Mary Rose

N. Robinson, R.P. Evershed, W.J. Higgs, K. Jerman, Eglinton, G., Proof of a pine wood origin for pitch from Tudor (Mary Rose) and Etruscan shipwrecks application of analytical organic chemistry in archaeology, Analyst, 112, 637 643 (1987). 

Evershed, R. P., Jerman, K., and Eglinton, G. (1985). Pine wood origin for pitch from the Mary Rose. Nature 314 528-530. 

M. Rule, The Mary Rose, Conway Maritime Press, 1982. 

Maurice jay, Marie-Rose Viricel, and jean-Frangois Gonnet... 

Harvey, J., "Analysis of dyes in fabrics recovered from the Mary Rose Site", in Dyes on Historical and Archaeological Textiles 1st Meeting, York Archaeological Trust, Aug. 1982, 3. 

Forster, M Buckland, K., Gardiner, J., Green, E., Janaway, R. C., Klien, K. L et al. (2005). Silk hats to woolly socks clothing remains, in Before the Mast Life and Death aboard the Mary Rose (J. Gardiner with M. J. Allen, Eds.). Portsmouth, UK Mary Rose Trust. 

Maritime Archaeologist Archaeological Director, Mary Rose Project 1967-1994 Archaeological Consultant 1995-2003... 

Objects, including large guns, were recovered from the sea prior to the formation of the Mary Rose Trust in 1979, and they were taken to the conservation laboratories of the City Museum the same day. Close planning and liaison with the people providing equipment to lift the guns from the wreck site and take them ashore, the road transport and the museum staff were essential. Once the operation became full-time in 1979, the Mary Rose Trust, a charity and a company limited by guarantee, was formed to excavate and, if feasible and... 

Figure 3 Silts between decks on the Mary Rose. The fine sediments that filled most of the lower hull had never been disturbed, and in this anaerobic environment organic materials such as silk, leather and wood were well-preserved...

Figure 4 Detached timbers eroded by teredo in the upper levels of sediment below the stern castle (Mary Rose)...

The need for on-site conservators and recorders is obvious. Some details like paint marks on wood or stone are often fugitive and fight labile, as were the markings on the parts of a seaman s chest from the Mary Rose indicating how they fitted together. Obviously it was a flat-pack kit purchased for later assembly. Within 20 minutes the marks had been photographed, but they were beginning to fade and there is no trace of them today. 

M. Rule, The Mary Rose - the Excavation and Raising of Henry VIII s Flagship, Conway Maritime Press Ltd, London, 1982. 

We would also like to acknowledge the valuable support of the following during our research on the Victory sail the Society for Nautical Research, Colin Appleyard (Hood Sailmakers), Kate Gill (Textile Conservation Centre), Peter Goodwin (Keeper, HMS Victory) and Mark Jones (the Mary Rose Trust). 

Silver items recovered from marine sites are often completely mineralised due to the non-protective nature of the corrosion products formed in both aerobic and anaerobic sites. The corrosion product is either silver chloride (AgCl) or silver sulfide (Ag2S). All silver artefacts recovered from the Mary Rose were found to be in very poor condition. 

Figure 2 Concretion and mud on a split ring gun recovered from the Mary Rose...

Finally, thermal methods such as placing the artefact in a hydrogen furnace at 400°C has been successfully employed on ferrous artefacts recovered from the Mary Rose. Any remaining concretion on the surface was present as a fine powder after conservation and was just gently brushed off the surface. An alternative thermal method involved placing the artefact in an inert atmosphere at 1066°C followed by quenching. The procedure is repeated until all the concretion has spalled from the metal. 

As an alternative to the use of acids, sequestering agents have been employed to dissolve the corrosion products without attacking the parent metal. The most effective formulations are based on the derivative of ethylene diamine-tetra acetic acid (EDTA). Lead artefacts from the Mary Rose were cleaned in a 10% solution of this compound. The use of EDTA is not recommended for cast iron as the graphite flakes embedded within the corrosion products are also dissolved. As with the use of acids, the shape of the artefact is altered if the corrosion layers are very thick and it is also difficult to wash out all the solutions from cracks, crevices and pores in the artefact after cleaning. 

A relatively simple method is to dissolve out the chloride by immersion in distilled or de-mineralised water. Most of the common metals and alloys will continue to corrode in this solution although at a slower rate due to the lower conductivity of these solutions compared to seawater. This can be serious if the artefact is to be immersed for periods up to 5 years, but has been employed if the immersion times are relatively short. A small copper alloy sheave recovered from the Mary Rose was soaked in running demineralised water for 27 days and the chloride levels dropped from 106 to 10 ppm over this period. 

By using boiled water, the dissolved oxygen is expelled and hence, there should be no corrosion as the cathode reactant has been eliminated from the electrolyte. Unless the boiled water is kept in sealed containers, air (oxygen) will slowly dissolve into the water and corrosion of the metal or alloy will re-commence. As an alternative, using hot demineralised or distilled water will reduce the concentration of dissolved oxygen and hence corrosion, but this must be counter-balanced by the rise in reaction rates with temperature. In open conservation tanks, a temperature of 70°C is required to notice a significant reduction in rates of corrosion of metals. Small copper alloy artefacts from the Mary Rose were treated in this way using water at 80°C for 30 days. At the end of this period, the chloride levels in the water dropped to below 1 ppm. 

The anodes that have been used include stainless steels, mild steel, lead and platinised titanium, while typical electrolytes for ferrous materials have been 0.5 M sodium hydroxide, 0.2 M sodium carbonate, 0.5 M sodium sesquicar-bonate and tap water. For bronze cannons recovered from the Mary Rose, both sodium hydroxide and sodium carbonate electrolytes were employed while pewter artefacts (plates) from the same ship were treated in similar electrolytes or in a 0.5% solution of EDTA as a sodium salt in alkaline solution. 

The furnace at Portsmouth was installed in the Conservation Department of the City Museum in 1975. The design of the furnace was influenced by the considerable number of large cannons recovered from the Solent and in particular, from the Mary Rose. It was a vertical retort furnace with a cylindrical bell type retort 2.5 m high by 0.7 m in diameter made of Nimonic, a heat resistant alloy. Once loaded with the artefacts, the retort was wheeled into an electrically-heated furnace with three banks of independently-controlled... 

The major criticism of this method of conservation is that the metallurgical structure of the artefact has been altered by heating the artefact to elevated temperatures. For this reason, relatively few artefacts with derived microstructures such as knives, axes, etc., were treated in the furnace at Portsmouth. If hydrogen treatment was the method selected for these, the operating temperature was reduced to 350°C and the process time extended in order to minimise the alteration to the microstructure. Nevertheless, this method is one of the best and quickest methods for the removal of the chloride ions. Guns from the Mary Rose were fully conserved within 2-3 weeks and even after exposure to the atmospheric conditions for nearly 30 years, they still show no sign of breakdown. 

Thermoplastics in the form of a lacquer have poorer mechanical strength than the thermosetting resins but are more easily removed, should this prove necessary. Polyvinyl acetate and polyurethane are good examples of this class of consolidants, particularly on wrought iron artefacts. Many of the copper and copper-based alloys, such as bronzes and brasses recovered from the Mary Rose, were consolidated with a solution of acrylic resin dissolved in toluene (Incralac). 

The Mary Rose Trust, HM Naval Base, Portsmouth, Hampshire, POl 3LX, UK... 

Table 1 Marine fungal species isolated from Mary Rose timbers...

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