This project emerged from SA Water’s desire to trial trenchless technology using established local contractors. Originally, two options were tabled: slip lining and swagelining, with the later chosen as the preferred option.
CLM Trenchless offer swagelining as a rehabilitation process for the renewal of pressure and non pressure pipelines in water, sewer and industrial applications. The process is ideally suited where techniques such as open trench or pipebursting are not suitable.
The swagelining system uses polyethylene (PE) pipe, which has an outside diameter slightly larger than the pipe to be rehabilitated. After sections of PE pipe are butt fused together to form a continuous string, the PE pipe is pulled through a reducing dye to temporarily reduce diameter. This allows the PE pipe to be easily pulled through the host pipe. After the PE pipe is inserted, the pulling force is removed, allowing the PE pipe to return naturally toward its original diameter until it presses closely against the wall of the host pipe. The new tight fitting pipe results in a flow capacity close to the original pipeline design.
This technology is suitable for applications ranging in diameter from 300 mm up to 1,000 mm, and a wide range of fittings are available from various manufacturers.
CLM Trenchless is a licensee to Advantica and currently is the only contractor performing swagelining in Australia having also completed a project in Hobart and in Sydney recently for Sydney Water.
The South Parklands project involved the rehabilitation of 1 km of DN600 cast iron watermain in an environmentally sensitive location (open parkland adjacent to the CBD) using the technique of swagelining in four 250 m sections.
The PE used for this project was PN12.5 HDPE 630 mm with a 47 mm wall thickness. The swagelining process involved setting up five 12 m long launch and receipt pits, butt welding 20 m lengths of PE and positioning of the swagelining rig and hydraulic pulling equipment (Tracto Technik 800G). Installation took two weeks to complete with each run taking approximately 4 hours at a consistent pulling load of 60 tonnes. The equipment required for this project was manufactured by CLM Trenchless.
SA Water has encouraged the investigation of new rehabilitation techniques. In particular, John Ringham, Chief Operating Officer for SA Water, has wanted to see Trenchless Technology embraced as part of their renewals program given his extensive experience in the UK with large scale rehabilitation programs of water networks.
Swagelining has been around for some time but with recent developments in pipe manufacture and specification, it has now opened up the range of application for this technology.
CLM Trenchless General Manager Trevor Groeneveld said “With the experience we have gained from this project, we are now quite excited about the potential growth in large bore pipeline rehabilitation.”