Pit & Quarry • February 2021 • EXCAVATORS

Leaning on Hills Machinery, South Carolina’s Oconee County Quarry selects the right excavator for the job of feeding its sizable jaw plant

Oconee County Quarry, located in the foothills of the Blue Ridge Mountains in South Carolina, has served its community and customers since 1948.

Owned by the county, the quarry is in the unique position of providing stone – blue granite – to not only meet the county’s needs but to supply aggregate products to local residents and business owners. The quarry is, in a sense, a massive piece of local infrastructure that returns profits directly to its citizens.

“I take a lot of pride in the fact that we are here for the citizens,” says Billy Buchanan, assistant manager of Oconee County Quarry. “We are not out to make every dollar we can make. Our goal is to provide stone for the county. That’s our first goal. [The] second goal is to sell as much as we can because the more rock we sell, the more we can put back into the general fund and people’s taxes are lower because we exist.”

In addition to providing aggregate products for municipal work like road-building and repair, Oconee County Quarry has hundreds of customers throughout the area.

“[We serve] anything from a local resident who wants stone in their driveway, to farmers, and on into commercial developers that are building subdivisions, large pad jobs for industrial work,” says Thom Moxley, manager of Oconee County Quarry. “A lot of our stone is sold to the local university down here at Clemson. They’ve done a lot of upgrading over the last few years. It’s a wide range of product base for different customers.”

BRINGING THE PLANT TO THE ROCK

Located on 100 acres, quarry management decided it no longer wanted a stationary crushing plant that would have to be moved from time to time to access the valuable rock underneath it.

With that, a plan was hatched to bring the crushing operation to the face of the rock and load out trucks there with already-crushed product. As an excavator works away at the face of the rock, the plant moves with it and loads directly into haul trucks.

“It provides us with the ability to not have to be set in one place,” Moxley says. “We probably have about 50 years of reserves, but over time we will move the plant in different places, different positions, to actually be able to get the rock that we need to, and not have it underneath a static plant. We’re excited about that. That’s not going to hold us up in the future.”

As the quarry upgraded to a new mobile plant, it needed an excavator that would keep up with production goals.

“Our old crushing plant was producing roughly 384 tons an hour,” Buchanan says. “Our new crushing plant is crushing over 600 tons an hour.”

Adds Moxley: “After going and visiting over in Sweden, where we ended up purchasing this new plant, we saw the type of excavators they were using. We knew that we had to have something in a class larger than 150,000 pounds.”

Moxley worked with Hills Machinery, a Case Construction Equipment dealer, to find a machine. He decided on a Case CX750D ME (mass excavation).

The Case CX750D is the largest and most powerful machine in the current Case excavator lineup. Operating at 512 hp, the CX750D is available in standard and mass excavation configurations.

The mass excavation configuration features a shorter boom and arm, allowing for greater breakout forces and faster cycle times. The configuration also allows for handling larger buckets for added capacity.

“We decided to go with the mass configuration so that we would have more breakout force and have the ability to get into the pile and cycle quicker,” Moxley says. “It’s got a large cab – I think it’s the largest in the series that it has – and it’s very comfortable for the operator.”

According to Case, the CX750D is built to achieve faster cycle times, improved control and responsiveness, and greater fuel efficiency than previous generations of equipment. An electronically controlled hydraulic pump and larger control and solenoid valves boost breakout forces, increase lifting strength and improve responsiveness, Case adds.

These features combine with the Case Intelligent Hydraulic System and its four integrated control systems to make best use of the machine’s hydraulic power and momentum, resulting in added strength and fuel efficiency.

“The Case is keeping up,” Moxley says. “We had to have an adequate size machine just to keep up with the jaw that we have. We have a 40-[in.] x 60-[in.] jaw, and it requires a lot of rock to keep it fed. It’s a very smooth operating machine that efficiently does its job day in and day out.”

“We decided to go with the mass configuration so that we would have more breakout force and have the ability to get into the pile and cycle quicker.” THOM MOXLEY OCONEE COUNTY QUARRY

A KEY PARTNER

To Oconee County Quarry, its relationship with Hills Machinery has proven invaluable to keep the operation moving.

“They realize what we need and how critical this piece of equipment is to stay in operation,” Moxley says. “Over time, they have continued to support us in a way that they get here as soon as they can. They’ve really worked around us, and came in early and stayed late so they could keep our machine running during operating hours.

“I feel good about our relationship because I think we’ve always been honest with each other and we’ve worked through issues and been willing to agree that we don’t live in a perfect world,” Moxley adds. “Having each others’ trust, and being able to comfortably know that, on both ends, we’re doing the best we can to support each other, we just are going to continue that kind of relationship. It makes us feel comfortable to know that somebody’s got our back.”

As the operation is owned by the county, Oconee County Quarry takes pride in its civic role and works hard to make sure the quarry continues to serve the needs of the growing communities of Oconee County.

“We pride ourselves in the ability to produce what we produce,” Moxley says. “We are satisfied to meet the demands locally here for the county, and then be able to try to help the local customers. We’re sitting on about 100-plus acres. We do purchase land when it comes available so we can plan for the future. We’ve probably got a 50-year reserve, and we will continue to add to that as we get the ability to. We actually set aside a little bit of money per ton to go back into land acquisition so we can keep this a viable operation for Oconee County.”