Pipe installation company Trenchless Technologies has recently completed and continues to work on a number of new pipe installation and rehabilitation projects to improve South Africa’s ageing sewer pipe infrastructure.
One of its most recent projects was an R11-million sewer pipe rehabilitation contract for the Nelson Mandela Bay municipality, which Trenchless Technologies managing member Sam Efrat says was a milestone project for the company. The project was runner-up for the South African Society for Trenchless Technology Award of Excellence in 2011.
The project, which was started in May and completed in December 2011, entailed the rehabilitation of two existing parallel concrete sewer pipelines beneath Govan Mbeki drive from the City Hall towards Russell road up to Manchester road – the main road in the Port Elizabeth central business district.
The existing infrastructure comprised two parallel running sewers, one 600-m-long pipe with a diameter of 525 mm and one 720-m-long pipe of 1 050 mm in diameter.
Trenchless Technologies used its RibLoc Expanda technology to line the 525-mm-diameter pipeline, while a RibLoc Rotoloc liner was wound inside the 1 050-mm-diameter existing pipeline.
This nonintrusive method of sewer renovation required no excavation and was chosen to limit the potential disruption that may have occurred if a traditional trenching method was used.
Another project undertaken by the company in Port Elizabeth entailed the rehabilitation of pipelines in the Helenvale area.
Directional drilling technology was used on three 150-mm-diameter sewer pipes to back ream the existing pipe to a larger diameter. Thereafter, a 400-mm-diameter high-density polyethylene (HDPE) pipe was pulled through