Grading and Excavation Contractor

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Grinders meet the growing demand for working with materials recycled at the job site.

By Peter Hildebrandt

Work on a construction job site yields a mess, plain and simple. Past years saw that stuff hauled off to landfills or burned onsite, filling the air for miles around with thick smoke. But those scenarios are swiftly becoming a thing of the past. Now demands for different options have grown for processing waste materials onsite. New air-quality regulations and landfill requirements oblige contractors, operators, and manufacturers to continue working to keep up with all the change. But despite all the different conditions, needs, and changes out there, the list of options also continues to grow.

To Tub, or Not to Tub
Vermeer Manufacturing of Pella, IA, designs its equipment to process organic materials, including whole trees, root balls, branches, or canopy debris. Typically, grinding is done before material is either blended back into the site for erosion control or, if it is later in the development period, used in decorative landscaping.

“The last thing we want to see is for that end product to head for the landfill,” says Mark Rieckhoff, environmental segment manager, tree products. “Such material is filling up our landfills, plus customers save on fees paid to the landfill to take work site debris. Anything we can do to stop this cycle is better for everybody.”

Rieckhoff sees differences regionally in various approaches to this issue. In past years, he points out, the equipment his company has manufactured since 1948 would be taken to a site, and trees would be completely leveled in clear-cutting operations.

“Now things usually go in a more selective harvest fashion,” says Rieckhoff. “It’s almost like a so-called selective harvest logging operation. I was on land-clearing jobs in northern Indiana and southern Michigan just last week, where they wanted to leave as many trees behind as possible so that when these new houses go up it looks like it’s an established neighborhood—not just a bunch of houses out on the grass. It adds to the property value aside from being better all around for Mother Nature, decreasing greenhouse gases, and other related issues.”

Typical construction and demolition (C&D) waste is not usually left behind. If there is a solid separation, such as having all the drywall in one area, there are some applications for ground-up drywall. “We do have customers doing nothing but grinding up drywall out there. They then take the material to a drywall reprocessing facility, or they’ve found other unique uses for it.”

With 125 different products, Vermeer celebrates its 60th birthday in 2008. The company services the tree-care or woodwaste reduction industries with brush chippers, stump cutters, tree spates, and horizontal tub grinders, not to mention a new line of compost turners.

Vermeer has three basic models of tub grinders with three basic chassis sizes. These can be manufactured in multiple configurations with the size increase corresponding to an increase in horsepower as well as the size of the mill opening. Likewise, with its horizontal grinders Vermeer has three chassis sizes. Tub sizes are designated 5000, 7000, and 9000; as the numbers increase so does horsepower and capacity.

Expanding Mulch Specialties
Mulch-coloring operations are possible on job sites, but usually such functions are done at a permanent location. Vermeer has coloring systems available on its horizontal grinder, which sprays the liquid dye as material enters the machine and as it departs from the machine. “This guarantees a nice, high-quality color chip or mulch,” says Rieckhoff. “At a southern Michigan job site recently visited, one of our customers had some 10 different colors of chips—from Notre Dame blue to blacks, reds, and golds—all in fulfillment of his customers’ demands. In the grinder world, that’s a distinctive customer base, and their application changes more often than most of our customers. This is because these customers will go from job to job, especially on a mobile job site. Since one contractor may want grinding done to a particular size and another a different size, our customers have got to roll with the punches and be able to accommodate their customers.

“They also must be able to do the same when it comes to different materials. We’re looking at better ways that we can work it with our customers to customize our machinery to fit their needs as well as working with them to better understand costs of operation and trimming out the fat on a job site, with the ultimate goal of making our customers more profitable.”

When it comes to its composting operations as well as with its grinders, Vermeer sees tighter regulations on roadsides as well as new developments. Standards are put in place specifying that if the soil is disturbed there must be a control program in place to avoid increased washout of the land.

“It all depends on the area of the country in which you’re located, as well as local regulations,” says Rieckhoff. “This, especially, is where we get into the area of customization.”

Vermeer has patented safety technology on its grinders for tub coverings and horizontal feed openings. These come in handy in avoiding thrown objects, a common problem with such equipment. “Without our safety material in place, material will be ejected further in most cases,” says Rieckhoff. “We’re able to take our machine into a smaller job site and work in tighter operating conditions than many of our competitors can.”

Vermeer’s duplex drum has a unique configuration of a cutting pattern that maximizes performance and also simplifies service and maintenance, according to Rieckhoff. “That’s a huge advantage for our customers in that a hammermill or duplex drum of the machine is typically the high-maintenance area. Anything the manufacturer can do to replace the hours spent in that area for an owner makes them leaps and bounds ahead of themselves in actual grinding time versus maintenance time.”

Thanks to hydraulics, the machines open easily for drum access. At that point it’s a mechanical setup for the operator or mechanic; everything’s either bolts and plates or steel plating, and everything has a dual life, whether it’s the drum skin itself, the hammers, or the cutter blocks.

“They all serve two purposes with two life cycles. Therefore, you’re getting two lives for the cost of one,” adds Rieckhoff.

Photo: HogZilla

Track grinders have grown to become nearly half of HogZilla’s business.

What to Do With Pallets
Michigan’s Watson Tree Service (WTS) uses its Vermeer equipment chiefly for processing wood, including pallets. This 30-year-old business has 525 and 7000 Vermeer grinders. WTS uses them mostly for the production of mulch in the course of its work servicing a large tree, soil, and mulch farm. For processing pallets, the company installs a chute on one end and feeds the pallets in while the material comes out on the other end. It also makes about 12 different types of mulch, including customized blends of hardwood or chips.

“We use both pieces of equipment for grinding the large logs, and both the larger and the smaller machines for woodwaste, which is colorized after we grind it up,” says Warren Watson, one of the owners of the business. Watson’s main business is residential and commercial tree service. He does some land clearing and does have some contractors wanting him to come and grind stumps and larger wood, but he has quite a bit of production on his own. The company uses its equipment mainly in-house. “But I think we’ll probably be going on the road shortly, as far as stumps and larger logs being cleared out for subdivisions,” says Watson. “We do a great deal of chipping onsite. We also bring a lot of the larger wood from a clearing operation back to our farm where we’ll grind or chip it. Every stick of product—sticks, logs, chips, or whatever—is used in our process to create our mulches. Some people leave stuff onsite because they don’t want the trucking costs; but we’ve got enough call for it. We’re a fairly good wholesale producer here in Michigan for most of the landscapers in this area.”

Motorized Attachments In Situ
Some equipment even works while excavator-mounted and not off machine hydraulics. Sneller Machine supplies such machinery. The engine attaches directly to a machine’s arm. This comes in handy, especially for stump grinding, as excavator mounting means the tool for doing the work may be taken as deep as necessary to chase any especially deep roots.

The hauling away of tub-grinding material is eliminated when the roots are ground onsite. “This equipment definitely has unique benefits,” says Jean Bennington, Sneller Machine business manager. “It’s also quicker and more economical. This is hard to explain to some, who may be set in their ways of tub grinding or pulling the stumps out.”

Photo: Hammel

Hammel shredders work with 95% C&D, often with contractors onsite.

Sneller’s stump grinder has been on the market some 20 years. “At first people laughed and asked, ‘Why would you want to do something like that?’” says Bennington. “Well, now because of air-quality regulations, you can’t burn—and dumps or landfill will not take the stumps. Now people understand: You simply cannot rip and pull [stumps] out of the ground, pile them up, and burn them as before. Grinding stumps in place is definitely more economical and quicker. Our other attachment, the brush-shredder, also has its own engine and is an excavator-mounted machine. This means you can just go in and clear brush and trees up to medium in size. The material can be left in place in many cases.”

Sneller Machine is coming out with a smaller stump mill, as well, for smaller excavators. The company will also be coming out with a much smaller brush shredder. This will give the company three different sizes. These will have 275- and 130-horsepower motors. This summer Sneller plans to bring out a 60-horsepower motor for use on the smaller units in the brush-shredder area. Sneller uses Cummins engines on its equipment.

Power Without Hydraulics
Ron Hodous and Mike Heiss, owners of H&H Land Clearing in northeastern Ohio, use the Sneller Machine equipment for clearing land for housing and commercial development projects. What they like best is the increased power available. This means the hydraulics from the main machine do not have to be used.

“Having its own engine or power unit, a Cummins 275 engine really eats the stumps up,” says Hodous. “Also, by attaching this to an excavator unit, you’re able to sit in one place and still reach all the stumps in one area. You simply swing and hit—making it especially good in muddy conditions. In this business you need speed. Stumps must be ground fast.

“They’ve got their technology down. These are not blades but rotors, and [they do] a lot cleaner job. They may [cost] a little more money, but you pay for what you get. When we’re clearing 50 to 60 acres, we’ve got to move and get down fast.”

H&H sets its four pieces of Sneller Machine equipment on Kobelco and Komatsu mounts. The company also has Sneller grapples, stump grinders, and shredders—at least two of everything the company manufactures—according to Hodous.

Since northeastern Ohio is a muddy area, the company uses predominantly tracked vehicles to do the work. “The folks at Sneller Machine started out as land clearers themselves,” says Hodous. “They already knew what works in that area. They have a good product. People have started to look at them. Some may not want to spend the money, but we got bigger and needed the production capabilities they’ve got. If we need parts, too, they’re right here for us.”

Nothing to Fear From This Monster
C.W. Mill Equipment Co. Inc., based in Sabetha, KS, finds its tracked HogZilla monster tub grinders extremely popular lately, according to Tim Wenger, president. From the early 1970s, the company’s background was in agriculture, specifically hay-grinding tub grinders. However, since the late ’80s, land-clearing contractors and others doing custom grinding for dirt contractors make up a substantial segment of HogZilla’s customer base.

Track grinders have grown to become nearly half of C.W. Mills’s business. Grinders on tires are easier to transport and get around on a job site in dry weather, but if heavy rains set in, operations could shut down. Tracks on the grinders help keep them up and running even in wet, boggy conditions. “If an area has an especially wet summer, tracked equipment becomes almost a necessity,” says Wenger. “Also, for doing right-of-way work, where several miles of clearing must be blazed for gas lines or utilities, roads don’t have to be built. A track grinder and excavator can simply be walked in through the woods, and grinding can be done much quicker and cheaper.”

Wenger knows land-clearing contractors who have also had to get into the mulch business to get rid of the wood chips, as well as those in the wood chip business who’ve gotten into the land-clearing business. “In general, I think the clearing contractors would prefer not to be in the mulch business, whereas the mulch folks see it as extra revenue. It depends upon the nature of the job as to whether material is kept onsite for erosion control. Some customers place wood chips into giant panty hose–like socks to make ‘silt fences’ for erosion control.”

Tire grinding is another area of growth for HogZilla. “With over 250 million tires disposed of each year, many are ground for fuel and the metal recycled,” Wenger says. “Ground tires are stored in a monofill separated from the rest of the trash. The idea is that when the technology is developed, the heat energy can be used. It’s kind of like stockpiling oil reserves. The grinder reduces volume by approximately eight to one.

“It seems to me more and more dirt contractors are getting into the grinding business just so they have more control over their own destiny in not having to wait for an available grinding contractor—something which can take days or weeks. Everybody wants the grinding done yesterday because no one can move dirt until the trees are gone. Much of the time, clearing and contractor folks can never be off the job fast enough.”

Storm cleanup is another use for HogZilla grinders. “There was a big ice storm in Springfield, Missouri, last winter, and we were getting phone calls from tree companies,” Wenger says. “Everyone wanted to get in on the action, but the bid required grinders, often specifying 1,000 horsepower for maximum production. The calls ran the gamut from customers who already had grinders to those who didn’t even know what one looked like.”

Wenger sees the push to use all the energy possible from wood chips and waste as a driver for his grinders. Also, the regulations and even lawsuits involved with burning of waste material can be another driving factor. “Contractors who thought they were out in the boonies when they burned materials have had auto dealerships a quarter-mile away come to them with claims from embers burning holes in the paint on their new cars. Now they want tens of thousands of dollars for damages.”

Tracks to the Rescue
Peterson Pacific Corp. manufactures horizontal grinders designed for grinding virtually any type of woodwaste, including storm debris, municipal woodwaste, backyard greenwaste, pallets from manufacturing waste, and C&D wastes. The company’s equipment, though portable, features a loader or an excavator.

“Because our equipment is mobile, we find great acceptance of it in the land-clearing business,” says Dave Benton, marketing manager.

Peterson Pacific builds machines on rubber tires and tracks alike, with tracks growing in popularity, according to Benton. “The demand continues to shift to where that has a slight lead in terms of numbers of machines we manufacture. We didn’t quite anticipate this, but the larger the machine is and the more material it can process, the more beneficial it is to have that machine on tracks. We originally thought there’d be more of a demand for mobility off-road instead for traversing the woods.”

Benton finds much of the company’s machinery is being used in central lots, where material is brought to the machine and stockpiled. When the operator starts in the morning, he typically positions the machine nearest the debris pile. But for a 1,000-horsepower machine, it doesn’t take long before the supply pile’s been exhausted.

“If the machine’s on tracks, a button on the remote can be pressed, and, effectively, with one operator, two pieces of equipment can be run as the grinder’s moved closer to the pile,” says Benton. “Keeping throughput at the maximum amount with equipment this size running all the time is crucial to profitability.”

Peterson’s biggest tracked machine weighs 103,000 pounds. Instant maneuverability has become a big issue, despite the size. A customer in northern Washington had cleared the land for a new subdivision, placing the debris and logs in piles arranged like a checkerboard.

One of Peterson’s rubber-tired grinders was brought in, and a dolly with a cable was placed in the front. As soon as one pile of debris was exhausted, the operator reached down on the ground without even shutting his machine off, grabbed the loop hooked to the dolly, and drove his excavator to the next pile, dragging the grinder behind him.

“I thought that was an innovative solution to the transportation issue,” adds Benton. “This shows how much it means to keep machinery running at all times. But the majority of our customers are using these grinders for this same debris material, and it’s not necessarily for use on that site; it’s actually a value-added material when it’s ground up, often trucked offsite to be used elsewhere. Rarely is it ground up and used as a mulch directly onsite.”

Some of Peterson’s customers are grinding material for use directly onsite when it comes to landfills. In that case the grinding is done to reduce bulk or volume. Aside from better compaction, material is also now more biodegradable due to greater surface area.

Peterson also manufactures whole-tree chippers used for producing pulpwood chips for the paper industry, with the largest of these having the ability to take an entire tree and reduce it to chips with no other processing or handling steps, such as debarking. The company’s machines may also be modified for grinding up asphalt shingles.

“Unfortunately there are not a lot of applications for reuse or recycling of that material,” says Benton. “The largest use is grinding the material up for reuse in new shingle, followed by another fairly large use, adding the waste to hot-asphalt road mix for use in roadbed construction. We don’t have a lot of customers doing this now, but it is a growing area, and it is a waste material needing a place to go besides a landfill. It’s great anytime a reuse can be found.

“We’ve always been known for our durability and toughness. We hear this from both customers and our competitors. During the last few years, we’ve spent an extensive amount of time on improving the ability of our machines to protect them in the unexpected event of ungrindable material getting into the feedstock.

“Recently, one of our Los Angeles customers had a 200-pound chunk of tool steel—a well-drilling coupler buried in greenwaste—go into the grinder. When it hit, everything did what it’s designed to do, breaking down components of less-expensive areas to avoid much higher costs in repair through a latching mechanism in our grinding chamber, allowing for a trap door to open up and eject the material before it does more damage to the grinding chamber.”

Work on Rights of Way
Carl Greenlund, president of Pacific Hog in Yamhill, OR, is a general contractor doing mainly grinding work. He uses 4710 and 7400 Peterson grinders for his land-development work, grinding independently in the foothills of Oregon’s Coast Range. His customers call him to rent his equipment for a day of use or more.

“We use the 4710 on tracks quite a bit,” says Greenlund. “It’s very portable and useful for mid-sized trees. We can get into a lot of job sites and move around with that. We’ve had our 7400 since 2000, and it’s a 1,000-horsepower machine. We also grind old plants and other materials that nurseries discard and compost them. We also have a contract with the local garbage company where we grind greenwaste for composting as well as woodwaste, such as pallets and boards.”

Sometimes Pacific Hog will work on road rights of way, often using the 4710. The company’s larger equipment requires reasonably good roads so that it can be towed to a job site.

Photo: Vermeer

Vermeer has patented safety technology on its horizontal grinders.

In a recent project, installing a road to a housing development in Yamhill, the debris at the end of the land was ground up and spread on the bank at the edge of a field for erosion control, explains Greenlund.

“There aren’t lots of people doing what I do—working strictly with grinders. Most operators have their own yards and their own process. They’ll do a little bit of grinding on the side. I don’t have my own yard and am fundamentally a mobile contractor. On a recent project for an area farmer, we discovered he’ll be using the mulch produced around the base of his many blueberry bushes.”

Getting to the Bigger Stuff
Hammel New York LLC has shredders that work with 95% C&D waste in transfer stations and for demolition contractors, taking the machines to demolition sites. Hammel tries to recycle as much as possible, and the rest of the material goes through the shredder and then to a landfill. When one of the company’s machines is mobile or track-mounted, it can be used to pre-shred trees, stumps, or related material much more economically, according to Gert Semler, owner of the Holtsville, NY–based company.

“Our machinery operates at speeds allowing it to react to damaging objects better than many of the others,” says Semler. “But one of the beauties of this is that any rocks, steels, or anything that badly damages high-speed grinders will not distress us. If such a point is reached with the hydraulic system, the mill will reverse automatically so that you’re not hurting it. You simply rearrange things and try to shred it once again.”

The Hammel equipment comes in four different models: 450, 750, 850, and 950. “I tell my customers to use their common sense,” says Semler. “If you see a huge slab of concrete 8 feet long and 2 feet thick, don’t throw it into the machine. But if something is hidden and is of manageable size, it goes easily through the machine.

“I like to say we shred the kitchen sink—and the bathtub and even cars in our 850 and larger machines if there is such use for them. We often do that for demo purposes, engine and rims still on—everything. One beauty of our grinders running at a bit slower speeds to handle such materials is that the safety area around the machine is kept down to 50 feet. You’re actually safe at 30 feet, but officially it is 50 feet. The motor runs at 40 revolutions per minute or slower; it can’t throw anything out very far.”

The company’s rock-crushing machinery is dual-shaft, slow-speed mill, and high-torque. It easily handles earth, clay, and rocks. Hammel New York started out six years ago, focusing completely on the C&D market in the beginning. “But now we are spreading out more and more to tree people, volume-reduction of wood at landfills, and shredded material, perfect for road construction in the building up of slopes,” says Semler. “Our grinders can handle reinforced concrete. They are the primary grinders for the coarse product. We can even do concrete railroad ties containing rebar.”

The company’s rock crusher was developed some three years ago, according to Semler. When there is a need to install a sewer line along a road, earth-and-rock mix is removed and run through a crusher. That product, less than 6 inches in diameter, is refilled around the new piping.

Hammel’s smaller machines, the 450 and 750, are built and available in rolloff models that go on the back of a regular dump truck instead of the container. Bigger machines are track-mounted, as are the smaller ones if specified.

It’s great to have a work site where unneeded materials have found a useful place, whether it’s on the ground for erosion control, at the recycling center, or sent off for mulch.

Breaking Up Stumps—Prior to Grinding
Hammersmith Manufacturing Inc. of Horton, KS, has come up with a way to make stump grinders last longer, reducing fuel costs, man-hours, and maintenance costs. An attachment mounted on excavators is designed to break up tree stumps and logs before grinding them. The new Stump Shear product line has been on the market for a year now. Ryan Goyer, marketing manager for Hammersmith’s Vail Products Inc., says that because of the expense of grinders there is a clear incentive to protect them. In such regions as the northeastern United States, rocks and hard clay packed inside stumps can cause havoc for a grinder.

Goyer says the Stump Shear’s 4050 and 5500 models have a patented dual-pivot design superior to the scissor shears presently used in onsite materials processing. The Stump Shears can pull tree stumps from the ground before grinding operations.

“By breaking the stumps up, you can remove the uncrushables such as rock, hard clay, or even metal posts lodged in wood,” says Goyer. “So, you save on maintenance of your grinder with our attachment. Not only that—your grinder will now have to run far fewer hours. Each time you break up a stump, it will now be processed by your grinder faster. Operators tell us that what used to take 12 hours to grind now takes only six to eight hours with one of our Stump Shear products—an incredible savings in both fuel and man-hours.”

Instead of a single pivot to break up and cut, this equipment uses a dual pivot. The stump can now be held in a clawlike fashion and easily sheared. The Stump Shear comes with its own hydraulic cylinder to operate the knife side. The excavator uses an auxiliary hydraulic line to work the Stump Shear cylinder.

The equipment has found good use in Florida, in the northeastern US (where the majority of Hammersmith’s shears are in use), and in the Pacific Northwest region, where it’s used primarily for taking debris from stumps in order to have a cleaner mulch product for sale following the grinding operation.

“Our attachment is there to make your grinder shine,” says Goyer. “As far as maintenance, my only suggestion is to keep the equipment lubed up.”

Peter Hildebrandt specializes in science and engineering topics.

GEC - July/August 2007

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