'Big push' pays off in Plymouth
May Gurney Utility Services has completed a major project to improve water quality at Mutley Plain, Plymouth three weeks ahead of the agreed 28-week programme.
Mutley Plain is a four-lane main route into Plymouth, with a water main located underneath. The project is thought to be one of the longest 'single push' PE slip-lining jobs ever undertaken in an urban area.
The project, for customer South West Water, has improved two 24" cast iron trunk mains and a 9" cast iron distribution main that feed 25,000 customers and two major industrial users. The scheme comprised 2,752 metres of water mains rehabilitation and associated works.
Detailed consultation over a two-year period included agreement from all the key stakeholders - including the public, business owners, police and emergency services, Plymouth Highways, Plymouth City Traffic Control & Transportation Services, and two local bus companies.
Because commercial properties line Mutley Plain, a strict working day was adhered to and the programme was accelerated to reduce disruption. By maintaining access wherever possible, South West Water was able to build positive relationships with its customers, and compensation claims were minimized.
Following assessment of several trenchless options, a hydraulic slip-lining and pipe push technique was implemented. The optimum solution - to avoid major disruption to the local infrastructure and highway congestion - required insertion of a new PE main for the entire length of the most sensitive section of Mutley Plain.
This challenging 816 metres of PE insertion 'in one push' meant no visible or physical disruption to a good proportion of this main artery.
The Mutley Plain scheme was a triumph for trenchless technology. At a South West Highway Authorities and Utilities Committee meeting on 1 February, local highways engineers said: "The planning, liaison and implementation of extensive rehabilitation works in Plymouth has been invaluable and sets the benchmark for others utilities to follow." |
