Lewis is a tier one contractor carrying out work on behalf of the principle contractor Laing O’rourke. The scheme has resulted from the necessity to replace the existing 19” cast iron pipe laid in 1910-1920 because of poor water quality and accessibility problems.
The length of the Trunk Main is 24.6 klm, starting at Hedrefydd Reservoir north of Glynedd and ends at Tynywaun Reservoir. The Trunk Main diameter varies from 400mm to 600mm. 2.44 klm of cast iron main was pipe burst in a time period of 5 weeks.
The route incorporated areas of engineering difficulties such as river and rail crossings and existing bridge structures. Proprietary work in order to thrust bore below rail tracks is currently being concluded in conjunction with Rail Track.
Environmental considerations concluded the benefit of utilising Pipe Bursting methods along various sections of the work, for example in wooded areas.
To date, September 2003, two river crossings have been successfully completed, satisfying environmental agencies specifications.
To carry out this burst a 1000g Grunderbust rig capable of puling 100 ton’s was used, the largest unit of its kind in the UK. Bursting an existing 19" cast iron pipe and replacing with 450 od and 500 od HPPE pipe.
