Techniques for Cleaning and Preserving Shipwreck Artifacts After Recovery

Shipwreck artifacts carry immense historical, cultural, and archaeological significance. Recovering these items is only the first step. Proper cleaning and preservation techniques are essential to ensure that these artifacts can be studied and appreciated for generations to come. This article outlines the various methodologies employed in the cleaning and preservation of shipwreck artifacts following their recovery from underwater sites.

Initial Assessment and Documentation

The first step after recovery involves a comprehensive initial assessment of the artifacts. This includes documenting their condition, material composition, and any evidence of corrosion or biofouling. High-resolution photography, detailed notes, and condition reports are crucial in creating a baseline for further treatment.

For example, the Mary Rose project, which focused on the recovery of a Tudor warship, involved extensive documentation of over 19,000 artifacts. Each item was carefully photographed and logged, providing a detailed record that guided subsequent preservation efforts.

Cleaning Techniques

Cleaning is a critical aspect of preservation, but it must be conducted carefully to prevent damage. The cleaning process varies based on the material composition of the artifact:

Metal Artifacts: Commonly found shipwreck artifacts include cannons and tools made of metal. Cleaning often involves the use of ultrasonic baths that employ high-frequency sound waves to dislodge corrosion and corrosion products without abrasive damage. Chemicals such as sodium bicarbonate are also employed in a controlled method to neutralize rust.
Wooden Artifacts: For wooden objects, such as ships timbers or personal belongings, the initial cleaning typically involves careful washing with fresh water at low pressure to remove particulate matter. Afterward, stabilization is crucial. A common method is treatment with polyethylene glycol (PEG), which replaces water in the woods cellular structure, preventing shrinkage and cracking.
Glass and Ceramics: Fragile items like glassware or ceramic dishes require gentle washing in distilled water with minimal abrasives. In some cases, chemical agents might be used to remove unwanted deposits or stains. Protective treatments can subsequently be applied to strengthen their structure.

Preservation Techniques

Once artifacts have been cleaned, various preservation techniques ensure their longevity:

Controlled Environmental Storage: Shipwreck artifacts should be housed in climate-controlled environments where factors like temperature, humidity, and light exposure can be monitored and regulated. For example, a relative humidity level between 40-60% is ideal to prevent mold growth on organic materials while minimizing metal corrosion.
Coatings and Treatments: After thorough cleaning, metal artifacts may benefit from protective coatings, such as wax or lacquer, which can act as barriers against moisture and corrosion. For wooden artifacts, the use of PEG helps to stabilize the material, while also providing moisture resistance.
Public Display Considerations: When artifacts are showcased, it is important to ensure they are housed in display cases that protect them from environmental fluctuations and physical damage. UV-filtering glass and climate control inside cases are essential to preserving delicate pieces.

Case Studies and Real-World Applications

Several notable projects showcase successful cleaning and preservation techniques:

The Titanic Artifact Exhibition: Artifacts recovered from the Titanic have undergone extensive preservation practices, including cleaning with non-abrasive methods and careful stabilization processes. Artifacts are maintained in glass cases with strict environmental controls to reduce deterioration.
USS Arizona Memorial: Ongoing preservation efforts for the USS Arizona artifacts focus on electrochemical treatment and controlled storage conditions to mitigate the impacts of corrosion and maintain the integrity of historical items.

Future Directions and Innovations

As technology advances, new methods of cleaning and preservation continue to emerge. Innovations like 3D scanning and digital conservation allow for the creation of digital replicas, enabling researchers to study artifacts without direct contact. Plus, nanotechnology explored for protective coatings, which promise enhanced durability and resistance to environmental factors.

Conclusion and Actionable Takeaways

Cleaning and preserving shipwreck artifacts require a combination of expert knowledge, careful methodologies, and innovative technologies. By following rigorous standards in the assessment, cleaning, and preservation processes, we can ensure that these invaluable pieces of history are safeguarded for future generations.

Professionals in the field are advised to:

Thoroughly document artifacts as they are recovered to inform future preservation strategies.
Choose cleaning methods appropriate for the specific materials of the artifacts to avoid damage.
Use robust storage and display protocols that prioritize environmental stability.
Stay informed about new preservation technologies and techniques to enhance ongoing efforts.