McRobert Contracting Services (MCS) is an Australian-owned and operated industry leader in the refurbishment of underground assets and polyvinyl chloride (PVC) pipeline technology. Operating out of Perth, WA, the company has been in operation for more than 30 years and has evolved into a business whose specialised services are sought out by both public and private sectors around the country.
MCS has worked on hundreds of projects across its lifetime and has developed a unique patented method for the structural relining of access chambers suffering from sulphide corrosion. The company’s strong relationships with a range of water operators across Australia are helping it achieve its vision of being the first choice for rehabilitation services, backed by its consistent ability to offer industry leading services and products to existing and future customers.
Doing what MCS does best
On 12 June 2020, MCS – in association with the Water Corporation – completed a contract to rehabilitate 22 access chambers that were deemed to be of an extremely poor condition in Cottesloe, WA. Before the actual refurbishments began, MCS employed its latest 3D scanning technology to assess the structural integrity of each access chamber and cross reference detailed measurements to determine the assets’ conditions.
These reports provided critical information for the method of rehabilitation MCS would use. The chambers were predicted to be challenging due to their high flows, silt/debris content, already fragile overall structure, advanced age and proximity to Cottesloe’s popular beach front.
After careful deliberation, it was decided to carefully jet-wash and e-duct approximately 5 m either side of each chamber to reduce the otherwise high cost to clean and e-duct kilometres of pipeline. This jet-washing/e-ducting process was also able to assist in reducing the amount of silt and debris in each chamber.
Additionally, the jet-washing and e-ducting significantly lowered the flows along with the isolations provided by Water Corporation to a workable level. This decision, as well as having the capacity to work with the prefabricated channels, allowed MCS to specifically adapt and design a solution to allow for the successful and safe installation of channel and benching with the remaining refurbishment works to be completed prior to the allocated project schedule.
The specific scope of works for this project comprised the design and development of structural rehabilitation for the current asset structure using approved remedial methods, including surface preparation for rehabilitation, channel and bench fabrications and the installation of the PVC lining system.
This also included the supply and installation of all required lining materials, supply and installation of PVC lined lids, reinstatement of property to previous conditions, spark testing completed to Water Corporation standards and the provision of quality assurance documentation.
Track record of success
When faced with a relining project, MCS uses a minimum 10 mm rigid PVC sheeting, with the chamber walls prefabricated into sleeves that can be lowered into place directly onto the asset. MCS also prefabricates the PVC channel and benching components, which are then plastic welded into place in the chamber.
After installation, the preformed sleeves, channels and benching are secured to the original asset using a minimum 40 mm of high strength grout. MCS relines the access chambers from top to bottom including pipe connections, channel and benching resulting in a 100 per cent gas tight structural PVC lining. This ensures complete protection of the asset from concrete deterioration.
Although MCS guarantees a period of 50 years for the plastic lining of utilities access chambers and sewer pumps, PVC linings should last significantly more than 100 years, provided no physical damage or prolonged exposure to UV occurs.
Continued excellence
MCS has developed its relining methodologies to ensure it maintains a safe working environment while completing tasks in the most efficient manner possible. The company aims to spend as little time in the chamber as possible, equating to less time spent onsite and minimising extra costs that can accompany issues like traffic management.
Although based in WA, MCS has, and continues to, offer and complete its services around Australia. Along with access chamber refurbishments, these services include sewer pump station refurbishments, plastic fabrication, onsite fabrication, 3D laser scans, pressure jetting and CCTV inspections.
This article was featured in the September 2020 edition of Trenchless Australasia. To view the magazine on your PC, Mac, tablet or mobile device, click here.
For more information visit the McRobert Contracting Services website.
If you have news you would like featured in Trenchless Australasia contact Assistant Editor Sophie Venz at svenz@gs-press.com.au