The Cutty Sark Trust - Press Release
21ST Century Technology to Save Famous 19th Century Tea Clipper
This week the aft peak chamber behind the bulkhead (a compartment at the back of the ship!) of the Cutty Sark was flooded by seven thousand litres of water to a depth of 12ft. This was the preparatory stage of pilot scale electrolysis experiments due to commence in January 2004. The reason the work is necessary is because salt and chlorides from the sea have penetrated the micro-structure of the ship and, when mixed with water or humidity, caused rusting. Over the years the wrought iron has corroded to the point where taking it apart to clean off the rust (to prevent further corrosion and hence loss of structural strength) could be very destructive, if not impossible. This is particularly true of the lowest area of structure, which is also the most complicated. Electrolysis involves the passage of a current through a solution and use of this technique allows chloride ions to be removed from the metal and wood structures within the ship.
The area will remain flooded until after Christmas. This trial results from scientific research undertaken by the University of Portsmouth in partnership with Hampshire County Council Museums Service following the Heritage Lottery Fund’s maximum planning grant of ?50,000, which will also indicate whether electrolysis could be the solution to the rust damage, which is forcing the timbers apart. This method has been used successfully on an all-metal ship, but would be its first application on a composite hull. An additional experiment will take place after Christmas when the largest and most complicated strake (plank) and frame will be removed for inspection. It should be stressed that electrolysis will be only one aspect of the conservation programme aimed at devising appropriate prevention and protection measures against deterioration of the ship’s construction materials.
These and subsequent experiments should result in an assessment of the overall cost of complete refurbishment, and are the first aspect of the ?10 million fundraising campaign by the Cutty Sark Trust, to preserve the ship for the nation.
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The Cutty Sark Trust
2 Greenwich Church Street, London SE10 9BG
Registered Charity No. 1080462
The Cutty Sark was launched on 22 November 1869 and is the last surviving example of an extreme clipper built for the profitable China tea trade. Between 1850 and 1872 about 80 such ships were built for this trade but the opening of the Suez Canal in 1869, which allowed steamers, access to the Far East via the Mediterranean, resulted in their demise. The last cargo of tea carried by the Cutty Sark was in 1877. After achieving record-breaking trips carrying wool from Australia, she then had a rather chequered history until 1954 when she was moved into a specially constructed dry dock at Greenwich.
The 963 tons gross Cutty Sark is now the world’s only surviving tea clipper but a recent full structural survey revealed that the hull is in a severe state of deterioration. The ship is constructed of a combination of wrought iron and timber, known as composite construction.
Ground-breaking scientific work being undertaken by Portsmouth University in partnership with Hampshire County Council Museums Service, will indicate whether applying electrolysis could provide a solution to the rust damage. . The use of electrolysis opens up the possibility of treating the wrought iron in situ and then preventing further corrosion. The method has been used successfully on an all-metal ship, but this will be its first application to a composite hull.
It is known that electrolysis can work on metal, however, it could damage the wood by encouraging the growth of microorganisms associated with wood and metal. Such growth, if allowed, can lead to timber deterioration. Laboratory trials have shown that addition of a biocide inhibits microbial proliferation.
The experiments will demonstrate the impact of electrolysis combined with the biocide application on the timber. It will also reveal how long it will take for chloride ions present to be removed and also the time needed for the timber to dry out and whether the quality of the timber is enhanced or undermined following the treatment.
The study will be conducted only in the aft peak area on the ship and, if successful, will enable estimates to be calculated for extending the work to the whole ship. It is anticipated that this and subsequent experiments will result in an accurate assessment of the overall costs of ship’s complete refurbishment.
The Cutty Sark is a treasure of Maritime Greenwich and must be preserved for the nation. These experiments are the first step in what is part of a major bid for Heritage Lottery funding (which will be submitted in June 2004) to ensure that this unique part of Britain’s maritime heritage remains for the 21st Century and beyond.
A press conference is scheduled for early January next year when the experiment proper commences.