By Atilio Nasti, Director of Maldonado Bay Underwater Archaeological Project. En español.
The Spanish ship Salvador, sank on August 31, 1812 in Maldonado Bay in front of the city of Punta del Este. It was a merchant ship of 50 m length, that was used for a troop transport originally destined to Santa Marta, New Granada, in present Colombia. The Salvador anchored off the port of Cadiz on September 23, 1811. On board were the 520 men of the 11th battalion of Albuhera, veterans of the Napoleonic wars. The battalion was commissioned to the Oriental Band to River Plate, present Uruguay, to fight a local revolt against the Spanish government. At dawn and in the middle of a violent storm, the ship ran aground on the sandy sea floor and was pressed down by the strong wind. According to the historic documents, the passivity of the Captain and officers added to the panic of all the crew, and a major nautical disaster. Only 130 persons survived.
The Maldonado Bay is in front to Punta del Este City in Uruguay. It is a narrow and poor deep bay, but rich in dangerous sand banks. Except for the Gorriti island, all the bay is open to the frequent winds coming from the Atlantic ocean. The bottom currents cover the marine floor with sediments. The Gorriti island partially covers the entrance of the bay, decreasing the actions of marine currents and other turbulence, protecting, in a way, the cultural items from the sea action.
Since 1997 the Maldonado Underwater Archaeological Project is working over the wreck of Salvador and is carrying out one of the most complete research of this type in this part of the continent (Lezama 1998; Nasti 1999, 2000).
Since 1997 the area was prospected by local professional divers who made the first site plan of the wreck. The wreck area was sampled based on a grid system and all the objects were mapped and recorded. For the first time we have a complete data base of the wreck. More than 6000 items were recovered during the most recent fieldwork. Among the recovered items, we have recovered wood artefacts and leather objects in good state, such as a shoe and a little bag that have received special attention.
The inorganic component of sediments are clay minerals (silicates) and calcium carbonate has formed from organic remains or precipitated by biological activity. When the material is placed in seawater, it becomes covered with slime films of bacteria and diatoms and the cycle of bio deterioration starts (Pearson 1987).
The alteration of the natural material to convert in an utilizable artefactual item, not only reflects their availability and good working properties, but often relates directly to their reactivity with water. For example, in according to Perason’s argument (1987:122), tanning decreases the solubility and shrinkage of skin as well as its tendency toward decay.
Take into account the above principles, immediately taken of the marine environment (Figure 1), and before starting the treatment process, the shoes were completely dismounted in all their components. The objects were subjected to the desalinisation protocol during two years with deionised water, alternating with borax solutions bath. During all this time we controlled the salt and pH concentration.
Figure 1. Shoe before conservation treatment.
After the desalinisation process, the objects were submerged in ethanol with 50 % ionzed water, beginning the dehydration stage very smoothly. The concentration of ethanol was augmented during 30 days to 100%.
After to conclude with the dehydration process, the object was submerged in polyethylene glycol 400 (PEG400) with an period to 2 month. When the PEG was penetrated into the leather structure, we re-built the shoe using original holes. In figure 2, we show the shoe after it was covered with a Vaseline layer to protect the humidity and keep the leather flexibility. For a better assembly the shoe was put over a wooden frame.
The information obtained from The Shoe Museum (Spain) show that this shoe model could be used with gaiters and with two long shoe-lace over the calves. The bag received similar treatment. Inside it we found an bronze rosary and crucifix in perfect condition.
Figure 4. Bronze rosary and crucifix.
When we started this conservation program, we hesitated about conservating this type of marine objects. We preferred bronze and iron object before leather or other organic artefacts. Today with a rigorous methodology and trained staff, we think it is possible recover and preserve this class of materials better than ever before. The shoe and bag of Salvador is an example to this principle.
The leather remains are less that 2% of the total of sample, so we thinks that this material was covered with sediments and was protected from bacteria and the normal cycle of bio-deterioration.
Waterlogged conditions such as those found in Maldonado Bay can promote the preservation of wide range of organic and inorganic material. Generally we think that well preserved materials are only in deep water and soft sediments. However, the degradation of organic materials on an underwater site is dependent on chemical, physical, and biological factors (Hamilton).
by Atilio Nasti
Hamilton, D. 1997 Basic Methods of Conserving Underwater Archaeological Materials Culturals. Nautical Archaeological Program, Department of Anthropology, Texas A&M University.
Lezama, A. 1997. Proyecto de Rescate del pecio del navío Salvador. (Inédito)
Nasti, A. 1999. Proyecto de Rescate de restos humanos del naufragio del Navío Salvador
---- 2000. Underwater Shipwreck Technology. UI 2001. Tampa FL.
---- 2001a. Spanish troopship Salvador. Nordic Underwater Archaeology.. On line.
-----2001b Conservation of navigational instruments from the spanish troopship Salvador which sank in 1812 in Maldonado Bay, Punta del Este, Uruguay. The International Journal of Nautical Archaeology (in press)
Pearson, C 1987. Conservation of Marine Archaeological Objects. Butterworths, London.
published on Nordic Underwater Archaeology Nov '01, rev jul '03
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