Motor graders play an important role in aggregates operations

Contributed

August 8, 2017

By Tina Grady Barbaccia, Contributing Editor
This Supporting Player Has an Important Role

Aggregates Manager: Operations Illustrated“Although a motor grader and skilled operator to run it are essential to sand and gravel and aggregates operations, both assets are often underutilized, and their importance is not always recognized, explains Wade Porter, motor grader product specialist for Caterpillar.

“The motor grader is an asset that is not used nearly enough,” Porter says. “In many cases, when there is a motor grader on the jobsite, it sometimes has rust on the blade. The mindset is often that it’s not our primary focus, and we just get it out once in a while, only when needed.”

Focus remains on manufacturing the product efficiently and delivering it to the customer as quickly as possible. However, the production and performance of the trucks directly correlate to the condition of the roads and the use of a motor grader.

“The motor grader is considered a support tool, not a production tool,” Porter points out. “Customers should get in the mindset of using it more often to maintain haul roads, improve rolling resistances and cycle times, and clean up the yards where customers come in to receive products. Increasing the efficiencies of these systems with a motor grader demonstrates the productivity and value of this support tool.”

New technologies, such as cross-slope and blade assistance features, enable these machines to be “more intuitive” and are adding to this increased productivity. “When you think of all the functionality incorporated with two joysticks, it’s truly amazing what a properly trained person can do without a lot of effort,” says Don Weinhold, senior market professional for the construction materials industry at Caterpillar Inc. “Cross-slope is huge because operators just choose the slope target they want the blade to stay at to create a consistent slope. This is valuable for less-experienced operators and helps ensure a haul road or yard area is being properly maintained.”

To that end, Stable Blade — a Cat proprietary technology which regulates engine speed with onboard sensors to detect when a bounce is about to happen — can be used in haul road or yard maintenance, but also to protect these surfaces and the machine from damage.

Speed promotes a harmonic bounce, which becomes exponential once phasing begins if an operator doesn’t change the machine’s attitude or speed. This system works with the throttle control to slow down the motor grader when a phasing or harmonic bounce is about to occur.

“A yard that is not well kept affects the ability of customers’ trucks to get in and out of the yard quickly and with the least amount of wear and tear on their vehicle,” Weinhold adds. “It’s important to put together a road program that involves the motor grader and all parts of the operation in which it’s used, and taking into account the actual construction of the roads.”

Our Experts

Zachary Aragon

Zachary Aragon is fleet manager at Vista Sand. He maintains equipment operations and web systems. Previously, Aragon was a training supervisor in the U.S. Navy and a naval air crewman. He has a Bachelor of Arts in organizational management from Ashford University and studied business and criminal justice at Liberty University.

Don Weinhold

Don Weinhold is a senior market professional for the construction materials industry at Caterpillar Inc., where he focuses on products and services going into the aggregates industry and provides training for customers and internal Cat dealers. He has worked at Caterpillar for 36 years.

Wade Porter

Wade Porter is a motor grader product specialist for North America at Caterpillar. He has held the same position for Caterpillar in South America, Europe, Africa, the Middle East, and Russia. Global experience helps Porter understand customer and dealer equipment needs in many different aggregates environments.

 

Zachary Aragon

Size matters when it comes to efficiently and effectively using a motor grader in an operation. “Bigger is not always better, especially in our environment,” explains Zachary Aragon, fleet manager at Vista Sand, a sand producer in Granbury, Texas.

When Aragon began managing equipment at Vista Sand, he quickly discovered that the “bigger is better” mantra was inaccurate. Vista had been operating a Caterpillar 16M motor grader with a 16-foot blade, but Aragon determined that “it was too big for our needs.” Different features, such as front-wheel drive, also were needed for maximum efficiency.

“Just because you can blade more road at a time doesn’t make it a good fit,” he says. “Any time it rained or got muddy, it did not do well in the pit, so we didn’t get to use it when we really needed it.”

The lesson learned? Buying the right motor grader for an operation’s needs, and terrain is crucial. This means using any resources available and working with the dealer to pick the right machine for your operation. For Vista, this included Caterpillar conducting a site visit, measuring haul roads for width and distance, looking at the slope, and taking aerial views of the operation. Vista ultimately scaled back to a 140M motor grader with a 14-foot blade and all-wheel drive.

“The haul roads are wide, but places in the pit are pretty tight, so a smaller machine and blade better fit our needs,” Aragon says. “We use our motor grader almost 24 hours a day, five to seven days per week, and average anywhere from 600 to 1,000 loads per day. We need the best motor grader to cover up potholes from rain and mud, and to smooth out the deep sand in the pit, which gets rutted out constantly. This means a smoother ride for operators and, ultimately, faster cycle times.”

Wade Porter

Using correct techniques for a motor grader can help boost productivity and reduce cycle time — while protecting an operation’s equipment investment.

“Train operators on how to properly operate a motor grader to crown a haul road and achieve the proper grade and slope,” says Wade Porter, motor grader product specialist at Caterpillar. “Crowning from the haul road’s center line to the shoulder or ditch will allow proper drainage.”

However, it’s not as simple as it sounds. While grading and crowning, the motor grader operator could cause soil erosion if the slope is too steep and cause water to pool in the middle of the road if it’s too shallow.

“Motor grader operator training is important to every aspect of aggregates operations from haul road and yard maintenance to working in the pit,” Porter says. “Train operators on good techniques for machine frame and wheel lean setup, blade pitch, and blade rotation angle. The more forward you tip the blade, the more aggressive it cuts, because it puts the cutting edge at a more aggressive angle. The further back, the easier it is to spread and comb off large rocks that could cause tire damage.”

As an operator rolls the moldboard forward and backward, the cutting edge’s depth changes by 7 to 9 inches. “Utilizing the pitch is a great technique for achieving grade, because it makes a uniform elevation change across the entire cutting edge and doesn’t change the blade slope, which the operator is trying to keep consistent,” Porter says. “The operator should roll the moldboard forward to cut the deepest pothole or corrugation to achieve a smooth surface. Any loose material should be placed in a windrow and then spread back evenly on the road with added moisture so it can be sealed for a good load-bearing road cap.”

Don Weinhold

Amotor grader may seem like just another piece of equipment, but it is “critical” to the entire aggregates operation — and many aggregates producers admit they underutilize them, says Don Weinhold, senior market professional for quarry and aggregates at Caterpillar.

“When thinking about a motor grader and how it impacts cost per ton, we typically think about going from the face to plant, but they also play a role in maintaining the yard area, haul roads, and so many other parts of the operation,” Weinhold says. “Everything in an operation is part of a system.”

In addition to haul road construction and maintenance in an operation, motor graders are essential for blasting cleanup, loading area cleanup, dust maintenance, reclamation, and snow removal.

“When we train field reps and dealers, we take a look at the whole aggregates operation,” Weinhold says. “Every piece of equipment impacts every other piece.”

Although frequency of motor grader use varies by operation, the equipment itself and the techniques used to operate it need to be looked at holistically. “They need to be considered as part of an overall system, especially because some aggregates manager may be supervising a quarry or sand and gravel business that has been in operation for 50 or more years,” Weinhold says. “The people before them have made decisions that had an impact on the operation.”

When Weinhold conducts motor grader training, he advises on “rules of thumb” that speak to motor graders as part of the whole aggregates operation. This includes the proper size motor grader for the operation, which is a function of what size haul trucks are being used. “You need to consider the width of the haul road, load carrying capability, berm heights, primary crusher hopper capacity, and other plant modifications when looking at motor graders,” Weinhold says.

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