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Brian Morton discusses
the renovation of
an unusual conservatory


‘SUPPORTING COLUMNS’
RESTORING A CAST IRON
CONSERVATORY
The conservatory at Broughton Hall near
Liverpool is built as an addition onto the
side of a Gothic style house, built in 1860
for Gustavus C. Schaube of Hamburg, a
prominent Liverpool merchant.
At a dinner in 1868 he entertained
Thomas Henry Ismay and a Mr Wolfe,
Schaube’s nephew. Over a game of
billiards it was agreed that if lsmay agreed
to have ships built by Harland & Wolfe
then Schaube would finance a company
called the Oceanic Steam Navigation
Company, which latterly became the
White Star Line and then the Cunard
White Star, a very famous shipping line
out of Liverpool. In 1868 the first ship
built for Ismay was named Broughton, a
580 tonne vessel which plied for Ismay
until 1875 and was finally wrecked in
1902.
The significance of the information
given above is that I believe that this
conservatory is unique and was probably
built in the Shipyards as a ‘one off for Mr
Schaube, probably between 1870 and
1880.
When I was asked by the Victorian
Society to look at the conservatory, it had
been suggested by previous engineers
that it was in a state of collapse and
perhaps demolition was the only option
because of the expense of carrying out a
very detailed examination associated with
preparing a full specification. Fortunately,
Helen Hutchinson of the Conservation
Department for the City of Liverpool, had
the foresight to realise that perhaps it
could be restored, and approached
Edward Distelkamp, an expert on the
history of conservatories, who asked me
to look at the conservatory on behalf of
the Victorian Society.
It was with some excitement that I
first visited the conservatory (top
photograph). Originally it apparently had
a semi-circular dome at its top and the
sloping roof was glazed onto the existing
rafters which still remain. Internally, the
very thin structural columns helped to
create the feeling of space and light
(bottom photograph).
Weightman & Bullen, who act as
architects for the owners of the Hall, had
originally felt concerned for the rusting
of some of the external columns; indeed
some had previously been replaced; and
also there were hair cracks to the thin
internal columns supporting the cupola.
Engineers called in by them had
recommended a very much more detailed
investigation and implied that it was
almost inevitable that demolition would
be the most cost-effective option.
Initially, looking at the condition and
stability of the structure, it was apparent
that the long sides were subjected to
thrust from the rafters without there
being any ties. Lining through these long
sides by eye there was in fact very little
distortion. When I looked at the detail at
eaves level, it appeared that there was a
very substantial timber wall plate running
around the periphery of the building
linking each of the panels of the iron
frame. This helped the stability
considerably while the plan shape of the
building was also of considerable help.
I felt that this structure was working as
do many structures of its type, where the
load is being spread around the elements
of construction and you could probably
knock out one of the elements without
there being a complete failure because
the load would redistribute itself.
Inspection of the internal columns
showed that one of them clearly was
cracked and a further column had possible
cracking; thus the structure was
satisfactorily holding itself together with
one of the columns in a effective ‘failure’
mode. If, then, we repaired the column
and sorted out the rusting external
columns, the conservatory could be safely
restored structurally. The filigree brackets
at the column heads also of course helped
the stability. -~
The intriguing factor associated with
the construction is undoubtedly the
filigree work which is applied both
internally and externally as infill over the
arches just below eaves level, because
this encloses glass (photograph 3). All of
the ironwork and the frieze directly above
it externally appeared to generally be in
good order; the problems occurred with
the column heads and the external
ironwork to the external columns. In
carrying out the investigation we were
influenced by a feeling that the walls
must be constructed as two skins; of
course, the implication of this was that
the columns were cast in semi-circular
form.
We were able to take off a section of
column externally (photograph 4). To
our surprise this revealed what can only
be described as a softwood timber bauen
45mm thick by 100 mm wide (the width
of the column). To this was fixed the
timber window frame.
This opening up, of course, cleared up
the problem of how the glass had been
inserted between the iron panels over
the window, in that the structure must
have been erected with much temporary
support as a timber framework which
was then clad with iron. It must have
been intriguing to have been dealing
with a structure which was intrinsically
unstable until the iron cladding had been
added. I believe that the addition of the
glass will in itself have added to the
stability, helping the interaction between
the various structural components.
After I had made my initial inspection
and passed my comments back to Edward
Distelkamp, he lobbied English Heritage
with the result that the main building and
the conservatory were lifted from Grade
II to Grade II*. This of course had the
effect of making the conservatory grant
eligible, and I am pleased to say that a 40%
grant was eventually made available from
English Heritage.
Clearly, with a structure of this kind it
is important to establish a methodology
for carrying out the work and to make
sure the contractor allows within his
price for dealing with the form of
construction. Full temporary support has
Above: the conservatory as originally seen by
the author.
Below: very thin structural columns giving a
sense of spaciousness.
CONTEXT 48

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