London Bridge
The wooden bridge that had sufficed the Romans was replaced in 1176 by a stone one, with nineteen
'starlings' or `sterlings'
resting on the riverbed and supporting the bridge piers. This primitive construction lasted nearly 600 years. From
time to time the starlings were strengthened by additional stone. A fishpond was
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built on one, handy for apprentices
`who had the convenience of rope ladders, to let themselves down on the sterlings [to lay] baits and lines to catch
eels and other fish'.
By 1750 the starlings occupied five-sixths of the riverbed, and the river roared through the gaps
like water through the sluices of a dam.
The result was that 'shooting the bridge is almost universally dreaded
as the
risque of life', and the watermen - whose job it was to convey people up and down, and across, the river - complained that
their custom was suffering. The arches at the north end were further obstructed by waterwheels to supply water to the
nearby district. One had been enough in 1581, but London had grown since then and by 1720 there were four.
Something should be done, but it was far from clear what. Should there be a new bridge, funded by a lottery?
Or should the existing one be improved by removing the starlings and enlarging the arches? If the water wheels were demolished,
what about the water company's customers? And its shareholders? What about removing the houses and shops on the bridge that for centuries had precariously overhung the river? Would the receipts from tolls outweigh compensation to the house
owners and the mounting cost of repairs? According to the most recent survey, the foundations of the bridge were still
good, despite the worrying tendency of most of the houses on it `to decline so much out of the perpendicular', and if
the houses were cleared away, it could be made wide enough for four carriageways and a good footway
on each side.
Very sensibly, the whole matter was referred to a committee in 1746, which after due consideration referred it to a
subcommittee, and there it stayed. Meanwhile the old Tudor houses on the bridge were pulled down. The workmen found
`three pots of money , silver and gold, of the coin of Queen Elizabeth' - at least, they declared
three pots.
New piazzas were put up instead, in which shopkeepers prospered. Parsimonious ladies drove all the way from St James's,
lured by the rumour of bargains on the bridge in pins and needles, gloves and hats and brushes, seeds and prints and
wallpaper. By 1755 things began to move, all too literally. The City decided to demolish all the buildings on the bridge and make
the central arch twice as wide by removing one pier. This did not go down well with the inhabitants. A temporary wooden
bridge erected over the gap was burned down twice, leaving the City completely cut off from Kent and Europe. The Lord
Mayor hurriedly licensed 40 extra boats to ferry passengers and goods across, even on Sundays, but their passage was
obstructed by beams fallen from the temporary bridge. By April 1758, 500 workmen were employed on the new bridge,
every day of the week.
Eventually the successor to the medieval bridge emerged, shorn of its buildings and given an
elegant Italianate balustrade. It was much admired, although the watermen were still dissatisfied. ‘There was so
great an eddy at the great arch that craft or vessels passing through were whirled round for a long time before they
could get disengaged, and in the utmost danger of being dashed to pieces against the sterlings, overset in the vortex,
or staved against each other ... whereby great damage might be sustained as well as lives lost.’ Perhaps the improvement
was more cosmetic than functional. London Bridge was finally demolished in 1830. Not a bad innings.
Extract from “Dr Johnson’s London Life in London 1740-1770”, written by Liza Picard. Weidenfeld & Nicolson London: 2001.
Amazon eBay: LONDON BRIDGE
"London Bridge is falling down,
Falling down, falling down,
London Bridge is falling down,
My fair Lady."
The London Bridge of the old nursery
rhyme, a structure twenty feet wide with
nineteen arches, took thirty two years to
build from 1176 to 1209. Designed by a
monk, Peter of Colechurch, it was weighted
down by shops and dwellings and was a
centre of London life for 622 years. Its
successor, three times wider with only 5
arches, was built in 1831 and lasted only a
quarter of that time. It was moved to Lake
Havasu, Arizona in 1971. A stone from the
second bridge rests in Storybook Gardens,
given as a centennial gift in 1967. The third
London Bridge was opened in 1970.
Can you imagine a world without bridges?
How would you get from home to school to
downtown without bridges over the Thames?
How would London have developed without
any bridges? What holds a bridge up? When
you stand on a bridge, you exert a force
downwards on it. Where does the force that
the bridge exerts upwards on you come
from? How many different designs of
bridges are there? Why did the Takoma
Narrows bridges fall down? Why are some
Roman bridges still standing? How did they
know how to build such good bridges about
two thousand years before anyone knew how
to analyze the forces involved in any detail?
Are the struts in tension or compression? As
you see, it is easy to think of difficult
questions.
What does a good design for a wood and
glue bridge look like? How do you choose
good popsicle sticks? Where can you buy
them? How do you form a strong joint
between wood and glue? How do you build
a bridge so that it does not twist when you
load it? All these questions require study
and research.
To help you get started we have organized a
workshop, where we will show your pictures
of successful designs, give you some tips on
successful strut design, and give you the
opportunity to build some simple struts using
hot glue guns, because the glue dries quickly.
We will also show you the test device. If
you are interested in this competition, we
strongly urge you to come to the workshop.
The figure shows a diagram of a sample
bridge design with the minimum dimensions,
and the testing device.
| A manual that describes the theory of trusses
| and gives detailed design instructions is
| available in pdf format from the web.
If you require further clarification, please
contact Brian Nikota at Regina Mundi,
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