On 9 May, 1901, the first Australian parliament was opened at the Royal Exhibition Building in Melbourne. This World Heritage-listed building had been constructed 20 years earlier; erected in just 18 months, it hosted the 1880 Melbourne International Exhibition, the first World Fair in the southern hemisphere.
Among other things, these fairs were catalysts for extraordinary feats of construction (eg Gustave Eiffel designed and built his tower as the entrance to the 1889 World Fair) and the Royal Exhibition Building has become one of the city’s most enduring and iconic landmarks. Built by David Mitchell, father of the world-renowned soprano Dame Nellie Melba, it embodied the hope and optimism of late 19th century Victoria, still basking in the plenty of the gold rush era.
Mitchell, a Scot who immigrated to Australia in 1852, supplied the limestone from his Cave Hill Quarry in Lilydale in Victoria’s Yarra Valley. He also built several other notable Melbourne landmarks, including St Patrick’s Cathedral and the Scots Church in Collins Street. Even now, his limestone can be found in gardens across the country in the form of the much beloved Lilydale toppings.
The quarry was one of the primary sources of limestone in Victoria from its establishment in 1878 to its closure in 2015. The site’s historical significance can still be seen in its physical fabric: Mitchell constructed an extensive battery of pot kilns in response to the limitations of intermittent burning technologies, which enabled round-the-clock production.
These heritage features – painted by one of Australia’s best known painters, Arthur Streeton, in 1935 – will be incorporated into the $2 billion residential and mixed-use development, which is expected to eventually house 8000 residents. The 162ha property was bought from Belgian multinational Sibelco in late 2016 as part of a joint venture with Bayport, Intrapac and Brencorp Properties.
On a tour of the site, Daniel Petroni, development manager at Bayport, told Quarry that the old kilns would form the centrepiece of the future Heritage Quarter, home to farmers’ markets, paddock-to-plate-style eateries and space for family-friendly events.
“There are plenty of examples where quarries of 30m to 40m have been successfully rehabilitated and developed on. This is the first quarry of its depth (100m plus) anywhere in the world that’s been rehabilitated with a plan to build on it,” Petroni told Quarry as we stood overlooking the 25ha pit. “Originally, the quarry was 120m deep.”
All the material that will be used to fill the pit will be sourced from within the site.
“Sibelco extracted around 13 million cubic metres and only around 25 per cent was removed from the site. The other nine million cubic metres was placed into overburden mounds,” Petroni said. “About eight million cubic metres will go back into the hole.”
McCloskey equipment, supplied by MSC Group, is being used for all the on-site crushing and screening. The McCloskey J50 V2 jaw crusher, with its high jaw speed, ensures better reduction and faster processing of material through the crushing chamber. The McCloskey C44 V2 secondary cone crusher has a high material capacity and throughput.
The McCloskey R155 reclaimer has an open feed hopper and heavy-duty apron feeder, making it well suited to processing bulky material. The McCloskey S190 secondary screen features adjustable screenbox angles that allow adaptability to a wide range of material applications. Rounding out this mobile circuit is the agile and robust TS4065 tracked stockpiler. The tracks offer on-site mobility and the metre-wide belt ensures maximum capacity. It also integrates easily into the McCloskey range of crushers and screens.
“To date, in terms of product, Bayport have produced a 50–300mm normal-style rock for the rock drainage blanket. They have done roughly 105,000 tonnes of that,” MSC Group’s Victorian sales manager Ian McCartney told Quarry.
“They’ve also produced 12,000 tonnes of a 50mm aggregate and 40,000 tonnes of a 40mm class 3 product. They’ve also processed topsoil and screened stockpiles of old material and other bits and pieces. And there remains a lot more work to be done.”
McCartney said that in the early stages of the project the McCloskey machines played an important role in cleaning up the site.
“When it was a working quarry, all the overburden – the topsoil, the rock and the rubble – all that other stuff was pushed off to get the lime. So, all that stuff was around the quarry, which technically wasn’t waste, but it wasn’t the used product either. This overburden needed to be sorted and screened and crushed to make material out of,” McCartney said.
It is estimated that the quarry pit will take six years to fill, but it’s a 12- to 15-year development project for the group, Petroni said.
Once the quarry is filled, the spoil will be left to settle for at least three years. The work is being undertaken under the supervision of the project geotechnical consultants Tonkin and Taylor.
“There have been several similar developments on other quarries that are much shallower than this – maybe up to 40m deep,” Roger Olds, principal geotechnical engineer at Tonkin and Taylor said. “They’re usually quite challenging in terms of getting the right materials and so forth. But this one is unique in the depth and the stresses that are applied to the soil at the base of the pit.”
In an effort to forestall any problems, the ground is being over-compacted. As part of this process, a heavy-duty pump operates 24 hours a day, seven days a week, pumping 1.8 million litres of ground water per day. Ordinarily, soil needs to be compacted to 98 per cent density on commercial projects and 96 per cent on residential. But the soil at the former quarry is being compacted to a minimum of 101 per cent and an average of 103 per cent.
Bayport has turned to Caterpillar, a supplier with which it has had a relationship with since the 1960s, to help it complete this unique project. Two Caterpillar 825K compactors and two Cat 19-tonne vibratory rollers – a CP76 padfoot and a smooth drum CS78 – are being used at the site to provide superior compaction as each layer of the quarry is filled to the specified density. Each compactor has a GPS record for ease of operation, helping operators to distinguish between areas that have been compacted and those that still require attention.
There are also seven large Cat 773 50-tonne dump trucks carrying material from the top to the bottom of the quarry. The largest of the machines on-site is the Caterpillar 390F L hydraulic excavator, which is one of two 390s on-site. This machine ensures production numbers remain high, while reducing operating costs and providing the power, fuel efficiency and reliability to maximise productivity. The excavators are used in conjunction with Cat 773 G trucks, guaranteeing that haul material can be loaded at a lower cost per tonne. The latest additions to the Cat fleet at Cave Hill are the D8T dozer and the Cat 982M series wheel loader.
Upon completion, the land will hold about 3000 new residences and a host of local retail, community and commercial facilities. The old quarry will become Kinley, a new suburb set among natural parkland.
The first 35 premium lots were released in October 2018 through an on-site ballot. The first stage release is adjacent to Hull Road, Lilydale with selected lots enjoying views to the Dandenong and Yarra Ranges. In mid-March, the second stage was released, featuring 11 lots ranging in size from 400m² to 526m² with a selection of frontages.
The developers envisage Kinley being a “walkable suburb” where people are in pedestrian proximity to vibrant infrastructure such as retail, culture, restaurants, education and general street life.
In much the same way that the Exhibition Building stands as a testament to a particular period of Melbourne’s history, Kinley embodies the contemporary mood.
Australia, it’s sometimes said, was the first suburban nation; the dream of owning a home in a leafy suburb, away from the hustle and bustle of the city, is something of a national obsession.
Moreover, Kinley, as the last major parcel of land east of the capital, offers a rare opportunity for many more people to realise that dream.