Site clearing can demand a lot of niche or application-specific equipment. Most equipment that serves in those applications has application-specific features, which makes it great at its intended use, but not very versatile.
However, a few machines show some versatility. The most versatile (and one of the most popular) machines on a site clearing project are the tracked excavators.
The excavator is one of the most versatile machines no matter the application. With its ability to equip dozens of different types of attachments, its reach potential, and its travel capability, it can do a lot.
On-site clearing projects, excavators are often equipped with a brush cutter, mulching attachment, a forestry head, a mower, a grapple, or a bucket (such as a general purpose bucket, a severe-duty bucket, or a screening bucket). The excavators are used for cutting brush, moving debris, digging out rocks, general excavation, material separation, loading trucks or processors, and more. Occasionally, excavators are equipped with harvesting heads or other forestry application attachments, if the site clearing project also includes harvesting of the trees.
Skid steers are arguably as versatile as the excavator and they can be found on a lot of site clearing projects; they are on almost every kind of job site. They too can be equipped with dozens of kinds of attachments and provide speed and versatility at a low cost. They are often equipped with brush cutters, mulching attachments, tree spades, stump grinders, V-shears, grapples, or rakes. They are often used to cut brush or even fell small trees, for stump removal, and to move debris from the removal area to another area of the job site either for burning or to feed on-site processing equipment or to load trucks.
If the terrain is really wet or soft, a compact track loader will often be used instead of a skid steer loader.
Although attachments make skid steer loaders and excavators more versatile, they, however, are usually designed for very specific purposes; being excellent at one or two applications is their strength. A bucket is very good in excavating applications and is sometimes used in lifting and craning applications but it can’t cut, compact, or smash. Likewise, a breaker isn’t very useful at anything but breaking rock, and a brush cutter could be used to mow grass and cut shrubs but not for much else.
The next most versatile machine on site clearing projects is the dozer; it has the pushing power to push over almost anything in its way—and not just above the ground, but also below ground, so it can help remove roots and rocks. It’s used for creating rights of way (ROWs), grading, tearing up the soil with its ripper, grubbing stumps, and more.
“A lot of people prefer to use John Deere crawlers for land clearing projects, because of their versatility,” says Nathan Horstman, crawler dozer marketing manager, John Deere Construction & Forestry. “Deere crawlers can be equipped with limb risers, window screens, rear rippers, and winches right from our factory, which makes them useful in land clearing operations. They’re also very flexible. For example, if the machine is going into soft/slippery/wet conditions, it can be equipped with LGP—low ground pressure—tracks for better flotation. If it’s going into a rocky or a hard pack material, the machine can be equipped with a standard track or XLT configuration.”
Horstman continues, “A root rake is often added to the dozer to help clear vegetation and roots. Equipped with a V-shear blade or clearing blade, it can be used to fell trees and remove stumps. The dozer can then be used to push the vegetation into a pile for hauling, processing, or burning. A feature called live power turn allows full power to both tracks when making a turn. This is really useful when grubbing a stump. Simply push [the blade] into [the stump] and then turn out to pull the stump apart.”
All John Deere dozers have a dual hydrostatic transmission with variable displacement pumps and motors. “This is great for land clearing,” says Horstman. The technology allows for infinite speed control. “This means that the operator sets the desired top speed and the machine takes care of the rest. It allows for a lot of flexibility to match ground speed to specific applications or terrain conditions. And, when under a heavier load, the machine will pull down and not stall, unlike dozers with conventional transmissions.
And, since site clearing operations are rarely on an even grade, site clearing equipment that offers technologies to mitigate the effects of site clearing on slopes offer a big advantage over other machines. John Deere dozers come equipped with a feature called hill hold; it automatically applies the parking brake to keep the machine from creeping when working on a slope.” Winches also aid in steep slope site clearing. And, when traveling down slopes, machines tend to accelerate, meaning the operator needs to counteract the action by braking. “John Deere’s dynamic braking allows the machine to maintain constant ground speed for better, more predictable operation.”
Site clearing includes several applications that aren’t always present on each site-clearing project, but some of the most popular site clearing operations include harvesting, brush cutting, and processing.
Harvesting
Harvesting is in many ways a very different activity from other site clearing operations, and it demands different equipment and expertise. Logs destined for plywood, lumber, and pulp each have their own price and specifications for length, diameter, and defects. For these reasons, the work is often performed by harvesting contractors instead of by site clearing contractors.
Common equipment found on harvesting projects include harvesters, feller bunchers, forwarders, skidders, and loaders, as well as trucks for hauling the trees to a mill. Harvesters cut down the trees, delimb them, and buck them (turning the fallen tree into logs). Feller bunchers cut down several trees at once. Forwarders and skidders move the fallen trees to the loader, and the loader loads the trucks.
The John Deere 3756G Forestry Swing Machine, which was released in 2016, was recently recognized with a 2017 GOOD DESIGN Award, presented out by the Chicago Athenaeum Museum of Architecture and Design. (A swing machine is sometimes referred to as a log loader; it is similar in appearance to a harvester, but its purpose is to load logs.) The award acknowledges the most innovative and cutting-edge industrial, product, and graphic designs produced around the globe. The panel of distinguished design professionals that selected the 3756G, called it a “rugged, efficient new player” that is “all about” improving productivity and uptime in some of the toughest working conditions possible. The machine combines “strong proportion, active stance, and bold graphics” to make it an industry success.
New John Deere forestry machines are available with John Deere ForestSight. The technology gives remote access to fleet location, fleet utilization, and diagnostic data via JDLink; it analyzes data from JDLink, fluid analysis, and machine inspections and then emails the dealer and customer with recommended solutions to avoid costly downtime (called Machine Health Prognostics) and it enables dealers to read and reset diagnostic trouble codes, record machine performance data, and even update software without a technician visit to the job site.
However, the technologies that John Deere forestry equipment utilizes—fleet monitoring and machine health—aren’t industry specific and are popular in general construction.
Although Tigercat Industries has patented a technology that is industry specific, it addresses the issue of steep slope logging. The company has developed a leveling system that provides exceptional stability in steep slope applications. The system includes massive cylinders, thick steel, and tapered roller bearings.
Since harvesters and feller bunchers have a carrier structure similar to excavators and the ability to change the attachment, those machines can be equipped with different attachments, such as grapple or brush cutter, but these tasks are often performed by other equipment since any essential brush cutting and debris removal get completed prior to harvesting.
Brush Cutting
“Classic approaches to land clearing include labor (chainsaws crews), chemicals, prescribed burns, or mechanical means,” says Pierre-Luc Boisvert, marketing agent, DENIS CIMAF. “Each of the methods has their pros and cons, but the mechanized removal of the vegetation, also known as forestry mulching, is the safest, most productive, and eco-friendly way to do land clearing.”
Brush cutting usually involves a mulching attachment, whether that’s attached to an excavator, skid steer loader, farm tractor, or a dedicated mulcher, such as the line of Fecon FTX line of mulching tractors.
Fecon’s line of compact tractors with mulching heads can do fence line work, detail work, and can handle some of the heavier grasses. Low ground pressure and even weight distribution make the FTX128L an ideal solution in soft ground conditions. For pavement crossing, working in soft conditions and low ground disturbance, the FTX128R comes equipped with rubber.
Fecon’s mid-sized mulchers include the FTX250 and FTX290. The FTX250 is purpose-built for particularly difficult applications; its unique undercarriage keeps the track on the ground and reduces bridging, thereby providing better contour-following characteristics and a better ride quality. The FTX290 provides smooth control response and good operator visibility of the mulching head and tracks for working in tight areas or in dense forest.
For large-scale projects where the volume of work is the key factor, the larger tracked mulching tractors will yield both a workable finish and the acres-per-day for maximum productivity. The FTX400LGP is large enough to power the Fecon SH500 stump grinder, and the FTX600 features twin hydraulic circuits to the work equipment to power the BH300 Bull Hog mulching head for aggressive cutting performance.
It is important to understand the capabilities and relative advantages of the different tools available. Mel Peterson of Diamond Mowers points out that rotary mowers have proven to be an affordable, widely-adopted solution. The blades are inexpensive and long lasting, and they can cut brush up to 10 inches thick while still being effective as a grass mower. Among the reasons for their popularity with those who already own an excavator is their ability to mulch material up to 4 inches thick and to run on excavators with a lower hydraulic flow. Peterson points out that forestry mulchers are dedicated brush-mulching tools specifically designed for fast removal of large material and require a very strong excavator. The higher purchase price and cost of operation means they are more commonly used as tools for contractors, municipalities, or very large landowners.
The Diamond Mowers Rotary Mower effectively cuts grass and brush up to 10 inches in diameter, whereas the Diamond Mowers 48-inch Forestry Mulcher is a dedicated brush-mulching tool designed for very fast removal of large material and it is capable of cutting material up to 12 inches in diameter.
“So, the forestry mulcher cuts small-diameter and large-diameter brush better than the rotary mower, but the mower mows grass better than the mulcher,” says Mel Peterson. “Therefore, if you have a lot of large-diameter brush, you should use the forestry mulcher. You could use a rotary mower on the same material (up to 10 inches) but it would take more time.”
Next, consider the carrier. “What machines do you have in your fleet? The forestry mulcher uses a lot of hydraulic flow and therefore needs a more powerful (and probably larger and more expensive) excavator to operate it, whereas the rotary mower uses much less hydraulic flow. If you need to cut large-diameter brush quickly and you already have an excavator that can handle the Diamond Mowers 48-inch Forestry Mulcher, excellent. If you don’t, are you willing to purchase or rent another machine? If not, you may want to choose the rotary mower.”
Peterson continues, “When matching either a rotary mower or forestry mulcher to your excavator, it is not only important to consider hydraulic flow, but also the over-the-side carrying capacity. This is the weight carrying capacity of an excavator when it is working over the side of the tracks. This is the least stable position, so it is important to consider when sizing a head to an excavator.”
In this case, the Diamond Mowers Rotary Mower has an over-the-side carrying capacity of 1,300 pounds and the Diamond Mowers 48-inch Forestry Mulcher has an over-the-side carrying capacity of only 850 pounds. Although the Diamond Mowers 48-inch Forestry Mulcher has higher hydraulic flow, it weighs less than the Diamond Mowers Rotary Mower.
“Next, do you want to create a usable or saleable product from the cuttings? Rotary mowers and forestry mulchers produce different products. The Diamond Mowers Rotary Mower will produce 3 to 4 inches of stringy mulched material. It is recommended for keeper-trees (firewood, sawmills, and lumber). The Diamond Mowers 48-inch Forestry Mulcher, on the other hand, produces 2-inch mulched material, and it is great at cleaning and processing all material on site,” says Peterson.
Finally, consider the price. The starting price of a forestry mulcher is about 50% more than the starting price of a rotary mower. “How many hours will you put on the attachment in a year?” asks Peterson. “If you are only using it occasionally, then perhaps you should select the rotary mower, and you can remove any larger-diameter material manually. If you will be running the attachment a lot, perhaps you want a forestry mulcher.”
One of the latest trends in brush cutting is using knives instead of carbide teeth.
DENIS CIMAF has been producing mulching attachments with knives for 20 years. “Our late president, Laurent Denis, used to answer this question with another question. ‘When it’s time to cut a tree down, would you rather use the blade or the back-end of the ax?’ This was, of course, a jab at using hammers on a mulching attachment like some competitors do,” says Boisvert.
Loftness recently published a case study on the matter. “The vegetation management industry has seen some recent changes when it comes to the use of mulching heads on skid steers, excavators, and other power units,” says Bill Schafer, product development supervisor, Loftness. “And the design of mulching heads has also changed to better accommodate operators, helping them become more productive and create a better finish.”
Traditionally, carbide cutting teeth were the most popular tooth option for mulching heads. “That’s because they’re highly durable, cost-effective, and virtually maintenance free. As a result, many mulching heads were once optimized for the use of carbide teeth,” says Schaefer. “Lately, however, the industry has seen a shift, and many more vegetation management professionals want to use knives on their mulching heads. Although they need to be sharpened regularly and have a heightened risk of damage when striking rocks and other foreign objects, the knives offer unmatched aggressiveness that can provide a big productivity boost on the job. Also, the use of sharpened knives naturally results in a finer particle size, providing a more attractive finished product for the customer.”
Manufacturers have responded to the greater demand for knives with newer mulching head rotor designs that better accommodate the performance of knives. “Because the knives are so much more aggressive than carbide teeth, some of the newer rotors are larger in diameter and often include some type of limiter to keep the knives from biting into too much material at one time. These limiters are intended to feed the proper amount of material into the knives for maximum efficiency, as well as produce ideal particle sizes,” says Schaefer.
Processing
When wood from site clearing operations isn’t harvested, hauled away, or burned, it’s processed on site. Processing can include wood waste, green waste, soil remediation, and rock crushing. Equipment used for processing includes chippers, horizontal and tub grinders, trommel screens, and crushers (or screening buckets and crushing buckets for smaller operations).
“Most of that equipment would be tracked based,” says Jay Sarver, commercial business manager, Vermeer. The processing side of site clearing is the area over which Vermeer has expertise. They manufacture horizontal grinders for both track and trailer platforms, tub grinders with on-board loaders, a line of whole tree chippers for both track and trailer platforms, forestry mulchers, and trommel screens. “If the contractor is grubbing the stumps—taking them out of the ground—in some cases, they will shear that stump up or bust that stump up and will run it through a trommel screen to get the dirt out of it; by removing the dirt, this puts less wear on the grinder.”
Last year, the company released an HG6800TX horizontal grinder that is designed for whole tree processing. “The HG6800TX features an infeed design with a low sidewall profile that helps reduce restriction of the canopy side (top side) of the tree, helps the tree engage the live floor to be processed through the machine, and increases operator visibility,” says Sarver.
An alternative to horizontal grinders is tub grinders. “Tub grinders are used in land clearing sites, probably more often in commercial land clearing sites, and usually for processing stumps and large-diameter trunks. Tub grinders are better at processing stumps, but there’s more prep work when processing whole trees because the material lengths have to be capped at 12 feet in order to process.”
Sometimes, wood chips created by processing wood debris can be left on site and mixed in with the soil. To aid in the distribution of the chips, Vermeer has recently added a broadcast feature on the company’s WC2500TX whole tree chipper; the machine’s discharge chute oscillates 45 degrees from center in either direction to spread the chips.
Bandit offers a product line of whole tree chippers and The Beast horizontal grinders with both towable and self-propelled track options to fit for any site clearing operation. Bandit’s whole tree chippers available from disc or drum-style with capacities ranging from 18 inches to 36 inches and throw chips with tremendous velocity, fully packing the largest trailers without the need for power-robbing auxiliary chip throwers. Even outfitted with a dedicated microchip drum producing 1/4-inch microchips, Bandit whole tree chippers fill trailers faster while producing a better end product. The Beast provides various tooth and screen options further allowing The Beast to easily serve a variety of markets with capacities ranging from 18 inches to 45 inches.
“Bandit whole tree chippers feature the proven Slide Box Feed System which provides direct down pressure to material entering the machine,” says Paula Balhorn, advertising and project coordinator, Bandit Industries Inc. “Combined with multiple feed wheels, the feed system delivers incredible pulling, crushing, and compressing power to process large whole trees, wide forks, and limby tops with virtually no trimming required. Bandit’s whole tree chippers are equipped with a clean-feed system will increase chip yield per-load by approximately 5%. The key to The Beast’s success is its unique cutter mill. Using a spiral pattern with a series of teeth, cutter bodies, and rakers, the cutter mill processes material using a cutting/splitting action versus other recyclers that attempt to bash material through hammering and grinding. The difference is best explained like this: it’s far easier to cut down a tree with an ax than a sledgehammer.”
To increase versatility, every Bandit model can be equipped with a rugged steel track undercarriage. This feature is a must-have option for land clearing applications to travel over rough terrain not accessible by towable units. It also eliminates the need to forward or skid material; you can virtually take the chipper to the trees instead of the trees to the chipper.
The Diamond Mowers Rotary Mower effectively cuts grass and brush up to 10 inches in diameter and is well-suited to roadside maintenance.
Morbark has a broad range of equipment that can be used for site clearing operations but two of the most common are the Model 3400XT Wood Hog (high-speed grinder) and the Model 40/36NCL Track Drum Chipper (whole tree chipper). ”What sets these two units apart are their compact size along with their high-production capabilities; these self-propelled units can be operated on the most rigorous job sites,” says Michael Stanton, Morbark president.
“In a site clearing application where the primary feedstock of material is whole trees, the Model 40/36NCLT is more efficient, more productive, has lower operating costs, and significantly less capital cost compared to an equal horsepower (hp) high-speed grinder. Also, an additional advantage of the 40/36NCLT is that it can be configured to produce various size ‘chips’ ranging from 1/4-inch micro up to 7/8-inch whole tree fuel chips, which will allow contractors more options for end markets on the processed material, which in turn creates an additional revenue stream. Generally, chips bring a higher yield than grindings from a clearing job.”
When it comes to selecting the proper piece of equipment, Canton has this advice: “The contractor must understand what their biggest needs are and how that piece of equipment fits into their current operation. If their biggest demand is production, then a larger machine should be considered, but at the same time they must make sure their support equipment (harvesting equipment, loaders, and trucks) can keep up with the production rates the large wood processing machine can produce.”
Conclusion Site clearing operations are a lot like other operations that employ heavy equipment. A few versatile machines, such as excavators and loaders, with their ability to be outfitted with many kinds of attachments, have found a place in just about every operation that uses heavy equipment. Yet site clearing operations, such as many other operations featuring heavy equipment, employ very specific machines that aren’t found in any other or many other applications.