 Anderton Boat Lift has been restored to its
original 1875 hydraulic status with both caissons operational. This nearly
130-year old structure is a magnificent feat of engineering. However, in
full operating mode, with regular boat movements through the Lift, British
Waterways did discover some difficulties with elements of the historic
workings.
The most significant issue is the way that
the wedges were originally designed to separate the River Weaver sluice
gates from the caisson gates. They are not effective enough to prevent
significant water loss over an extended period and the pumps are being
overwhelmed. Visitors to the site may have seen the excess water flowing
from the top of a manhole adjacent to the Lift as a result of this.
The original 1875 Lift design featured a
flooded well into which the caisson tanks fitted into at River Weaver level.
Modifications to the Lift in the early 20th Century included the removal of
this feature and the caissons subsequently operated in dry wells until
Anderton was closed in 1983.
British Waterways and its partners have
preserved the original wrought iron caissons which for 75 years, had
operated in a dry environment at the base of the Lift. The significant water
loss now being experienced as a result of the original wedge design has
meant that the well has been flooding. Consequently undue stresses are being
placed on the caissons and the structure itself by operating the caissons
into a flooded well. Furthermore, the state-of-the-art rams and their
associated safety systems are not designed to operate in a permanently
submerged environment.
As a Scheduled Ancient Monument, any changes
to the wedges to allow them to operate more effectively must first be
approved by English Heritage. However some amendments to the river
wedges and the gate seals have now been undertaken and the lift has been
operating more reliably as a result.
Consequently
BW has been able
to fulfil all bookings and 'business is booming' at the showpiece Boat
Lift with over 70,000 visitors converging from across the world to see
one of the “wonders of the canals” in the first three months since
re-opening. However the structure is
nearly 130 years old and nobody in England has operated a hydraulic boat
lift since 1908. Managing such a complex structure in a working
environment will continue to present its challenges to our engineers and
operators. BW expects more of the
lift's historical idiosyncrasies, which are of course part of its charm, to
come to light during its bedding in period and asks the public to please
bear with us. Bookings are being taken now for the passage
of private vessels through the lift. These can be made by
calling the Anderton Visitor Centre on 01606 786777. More information about
the lift can be found at
www.andertonboatlift.co.uk. The site
has a webcam.
We've
more photos and reports of the opening.
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