Achieving Efficiencies Beyond Expectations: Sydney Metro Northwest

At Hilti, we are privileged to work on a raft of unique and innovative projects - ranging from residential and commercial developments right the way through to large-scale infrastructure projects. Our team relishes the chance to push the industry forward and develop new ways of working that are faster, safer and produce high-quality outcomes.

Among the various facets of what we do, there's always something very special about civil projects. It's not every day something comes along that will shape the future of a city and massively affect the people who live there. The Sydney Metro Northwest projects is one such endeavour.

The $8.3 billion Sydney Metro Northwest is the first stage of Sydney Metro, Australia’s biggest public transport project. Sydney Metro will be the first fully automated metro system in Australia. Sydney Metro Northwest includes 13 stations and 4,000 commuter car parking spaces for Sydney’s growing North West. Trains will run every four minutes in the peak, that's 15 trains an hour. Commuters won’t need a timetable, they will just turn up and go.

The project is part of the biggest urban rail infrastructure project in Australian history, with engineering challenges during design, planning and construction. Some of these involved drilling and anchoring, which is especially complex on the curved walls of rail tunnels. This is one of the areas where the Hilti Civil Team was able to assist.

Our Civil Team is a specialised division within Hilti, offering project management and technical support on large-scale civil infrastructure projects around Australia. The experienced members of this team partner with other industry leaders across all levels of these projects.

As both manufacturer and supplier, we are unique in being able to provide end-to-end solutions and ensure the very best results on each and every project we take on. Over the last few years our team has been busy with a number of large-scale projects, including the CLEM7 and Airport Link tunnels in Brisbane, the Webb Dock redevelopment in Melbourne, and the NorthConnex and WestConnex projects in Sydney.

We were also involved on the Legacy Way project in Brisbane which involved a similar holistic approach to Sydney Metro Northwest. We needed to find a smart way to drill thousands of holes inside a tunnel - an approach that was executed with great success thanks to our great working relationship with industry partners Herrenknecht.

Our involvement in the Sydney Metro Northwest project began in 2013, when the Tunnels and Stations Civil works (TSC) contract was awarded to CPB John Holland Dragados (CPBJHD) to build Australia’s longest railway tunnels. Our team approached key stakeholders on the project to offer services and solutions, providing a dedicated project engineer and project manager to support CPBJHD and the designer Hyder with the challenges of anchoring applications inside the tunnels.

More recently our involvement has been with the Operations, Trains and Systems (OTS) contract, granted to Northwest Rapid Transit (NRT) - the largest Public Private Partnership ever awarded in NSW. The OTS contract includes the fitout of the twin 15km concrete-lined tunnels. The systems inside the tunnel needed to be post-installed in several locations, including directly overhead and horizontally. Many of these connections are for critical elements of the rail network - such as the overhead wiring that powers trains, pipes that transport water for fire extinguishing, and the emergency passenger walkway.

We consulted with NRT and the OTS contract’s Design Joint Venture (DJV) on an anchoring system that would meet all the necessary performance and compliance requirements. At the same time, we highlighted key issues such as productivity and safety to provide a complete solution that ticked all the right boxes.

With the challenges of the project outlined, we approached Herrenknecht and began to work on a technical proposal.

Herrenknecht designed the rig and gantry which would move through the tunnel, while Hilti provided the drilling systems that would be integrated with the rigs. These two machines, affectionately nicknamed Emily and Edith, move across 10-metre sections at a time, and the drilling platforms can be repositioned to the precise locations of the anchors.

A key part of this solution was Hilti’s innovation in dustless drilling which had been successfully used on the Legacy Way project. Dust can be a hazard on any construction site, but especially when working in confined areas underground. When drilling over the heads of operators, minimising airborne irritants is crucial. Additionally, dust landing on machinery makes it more likely that work will need to be stopped for maintenance. Dust also needs to be cleaned out of drilled holes before installation of an anchor or load capacity will be compromised.

In 2016, the Civil Team received a concrete section identical to the ones used in the tunnels for testing. We were provided the segment to proactively evaluate the best anchors to use in different applications before presenting solutions. The testing process ran for several months, giving us the chance to trial various options and come up with a full-system solution, which involved anchors from our HSA expansion anchor range and a design based on the European Technical Approval Guidelines (ETAG) - which form the basis of Australia’s new anchoring standard SA TS 101.

Another consideration here was that the walls of the tunnel are curved. Unlike installing an anchor into a flat surface, the curved surface profile presented a few unique challenges that needed to be addressed. A standard, flat washer simply wouldn't sit flush or allow correct setting of the anchor. Instead, anchors needed to compensate for the curved sections and we decided on the use of a conical washer design that was able to do so. These washers are made of two parts, and the design makes it possible to install the anchors consistently on the curved surface.

Our relationship with Herrenknecht shored up a complete solution, and the tender for the project went to market in May 2016, with Hilti and Herrenknecht chosen to supply the custom drilling rigs fitted with Hilti drills. Meanwhile, our team arranged for the first shipment of Hilti anchors, hollow drill bits and other equipment. Herrenknecht supplied four drilling gantries in total, each having between eight and twelve Hilti drilling machines. All these machines are locked on to drilling arms and fully automated. The drilling gantries utilise SafeSet drilling systems that are connected to a bank of Hilti vacuums in the centre, providing a solution that is both safe and incredibly efficient.

By August 2016, the rigs were ready for their first on-site trial. Our team conducted training for the operators who would be drilling the holes and installing the anchors. At this early stage, we also carried out several site tests to make sure the anchors were performing as expected. Once everything was ready work could begin, with ongoing support from our specialist team.

As of February 2017, the drilling rigs have completed 100 per cent of their work, far outpacing the projected timeline. The original goal was to cover more than 100 metres each day, but Emily and Edith have achieved a personal best of 400 metres, exceeding all expectations.

Hilti will continue to be involved in the project until completion in 2019. We'll be looking after fixings for the entire project, so after the tunnels are completed we'll be turning our attention to the new stations. It's been an enormous undertaking. The project has also been incredibly fulfilling, and the entire Hilti team look forward to seeing how residents take to the Sydney Metro over the coming years.

To find out more about the systems used in Sydney Metro Northwest, or any of Hilti's civil projects, get in touch with us today.