Contractors World UK & Ireland Vol 6 No 1
aving been in service for over
75 years, the tidal gate on the
River Idle at West Stockwith in
Nottinghamshire has been replaced as
part of a continual improvement pro-
gramme being carried out by the
Environment Agency (EA).
The project, which took just over 3
months to complete, was awarded to
ECS Engineering Services as part of its
framework agreement with the EA.
The West Stockwith sluice gate forms
part of the tidal River Trent flood de-
fence scheme and was originally installed in 1938.
It operates automatically at every high tide to pre-
vent the River Trent flowing into the lower River
Idle, which prevents local flooding, reduces the silt
build-up in the River Idle and stops salt water
The sluice gate works in partnership with the
nearby pumping station located just upstream on
the River Idle; between them they can act as a large
lock to allow narrow boats to navigate up the
ECS, as the appointed main contractor, was re-
sponsible for the complete refurbishment contract
including the gate removal, installation and
The company has completed several projects previ-
ously at this site.
The timing of the recent project was planned for a
time of year when flooding was least likely to occur so
that the brief period between the removal of the old
gate and the installation of the new gate would not pose
any flood risk to the local area.
One of the major logistical issues was getting a crane
on site that was large enough to lift the 26 tonne sluice
gate, especially with restricted local access.
The answer came from Walkers Crane Hire, a local
crane hire company, that managed to position a 120
tonne Grove GMK 4100L all-terrain crane on site and
then rig it with 76 tonnes of ballast to give the crane a
rated capacity of 220 tonnes. With the calculations done,
all that was needed was a calm day to allow the old gate
to be removed.
With all the electrical services removed, the top
platform of the sluice gate, which contains the lifting
winches and the control gear, was removed to allow
access to the sluice gate itself.
The lifting operation required almost perfect weather
conditions due to the weight of the sluice gate and its
tendency to act like a sail in the lightest wind.
The project included the replacement of the steel
ropes and the gate runners which guide the sluice gate
into position during normal operation. It also involved
a specialist dive team to install two limpet cofferdams
which allowed the engineers to remove and replace the
gate running tracks under dry conditions.
Due to the size of the replacement sluice gate it was
transported to site in sections and then assembled ready
for the crane to return and complete the installation.
With only a minor adjustment, the new gate was craned
into position and secured before the top platform was
replaced and bolted in place.
With the main structure reassembled, the new wire
ropes and all of the electrical services were reconnected,
including the encoders which are used to control the
position of the sluice gate.
Having completed the rebuild, the engineers com-
missioned the sluice gate to ensure that all of the con-
trols and settings were working as required before re-
turning it to the Environment Agency.
Contractors World UK & Ireland