Carrying aggregate from stockpiles to a bin for asphalt processing, Komatsu’s WA380-5 wheel loader is an integral part of MAC Construction Company’s operations.
Based in Shallotte, NC, MAC’s plant churns out the asphalt for its grading and paving projects for the North Carolina Department of Transportation (NCDOT) and other commercial and residential customers. Current MAC jobs in Brunswick County, its main operational area, include a bridge approach and NCDOT road resurfacing. MAC also has undertaken street building at Ocean Ridge Plantation and at St. James Plantation golf course communities.
Founded in 1966, MAC, with 56 employees, added the asphalt plant and facilities in 1986.
“The wheel loader is the lifeline of this plant,” Earl Tharp, MAC vice president and general manager, said. “When the loader is down, the plant is down, the trucks are down, the paving crew is down. In the summer — the paving season — when the loader goes down, the whole company might as well be down.”
When shopping for its wheel loader, MAC’s experience with Komatsu equipment automatically qualified the company’s products. It purchased two Komatsu D37 dozers in the last six years and recently acquired a D41 machine. According to Tharp, the dozers proved indispensable in utility and general grading in spaces too tight for a motor grader.
“As far as the Komatsu dozers’ performance, it has been excellent,” Tharp said. MAC purchased the Komatsu dozers from Mitchell Distributing Co., an official supplier of Komatsu equipment and other major brands. Over the past 16 years, Mitchell sales representative Frank Dunn has provided MAC with all of its paving equipment.
“We tried their Komatsu WA380-5 loader and several other loaders,” he said. “Our comfort level with Mitchell and our previous experience with Komatsu equipment also were very important criteria.”
MAC purchased the WA380-5 in January. By March, MAC had put only 200 off-season hours on its new wheel loader, but Tharp predicted he will put at least 50 times that number of productive hours on the machine before significant rebuild work will need to be done.
“I’d love to think that I’m going to get 10 to 15 years out of it,” he said. “This loader will be maintaining a production of somewhere in the area of 150,000 tons of aggregate per year. I’m confident it will handle any production requirement we throw at it. Plus, I think at the end of the year, our cost per ton for loading and stockpiling will be less, because this loader will have fewer maintenance requirements.”
On MAC projects, the WA380-5’s task is straightforward. Aggregate is trucked in from two quarries approximately 45 mi. away. When the trucks arrive at MAC, they dump their loads and the WA380-5 racks up the gravel into stockpiles to dry. As the plant needs asphalt — which can be continuous during summer — the loader will dig the aggregate from stockpiles and feed it into bins for processing. When it’s not dumping raw material into bins, the loader is responsible for maintaining stockpiles, another constant seasonal activity.
“If we run the WA380-5 on an average workday in the summer, when about 300 to 400 tons of asphalt is needed, it will work anywhere from eight to 10 hours without stopping,” Tharp said.
With its Komatsu SAA6D114E-2 187-hp (139 kW) engine, the 39,000-lb. (17,690 kg) WA380-5 has the ability to handle any workload it is given. Tharp said he also is confident the loader’s operator comfort features will add to overall productivity.
“Naturally, whatever environment you’re in — whether it’s in an office, or a loader or tractor — if you’re comfortable and content with what’s around you, you’re going to be more productive,” Tharp said. “Our primary loader operator, Kevin Long, said it’s quiet in the WA380-5 cab, the heater works well and the air-ride seat is comfortable and gives him a smooth ride.”
The high-back, air-ride bucket seat, new for the dash 5, is a standard feature offering 11-way adjustments, armrest, headrest and lumbar support for any size operator.
Dunn, of Mitchell Distributing, appreciates the new dash 5 features, knowing they are ideal for MAC’s loader application.
“The transmission cut-off pressure is variable,” explained Dunn. “The operator has the option to adjust that higher to enable the transmission to remain engaged at higher engine rpm and hydraulic pressure. That gives increased performance while climbing ramps or stockpiling. The WA380-5 also has a dual-speed hydraulic system that is very good for MAC’s application, because it diverts engine power variably depending on whether the operator is digging in a stockpile or lifting a load of aggregate.”
MAC officials also were impressed by the WA380-5’s Equipment Management Monitoring System (EMMS), which keeps the operator informed of the machine functions status by glancing at the main monitor.
“With this monitoring system, we’re able to see when it’s time to change fluids or if a system failure is going to happen at some point,” Tharp said. “That will give us enough lead time to shut it down, get it corrected or find out what’s causing a symbol to light up or an LCD readout to come on. That’s a lot better than hearing some sound and the next thing you know a system is going down. The EMMS allows us to be proactive rather than reactive in servicing the loader.”
Dunn added that the EMMS is a definite advantage of the WA380. “The operator can call the code in and 99 percent of the time when the mechanic arrives on the job site, he’s got the part in hand that will fix the problem,” he said.
Tharp is optimistic about the future and his new WA380-5, as his county seems to be in the crosshairs of some major development plans.
“MAC Construction has the potential to grow with what’s coming up,” he said. “Brunswick County is growing by leaps and bounds. We’re just now getting more of the rural areas developed. The beaches have been developed for years and are expanding out. The growth of Wilmington is coming toward Brunswick County rapidly, and the growth is coming from the other end as well — we’re right in the middle of it.”