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UNDER

THE BRIDGE

The Erskine Bridge is an iconic Scottish landmark, connecting commissioned within the three-year
the communities of West Dunbartonshire and Renfrewshire period before the bridge works began.
Faced with an ageing asset, located
across the Clyde for nearly 50 years. Now, a challenging in a harsh environment with ongoing
project has tested the skills of engineers at SGN, with the and expensive maintenance liabilities,
construction of an almost 2km-long pipeline under the river. SGN had already been looking into
Project Manager David Rae explains replacing this crossing.
Refurbishment and revalidation
n 2015, Transport Scotland notified formed a critical link in SGN’s central would have required a full
SGN that it proposed to undertake 39bar transmission system, with the
a full refurbishment of the Erskine 450mm diameter pipeline splitting into closure of the bridge and
suspension bridge which crosses the two 300mm pipelines, one below each complex temporary works
I River Clyde to the west of Glasgow. footpath on the extremities of the bridge. solutions to gain access to the
This bridge is a multi-span, cable- This pipework configuration meant
stayed box girder bridge spanning the that the bridge sections could not pipelines below the bridge deck.
river. It is over 1,300m in length and the be in-line inspected, resulting in a This option was discounted as
deck is 45m above the river, with the requirement for bi-annual, physical the road’s authority would not
pylons a further 38m above the deck. inspection of the two 300mm pipelines. permit a full closure of this vital
The main span of the bridge is 305m This required prolonged use of the
wide and connects the communities bridge’s inspection gantry vehicle, which link in Scotland’s transport
of West Dunbartonshire and incurred a significant recurring cost. infrastructure
Renfrewshire. As well as crossing the Planned bridge refurbishment
Clyde, the bridge also crosses the Forth works required the removal of the
and Clyde Canal and the North Clyde footway deck plates, presenting The bridge refurbishment presented
railway line. A local commuter railway SGN with the unique opportunity to an ideal opportunity to remove two
station is situated beneath the bridge at refurbish the existing pipelines or 50-year-old, high pressure pipelines
the north side. remove them, if an alternative crossing from one of Scotland’s busiest and most
Unknown to most people, the bridge could be designed, constructed and iconic bridges. The only drawback was

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