A brand-new hydrofraise, affectionately named Jackie and thought to be the first of its kind on Earth, has begun work at Chambers Wharf. This innovative and electrically-powered machine, to be used in the creation of diaphragm walls, will be dramatically quieter while in use compared to a typical diesel hydrofraise.
While in operation, it draws its power from the National Grid – a world-first for a hydrofraise – and ensures that Tideway’s impact on its neighbours is as quiet as possible. Neil Coyle, MP for Bermondsey, mentioned the machine in a piece on his website, lauding Tideway for taking steps to “minimise noise and local impact”.
‘Jackie’ the electric hydrofraise is on the right hand side – photo credit John Kinnear
Speaking on the day the hydrofraise began work, Ba Dan Nguyen, Geotechnical Works Manager at Chambers Wharf, said: “It’s very exciting that we’ve started using the hydrofraise. The power pack has come from the Netherlands, the machine has come from France, and it’s working in the UK, where you have different regulations. So, to make it UK compliant was a big challenge, but we got all our UK electricians that were involved from the beginning.”
Ba Dan added that having a site so close to central London brought a unique and complex set of challenges – not least with the neighbours. He said: “It’s a very different site here, right in the middle of London, where we have to think about every bit of noise we make. That’s why we’ve got this particular hydrofraise – to keep the noise down as much as possible. The neighbours are aware that we are trying to minimise the noise. We’re making a lot of improvements on all our plant to keep the noise down because we’re going to work late.”
John Kinnear, Project Manager at Chamber Wharf (who took the stunning photo), said: “The innovative thing about this machine is that we have an electrical power pack. Once it’s driven into position, you can turn the diesel engine off and it will run on electricity to do the digging. There is a big problem in London with air quality, so all the time we’re digging, which could be a number of days, you’d normally have big diesel power pack – here, we’re running on electricity so we’re creating no emissions and no noise. It’s not something we’re going to be able to do at every site, because you need a sufficient power supply to put it in. At Chambers, we have the power supply for the TBM, so we can use that to drive the hydrofraise.”
The machine started digging at the end of August and was developed by CVB in collaboration with a number of specialist industry partners. It will be used to dig shafts at Chambers Wharf, Deptford Church Street and King Edward Memorial Park.
Afterwards it will return to the Soletanche Bachy Group for projects elsewhere around the world.
Keeping the disruption to the neighbours as low as possible at Chambers Wharf has been a key priority, and in addition to the hydrofraise, there have been several other innovations in an attempt to quieten the jet wash, adjust the lighting to avoid glare, and add more insulation to the pipes pumping material around the site.