An anticipated working life of 30 years has now extended to 137 years, so it is not surprising that a full structural survey in the 1990s revealed serious deterioration of the hull structure due to the egress of water. A 1999 application to the Heritage Lottery Fund was rejected but a new bid was approved last year, resulting in a full £11.75m pledge and the highest project development grant the Fund has ever granted, a further £1.25m.

The Cutty Sark Trust has raised a further £5.25m. Two significant nautical funders, The Stavros Niarchos Foundation and the The Corporation of Trinity House, have contributed £250,000 and £260,000 to the project respectively.

The conservation project, which begins in October, has been conceived to halt the degradation of the ship's fabric and prevent its future recurrence through a combination of electrolysis, mechanical leaning, preventative coatings, selective repair, and the replacement of the main deck, keel and sheathing so that no further major conservation work is required for 50 years.

Buro Happold and Beckett Rankine Partnership are working in joint venture as the Cutty Sark Trust's structural and conservation engineers. They are responsible for the design of the ship's new support system as well as the conservation and strengthening work to the ship's original wrought iron frame and timber hull planking. The conservation of the ship is particularly challenging as the electrolysis process, which is required for removal of chloride ions from the iron, is damaging to timber, hence the need to remove all the ship's planking during the treatment of the iron.

This is the first time that electrolysis has been applied to a composite ship and a virtual Cutty Sark has been created at the University of Greenwich to anticipate stresses on the structure of the ship during the works. A skilled technical team will conduct repairs to the hull planking and frames, the main deck will be replaced with ethically sourced teak and the project will feature green energy systems, with boreholes for ground-source heat pump that pre-heat and pre-cool energy.

The architect's vision for the ship has its hull seemingly flying over visitor's heads. To achieve this vision requires a type of support that has never been attempted before on a ship weighing over 1,000 tons. The structural engineers have had to develop an intricate but unobtrusive internal support framework to carry the ship while minimising loads in its original, much degraded structure.

The works will take two and a half years to complete, but Cutty Sark is open until 30 September 2006 and, from April 2007 through to April 2009, hard hat tours of the works in progress will be bookable.

For further information visit the Cutty Sark Trust website at www. cuttysark. org. uk