Conserving Cutty Sark

The worlds last surviving clipper ship has been lovingly conserved despite a near-catastrophic fire and severe financial difficulties. Sarah Speight speaks to the construction manager behind this extraordinary project.

She has survived 143 years of storms, icebergs, even fire. She has endured continual repairs, refits and maintenance. But last month, after deteriorating in her dry berth in Greenwich, London for 50 years with a real threat of disintegration, Cutty Sark reopened to the public having had her most dramatic facelift yet.

The six-year, 50-million project, which culminated in an official opening by the Queen on 25 April, has produced a stunning result: Cutty Sark is now suspended three metres above the bottom of the dry berth, nestling in a sea of glass. A new exhibition and events space below shows off her shiny Munz metal hull finish, and an extra deck has been added to improve visitor access and create a theatre space. While it was delivered exactly on time and to budget, the project itself suffered its fair share of troubles. First there was the fire in 2007, caused by a vacuum cleaner that had been left switched on and overheated; this set things back by 14 months and added 10 million to the cost. Luckily, most of the important materials had been removed for restoration. Then there were cash flow problems during 2008 as the project hit dire financial straits and was stalled.

At this point construction consultancy Gardiner & Theobald was called in to restart the project, and in September 2009 was appointed project, cost and construction manager.

John Bell, partner, says that one of the first difficulties was to review a requirement by the Heritage Lottery Fund which put up 50 per cent of the cost to involve local people in the project and utilise it as a training ground to maintain traditional skills.

Cutty Sark Enterprises [which funded much of the other half] had taken on nearly 60 people from the local area to try to teach them shipwright skills, which was commendable, explains John. But construction work tends to be in relatively short bursts of relatively skilled work.

So it wasnt possible to train all these people in all the skills they needed to carry out the work to maximum commercial efficiency; this had proved to be a significant factor that had led to the difficulties the project found itself in.

While maintaining a core of the original Cutty Sark Enterterprises expertise, the team looked at the most efficient way of bringing together a combination of traditional skills and modern-day construction skills. For example, rigging is a very traditional trade, adds John. You cant go into the commercial construction market and say this is a piece of rope rig that ship. So we tried to employ the right people for the right elements.

To make the project viable both commercially and time-wise, Gardiner & Theobald worked with the architects and engineers to develop the design into a more efficient one and to fit more of the client brief. There were issues of sustainability, that could be improved in terms of glazing, so we changed the envelope from single skin to double glazed, says John. We then put the cost savings from that into the conservation of the ship.

The team also developed underground plant-room facilities to provide improved conditioning for corporate events within the dry berth.

We carried on with work on the ship itself, which was sitting in the dock as a skeleton, says John. The timber- clad iron frame had deteriorated quite severely. We pushed on with conservation installing new steelwork and blasting and painting original ironwork.

The teams biggest challenge was integrating conservation work with construction. It was a very linear project in the sense that you had to finish the cast iron frame and coat it with paint, prior to putting timber cladding on the outside, prior to putting on the new work. So in the early stages [the project] was driven by conservation. As the conservation work became well advanced, we could then open up different work phases.

Lift off

Because Cutty Sark had languished in her dry dock for so long with all her weight on her keel, her hull was beginning to warp and sag.

Grimshaw, the main architect of the project, had an off-the-wall idea to lift the ship and create a space underneath for events, cafs, post-museum activities and so on.
John explains: It was a fantastic, lateral idea, and it solved the problem of the sagging.

It was Gardiner & Theobalds role to manage the whole process of the lift, although John is keen to stress it was a team effort between his company and structural engineers, steelwork contractors and a specialist jacking contractor. The whole operation took five days in March 2011. Despite numerous risk assessments and contingency plans, safety measures, and monitoring by remote cameras, there was still an element of uncertainty.

The difficulty of course with the ship was the combination of very old material, areas that had been repaired, and new material, says John. We were lifting in excess of 600 tonnes; as soon as that ship was lifted a couple of millimetres, all the load was transferred so it moved from a ship sitting with its keel on the dry dock to a totally different suspension system.

So was it a nail-biting moment? It went very much as planned, says John. We were expecting to have the odd rivet to suffer distress, but the things we had planned for didnt happen, which is what you would hope! And the following day we were pushing on with the project.

The lift, unsurprisingly, was a high point for the team. Once lifted, you could suddenly see this cavernous space like a cathedral, and see the excellent vision that Grimshaw had.

Decked out

Originally there were two decks on Cutty Sark but a third deck had been introduced in the 1950s. With improved ideas of how to present the ship to visitors, a new steel deck has replaced it to increase access for visitors and provide new facilities this time designed so that the visitor can see over the edge and see the structure of the ship.

Controversially, the weather deck was refitted with new, modern materials rather than traditional teak, oakum (rope) and Jeffreys No. 2 compound.
John explains: When the ship was built in the 1800s, it was very easy to get 30-foot lengths of teak from the Far East. Those sources are not available any more so youre looking at sustainable sources of teak, which are fast-growing and, therefore, smaller.

He adds that traditional ships decks leak and need to be kept wet so that the materials (timber caulked with oakum and tar) can move and expand. This was clearly not a practical option: Cutty Sarks weather deck now needs to be kept dry because of expensive new computer equipment on the deck below, as well as the need to keep maintenance levels low.

So there was the traditional camp, and the modern camp, continues John.

There was a lot of debate between the Cutty Sark Trust, English Heritage and other stakeholder parties. We agreed on plywood with epoxy mortar, topped with teak. It was a compromise it lowered the maintenance cost, kept water out, and used available materials.

However, the team used traditional materials on the tween (middle) deck, as well as a traditional deck builder (Maritime Workshop). Within the project we were selecting where to use traditional skills and modern skills, says John. So the modern deck was done by modern-day carpenters, the traditional deck done by traditional tradesmen.

Nevertheless, he adds, the whole purpose of the project was to restore it to how it was in 1860.

Construction versus conservation

Gardiner & Theobald had already been involved with conservation projects such as Windsor Castle after the fire, as well as ships and yachts. But youre always learning, remarks John. There was lots of historic sailing vessel terminology that was new to us.

Key to progressing the project though was approaching it as a construction project. While we spent a lot of time appreciating the maritime terminology, history and so on, we took a construction approach. For example there were lots of debates as to how the sheathing should be laid. In the 1950s, when they brought the ship into the dry dock, theyd put the sheathing on like roof tiles. So when the rain ran down the sheathing, it ran past the joint.

The traditional way of sheathing a ship is the other way around because the ship is sitting in water. But from a construction point of view you are still fitting panels of sheathing material as you would if you were fitting a proper roof.

Despite the challenges, the legacy that John and the team were a part of hasnt escaped his attention.

Projects like this are brilliant to be involved in, enthuses John. Youre not only bringing together the skills and experience youve used over the years you get behind the scenes; you understand the history of the project; youre combining old and new skills.

It was difficult getting the project restarted, it was a challenge making it work commercially, but its great seeing the project concluding and the rigging and mast going up.

At the end of the day, it is of positive benefit and hopefully will keep the ship going for another 50 years.

Cultural legacy

Cutty Sark is not only a London landmark but also an icon of British maritime history. She is worlds last surviving tea clipper and, in her heyday in the late-19th century, was the fastest and greatest.

Cutty Sark has travelled across the world, sailing under both the Red Ensign and the Portuguese flag, visiting every major port in the world through the course of her working life. In admiration of her beauty and in recognition of her fame, she was preserved for the nation by Captain Wilfred Dowman in 1922. Since then, the old clipper has been berthed in Falmouth and Greenhithe, finally arriving at her current resting place in Greenwich in 1954.

Completion of the Cutty Sark Conservation Project means that no major conservation work will be required on the ship for a further 50 years. But there is a wider legacy one of cultural and educational benefit. The project has regenerated the site and greatly improved visitor access and experience. Having lifted the ship by three metres, visitors can now walk underneath a three-masted sailing ship. The offices and workshops that were in the ship prior to the conservation project have been removed, and the views along the length of the ship have been restored.

Plus, there is new lift access, alternative and accessible means of interpreting the ship, her collections and stories, and live web-cam links to areas of the ship that are inaccessible by wheelchair.

In numbers

90% the amount of original hull fabric Cutty Sark retains

50m the total cost of the conservation project

4.5 Cutty Sark has lasted 4.5 times longer than expected

900 ships total weight in tonnes

1,000m2 the amount of extra space created in and around the ship