SMS was established in 2003 to supply innovative and special fittings to the water industry. The SMS maintenance shaft was developed to satisfy a need in the market place for an alternative to concrete sewer manholes with its inherent confined space and OH&S issues.

The SMS maintenance shaft has been adopted by the industry and is now delivering significant savings both for construction and operations and maintenance of sewerage systems.

Concrete sewer manhole installations are still being built according to early 20 th century models, leading some contractors to believe that the fundamental construction processes of all manholes are somehow ‘locked in concrete'.

Modern plastics technologies, however, have led to some interesting alternative products that offer a range of improvements over old systems, not the least of which are reduced risks of injury and extremely rapid installation times.

One of the most reliable plastic manhole products on the market in Australia is available from SMS (Sewer Maintenance Shaft) Pty Ltd, based in Victoria.

SMS shafts are made from super-resilient polypropylene and are available in two sizes: 225mm and 300mm (inlet and outlet 150mm).

As such they are not meant to replace full-sized concrete manholes that accommodate a person,but are ideal as alternatives to conventional inspection chambers (ICs). That is, they are able to provide access to piping for CCTV devices, root cutting tools and other remotely operated cleaning and repair machinery.

While traditional concrete ICs can take up to two days to install, SMS plastic shafts can be in the ground and operational within about two hours, and the costs are approximately a quarter of those associated with concrete systems.

As for ‘real world' practicality, the SMS range includes designs with in-line or triple entry branches with rubber ring joint (RRJ) sockets, giving contractors flexibility to deal with tight projects in high-density building areas, and there are none of the ongoing problems associated with touch-up jobs to repair leaks – a common problem with new concrete fittings. In fact, the technology is so robust that SMS claims the plastic shafts will last for at least 50 years under normal conditions.

Tried and Tested

SMS products have only been available in Australia since 2004, but they have a 15-year heritage in Europe . The SMS range is sourced from BT Bautechnik Impex in Germany , where it carries full local Standards accreditation. In Australia SMS products comply with AS/NZS 4999 (Int.) PVC–U Maintenance Shafts requirements, and are also endorsed by the Water Services Association of Australia (WSAA).

Apart from the obvious financial and time savings, one of the biggest advantages of using high-strength plastic products is workplace safety. Protracted back-breaking activities are not required – installers simply ‘drop in' new fittings and attach them to VC, PVC, Ultra-Rib or polypropylene sewer pipes. There is none of the manhandling often associated with manoeuvring concrete structures into position.

Furthermore, few professionals miss the other great headache regarding concrete fittings – the setting of elaborate metal formwork casts before concrete pours.

Installers of plastic fittings are doing a favour to future generations of plumbers, as SMS chambers can be repositioned or removed without fuss in the event of building extensions or new project developments.

The old way of doing things – conventional concrete manholes take days to construct, usually requiring elaborate metal formwork. They are also difficult to remove in the event of building extensions. Inset: SMS Maintence Shaft

Industry endorsed
Numerous peak bodies and water authorities, as shown in the accompanying table, have offered full endorsement of SMS products.

SMS assemblies are rated to retain their integrity to a depth of six metres and require far less backfill than concrete counterparts.

According to SMS's sales manager, Kevin Kitchen, SMS products and accessories are now available in all States and Territories and are used by water companies in sewer maintenance works by sewer construction contractors, plumbers and land developers. New products are being introduced on a regular basis.

In the Field
Estimator Fraser McDonald from Bayside Construction and Plumbing Services Pty Ltd in Victoria says he has used SMS plastic chambers on 8–10 projects.

“For example, we're working on a big [residential estate] project at Portsea on the Mornington Peninsula ,and we've put a few in down there – basically wherever we can,” Fraser says.

“If you compare them to the old concrete systems it's chalk and cheese. Logistically it's so much easier and you don't have to get specialist plumbers in to join up a manhole as you do with the concrete variety. You can get pre-cast concrete manholes or make them in situ with formwork, but either way it's a nightmare compared to plastic.

And if you are making alterations, then getting the plastic ones out of the ground is not a major problem.”

Fraser says the other big advantage of SMS systems is environmental safety.

“We think these plastic products are going to make a big impact by offering an environmental advantage,” Fraser explains. “They simply don't leak, so you don't run the risk of effluent seeping into the ground.