The Technology

The Belfast Sewers Project employs a combination of traditional and modern trenchless technology.

Trenchless technology is less intrusive and more environmentally sound than alternative methods, making it less disruptive to traffic and the community.

Traditional ‘Open Cut’ Technology
Traditional method of working where the new sewer is laid with the contractor excavating down from the surface to lay the pipe. The pipe is back filled and surface reinstated.

Modern Trenchless Technology
‘Pipe Bursting’
A bursting head is inserted into the existing sewer via an access pit which the contractor excavates from the surface. Spacing of the access pits is based on size,length and wall thickness of the replacement pipe. The pipe is attached to the bursting head and is pulled along the existing sewer from one access pit to another.

‘Cured in Place’
A liner is pulled in from one manhole along the sewer to the next manhole. Two different types of liner will be used – one hardened by uv rays given off by a ‘light train’ subsequently passed through the liner, the other hardened by hot water poured into the liner. Once the liner has hardened a robot is sent up the pipe to cut open the existing laterals that feed into the pipe.