SVC Products CEO Shane Shepherd and Civil Business Development Manager Mark Jackson were enjoying post-conference drinks in a Bendigo pub after a busy day at the 2018 National Works and Engineering Conference. They soon struck up conversation with the gentleman seated next to them – his name was Peter Higgins, the Managing Director of a Victorian earthmoving company called State Plant Hire. Over a few beers, the trio shared stories about their respective roles and the challenges faced day-to-day.

Shepherd and Jackson learnt that State Plant Hire primarily delivered project works for Melbourne Water, as one of the select contractors on the water authority’s maintenance panel. Apart from offering earthmoving equipment and services, the company was also well-versed in all aspects of erosion control, utilising various methods such as rock beaching, gabion wall structures and soil stabilisation to rehabilitate roads and re-establish waterways following landslip events.

Higgins had amassed decades of experience working on environmental engineering projects for Melbourne Water, dating back to when it was a smaller public utility board operating as the Melbourne and Metropolitan Board of Works (MMBW). He shared his concerns about site safety on certain water infrastructure projects, where the construction of complex water control structures for wetlands and waterways required team members to work for extended periods within an unsafe environment.

Stormwater control pits are large-format, dual-chamber baffle pits that house important instruments to regulate the inflow or outflow of water from a large water body. The process to construct these complicated pits is an arduous and costly exercise, requiring the main body of water to be diverted while pit construction works takes place. Due to the size and complexities of the design, the time required to pour these control pits on-site is a minimum of two weeks. In forested or hilly locations, access to site can prove difficult for concrete trucks, creating yet another obstacle for in-situ construction.

Control pits must be installed at a lower level than the live waterway, meaning that the excavated ground cavity for the pit can extend up to 4 metres deep. Due to the hazardous nature of this environment, pit installation works are time critical, as workers are put at risk of ground collapse, falls from height or injury from falling objects. Unfortunately, these projects often incur delays from weather events, where build-up of rain and debris in the cavity results in instant disruption to project works, prolonging project timeframes.

Listening to Higgins’ frustrations, Shepherd and Jackson were eager to explore ways that SVC could help. Their manufacturing business was already supplying stormwater and drainage products to the civil construction market, and the SVC production team possessed decades of experience in custom fabrication of precast concrete products. They believed that a customised precast solution for safe, speedy installation in a live waterway was surely achievable.

Further discussions ensued after Bendigo, involving other members of the State Plant Hire and SVC Products’ cohorts. Eventually, the companies would embark on their first project collaboration; SVC would supply three custom-made precast twin-chamber pits to a State Plant Hire wetland refurbishment project in Frog Hollow Reserve, in the south-eastern suburb of Endeavour Hills.

According to Landon Bailey, Project Supervisor at State Plant Hire, the Frog Hollow project was the first he’d been involved in where such large, deep concrete control pits were required. Instead of contracting specialised pit installers to spend weeks pouring concrete deep down in a 4m ground cavity, the customised, ready-made precast pits that SVC could provide offered a much more appealing solution.

The pits were delivered to site as complete units, where they were placed into the prepared ground cavities via crane, and pit covers installed to complete the works. Gone was the need to build formwork, pour concrete and wait for the concrete to cure in the ground cavity, saving a significant amount of time and labour.

This first successful project at Frog Hollow was a stepping stone for more projects where State Plant Hire would utilise purpose-built precast concrete. Instead of time-consuming physical labour, their scope of work shifted to a more logistical task, coordinating specific windows of time on-site where large crane hire would align with the delivery of SVC’s custom-made control pits.

Though Melbourne Water engineering designs traditionally specify in-situ concrete for all stormwater assets, Bailey and his team now consult with Melbourne Water engineers, strongly advocating the use of precast concrete as a preferred solution. The precast methodology allows time-critical, dangerous works to be conducted within a fraction of the time, with large control pit installations able to be completed in single-day turnarounds.

The partnership between SVC Products and State Plant Hire has been mutually beneficial.

For SVC, the opportunity to create custom, large-format control pits has been welcomed, allowing the manufacturing team to build upon their repertoire while learning more about the infrastructure needs of the water industry.

For State Plant Hire, the option to use custom-made precast concrete has transformed their approach to complex pit installations, providing peace of mind regarding the most important factor on their jobs – the safety of workers. The additional benefits of reduced labour and time and cost efficiencies on-site provide extra layers of icing on the cake.

SVC thanks Landon Bailey from State Plant Hire for his insightful contributions to this article.