Although a subspecialty of the extractive industry, dimension stone quarrying is a significant part of Australia’s heritage – and continues to add flair and innovation to building infrastructure. A near century-old leader in the field explains how its extractive techniques differ to regular quarries and draw on fit for purpose earthmoving equipment to manufacture its products.
In 2022, Gosford Quarries will celebrate a century of operation in the dimension sandstone business. Originally trading as the Hawkesbury Sandstones Company in Gosford, in central New South Wales, the organisation’s “Gosford Grey” sandstone has shaped buildings and monuments all over Australia. The business built its reputation in the lead-up to the Second World War, and then continued to flourish in the second half of the 20th century and the first decade of the 21st century.
In 2014, the family-owned Sarkis Bros Sandstone business acquired ownership of Gosford Quarries. Sarkis Bros was formed in 1993 by siblings John, George, Issa and Sid. Prior to its acquisition of Gosford Quarries, Sarkis Bros built a strong, healthy business and reputation in sandstone manufacturing.
The merger of Sarkis Bros and Gosford Quarries was a natural fit and brought about long-term benefits. Not only did the economies of scale result in competitive prices and more options but they enabled Gosford Quarries to introduce a broader range of specialised services in design and architecture. These include highly trained personnel in in-house design, heritage consultancy and 3D modelling. The combined company has invested in state of the art capital equipment to modernise its sandstone processing prowess.
Today Gosford Quarries’ sandstone products comprise paving, slabs, capping, cladding, landscape walling, ballast, billets and logs. Its materials have been employed in many landmark Australian projects and monuments, including the Parliament of Victoria, the Australian War Memorial in Canberra, Melbourne’s ANZ Gothic Bank building, and Sydney’s Town Hall, GPO and St Mary’s Cathedral buildings. The company’s more recent contributions to modern architecture in Sydney include Barangaroo Towers, the Hilton Hotel, Westfield Towers and the Museum of Contemporary Art. In the heritage and restoration sector, Gosford Quarries also continues to supply “continuity of product” to developments which have used sandstone for the past 100 years.
Greg Cook, who is the quarry manager for five of Gosford Quarries’ eight quarries and the mine operator representative for the other three, told Quarry that dimension stone is unlike other quarry products.
“Our products are more on-show – the big difference is we compete on the world market, we’re up against imports that are coming in,” he explained. “Dimension stone is a very different product – to the uninitiated, it all looks the same but it’s a completely different market. The aggregates segment is pretty safe, as it’s mainly home-based, there are some cement imports from overseas but not many. Gosford Quarries has to compete as an Australian company against the world.”
Gosford Quarries currently exports its dimension stone products to China and the United States.
UNIQUE CUTTING APPROACH
Cook is not only a quarrying veteran – he is a Gosford Quarries doyen. He has worked in practically every aspect of Gosford Quarries’ business operations for 45 years. “I was a stonemason, then I did a degree in building, and I ran the factory, in production,” he recalled. “I’ve also worked on-site and off-site, I did a lot of heritage work in Sydney. I then trained in quarrying and have been the manager of Gosford Quarries in the past 20 years.
“I’ve always worked for Gosford Quarries – from the factory floor to the heritage site and into the quarries themselves. It might sound a bit boring but I’ve been able to move around within the company, and to the company’s credit, the education is ongoing. The whole 45 years I’ve been educating, so I haven’t just been sitting at the same desk for all that time.”
Cook is based principally out of Mount White Quarry, on the NSW Central Coast, about 60km north of Sydney. Mount White is one of six dedicated dimension stone quarries under the Gosford Quarries banner; the other two combine aggregates with dimension stone. The pit’s sandstone is renowned for its rich variety of colours and textures.
“The Mount White Quarry is producing and supplying 50 per cent of the Primary Block for our manufacturing factory,” Cook explained. “Of the eight quarries, it’s supplying 50 per cent of the Primary Block and it’s also supplying 50 per cent of the landscaping product that goes out the gate. Mount White is crucial, it’s essentially the quarry of Gosford Quarries. The main reason for that is that we quarry on spec. The colours and the quality that come out of this quarry allow us to produce blocks all the time and we know it’s going to be required.”
Gosford Quarries’ dimension stone sites do not operate to the same methods as most aggregate quarries.
“We’re quite unique because we don’t blast,” Cook elaborated. “We supply a high volume from our quarries but we’re not like aggregate quarries that are doing hundreds and hundreds of tonnes per day.
“We differ in our method of quarrying by working with the environment and extracting with low emissions by cutting and splitting,” he continued. “We have a fairly comprehensive drilling program that we use before we quarry. We identify exactly where we’re going and what we’re doing. We even test all the stone from the top layers to the lower layers. We now have what we call a landscape product – anything which is marginal because we deliver a high quality dimensional product. Anything that falls still within that product and that quality, we turn into a landscape product.
“The landscape products we’re generating now have probably more than doubled our quantities because the demand is just growing every year – we commonly nickname them ‘logs’. Barriers, retaining walls, they are in schools for seats. Gosford Quarries initially designed that product for retaining walls but now they are being used for everything but retaining walls. The logs used to be our overburden – where we just used to rip and push, now we cut, and we’re virtually using up to 90 per cent of the material we are producing.”
As the extractive process is very different to conventional quarrying methods, it calls for machinery that has to be configured and programmed accordingly.
“The excavators are more like robots to us, they have many attachments, they have cutting, grinding, ripping, buckets,” Cook said. “With our quarry, we work out the joint pattern. Our high walls are primarily a natural joint and we’ll cut and split. Our splitting process is with a hammer or a ply plate. Ply plate is excellent because we don’t use an eating motion or a splitting motion.
“So our emissions are really low in comparison for our cubic [output in cubic metres]. There’s no blasting. We do a bit of ripping with the dozer just to make a start on the pad. The rest of it is used with excavators and we have a couple of trencors. They’re trenchers for cabling but we’ve modified them to cut. We also use our excavators heavily with cutting wheels to do the work.”
Cook explained the excavators use push blades down at the tracks to level the machine and rely on diamond cutting tools and carbide cutting wheels to cut the blocks. A large drum is used for levelling out the floor. Standard rippers, cleats, GP buckets, mud buckets and narrow trenching buckets are employed where applicable.
Cook said the extraction process is a mixture of century-old and modern techniques. “Gosford Quarries has significantly invested in computerised robotics and computerised saws, so we’re still doing a traditional method of processing and manufacturing with excavators and loaders but we’ve really upped the game with computerisation.
“We still have three gang saws that are more than 100 years old. They are still being used today and were converted from steam to electrical. They are 99 per cent unchanged but they have a few computers attached to gauge their downstroke.”
Cook added the traditional gang saws can achieve a finish that cannot be matched by modern diamond saws. The older equipment has been retained to meet demand for sandstone with a texture that doesn’t reflect the light and provides a “nice finish more so than a diamond-type finish. Some of our customers require that. The gang saw is still a very efficient way of cutting stone”.
There are up to five employees who work on the site at any one time and operate three excavators, a bulldozer, and a couple of wheel loaders.
Of the plant and equipment on the floor of Mount White, Gosford Quarries has invested quite heavily in Volvo Construction Equipment (Volvo CE) products, courtesy of national distributor CJD Equipment. Its current inventory includes three Volvo CE excavators – two 35-tonne ECR355EL long track excavators and a 300D excavator – and four wheel loaders – two L70Fs and two L150Hs. Two more L150Hs are on order.
Cook said this fleet of Volvo CE machines is doing “all the hard yards, the cutting and prep works”.
He said the “stand-out qualities” of the “35s” (the ECR355EL excavators) is “their blades, so our set-up time is quicker and the operators can stay in the cab more than having to get out and put timber beneath the tracks to level up the blade levels of the machine. That’s a big plus in terms of exposure to silica, where the pressure in the cab and the air conditioning systems actually protect the operators. That’s a control measure so the more time they spend in the cab is a lot better for them”.
The L70F wheel loaders, he said, are “excellent for the landscape products” while the L150H loaders pick up “the big blocks”.
“Our L70Fs are picking up four logs – each log is about 650kg, so with four logs, that’s about 2.5 tonnes on tynes, not buckets,” Cook explained. “The L150H is picking up blocks from 6.5 tonnes to nine tonnes. You have to remember they are working on a hard quarry floor that is solid and clean.
“When you’re talking about the tonnage or the spilling, you have to look at where it is doing it. There is a big difference. You couldn’t pick up that sort of weight on a civil site.”
Cook said the feedback about the loaders and excavators from his personnel is very positive. “The current generation of operators just love the Volvos. The loaders are especially comfortable, and for some of the guys, they are like a spare ‘office’. The operators can be there all day long. Even in the excavators, the ergonomics of where the operator sits, how they operate the controls, a lot of thought goes into it. Volvo looks after the operators. There’s not an operator that gets out grumpy, they’re all happy to be in there.”
Given the importance of protecting workers from exposure to surrounding dust and silica, Cook said the compliance of the Volvo CE loaders and excavators was a paramount factor in Gosford Quarries’ purchasing decisions. “As a quarry manager, you’re not just looking at the grunt of the machine or how it produces or pulls its weight,” he explained. “The pre-starts are on the ground and can be done within the machine. The operators aren’t climbing all over the machines now, so someone in that spectrum [at Volvo CE] has done their thinking.”
He also credits CJD Equipment with an outstanding delivery and commissioning process, which in turn aids the operators. “CJD has a rigorous, thorough procedure. They’ll go through it with the operators. They will send out a technician who knows the product and explains it to (a) the operator and (b) our plant manager. There are a lot of compliance issues these days, compared to when I first started as a quarry manager, and the induction ticks the box for training and is a big requirement.”
CJD Equipment’s involvement with Gosford Quarries dates back 16 years but the company’s Sydney regional sales manager Steve Wilson told Quarry that the relationship with the Sarkis Bros business predates that relationship again.
“I’ve been dealing with Sarkis Bros since they bought their first excavator off us 18 years ago, and once they bought Gosford Quarries, our relationship grew,” Wilson said. “Initially I dealt with Greg Cook but since Sarkis Bros took over Gosford I’ve had more dealings with George and John Sarkis, and Bob Iles, who is responsible for fleet management requirements and maintenance.”
Wilson said the purchase of the first of Gosford Quarries’ ECR355EL long-track crawler excavators was initially for a construction job. “They purchased the ECR355EL for work in the Sydney CBD. That was to excavate dimension stone for a construction site. It has the reduced swing for cutting the sandstone along the boundary. It was in the hole cutting sandstone blocks. It was bought for a purpose – and they’ve since bought a second one because it serves a purpose in the quarry as well. It can run their single and double saws very effectively.”
Volvo CE excavators are long track machines, so generally have an advantage over other brands, which have shorter tracked frames. Traditionally, big swing machines with shorter track frames tend to be more difficult for operators to control, whereas “longer tracks are more stable and improve the lift capacity of the excavator”, Wilson said. As a result, the ECR355EL has a smaller radius swing and more lift capacity than the EC300D excavator which Gosford Quarries also runs at Mount White Quarry.
Wilson said that reduced swing excavators are not usually designed for quarries. “Most excavators have a regular tail swing but because of the requirements for this particular machine, Gosford Quarries bought it for the CBD job and because it worked so well, they decided to also run it in the quarry. The biggest benefit of the ECR355EL in the quarry is that its dozer blade provides greater stability.
“The ECR355EL generally has a reduced swing – in a quarry application, you’re more likely to use a regular excavator with a conventional counterweight like the EC300D. The reduced swing excavator is used for road jobs where you don’t want to swing the tail into buildings or otherwise. The EC300D is a good fit for a quarry. It also runs a saw at Gosford Quarries as well – Volvo have the hydraulics to handle the saws and hammers.”
Wilson added that particularly for the EC300D, there was no customisation or modifications to the excavators to accommodate the diamond saws, carbide saws and tynes that Gosford Quarries employs in its operations. “The excavators are pretty well specced up for anything to go on them. There’s a couple of things we have to do for safety requirements for jobs but not for the saws. The Volvo hydraulics handle that anyway,” he reaffirmed.
Wilson said Gosford Quarries has provided him with positive feedback about all the earthmoving plant CJD Equipment has supplied in the past six years. “They’ve been very impressed by the ECR355EL,” he said. “They like the excavator’s versatility because they can use it in the quarry and externally on the tighter jobs.
“Gosford went for the Volvo loaders because of the comfort for the operators,” he added. “They like the performance and operational advantages of the Volvo loaders such as the parallel lift. They like the reliability and the longevity of the loaders as well – the loaders can exceed 20,000 plus hours.
“The L150Hs have upwards of 20,000 hours on them. Gosford Quarries has a primary loader and a back-up loader (an L150) and they would like to have a new one in each quarry as the primary loader. Predominantly, they’re being used for the dimension stone – like forklifts and fork attachments rather than the bucket work.
“So they’re really impressed by the L150Hs. Across their quarries, Gosford is about to take two more L150H loaders – and there is talk of buying more.
“The L70F is used by Gosford Quarries for its sandstone logs, which are a smaller, light sandstone block to lift. The L70 is probably too small for a quarry but you would use them in a batching plant or a soil yard.”
Wilson said the L150H is best suited to hard rock quarries, such as blue metal. “They are designed for load and carry in a range of applications, whether it’s a stockpile, or a truck, or the face, they stand up in every application.
“The L150H is more like a sales loader, for loading stockpiles or hoppers. It is suitable for loading dump trucks and some highway trucks. It’s limited to its natural reach but it should be able to load A25s and normal dump trucks. The reach is about 1.36m, with the bucket at about 45 degrees, which is going to get you in the middle of the truck.”
CENTURION’S EXPANSION PLANS
With Gosford Quarries set to celebrate its 100th anniversary in 2022, Cook anticipates that the company will honour its past and engage its employees to mark a century of business. However, it won’t significantly change the company’s remit.
“Basically, in our industry, we just get on with it,” he said simply.
As a family-owned business, Cook added he expects the Australian market will always remain at the forefront of Gosford Quarries’ activities, even as it seeks further export opportunities. In particular, Gosford Quarries is likely to expand its manufacturing base.
“Sandstone is going to be more of a highly processed product as opposed to the bulkier product of the past,” he predicted. “There are more commercial buildings in steel and concrete that are being clad in sandstone. The shape of buildings are going from square to more rounded shapes, and we are able to comply to the architects’ whims.”
Gosford Quarries is also diversifying into civil and landscaping products. “People don’t seem to have the big backyards anymore,” Cook remarked, “so they are happy to invest in higher quality products for smaller courtyards. The landscape product is expanding quite rapidly. Plus two of our quarries combine dimension and aggregate – and that is the way of the future. We expect to expand into the aggregate market with the rest of the dimension quarries.”
To that end, Gosford Quarries’ partnership with CJD Equipment will continue to be fruitful and will undoubtedly grow. As unconventional as the application may be to regular quarrying stalwarts, the dimension stone and the earthmoving plant and equipment itself are clearly fit for purpose. •