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Scheme
History
Bristol’s floating harbour exists at the very
heart of the city and it’s the maintaining of this 70acre
body of water which this scheme is focused on.
The berthing of ships and management of the river Avon’s
waters has been an ongoing challenge for the residents of
Bristol for over a thousand years. With one of the world’s
highest rising tides it’s of no surprise that engineers
the world over have been presented with this challenge and
have consequently come up with some ingenious solutions.
William Jessop was commissioned by the Bristol Dock Company
in 1802 to perform vital improvements to the city’s
waterways. The Avon was dammed in three locations and the
river was diverted to create the Floating Harbour area (opened
in 1809). Jessop also built the Cumberland Basin (its two
entrance locks fed from the Avon) and the Junction Lock between
the Basin and the Floating Harbour.
No longer were the ships stranded in the mud at low tide
(placing stress upon the hulls of the merchant’s valuable
vessels) and consequently Bristol became a far more attractive
port for trade.
Thirty five years later the Floating Harbour was suffering
from severe silting and the UK’s most recognised engineer
of the period Isambard Kingdom Brunel was handed the task
of improving matters. He implemented new sluicing methods
which are still in use today and it is the Nova Dam sluices
which BAM Nuttall are upgrading as part of our scheme.
Brunel's lock has been superseded by the present North Entrance
Lock and North Junction Lock which were built by the Docks
Engineer Thomas Howard in 1867-73. It is these 140 year old
North Junction Lock upper gates which BamNuttall are involved
with replacing. An assessment report submitted by Bristol
City Council in 2006 found there was a "significant risk"
that the gates at Junction Lock could fail, causing the city’s
harbour to drain. Rapid draining could lead to the collapse
of the harbour walls, causing subsidence to buildings nearby.
The report suggested that the cost of repairing or replacing
the harbour walls alone could be up to £100m. In comparison
the cost of upgrading the lock equipment to reduce the risks
to an "acceptable limit" would be a fraction of
that.
BAM Nuttall commenced works on the 1.10.08 and if you care
to take a look at our photo’s page you will see how
the scheme is developing.
You will find maps and further information on Bristol’s
floating harbour at:-
http://www.bristol.gov.uk/ccm/navigation/transport-and-streets/marine-and-waterway-services/ |
