated
the condition of the ship at this point. The first five feet of the stem post
had no wood or framework attached to it, but at six feet the divers encountered
the cap rail to the bow section of the ship. It was discovered that the bolts
that had secured the cap rail to the stem post were broken and the rail had
separated from the sides of the ship. At this point, it was decided to remove
this section of the bow for two reasons. One was that the piece was loose and
there was a possibility that it might break away from the ship in the strong
current. Secondly, and more important, was that it could give valuable
information on the design of the ship. With the cap rail separated from the
ship, ropes were secured to it and the cap rail was lifted to the surface. Even
though the piece was large the wood was still buoyant, making the recovery
easy. Measurements of the stem post and the location of the cap rail in
relation to the ship were taken and the bow mooring clamp was fabricated and
installed.
Thus, all was ready to start back on the excavation in
the aft cargo hold. The first order of business was to remove the mud covering
our 1988 entry hole. After clearing a 15 foot diameter hole through the mud to
the deck, the plywood was removed from over the entry hole. Once the plywood
was off, work began on the enlargement of the hole. The divers started cutting
four more feet of deck along the bow side of the hole toward the center of the
ship, then made a four foot cut down the stern side of the hole and removed the
deck planking. The next line of work would be the removal of the deck beam
which ran down the center of the entry hole. The divers cut the deck beam flush
with the port side of the hole and left ten inches extending out on the
starboard side.
The excavation in the cargo hold began once the entry hole
was enlarged. One of the main goals in 1989 was to produce a four foot square
test excavation down to the floor of the cargo hold. To accomplish this, divers
would have to work outside of the four foot square core to keep mud or cargo
from sliding down into it. During June and July, the divers logged over 380
hours working underwater, recording 25 separate recoveries. These included
groups such as boxes completely intact, boxes starting to part with all parts
still together, boxes missing some sides but with contents still contained
within the box area, boxes completely missing with their contents still tightly
associated, and items that were randomly scattered in the core excavation area.
If a group of items was identified as belonging to an isolated area, the group
was assigned an individual recovery number. If items were randomly found in the
core area, all were given the same recovery number and marked as coming from
the same four foot by four foot core area. After working for ten days straight
on this preliminary core, the 1989 field session accomplished the recovery of
enough cultural material to provide a good overall view of the type of the
material that was loaded into this part of the ship.
The entry hole was sealed back up with the plywood and the hole down to the deck was back filled with mud from the site.
Future Work
For the next two years, all site work was suspended. All
of our time and effort was put toward working in the conservatory, getting
funding to help continue the project, putting together a group of professionals
to help with future planning and research, establishing a public museum exhibit,
writing reports, and working on a future project design.
Although different conservation procedures were identified after the 1988 season, SJAEI did not have all the equipment needed to implement these on a large scale. During 1989 and 1990, we proceeded with setting up larger treatment tanks, installing additional electrolysis units, acquiring a freeze dryer and installing it, and acquiring other specialized equipment needed for this type of work. The conservation of artifacts and the assimilation of data on these items continued well into 1991.
One of the major concerns at the end of the 1989 season
was the need for outside funding to continue work in the field and, especially,
the work in the conservatory. In 1989, in conjunction with the Museum of
Science and History in Jacksonville, SJAEI applied to the State of Florida for
assistance in funding to help in conservation, assimilation and publication of
data, getting assistance from the professional community, and producing a
public exhibit on the Maple Leaf.
In October of 1990, the Museum of Science of History (MOSH) in Jacksonville received a grant from the State of Florida (Division of Historical Resources) to help in the continuation of the Maple Leaf Project. It was mutually decided between the state and SJAEI that the funds would be used to help complete these several areas of work:
1. With the aid of a professional conservator, complete conservation on all
artifacts recovered in 1989 and produce a report.
2. With the aid of a professional historian, assimilate all historical data on
the Maple Leaf and produce a report.
3. With the aid of a professional archaeologist, assimilate all archaeological
data recovered to date and produce a report that would include project research
design for future work on the site.
4. Produce a public exhibit of the Maple Leaf artifacts and the story
behind them.
5. Produce a report on all aspects of the Maple Leaf Project to date
that is suitable for public and professional audiences.
6. Produce an electronic multimedia data base on the Maple Leaf for
distribution to the Florida school system.
7. Organize a public symposium on the Maple Leaf Project.
With funds from the State of Florida, SJAEI proceeded to
accomplish the work outlined in the state grant. The first goal was to get the
professional community involved in the project. This was possible with the aid
of East Carolina University (ECU). Because of their programs in maritime
history and underwater archaeology, as well as their expressed interest in
Civil War era maritime history, this school was a natural to be connected with
the Maple Leaf Project. Even more important than their programs were
their professional staff and the progressive curriculum they have developed to
cover all aspects of an archaeological site.
With the aid of staff members Dr. Bill Still (director of
the maritime history program), Gordon Watts (underwater research director), and
Bradley Rodgers (staff archaeologist and conservator), SJAEI was able to add
the insight, advice, and consultation of the professionals into the work and
reports. SJAEI was further able to define areas of work needing future research
and, at present, is working on a research design for the Maple Leaf Project
to cover future work in areas of historical research, archaeological field
work, and conservation.
The next area of work was the production of a museum exhibit. With the aid of MOSH, in June of 1991, the first permanent exhibit on the Maple Leaf was opened at the museum. This exhibit is a large interactive display viewed by over 300,000 people a year. In addition to the artifacts on display, there are exhibits on the history surrounding the Maple Leaf, the science involved in the recovery of the Maple Leaf and conservation of the artifacts, and the exhibit is used as a teaching aid for students coming through the museum. There is also a 30-minute video documentary on the Maple Leaf Project, produced by the Duval County School System shown at the museum exhibit. This film was originally produced as a teaching aid for students and is available to any school upon request.
In addition to the museum's large exhibit SJAEI has set up several small exhibits around Jacksonville. We are presently working on several other exhibits around the state and even outside of the state in areas that are interested in underwater archaeology, history of Florida, history of the Civil War, or the Maple Leaf. Volunteers from SJAEI continue to give talks about the Maple Leaf to schools, civic clubs, professional groups, and other interested groups around the country.
1991: Mapping of the Vessel
In March of 1991 we returned to the site for the first
time in almost two years. This time our intentions were not to excavate cargo,
but to do extensive site mapping, to examine the condition of our 1989
excavation core, and look at the possibility of conducting a field school with
ECU in the summer of 1992.
Field work began with mapping the port side of the vessel. To accomplish this a 20 foot square grid, subdivided into 10 foot squares, was installed onto the center base line. This grid system was designed with the ability to slide along the entire length of the base line (Figure 3).(to follow)
During the mapping of the port side, SJAEI had several objectives to accomplish. These included a profile of the port side of the ship from the bow to the stern, an estimate of the amount of over burden of mud on the deck, and the mapping of any obstruction or ship structure protruding out of the mud.
The divers started at the bow of the Maple Leaf with the grid, inspecting each 10-foot square first for mud depth. Using an eight foot probe marked in one foot increments, the divers would take a measurement at each corner of the grid, at each five foot mark between the corners, and at the center of the grid. Next, all obstructions within the grid were identified measured, and plotted on the map. The final data to be recorded was the profile of the edge of the ship in relation to the distance from the base line. The divers would probe out along each leg of the grid until they found the edge of the ship; then this distance was measured and recorded.
Once a 20-foot square grid was completely surveyed, the grid was moved 20 feet along the base line and the next area was surveyed. This process was followed all the way to the stern. The mud depths and the port side profile can be seen in Figure (4).(to follow)
1991: Condition of the Core
The second scope of work SJAEI wanted to investigate was
the condition of the 1989 test excavation core to determine if mud or cargo
within the ship had moved back into the core area. To accomplish this, divers
would need to enter the hold again. After removing the overburden of mud from
the deck, the plywood was removed from the entry hole. Upon entry into the
hold, it was found to be filled with a small amount of a light suspended silt.
Once this silt was removed, it was apparent that neither the mud nor the cargo
had moved into the core area. There was some concern that once the mud and cargo
had been removed from an area, creating a void in the cargo hold, the
surrounding mud and cargo would have a tendency to move into this void. If this
were to happen, it could possibly damage some of the artifacts or preclude the
proper mapping of certain items. SJAEI will continue to monitor this
possibility, and should this start to happen, we will have to produce some type
of system to prevent it from occurring. Several alternatives have already been
investigated such as shoring up the mud walls, back filling with mud, or using
some type of dunnage bag to fill the void.
East Carolina University
Field School
The last part of the field work was to allow ECU staff
members to dive the site for the purpose of designing a future site plan and
looking at the possibility of conducting a field school at the site. On August
10, 1991, the following group from ECU dove on the Maple Leaf: Brad
Rodgers (staff archaeologist and field school director), Steve Sellers (diving
safety officer for ECU), and Frank Cantelas (graduate student at ECU). They are
now working on a plan to cover areas such as site evaluation, scope and nature
of archaeological investigation on the Maple Leaf site, and the planning
of a 1992 ECU field school.
After the ECU staff visit, SJAEI was ready to shut down field operations. Over the next three weekends, the site was secured and diving was suspended for the summer.
Closing Statement
From the beginning, the Maple Leaf Project has
been mainly guided by a group of people: not professional archaeologists,
historians or conservators, but individuals who came together because of their
love of history and adventure. They were the first to realize the immense
importance of the Maple Leaf and knew that it would offer the public an
opportunity to learn more about our history and advance the science of
archaeology and conservation. Although this group (SJAEI) was scrutinized
closely by the professional community in the beginning, I believe that at this
point most of the professionals informed about the project (as to what has been
done and what is planned for the future) believe SJAEI capable of continuing in
the right direction, especially if it could have the aid and guidance of the
professional community. It has always been our objective to do what is best for
the Maple Leaf The investigation and excavation of this site is too
enormous and important to remain in the hands of a single group, but must be a
collaboration of many groups both professional and public with a single
interest in the Maple Leaf and what it can tell us about our past. The
main benefit of the Maple Leaf shipwreck site is what it can teach
students of all ages (regardless of their occupation) about their past by using
the disciplines of their present.
It is a great achievement that individuals who are normally
at odds, with conflicting points of view and ethical standards, have banded
together and are working unselfishly and in harmony to bring to light the story
of the Maple Leaf for public enjoyment. My thanks to those friends of
mine from the private sector, the staff and students of East Carolina
University, the Division of Archaeological Research with the State of Florida,
and the Department of the Army, Center of Military History.
The Maple Leaf. Copyright 1993 by