Page 9 - The Building Conservation Directory 2013

t w e n t i e t h a n n i v e r s a r y e d i t i o n t h e b u i l d i n g c o n s e r vat i o n d i r e c t o r y 2 0 1 3 9
Saving Cutty Sark for the nation
Despite the shortage in materials caused
by the first world war, Dowman did well,
restoring much of the clipper’s original beauty,
and he opened the vessel to the public. After
his death in 1936 the ship was sold to Thames
Nautical Training College in Greenhithe, Kent
where she was used for training cadets.
During the second world war Cutty
Sark’s masts were dismantled to reduce
her visibility, leaving just the stumpy lower
sections, and little maintenance was carried
out. It was in this condition that the now
redundant ship attracted the attention of
the National Maritime Museum and, with
the help of the Duke of Edinburgh, the Cutty
Sark Preservation Society was formed in 1953.
After some preparatory repairs the Cutty
Sark was moved a new purpose-built dry dock
at Greenwich. The plan was to preserve the
clipper as a memorial to the Merchant Navy,
including those who had lost their lives in the
two world wars.
A programme of restoration and repair
followed, primarily to keep out the rain and
to consolidate her surviving fabric. By this
time the iron frame no longer provided the
rigidity required to support her masts, the
lower sections of which were of wrought iron
and integral with the structure of the hull.
Repairs focussed on arresting the decay of the
surviving timbers and metalwork, and two
of the deck houses which provided the living
accommodation for the crew were completely
reconstructed. However, the work did not
address the fundamental problem posed by
the high salt content retained in the structure,
which acts as a catalyst for corrosion, and for
the next 30 years the ironwork continued to
deteriorate.
A survey carried out in the 1980s by Three
Quays Marine Services found that the structure
was dangerous. Props supporting the sides of
the ship had begun to cause the hull to deform,
some 60 per cent of its fastenings had failed
and the surveyors concluded that there was a
risk of catastrophic collapse.
The conservation philosophy
By definition, ‘restoration’ means to return
a structure to the form it had at a particular
point in the past. According to internationally
recognised principles set out in the Burra
Charter, this may include the removal of
accretions or the reassembly of existing
components without the introduction of new
material. The addition of new material is
termed ‘reconstruction’ by the charter, while
‘conservation’, on the other hand, means ‘all
the processes of looking after a place so as to
retain its cultural significance’.
Traditional boat restoration, where
the vessel is to be kept sailing, generally
involves a much greater degree of renewal
than is associated with building restoration.
Both the functionality of the boat and the
safety of the crew depend on the ability of
structure and fabric to withstand constant
exposure to abrasion, UV radiation, often
violent seas and even collisions. The least
intervention possible may therefore involve
the replacement of large elements of fabric.
A bid made in 1998 to the Heritage
Lottery Fund for assistance with restoration
did not take full account of the ship’s new
environment and its change in status. Not
only was the ship no longer afloat, Cutty
Sark had been a Grade I listed ‘building’
since 1973. The HLF rejected the bid but
encouraged a further application that
was more conservative in its approach.
The Cutty Sark Trust, as the preservation
society was now known, formed a limited
company to manage the work in 2000, and
engineering consultancy Buro Happold was
appointed to oversee the conservation and
restoration aspects. In turn, a conservation
steering group was set up with representatives
of the trust and its professional
consultants, with meetings attended by
representatives of the HLF, English Heritage
and Greenwich Council’s conservation
officer. The programme commenced in
2002 with a programme of investigation
and assessment that lasted four years.
Prime considerations were:
• to stop degradation, including
corrosion promoted by chloride
• to preserve fabric from her
sailing days (ie pre 1922)
• to prevent further distortion of the hull.
The Heritage Lottery Fund agreed a
programme of restoration in January 2005
and contributed £11.25 million towards an
estimated cost of £25 million. This included a
visitor centre with a controversial glass bubble
designed by Eden Project architects Grimshaw.
The programme of investigation
continued following funding approval. Clinker
concrete ballast in the hull was hacked out
and boards were carefully removed to expose
the extent of corrosion. Then, in May 2007,
a fire broke out in the ’tween deck, which
is the large cargo deck immediately below
the top deck. It raged for several hours and
initially it was feared that the ship would be
lost. Fortunately by then most of the original
timberwork had been taken down and stored.
The main casualty was the timber flooring of
the ’tween deck and some from the main deck,
which were to have been reused. Some of the
wrought iron of the hull was also damaged,
including areas of horizontal plating which
braced the frame. Although badly distorted,
the wrought ironwork was found to be
sound, and some areas of damage were left
unstraightened to tell the story.
Corrosion
The need to halt deterioration of the
composite hull structure proved to be one of
the most difficult conservation challenges.
Investigations had discovered that some
timbers retained levels of sodium chloride
similar to those of seawater (20,000 parts per
million). As it was not feasible to remove the
salt content from all the timbers, the focus was
on cleaning and desalinating the ironwork,
and on isolating it from its environment with
the best paintwork possible.
Preliminary trials indicated that
desalination could be achieved using
The ship today with replica masts and rigging and a
painstakingly conserved hull, rises from the roof of
Grimshaw’s visitor centre (Photo: Jonathan Taylor)
The floor of the ’tween deck was the principal casualty of the fire in 2007 and is now laid with Douglas fir and
caulked as in the past, but the ironwork survived (Photo: National Maritime Museum)