The Building Conservation Directory 2015

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T W E N T Y S E C O N D 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 5 1 3 5
3.4
STRUCTURE & FABR I C :
EXTERNAL WORKS
A variety of refinements occurred
in the late 19th century, such as William
Sugg’s Christina burner of 1874, which
produced a horizontal jet. However, it was the
development of the mantle in 1885 by Carl Auer
von Welsbach which resulted in the greatest
improvement in efficiency. Light was produced
by a non-combustible mantle of mineral fabric
suspended in the flame. The heat caused the
mantle to incandesce, producing more light
than ever. Furthermore, the gas mantle could
be located below the gas outlet. This enabled
curved brackets to emerge from the top of the
cast iron post with the mantle below, directing
light downwards where it was most needed.
Although invented in the early 19th
century, electric arc lamps did not come into
widespread use until the end of the century
when electricity generation became more
common. These produced an extremely harsh
light, far brighter than the incandescent bulb
invented by Edison in 1879, and were ideal for
lighting huge areas, such as factory floors and
streets, but they needed regular maintenance to
replenish their carbon rods. With each increase
in brilliance, lamp posts could grow taller,
casting the light further, and arc lights were
the tallest of the surviving Victorian cast iron
street lamps. As with the gas mantle, the light
source could be suspended from the fitting.
CONSERVATION
Victorian cast iron lamp posts were once
so common that the need for protection
was easily overlooked. As a result, in many
urban areas few now survive. Standing on the
edge of the pavement, the principal threat is
from traffic, including delivery lorries and
refuse-vehicles backing into them. Although
brittle, the cast iron might not break, but
the post could be left leaning at a drunken
angle. Lamp posts may also lean as a result
of ground movement, often caused by broken
drains. Rather than fixing the post in situ, it
is common for local authorities to take the
opportunity to replace the unit with a modern
one which requires less maintenance and is
taller, providing better light coverage over a
far wider area. While this makes the street
safer at night, there is a cost to the character
of the street.
Cast iron lamp posts may also be
removed because they are damaged. Often
this is repairable – some posts include an
inspection hatch at the bottom which is
more vulnerable to damage than the post
itself. Fractures and breakages which do not
affect the structural performance of the post
itself can usually be repaired by specialist
conservation engineers using plating, stitching
or welding. Structural reinforcement may also
be possible if the hollow core is straight and
free from obstruction, allowing a metal tube
to be inserted. This can then be then fixed and
sealed in resin.
Where replacement is unavoidable, many
local authorities still retain old cast iron lamp
posts which could be reused. New castings
can also be made by companies listed in
the metalwork section of this directory (see
page 128), using the surviving components as a
pattern. Modern castings can also use ductile
iron (spheroidal graphite iron) which is less
likely to fracture on impact.
Lanterns are rarely original as they are
easy to replace with a new unit purpose-made
to suit whatever lamp is currently being used.
Sometimes the result is bizarrely incongruous,
with modern light fittings fixed to classical
columns, but several companies supply
reproduction lanterns complete with replica
chimney finials and modern lamp fittings,
including low energy LEDs with an extremely
long service life.
Corrosion can also pose a problem,
particularly at low-level where the post
is exposed to de-icing salts during frosty
periods. Cast iron needs to be protected from
water and from salty water in particular.
Paintwork can be damaged by impact from
bicycles, car doors, signage fixings, and
countless other causes, and small areas
of damage lead to extensive paint loss.
Unfortunately, few councils can afford to paint
lamp posts with sufficient regularity.
In view of competing requirements for
funding and the need to keep streets safe
at night, local authorities are not naturally
inclined to conserve traditional cast iron street
lights unless they are listed, or unless specific
requirements are made in council policy for its
conservation areas.
PROTECTION
Listing varies radically across the UK. A quick
search for ‘lamp post’ in the National Heritage
List for England reveals 400 entries for lamp
posts, 88 of which are in or around Bristol. In
Wales there are 29 list entries of which over
half are in Llandudno. In Scotland, on the
other hand, there are 800 list entries for lamp
standards and holders. Many of our great
Victorian cities have none.
In Bristol the high priority given to the
historic streetscape is due to the tireless
commitment of a community group, the
Clifton and Hotwells Improvement Society.
Initially consulted on a conservation area
appraisal, CHIS developed a system for
recording the different types of lamp post
found locally, enabling a comprehensive audit
of surviving examples in the conservation
area. As a result, their protection was
enshrined in conservation area policy in
2010, and the system has been adopted in
neighbouring Redland. CHIS now works
closely with the local authority to ensure
surviving examples are at least retained in
situ, and salvaged examples in the yard of the
lighting department are being reinstated in key
locations where possible.
While Georgian light fittings are
generally well protected by listing, and are
usually in private ownership, Victorian street
lights remain at risk and their numbers are
dwindling, particularly in England and Wales.
Urgent action is required to secure their future.
Further Information
D Cruikshank and N Burton, Life in the
Georgian City, Penguin Group, London 1990
English Heritage, Practical Building
Conservation: Metals, Ashgate,
Farnham, 2012
T Fawcett, Paving, Lighting, Cleansing: Street
improvement and maintenance in 18th-
century Bath, Building of Bath Museum,
Bath
Clifton and Hotwells Improvement Society
website,
THE AUTHOR This article was prepared by
editor Jonathan Taylor with the help of The
Building of Bath Museum, Maggie Shapland
of the Clifton and Hotwells Improvement
Society, Geoff Wallis and Sugg Lighting.
One of several original Victorian lamps still lit by
gas in Canynge Square, Bristol: the lantern was
renewed by Sugg Lighting to a design that has
been in continuous production since 1897, and its
illumination is controlled by photo-cell. The cast iron
post dates from the mid-19th century.
One of two electric arc street lights in the Mall,
Bristol. A public electricity supply was available in
1893 and these lamp posts were installed in 1898.