Grading and Excavation Contractor

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Versatile, cost-efficient tractor/scraper setups are riding a new wave of acceptance.

By Carol Wasson

		A Pull-Type
	Scraper Primer

The tractor and pull-type scraper combination is clearly something old that’s new again. A mainstay in agriculture for more than 100 years, the setup is seeing increasing popularity in the construction market with an estimated annual sales growth of 5% to 10% over the last several years.

Beefier, industrial-grade tractors and scrapers have caught the eye of even the latest adaptors—plus few dispute that the price is right. A tractor and scraper combo is often only one-third the cost of a self-propelled scraper. And performance (in appropriate applications) from this duo, say its manufacturers, delivers versatility that cannot be gained from dedicated self-propelled scraper models. While the tractor can be used with any tow-type attachment on a given project, the pull-type scrapers allow for the freedom of sizing equipment to the job. Contractors realize cost-efficiency on the smallest to the largest projects by pulling single units or accessing up to three scrapers in tandem. Although we refer to these units as pull-type models, there is a distinction in this equipment category. A true pull-type scraper is a hitch-mounted unit, while a “towed” scraper is built with dolly wheels in front to support the front of the bowl.

“The growing market share for pull-type scrapers is made possible by tractor manufacturers who have developed features suitable for the construction industry. Scrapers are only as good as the tractors we put them on,” says Randy Rust, president of Ashland Industries, a manufacturer of both dump-style and eject-type scrapers. “The major tractor companies have really stepped up to provide contractors with high-flowing hydraulics, power shift transmissions, and most importantly greater horsepower combined with many different devices for better traction. The utilization of rubber tracks puts this horsepower down to the ground,” he says.

Rust says that over 80% of the pull-type scraper market is east of the Rocky Mountains, with a hotbed of activity in softer soil conditions, such as along the Mississippi River. “Tractor/scrapers are not suitable for abrasive, rocky soil conditions. Rocks larger than 8 to 10 inches have a tendency to tear up tractor tires. Some contractors will use heavy counterweights to hold the units down, but if you’re doing a lot of spinning in rock or sharp shale, you’re going to cut the tires,” he says.

Is Bigger Better?
Most pull-type scrapers range from 7-cubic-yard to 18-cubic-yard volumes. But recently, 24- to 31-cubic-yard units have been introduced to the market. But is bigger better? “The misconception in the market is that contractors think they may be better served by using just one large 31-yard unit,” says Rust. “That can be a problem as most tractor manufacturers give us parameters as to how much weight and capacity can be placed on the tractor by the lead scraper. Currently, lead scrapers should not exceed a 20-yard capacity and 21,000 pounds of transfer weight on the backs of most tractors. To safely gain greater capacity, the contractor should consider pulling two 17- to 20-yard scrapers in tandem,” he says.

Photo: Miskin

Pull-type scrapers often work better in sandy soils than motor scrapers.

Rust cautions contractors to always be aware of the maximum capacity and transfer weight that a pull-type scraper can place on a given tractor. “Consult with your equipment dealer to make sure you are within warrantable requirements,” he says.

“Tractor manufacturers are coming out with heavier and faster units, so I’m not sure where yardage capacity is going to stop,” says James Hausner, vice president of scraper manufacturer Reynolds International. “I think you can get too heavy on yardage capacity, what with the flotation that we have on these scrapers. Yes, we hear contractors want to go with 20- to 26-yard units, but consider that you have to maneuver them through mud and soft ground, so you have to have a power unit that will do that. For me, it looks like 17- to 18-yard units are the upper limit. In the over-20-yard category, I see very few scrapers selling,” he says.

Robin Pett, general manager for Bell Equipment North America, agrees that bigger isn’t necessarily better. Among its many offers, Bell Equipment manufactures construction tractors and articulated dump trucks. “We don’t believe that today’s scraper pans are built to handle larger-horsepower tractors than those that are currently on the market. Until the industry comes out with a more substantially robust pan, we don’t see the advantage of coming out with more and more horsepower,” says Pett. Bell Equipment 422-horsepower wheeled machines will pull a 31-yard scraper, with track-mounted units being limited to 28-yard pans, he says. “For us to come out with a 500-horsepower tractor is impractical. In theory, you could pull a 40-cubic-yard pan with that. But to pull a 31-yard scraper with a 500-horsepower tractor, I think that the pan would just fall apart. So to come out with a stronger, bigger tractor, you’re going to be mismatched with too much horsepower for the pan,” he says.

Haul More Using Less Fuel
“Working in tandem, our tractors and scrapers tackle the biggest earthmoving jobs, and they use less fuel while doing it. Unlike self-propelled models, you don’t need a push dozer for loading,” says Kent Stickler, product consultant with John Deere Construction & Forestry Co. Deere offers carry-all and fixed-blade ejector scrapers combined with scraper-ready, four-wheel-drive tractors. Heaped capacities range from 15 to 18.3 yards, with a total of up to 36 cubic yards if used in tandem. A recent test conducted by the company indicated that a John Deere tractor/scraper operation resulted in moving more than 37% more material per cycle, using 32% less fuel, than that of a comparable-size self-propelled unit.

Photo: Miskin

A tractor and single pull-type scraper combination is able to move dirt down to approximately 100-foot hauls.

To further improve efficiency, John Deere has recently introduced AutoLoad, its automatic scraper control system, which is compatible with John Deere 9020 Series Wheel Tractors. “This industry-exclusive system automates the scraper’s hydraulic lift functions during the loading cycle. Once activated, it automatically adjusts the scraper’s cutting edge height according to draft loads of the equipment without operator intervention,” says Greg Laudick, division manager of marketing for John Deere Waterloo Works.

Flexible, Lower-Cost Operation
In an issue of John Deere’s Construction & Forestry Review (November 2004), an Illinois-based contractor sums up the flexible, lower-cost operation of five John Deere 1050C crawler tractors, each with a 20-cubic-yard dolly-wheeled scraper in tow. The project entailed excavating material from a retention pond and hauling it 1,800 feet to a fill site. Mike Gabel, superintendent for Ryan Inc. Central, says, “We use these scrapers for their ability to work in very soft ground. Self-propelled scrapers would get stuck in these wet and soft conditions. We can use the pull-pans to haul earth both ways. Also, we can load out unstable material from one area, haul to the deep fill, and pick up topsoil or compactable material and haul it back. If we choose, we can top-load the pull-type pans with an excavator to haul one way or both ways. And these pull-pans can load themselves or be push-loaded.”

Gabel explains that if they used articulated trucks, they would need a loading tool at both ends of the haul. “The tractor/scraper teams make up a lower-cost system than that of an articulated dump truck and excavator. These pull-pans give us a much more versatile system that can be used for multiple applications. That’s how we justify them,” he says.

Bill Nordsiek, sales and marketing manager for scraper manufacturer E-Ject Systems LC, also stresses versatility. “A truck is a truck, but the pull-type scraper is a scraper and a truck, as you can top-load them with excavators. So it has more utility. When used in tandem, that’s where the economy comes in with the use of pull-type scrapers. For example, using two of our 17-yard scrapers will deliver a payload slightly higher than what you would get using a self-propelled scraper,” he says, adding that a study conducted by his company revealed that contractors could realize up to a 38% cost-per-yard savings by using tractor/scrapers over self-propelled units.

Photo: Ashland

Pull scrapers are designed to float over soft conditions underfoot better than self-propelled units.

Much flexibility can be gained from the use of compact scrapers. Hoelscher Commercial Products manufactures various compact scraper models, which are paired with 25- to 50-horsepower tractors. “Compact scrapers are able to operate in areas inaccessible to self-propelled units, doing jobs that previously had been done with skid-steer loaders, or even manually,” says Darrel Hoelscher, CEO of Hoelscher Commercial Products. “Contractors have not been exposed to the benefits of compact scrapers. They are only familiar with the lightly built, three-point equipment that has been on the market. Units available today are serious earthmoving machines. A heavily built pull-type scraper can get a site to grade quicker and faster than a skid-steer or other type of front-end loader. Additionally, pull-type equipment is heavier and offers more stability than mounted tools. Due to this inherent stability and accuracy, operator workload is reduced and productivity is increased,” he says.

Contractor James Hall, owner of LaGrange, KY–based Hall Enterprises, uses a Hoelscher RB-R (rolling box) scraper combined with his 50-horsepower tractor. With the unit, he can rip, level, and pack all in one pass. “It’s been the most used piece of equipment we have for a smooth compacted grade. It works well in hard, rocky dirt—taking it up, moving it, and then compacting it. By adding extra ballast, we can even move aggregate around and compact it. I can grade within an inch with this tool without a laser. It gives you the versatility that you don’t get from a mounted blade or a motor grader,” says Hall.

Reduce Mobilization Costs
Excavation contractor Danny Dumey stresses why the market is ripe for pull-type scrapers. “A new standard is being written right now in earthmoving. With the current fuel cost situation, I don’t think there is a contractor out there who is not reevaluating the way they do business.”

Photo: Hoelscher

Compact scrapers can be used in areas as narrow as 5 feet.

Dumey is also the founder of Double D Mfg. LLC, which manufactures pull-type leveling scrapers and compaction rollers designed to increase the production of his larger scrapers. The business grew from scrapers he designed himself to reduce costs within his own earthmoving operations. His contracting fleet includes no fewer than 20 agricultural tractors—most of them pulling two or three 18-cubic-yard scraper pans depending on distance of haul. He likes their efficient performance but also likes their lower mobilization cost. “We just moved our fleet (in 15 hours) from St. Louis to Memphis. We drove them right down the highway. If I had to haul all my equipment by truck, it would have been a two-week episode. If you have a mobilization cost of $200,000 and your competitor only has $50,000, he has a $150,000 advantage. That’s a big factor in getting the job,” says Dumey. “Everyone is saying, ‘How cheap can I move material, and how can I do that right now so that I can stay in business?’ Based on economics and remaining competitive, contractors who were laughing at agricultural tractors five years ago now own them,” he says.

Construction-industry writer Carol Wasson owns JCL Marketing & Communications Inc

GEC - November/December 2006

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