Scottish Water is progressing with the installation of a half mile-long new sewer tunnel beneath the streets of the Yoker area of Glasgow as part of a £7 million project to help improve the natural environment of the River Clyde and tackle flooding issues.
Work on the project, which involves the construction of a new sewer tunnel from the grounds of the former Blawarthill Hospital to the north bank of the Clyde, started in July. Following on from two months of preparatory work a state-of-the-art Tunnel Boring Machine (TBM) delivered last week has already been put into operation.
The TBM, which is 6.7 metres long, has a diameter of 1.8 metres and weighs more than 17 tonnes, comprises three sections.
These are the main cutting head drive motors and discharge unit, the operators’ area and auxiliary equipment and the eight hydraulic cylinders for forward motion which, in addition to two 97kw drive motors, will enable it to bore the tunnel at a speed of about 2.5 metres per hour, depending on weather conditions.
After cutting through rocks, boulders, earth and other materials, the TBM will discharge these onto a single conveyor system before they are removed via loaded skip. Working at depths of up to nine metres below ground, the TBM will be operated by two people driving it and four at ground level.
The project, which will also involve the construction of a new Combined Sewer Overflow (CSO) with powered screens at the former hospital site and another off the A814 road, will improve water quality on the Yoker Burn culvert and the Clyde and help tackle flooding issues which have affected a commercial property.
The new CSO at the former hospital grounds will spill waste water in storm conditions to the new sewer and the new sewer will discharge the waste water to the River Clyde, as permitted by the Scottish Environment Protection Agency (SEPA).
The new stretch of sewer is being installed using the TBM rather than using the open cut method of excavating because the method will minimise disruption.
Contractors George Leslie, working for Scottish Water, are expected to complete the work next summer, depending on weather conditions.