Precast production for major projects

NVC Precast supplied nearly 200 precast elements to the Bell to Moreland project.

NVC Precast is supplying significant precast concrete elements to one of the largest Level Crossing Removal projects in Victoria – Bell to Moreland. Once complete, 2.5 kilometres of elevated rail made predominantly from precast concrete will be up and running.

The Bell to Moreland Level Crossing Removal Project includes the construction of 2.5 kilometres of elevated rail to remove four congested level crossings between Brunswick and Coburg.

As an elevated rail project in a tight corridor, precast concrete beams and planks have been a critical element of construction.

To date, local Kilmore based contractor NVC Precast has supplied nearly 200 precast concrete segments for the project. Working right through the coronavirus pandemic, with strict safety measures, the team has been able to help keep the project on track.

Timing has been a critical element on the Bell to Moreland project as it was decided the rail line would be shut down for a three-month period to allow construction to take place. This meant any delays or disruptions would have significant consequences for the people relying on the line.

Roads & Infrastructure sits down with Matt Thorpe, Director of the Bell to Moreland Project, to find out just how crucial precast was to the major works.

“This 2.5 kilometre elevated rail project gets rid of four dangerous and frustrating level crossings and will include two brand new stations as well. The elevated rail will also create around two Melbourne Cricket Ground’s worth of new open space at ground level for the surrounding communities,” he says.

“A key part of this project, however, was to do it as fast as possible and this week the team placed the last L-beam after only 45 days on site. To make this happen we needed as many precast elements as possible so that we could put them into place quickly. When you are shutting the train line for a bit over three months you need the job to be done fast.”

To create the elevated rail section of the project, 268 L beams were needed with around 53 piers and 73 cross heads. Each L-Beam weighed around 110 tonnes and spanned from 25 to 33 metres in length.

“Using precast L-beams helped with consistency because we knew we were going to get the same cast every time and it also helps with the speed of installation, each beam essentially can just be slotted into place without the delays of concrete curing times,” Thorpe said.

He says the project is situated on a very narrow corridor, so the precast beams work well because they don’t have to be formed and poured on-site. Instead two gantry cranes, named by the team as Kath and Kim, lift most of the L-beams into place along the corridor.

“NVC Precast is one of our two main suppliers and being able to have the beams produced, from both suppliers, to such a high quality and sent to site for quick installation has been fantastic.”

Another innovation the level crossing team and its suppliers worked on was the challenge of load restrictions during transportation of the large precast elements.

“We attached 4G tracking devices into each of the beams which fed real time location data back to the site team. This way we could optimise delivery of the beams,” Thorpe says.

NVC Precast’s Victorian based manufacturing facility also meant travelling to the level crossing site was relatively straight forward, down the Hume Freeway from Kilmore.

“Our local suppliers of concrete are incredibly important to the project. We are getting really high-quality product and we are getting the volumes we need from our suppliers. Kilmore isn’t far, but its regional so they are supporting regional employment. With easy access for the delivery of the beams having that precast capability in Kilmore has been great,” Thorpe says.

An NVC build mold and test cage for the Bell to Moreland project.

Steve Reilly, General Manager of Construction & Engineering at NVC Precast, says this was the first time L-beams had been manufactured over 31 metres in length and with top flange rebates for stair access.

“The project also required a new design of a portal crosshead which was able to support both tracks on a single crosshead. So, we had to design and manufacture new moulds to ensure accuracy in the cast connection for the columns to the crossheads,” Reilly says.

Creation of the new mould and formwork solutions by NVC Precast ensured accuracy in the final product so that during assembly on-site there would be no complications.

NVC Precast also developed a jig to trial the placement of all precast crossheads, to ensure the ducts cast into the crossheads were accurate to the design to facilitate their on site installation.

“We not only manufacture precast, we also have a construction arm of the business that can work on site. This provides us with a unique perspective to create the solutions required and ensure the final product will meet the client’s standards,” Reilly says.

NVC Precast have a variety of different precast beds which enable the team to manufacture elements consecutively. With the various precast elements delivered to the Bell to Moreland project they could all be cast in a different area which meant the team could manufacture all four elements, L-Beams, T-Beams, Planks and Crossheads, at the same time.

The NVC Precast site is also set up with significant hard stand areas which are used to store precast elements upon completion of the manufacture so that production can continue prior to the units being delivered.

NVC Precast is well versed in the benefits of using precast concrete on infrastructure projects, though due to the unique nature of the Bell to Moreland project many of the benefits of precast were made clear.

“Precast enables very tight tolerances to be achieved before you get on site, minimising any delays due to misplaced fitments. Using precast also eliminates the time it takes to form, reinforce, pour and cure elements on site. Instead you take the element to site and install,” Reilly says.

“Especially when working in a rail corridor like the Bell to Moreland project it is usually not feasible to manufacture pre-stressed elements on-site, due to the bed and mould requirements. The only non-prestressed elements we built for this project were the crossheads. Doing all of this work away from site decreases the construction footprint also which often reduces public space required on projects.”

Reilly says on this major project there were challenges, though the achievement of each key milestone by the NVC Precast team was reached through a strong collaborative relationship with all of the project stakeholders.

Through these relationships and their precast experience, they were able to meet all delivery requirements and produce high quality works, setting the example that a regional Victorian business can make a major difference on major infrastructure projects.