Wednesday, January 4th, 2012
The start of digging work on the Lee Tunnel in London took a step closer last week, as the giant drill that will dig the four mile long tunnel was lowered into position into a gigantic shaft. The drill, ‘Busy Lizzie’ as was aptly named by local schoolboy Ryan Waters, who won a competition organised by Thames Water.
The drill has been lowered into the shaft in separate parts and will be rebuilt underground before tunnelling begins. When complete the Lee Tunnel will stop 16 million tonnes of sewage entering the River Lee every year when too much rainwater puts excessive pressure on the Victorian sewer system.
The drill is eight metres in diameter and 120 meters long and should take just under two years to complete the mammoth task.
The drill was transported to the shaft site at Beckton Sewage works on 60 lorries and was lowered into the shaft by a special heavy duty crane.
The chief executive at Thames Water, Martin Baggs, stated:
“This is a major milestone on our way to creating a cleaner, healthier River Thames and River Lee, by dealing with the unacceptable problem of sewer discharges into the river during heavy rainfall.
“The Lee Tunnel is the first of two tunnels, which will collectively capture an average of 39 million tonnes a year of sewage from London’s 35 most polluting combined sewer overflows.
“The Lee Tunnel will tackle discharges from the largest overflow at Abbey Mills in Stratford, which accounts for 40 per cent of the total discharge. That’s why we’re dealing with this, the worst one, first.”