It will cost ÂŁ11m to complete but the City Docks Capital Project could well have saved Bristol from disaster. Shipshape investigates
It wouldn’t take the most observant of you to notice there have been changes afoot at Bristol’s Cumberland Basin. Those oversized cranes, Portakabins, high-vis jackets and hard hats would be the giveaway. And let’s not even mention the traffic diversions around Merchants Road. But don’t expect to see any expensive flats going up anytime soon: the work is actually part of a four-year project that is set to secure the future of the floating harbour for the next 100 years.
The City Docks Capital Project, which is being carried out by BAM Nuttall Ltd, is set to cost around £11m and has been split into three phases – the first phase being the urgent task of improving and repairing the dock’s Victorian lock system.
Work started to take place in October 2008 after Bristol City Council found there was “significant risk” that the 140-year-old gates at Junction Lock could fail. If the gates failed then the water in the floating harbour would go out with the tide, causing the harbour walls to collapse and the nearby buildings and houseboats to go with them – the cost of such a disaster making the £11m budget look miniscule in comparison.
Perhaps unsurprisingly, this first phase was quite a challenge for the contractors, as site manager Matt Ewing explains: “Managing the interface between new and Victorian engineering and construction techniques created a few issues. Installing the new gates and ensuring they sealed was the biggest concern – the gates were manufactured in Holland and we would only know if they were right when they were fitted.”
BAM Nuttall had to first manufacture and install a limpet dam, which allowed them access to the lock floor while keeping water in the harbour – this limpet dam allowed the 140-year-old gate bearings to be replaced with modern equivalents in situ – before setting to work on the gates.
“The old gates weighed 80 tonnes each and were virtually rotten,” Matt explains. “We used a 110-tonne crane on a barge to lift the old gates out of their hinges and then manoeuvred the barge into Cumberland Basin for removal, which we did via a 500-tonne crane set up outside the Lockside restaurant. The new gates [50 tonnes apiece] were much easier to handle as we knew the construction and could design lifting points. Again, we used the mobile crane and floating crane to slot these into place.”
The new gates were successfully installed in March 2009 but the work didn’t stop there. Phase 2 of the project – which aims to improve Bristol’s flood defences through the installation of new floodgates at Junction Lock and by upgrading the current operating system at Entrance Lock – kicked off in September 2009 and, despite some incredibly inclement conditions, looks set for a successful finale in summer 2010.
“The weather through the winter months certainly gave us some problems,” Matt admits, “but hopefully a good spring will allow us to maintain the programme and achieve completion on time.”