Launched in 1843, SS Great Britain was the first wrought iron and screw-driven ocean going liner. After a remarkable salvage operation to bring it home from the Falkland Islands in 1970, it now lies in dry dock in Bristol.
However, the "dry" dock proved not to be dry enough to preserve the ship, which has continued to corrode rapidly to the extent that it would become unsafe within 25 years.
Conservation experts from the School of History and Archaeology at Cardiff University, have been called in to determine how dry the atmosphere needed to be to halt the progress of the corrosion of the 300-ft hull.
Senior Lecturer David Watkinson won grant awards totalling £40,500 to install a climatic chamber in support of experimental work at Cardiff and to employ a research assistant, Mark Lewis. Their laboratory work involved controlling relative humidity and temperature to determine corrosion rates and a relative humidity at which corrosion of chloride infested iron ceased.
Their results have been used to support a successful £7.2 million Heritage Lottery Fund bid by the SS Great Britain Trust, and data is now being used by architects and engineers to design a glass roof to cover the dry dock and mechanical plant to control moisture levels within the space created. It is expected that the enclosure will be in place in mid 2005.
"By controlling moisture levels the ship will be preserved for future generations to view," said Mr Watkinson. "This research has saved the SS Great Britain Trust thousands of pounds in design and running costs by ensuring that the system was not over-designed for the task in hand."
As a result of the Cardiff research, guidelines are being produced for the dry storage of archaeological iron, providing museums and heritage institutions with extensively researched standards for implementing such storage methods. Mr Watkinson and Mr Lewis have been invited to report on their work at the International Council of Museums Conference on the Conservation of Metals in Canberra in October this year.
SS Great Britain was salvaged from the Falkland Islands, where it had been used for off-shore storage and was partly-sunk, in 1970. In a major operation, it was transported "home" to the Great Western Dockyard in Bristol, which had been constructed especially for the building of the ship, making it the first integrated iron shipbuilding yard in the world and an important heritage site.