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tendered and subsequently awarded by industry-leading experts OGI solution to retain the adjacent ground.
to J Murphy & Sons (JMSL) in January Groundwater Specialists. Controlled SGN appointed Malcolm Hughes
2018, under an NEC Option A contract. abstraction and recharge were a Surveys to undertake continuous
JMSL appointed LMR Drilling UK L to critical part of the design to prevent monitoring of the structure to ensure
undertake the HDD crossing and Joseph any settlement issues with the Erskine the excavations had no impact on the
Gallagher to undertake the shafts and Bridge and Network Rail infrastructure. operation of the road above.
micro tunnel below the railway station. The final construction challenge During the summer of 2018, SGN
Construction work began in late involved crossing below the A82 Great shut down the existing pipeline and
February 2018, starting with site Western Road to Loch Lomond and installed revised connection points at
clearance and set-up for the HDD and the western Scottish Highlands. The either end to allow the final connections
micro-tunnel launch shaft. Establishing planned route was through an existing and commissioning of the replacement
the pilot hole through the soft glacial till underpass constructed in the late pipeline without any further interruptions
quickly became problematic due to the 1960s. This was located at the foot of to the gas flow. During this phase, the
complexity of the ground composition. the Old Kilpatrick Hills and also had to existing pigging facilities were removed
The combination of boulders, very soft pass through the line of the Antonine from the AGIs at either end of the project.
silts and stiff clays resulted in a slow Wall, which was constructed around The new pipeline was successfully tested
drilling process with numerous manual 142 AD by the Romans to mark the and commissioned in summer 2019 and
cleaning runs and fluid changes. The north-west frontier of their empire and it has subsequently been in-line inspected
soft silts also caused steering issues is also a Scheduled Ancient Monument by Baker-Hughes on behalf of SGN.
and resulted in a number of side- and World Heritage site. The Transport Scotland works to
tracks which had to be abandoned and High levels of ground water in this refurbish the Erskine Bridge are now
grouted before drilling could continue. area meant that further bore holes well underway and the removal of the
Ultimately, after an extended drilling were required to better understand now redundant 300mm pipelines is
period, the HDD was successfully the local geology and develop a included within the scope of that work.
completed in early September 2018. geotechnical solution to allow the pipe
At this stage, sinking of the launch to be installed without compromising SGN commissioned Broadcast Media
and reception shafts for the rail crossing the integrity of the bridge. A series of Services Ltd to capture the key aspects of
was almost complete. Ground water dewatering well points were installed the construction of this prestigious and
at the reception shaft was controlled to control the groundwater and JMSL challenging project in a short film. Watch
by a series of filtered wells designed designed a complex temporary works at IGEMtv via bit.ly/IGEM-tv

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