Dalmacoulter Resilience Scheme

Project Details:

AG Wilson delivered the Dalmacoulter Resilience Scheme, involving the installation of a new water main to provide network resilience for Scottish Water’s customers in North Lanarkshire. The new water main is designed to operate in tandem with an existing main.

This project required installation of 5km of 1000mm HDPE clean water supply main with 11no washouts 4no sleuce valves and 9no air valves.  Connections to ductile iron and complex crossing of a SGN and NGN gas mains were also encompassed within the scheme.

Installation of the 1000mm HDPE pipeline required crossing below an SGN 300mm diameter high pressure gas main. The 300mm diameter high pressure gas main was in the postcode area ML6 7ST in farm land. The high pressure gas main had an operating pressure of 68bar and was a transmission pipeline installed from Glenmavis, Airdrie to Westfield, Fife.  A trial hand dig excavation was conducted to expose the high pressure gas main, find the welds in the 300mm pipe and plot the distance between both welds in order to identify the 1000mm HDPE pipe route in the centre between both of the existing high pressure gas main welds. All of the excavation hand digging was supervised by an SGN Engineer.

A 3m exclusion zone was maintained outside the gas pipeline at all times during use of mechanical excavators and equipment. The high pressure gas main was supported and suitably protected throughout the duration of the excavation and 1000mm HDPE pipe installation.

The 1000mm HDPE pipeline was successfully installed in the excavation below the high pressure gas main, backfilled and reinstated to make good the land.