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"Excavations" in the Laboratory

La Belle and her artifacts presented a formidable challenge to the Texas A&M Conservation Research Laboratory (CRL) and the Texas Historical Commission. At the time of the initial survey of the bay in 1995, no one had a clear concept of what it would take to excavate and conserve the French shipwreck and all of its remains. Due to the very active nature of the Matagorda Bay site, it was assumed that there would be few organic materials preserved and that remnants of iron and other metallic artifacts would constitute the bulk of the material culture to be recovered.

As is now well known, the excavations of 1996-1997 revealed that La Belle was a fully packed hull containing well over a million individual artifacts, ranging in scale from remnants of insects to the ship's hull itself. Many of these artifacts were not excavated in the original archeological site but, rather, in the CRL laboratory in College Station. Though receiving less media attention than the bay excavations, the long and painstaking conservation phase was just as critical to the project, since few of the artifacts from the waterlogged ship could have survived without being carefully processed and conserved. In the case of La Belle, not only was her cargo cleaned, treated, and stabilized, but her hull was completely reassembled in what was one of the largest conservation projects ever attempted in the United States!

Wooden boxes and casks, coils of rope, sections of textile in sediment and-most daunting-hundreds of pounds of cemented iron concretions were carefully recovered, packaged, and transported to the CRL to be excavated under controlled conditions. And buried within many of these artifacts were invariably numerous other individual artifacts, at times numbering into the thousands! Coils of rope, for example, were tantamount to an entire archeological excavation. Inside the sediments encasing the rope were hidden rat bones, insect parts, cockroach egg cases, hair, textiles (grosgrain ribbon, silk thread from a buttonhole), a wood button, and individual glass beads. Lab analysts carefully recovered these fragile finds, bits of minutia that would help flesh out the story of life on the French ship and what had been envisioned for La Salle's colony in the New World.

Challenging Logistics

Logistics of the dual projects were complex. As the excavation progressed in Matagorda Bay, full-scale operations also were being conducted four hours away at the conservation laboratory. There, researchers and students were cataloguing and storing the thousands of shipwreck artifacts delivered to the lab twice weekly. Each new arrival triggered an array of tasks to assess and care for the materials-identifying, unwrapping, re-wrapping, and storing the objects in containers and solutions to maintain optimal conditions- all before the actual conservation process could begin.

The vast amount of materials coming in sent lab crews rushing to accommodate them. As chief conservator Helen Dewolf noted, "Amazingly, not everything could fit into basic plastic storage tubs. We scrambled weekly for more water troughs from the local co-op as we learned what was likely to arrive with the next delivery of artifacts." She notes they even had to resort to acquiring two BFI solid waste containers (dumpsters) that could open at the end and be sealed to be watertight.

The crew constructed shelves to support the larger objects and medium-sized hull pieces inside the BFI vats. At the Palacios excavation headquarters on the coast, the THC excavation crew had to custom-build reinforced plywood containers to house and transport the larger hull pieces of the ship-frames, planking and ultimately the keelson and keel. Meanwhile, Texas A&M lab workers had to design, build and fill a concrete vat to serve as a conservation tank for the hull.

Reconstructing La Belle's Hull

The hull was the largest and most important artifact from the site, and its transport to the laboratory entailed strategic planning on a large scale. Some thought that the hull should be lifted intact out of the cofferdam and shipped as a whole to the CRL. Given the potential hazards of moving an entire shipwreck more than 100 miles down a highway, however, it was determined that a safer approach would be to disassemble the hull and deliver it in pieces. Field crews carefully disassembled the hull in the bay site, ultimately packaging some 380 pieces of timbers and ship parts for transport.

Meanwhile, months of planning and construction had been underway at the CRL in order to receive and store the hull. It was determined that as much as possible of the hull should be reassembled and conserved as a unit to reduce the warping and distortion that waterlogged wood often undergoes during conservation treatment, especially if the wood has suffered from a variety of degradations. That being the case the conservation tank needed to fully submerge the reconstructed hull initially in water and later in the conservation solution, and allow enough space to allow the reconstruction and conservation crews to maneuver around it. This meant a vat with interior dimensions of 60' X 20' with a depth of 12' was needed.

Construction on the state-of-the-art vat began in 1998. The geology of the area required a highly engineered complex and highly re-enforced concrete vat, a structure that would be able to "float" on/in the area's clay soil when the soil was supersaturated with rain water and not be subject to the torquing nature of the drying clay in the driest months of the year. The vat also was designed to allow for the contents of the vat to be lifted and lowered on a platform to ease the initial installation and ultimately removal of La Belle herself, and allow for periodic inspection. Working through drought and the inevitable periods of rain and flooding, construction crews completed La Belle's new home at the CRL—the largest wood conservation vat in the United States.

Before reassembly could begin, crews spent months cleaning the wood and removing all the wooden "treenails" as well as remnants of iron bolts and spikes. Then structural timbers had to be aligned on the platform in the vat, following the coded numbers carved onto each timber, so that all the holes for the nails lined up. In lab director Donny Hamilton’s view, it was "like working on a giant jigsaw puzzle."

As reconstruction stretched into the cold winter months, the process became increasingly more uncomfortable. To keep the wood from drying out, the hull was constantly sprayed with water, and frequently lowered into the vat throughout the day and at the end of each day's procedures. Crews donned wet suits to work inside the vat, lifting and refitting the heavy pieces into place. Slowly the ship came together. Once the frames were bolted in place and properly aligned, a carbon fiber-fiberglass composite support was placed under it to ease stress on the hull.

In This Section
  • The artifacts and even the hull of La Belle herself made the 100-mile journey from the Texas coast to a "sea" of conservation vats stretched along an old World War II runway at the Riverside Campus of Texas A&M University.
    More than 770,690 tiny glass trade beads were cleaned and classified from the shipwreck.
    Wooden boxes, coils of rope, and the ubiquitous concretions were transported to the lab to be "excavated" under controlled conditions. Within these artifacts were invariably numerous other individual artifacts, at times numbering into the thousands!
    Coils of rope were among the many organic materials recovered from the shipwreck, a surprise to both excavators in the field and in the conservation laboratory. As they cleaned and conserved the rope, lab crews picked through dozens of tiny artifacts-bits of hair, tiny animal bones, seeds, beads, and other remains-concealed within the twisted fibers. More than 2000 feet of rope has been painstakingly examined and conserved, with more remaining to be processed.
    Transported to Texas A&M in more than 380 parts, the ship is slowly reassembled on a mechanical platform which lifts it in and out of the water in its concrete vat. During reconstruction, the hull pieces were sprayed constantly with water to prevent deterioration of the wood.
    Like putting together a giant jig-saw puzzle, reassembling the hull was a challenge, even in the best of conditions. Wet suits were the order of the day for crew members working in the vat during winter.
    The reassembled hull of La Belle rests in its special vat filled with conservation chemicals. The fragile vessel still has to absorb more of the chemical solution to stabilize the wood. Then it will be slowly reintroduced to the natural environment and air dried.

    The hull is still several years from being fully treated, as the wood has to absorb a substantial portion of the conservation chemical. Once that threshold has been achieved then excess chemicals will be pumped out and very slowly/gradually/carefully allow any excess to drain out while the hull is air dried.  During this period the timbers will be cleaned of excess chemical and debris. Once the wood is dried, stable and strong, then the lab crews will begin the systematic disassembly of the ship for transport and eventual reassembly for display in the Bob Bullock State History Museum in Austin.

    While the actual hull has been undergoing conservation, a 1/12-scale model of the Belle also was being constructed. Both the ship and model were used for teaching nautical archeology classes. Another model, destined for the Rockport Maritime Museum on the Texas coast, was constructed by model builder Glenn Greico—a process spanning three years. (A model of La Belle also was built in Paris and is now on display at the Maritime Museum of the Louvre Museum system.)

    Uncovering the Artifacts

    Once the last of the artifacts had arrived at the lab, Dewolf and Hamilton were better able to assess what was needed to manage the processing, analysis, and treatment strategies for such a large quantity of artifacts of such different materials. As Dewolf noted, "This was not a matter of processing a single artifact at a time, but literally thousands!" Each artifact would have to be handled, cleaned, examined, conserved, drawn, photographed, documented and stored before, during and after conservation. There was also considerable research into historic documents and comparative collections to help identify a number of the more unusual objects.

    Time, space, and funding were a constant concern. According to Dewolf, there is a general rule of thumb for conserving artifacts from underwater sites. Under the best of all circumstances, for every month spent excavating in the field it takes at least a year in the conservation lab. Given that it was anticipated that the La Belle recovery would entail little more than a ballast pile, concretions, and a few small organic remains under the ballast pile, the excavation was planned to take approximately 5 months and thus the conservation, 5 years.

    As it turned out, the field excavation took approximately 9 months, meaning researchers needed to allow for at least 9 years in the conservation lab. That "rule," Dewolf notes, never took into account the conservation of an entire ship's hull or the enormous quantity of organic material found inside the cargo holds, which was not anticipated.

    Conservation on an Unprecedented Scale

    Conservation on the scale required by the material culture assemblage excavated from La Belle is rarely seen. Some artifacts were composed of several different materials and thus required more than one conservation treatment. Among these "composite" artifacts were such distinctive items as polearms, weapons with pointed iron blades attached to long wooden shafts. There were also tools with wooden handles, muskets with wood, brass, and iron elements, and other objects of varied constituents. One wooden chest, dubbed "the Mystery Chest" because of its odd contents, contained a variety of composite tools for farming, fishing, wine making, and coopering. (For more detail, see "Uncovering the Mystery Chest" in the section, Treasures of La Belle.)

    Other artifacts needed extra care because of their fragile state of preservation. The very simplest process required an artifact to be cleaned and rinsed (to remove the chlorides/salts), then air-dried and documented. This process was used on ballast, slate and gun flints. Ceramics, and galley bricks required the additional steps of dehydration, consolidation, and reassembly to the basic process.

    The metal artifacts underwent three types of treatment. Those in better condition were treated with electrolytic reduction (ER), which reduces the corrosion products on the surface of the metal back to a metallic state, forces the chlorides from the material, and physically removes some corrosion products and concretion from the surface of the metal. The more fragile metals underwent a chemical treatment to accomplish the same effects as ER without the potentially destructive evolution of the hydrogen bubbles. After these treatments the metal artifacts were boiled to remove the last of the residual chlorides, then chemically sealed and treated to prevent future corrosion.

    "Excavating" Concretions

    For shipwreck projects, every month spent excavating in the field usually translates to at least a year spent on the recovered material in the conservation lab. This rule of thumb did not take into consideration the recovery of the ship's hull! - Helen DeWolf

    Chief conservator Helen Dewolf spent numerous hours cleaning a wooden nocturnal, a rare navigational device found in the shipwreck. "The nocturnal is particularly interesting and close to my heart just because it took so long to work on and clean each incised line. The artifacts that most intrigue me are those that show the marks of being made and used by human hands. I think they bring us across the centuries to touch the 1680's and that is my favorite thing about this work." See artifact.
    Covered in sediment, hundreds of pieces of lead shot are removed from the wooden cask packed aboard La Belle.
    Numerous surprises were encountered while processing even the most mundane objects. Cleaning this rusted mound of cannonballs revealed a well-preserved wicker basket, the container in which they had been packed.
    See wicker basket
    Polearms, archaic weapons made of wood poles with pointed iron blades, were among the numerous composite artifacts from La Belle requiring special conservation treatments. Covered with thick layers of marine encrustations, the objects had to be x-rayed to determine how much metal remained inside and what types of treatment were necessary. As shown in the graphic above and x-ray image on the top row (second from right), there was little intact metal remaining in this polearm. Its hollow interior was cleaned out and filled with epoxy (image top right). A perfect cast of the original thus was created.


    Some metal artifacts-primarily those made of iron-were found covered in what is known as concretion, a multilayered covering of calcareous mineral deposits and corrosion products that formed on the surface of the artifact as the material corroded underwater. When a metal object is immersed in saltwater, a layer of marine encrustration almost immediately begins to form. In many instances, the iron completely corrodes away over time and the concretion forms a natural mold of the original object.

    This mold was cleaned out and an epoxy resin poured inside to make an exact cast of the original. Often, X-rays of the artifacts indicated that not all of the original iron had corroded away. In these instances, the hollow area of the mold where there was no iron was cleaned out and epoxy poured into the void. The concretion was then removed from the surface of the artifact, a mold made of the whole object, and a cast made of the now composite object.

    From Ribbons to Rope: Preserving Organics

    An extraordinary variety of organic materials also was discovered among the remains of the shipwreck. These included artifacts made of leather, wood, and textiles. There were fragments of paper as well as the remains of baskets, and coils of rope. Excavations in the lab even revealed food supplies or perhaps the remains of meals served on board the ship. Some of the animal bones, seeds and nuts represented foods brought from France; others, including bits of cactus seed, clearly had been gathered locally and brought on board by shore parties.

    The smaller organic artifacts were treated using polymer passivation polymers, an innovative technology that allows for better long-term preservation of the artifacts and future retreatment if necessary. Developed at the Texas A&M Archaeological Preservation Research Laboratory (APRL) by C. Wayne Smith, this technology enabled conservators to streamline the dehydration, immersion and catalyzation steps of the conservation process of organic materials and thus process multiple artifacts of differing sizes and materials at the same time.

    This made the process of treating artifacts efficient in terms of time, chemicals, space, hands-on manipulation by the conservation lab staff, documentation, photography, etc. The chemical nature of the polymer treatment allowed the lab crew to devise a schedule that accommodated the divergent materials found on La Belle. The passivation polymers technology works on the cellular level of the material and, once impregnated, all organics are treated on a cell by cell basis.  The largest and densest materials were used as a guide for the treatment schedule.  The smaller, less dense materials were never adversely affected by being in treatment for a prolonged schedule.  Once the polymer was introduced into the cell of the material no more could be forced in to distort the cell.

    Other practical considerations came into play with the larger quantities of organic materials, including approximately 300 feet of bow rope, 75 wooden casks and the hull itself. Because the cost of solvents and chemicals for the polymer treatment (not to mention risk of flammability) was prohibitive, a conservation strategy using Poly Ethylene Glycol (PEG) was used. For efficiency of space and materials, some of the remaining wood casks were conserved with the hull in the same vat. The rope was conserved using PEG as well but needed a shorter immersion timetable. This required large vats dedicated specifically to the rope treatment.

    Funded by the THC, private donors, and foundations, the conservation of La Belle and its myriad treasures has spanned nearly nine years. Because of innovations in organic conservation technologies and strategies and a group of graduate students working part-time and volunteering to aid the three full-time conservators, the CRL lab and the THC successfully conserved approximately 95% of the total number of artifacts from La Belle. This includes : several hundred feet of rope in lines and coils; 45 wood rigging pieces; almost 1800 small wood finds including 200+ wood knife handles; 100+ wood buttons; 24+ wood combs; 770,690 glass beads; 1038 shards of other glass; 1413 pieces of leather; 366 pieces of textile; ); 1786 seeds & floral material; 2071 bones/faunal material and insects; 19,743 brass objects including 5,000+ brass straight pins; 1500+ brass rings; 1000+ brass bells and 3 bronze cannon; 180+ Pewter objects; 700+ pieces of ceramic and brick; 675+ iron axe heads; 1 swivel gun; 1344+ concretions containing a minimum of 2133 artifacts; 209,584 lead shot and one box containing 59 artifacts including tools and miscellany.

    More remains to be conserved, and the THC has raised additional funds to complete the task. According to Dewolf, "We are down to the last 75 casks and barrels, 8 boxes; 19 swords; 32 muskets;156 priority concretions and 1076 non-priority concretions; a couple of hundred feet of rope and the hull itself—almost all of which have started but not yet finished conservation treatments."

    The remains from La Belle constitute one of the largest collections of 17th-century French artifacts ever excavated in the New World. Several of these artifacts are now on display for the public at the Bob Bullock State History Museum in Austin and the six La Salle Odyssey museums along the Texas coast. In the near future, La Belle's hull will travel to its final destination, to be permanently displayed in the State History Museum.

    (To view more examples of artifacts see the section, Treasures of La Belle.)

    Watery vats house masses of iron concretions, their contents waiting to be revealed.
    Surrounded by boiling pans, electrical wires, vats of chemicals, and other equipment used in conservation, a lab worker removes the outer concretions from the swivel gun found in the sediments next to La Belle. The lab environment can be shocking to the senses, with the jarring sounds of machinery, acrid odors, and the constant feel of old dust and grime.
    Artifacts made of perishable organic materials ranged from finely carved bone tool handles and wooden buttons with threads still attached, to seeds and nuts, the latter representing food stores or meals on board the ship.
    A number of artifacts, such as this wood and iron musket with a decorative brass sideplate inlay, required different treatments to conserve the varied materials of which it was made.
    Leather items, such as these shoes, were preserved in silicone oil.
    Examples of the dazzling array of artifacts conserved in the lab, one of the largest collections of 17th-century French artifacts ever excavated on the New World. .