Conserving a national treasure

Buro Happold

09/05/2012 Written by: Gill Sincock No comments

After a major conservation programme lasting eight years the world famous Cutty Sark, the UK’s last surviving tea clipper, has reopened to the public.

Giving the ship the royal seal of approval, Her Majesty The Queen paid an official visit to the Cutty Sark on 25th April to see how this cutting edge conservation project has returned one of Great Britain’s best loved maritime attractions to public viewing, and to inspect the other new additions to the site which include a new exhibition space, cafe and events venue. 

Keeping the ship within its original 1950s concrete dry berth, Grimshaw’s revolutionary new design raises the 963 tonne Cutty Sark up by 3.3 metres on an innovative series of triangulated steel frames. This extremely complex but elegant pre-stressed system hangs and stabilises the ship in its new position. Constructed from steel, the structure will preserve the shape of the ship’s iconic hull and has enabled an additional space to be created in the dry berth below, allowing visitors to walk underneath and admire the ship’s form.

Multidisciplinary engineering consultancy Buro Happold was appointed to the project in 2005 as the structural and conservation engineers. Part of the consultancy’s role was to design and implement new interventions that respected, repaired and adapted the original fabric of the ship for her new use. This multi-layered approach required the engineers to step outside their conventional discipline boundaries to use their talents to solve a wide variety of unique problems with equally unique solutions.

One of Grimshaw and Buro Happold’s key concerns was to ensure that the new steel cradles caused minimum visual distraction from the ship’s own structure and so the cradles have been integrated with the existing fabric of the ship where possible.  In other locations the fabricated steel of the new support cradle sections minimise the impact.

The process of raising all 963 tonnes of the tea clipper over three metres into the air to permanently suspend her within the dry dock took place in three separate lifts across a period of seven weeks in early 2011. Since then the addition of a new glazed canopy which runs from the bow along both sides of the ship to the stern has been made, enabling the dry berth beneath the lifted hull to be opened up to the public for the first time.

Overseen by the Cutty Sark Trust, the Grade1 listed landmark was undergoing its biggest overhaul for 50 years when fire swept through the wrought iron and wooden structure in 2007, causing extensive damage to the centre of the ship which necessitated rethinking and enhancing the original conservation plans for the project. Luckily the process of dismantling the ship’s structure had already begun; a significant amount of original timber material had already been taken off site so most of the original fabric existing prior to the fire survived.

Chris Nash, Partner at Grimshaw said: “We are very proud of our work on the Cutty Sark conservation project. The finished project is a fantastic example of conservation and 21st century architecture working in harmony. The ship is now imaginatively presented and accessible to everyone in a way that will delight all visitors, and ensure the long-term financial sustainability of Cutty Sark.”

Buro Happold project Principal Steve Brown commented,” We are thrilled to have played a major part in delivering this futuristic vision for one of the UK’s best loved maritime treasures. We have been involved in all aspects of the project from conservation through to the innovative proposal to suspend the ship in mid-air. We’re proud to be able to say we’re a part of the team that has delivered this amazing outcome.”