Bulldozers first appeared around 1930 and typically have a tracked undercarriage, which distributes the machine’s weight over a larger area than do tires, producing less ground damage, in addition to providing better mobility in rough terrain. A number of companies manufacture bulldozers, including Caterpillar, Case, Komatsu, Bobcat, John Deere, New Holland, and others.
Tractors are generally used for hauling implements across a field or job site; the word “tractor” is derived from the Latin trahere, meaning “to pull.”
Very generally, tractors fall into one of several categories: two-wheel drive, two-wheel drive with front-wheel assist, four-wheel drive, and track tractors (with two or four powered tracks).
Skid-steer loaders are smaller machines, with lift arms to which a variety of attachments can be connected. Typically these are four-wheel drive vehicles, although sometimes they may have a track system. A unique aspect of many skid-steer loaders is their ability to perform zero-radius turning, making them ideal machines to use when maneuverability is required in tight quarters.
Because of these machines’ versatility and the large number of attachments that can be used with them, a number of manufacturers produce entire lines of skid-steer loaders. Caterpillar, for example, makes over half a dozen of these items.
In addition, attachments are available for nearly any purpose imaginable. CE Attachments is one of several companies that produce attachments both for erosion control and general construction applications. There is a veritable alphabet soup of attachments, from auger bits to buckets to graders to trenchers.
Silt fence installer attachments are, of course, especially relevant for sediment control projects. The Bobcat Silt Fence Installer, for example, can install thousands of feet of silt fence per hour, and can be mounted on a variety of loaders and tractors. This particular silt fence installer attachment works with 36-inch, 42-inch, and 48-inch silt fence.
Mini-excavators are frequently used on job sites as well. A number of manufacturers produce these machines, and several attachments are available, with some overlap between attachments for mini-excavators and for skid-steer loaders. The machines’ small size makes them convenient in tight spaces.
One Tough Animal
Bobcat Co. has long been a leading provider of compact construction, landscaping, and agricultural machinery. Its tagline, “One Tough Animal,” refers not only to the company’s namesake creature, but also to its goal of producing dependable, durable, rugged equipment.
Among its dozens of types of equipment, many are mainstays on job sites involving erosion and sediment control. Two recent additions are the S850 skid-steer loader and the T870 compact track loader.
The S850 is the largest skid-steer loader that Bobcat produces. With its 12-foot lift height, it is also the highest-lifting machine on the market. According to the company, the cab size has been increased 10%, while noise levels have been decreased by 60% due to its engine mounts, which decrease vibration. As with any skid-steer loader, dozens of attachments are available, such as various buckets, graders, and silt fence, sod layer, soil conditioner, and spreader attachments.
Similarly, the T870 is Bobcat’s largest compact track loader, also with a 12-foot lift height. The manufacturer touts its more powerful hydraulics, increased fuel capacity, increased reach and pushing power, and higher horsepower. As with the S850 skid-steer loader, Bobcat has worked to make the cab a more comfortable environment in the T870 machine.
Several options are available for the undercarriage in Bobcat compact track loaders. The standard solid-mount undercarriage provides sufficient traction to work in soft conditions such as sand, mud, and dirt and works well for grading operations. Cleanout holes in the undercarriage allow easy pressure-washer access.
A roller suspension option is also available, utilizing all-steel components. The rollers are suspended by high-strength steel leaf springs that minimize vibration and add to operator comfort. In addition, the steel rollers are permanently sealed and lubricated, so no greasing or adjustment is necessary.
The steel track undercarriage option is similar to tracks used on bulldozers and is especially useful in conditions where rubber or rubber-reinforced steel tracks might be damaged, such as in demolition and forestry work, or on rocky terrain. In addition to increased track life, this undercarriage option also provides increased traction and pushing force due to the increased weight of the steel track system, making this an option to consider for earthmoving operations.
In addition, Bobcat manufactures nearly a dozen mini-excavators, from a small unit with a 28-inch track to larger, more versatile machines. The company notes a number of advantages that mini-excavator users may benefit from, compared with traditional tractor loader backhoes:
- Full 360-degree rotation, versus 180 degrees for a backhoe
- Lower fuel consumption for the mini-excavators themselves, and the ability to be transported on lighter, more fuel-efficient trucks
- More flexibility in tight spaces
- Hydraulic systems that may provide more powerful digging than from larger machines
- Better visibility, since the operator sits offset relative to the boom
A large number of attachments are also available. One such attachment is the Bobcat rock bucket, helpful for preparing or clearing land. When the operator submerges the tines below the grade then raises the bucket, larger objects remain in the bucket while loose soil falls through the tines, helping separate material minimizing ground disturbance. Rock buckets come in four different sizes, ranging from a 62-inch width to 82 inches, and can be used on a variety of machines, including skid-steer loaders, compact track loaders, all-wheel steer loaders, and the Toolcat utility work machines.
“The most challenging site in middle Tennessee right now is the Interstate 840 project, running through the town of Leipers Fork,” says Chris Richey, owner of Mid TN Erosion and Sediment Control, in Nashville, TN. “There are a lot of influential people living out there. They really didn’t want the highway to go through there, so they did all they could to stop it, but finally the road was started.”
Highway 840 in Tennessee
Indeed, local property owners have protested the State Route/Interstate 840 project for much of the past decade, shutting it down for several years. Concerns included disruption to fragile waterways and Native American burial grounds, and simply the loss of property as the highway is built. One irritated property owner went so far as to display the American flag upside down in protest of the proposed thruway.
The Tennessee Department of Transportation (TDOT) addressed the issues to the extent that the project was restarted and is currently in progress, about 40 miles from Nashville. “It’s a three-year project, with one more year to go,” says Richey. “We’re doing erosion control on the project. We don’t do any of the seeding, but just do the erosion control-silt fence, tubes, and enhanced fence. It’s a project the state really watches closely.”
For this project, Richey has been using a John Deere 322 compact track loader coupled with a trencher and a smaller Toro Dingo compact utility loader. “We’ve got some rough terrain over there,” he explains, “with hills that are practically straight up and down, so there’s no clearance for any equipment until our erosion control measures are in place. So the Dingo is very useful for something very steep or very narrow.
“Caterpillar, as far as we’re concerned, makes the best trenchers, so we use a Cat trencher with our Deere 322, and it does a really good job. It seems to hold up better than the rest of them.”
Although the Deere has proved to be maneuverable, there are times that a given terrain has limited its use for Richey. “Sometimes we have to do things by hand, do all the trenching with hand tools. So that makes it a challenge.”
He also has about a half-dozen skid-steers among his equipment. “It’s hard putting in erosion control,” he adds. “There’s not a whole lot of big equipment we use other than the skid-steer, which has been a very good piece of equipment for us. It holds up well, although we’re burning up the hydraulics on it. I don’t mean literally burning them up, but when you’re trenching all the time, or landscaping, you’re using that hydraulic all the time with that trencher. But it’s done a good job for us. We use smaller machines when the area is too steep, or when the areas are just too small to get the big machines into.”
Richey comments that he is satisfied with the horsepower provided by these smaller machines: “We really are, for what we’re doing. It’s a smaller machine, and does a really good job.”
In addition to difficult terrain, the roadway project has also presented environmental challenges. “That’s the biggest concern out there. They have a lot of streams and a lot of ponds in that area, and they just do everything they can to keep the water clean out there. We even made it through that flood-the biggest flood we’ve ever had, about 16 inches of rain in two days last spring. It flooded everything, including downtown Nashville.
“TDOT is so strict that they pretty much won’t let you work December, January, and February, because those are our wet months,” he adds. “They actually shut the project down so that no sediment can leave the site. We don’t have any work going on during our wet months.”
Richey has chosen to purchase his equipment, as opposed to leasing. For the most part, maintenance has not been an issue, although he notes that he replaces tracks fairly rapidly on his track loader. “We go through tracks; maybe that’s just the way it’s going to be, because we can’t work on dirt all the time. That would be our biggest maintenance issue.
“Another issue we have, and I don’t know how you fix it, is that under the seat in the machine, there will collect dirt, dust, mud. It’s very difficult to get out of there; it builds up. You’ve got your hydraulic lines in there. Over time, you can actually get 3 or 4 inches of dirt in there. It’s a real pain to clean that out, but I don’t think there’s an easy fix to that. If there was a way to put a pan in there, you could pop it out, and all the mud and everything would just fall out, spray it clean and put it back in, that would be great. But I just don’t think it’s that easy.”
Other projects, of course, may call for other equipment, as Richey explains. “As far as bulldozers, we do streambank renovation, so we use that type of equipment because we have to create areas for the water to go along as per the plans that are provided for us, to change the streams where they are eroding or washing out badly.
“Oftentimes, we use a John Deere backhoe. We do have a John Deere bulldozer, a model 450, and we use that for streambank renovation. Skid-steers can be used on that type of job, too. We also used the skid-steers on the Interstate 840 project.”
Landscaping in the Pacific Northwest
Anderson’s Erosion Control, based in Junction City, OR, does landscaping work. “We do a lot of hydroseeding, bark blowing; we deal with all the erosion fabrics,” says Jim Anderson, a second-generation family member in the business, which services much of Oregon and southwest Washington.
“We’ve got a couple of ASV track machines. We use these quite a bit for trenching, with silt fence and the like,” he says.
The company also plans to buy a Kubota track machine. “We have done business with the local Kubota dealer for quite a few years. The decision was made because of affordability and maintenance. We wanted something we could pick up parts for at a reasonable price. We’ve been really pleased with the machines. They’re tough little machines.
“We’ve got two of the Kubota 121 mini-excavators, and we’ve got a mid-size tractor with a bucket on it. We do a majority of our trenching with the mini-excavators. We’ve found we can almost do more with those than with the trencher. We’ll place topsoil and soil conditioner with those machines, and we’ve had good luck with that.”
Anderson mentions that his mid-size tractor is a tire machine, while the two mini-excavators run on tracks. “We use the mini-excavators for roto-tilling,” he says. “We hook up a roto-tiller to it, and we’ve got a power rake attachment that makes life a little easier for fine-grading stuff. This is attached to the tractor.” For his tractor, he has a couple of other attachments available as needed-a mower and a fertilizer spreader.
For working in tight quarters, Anderson likes his mini-excavators, noting that “The mini-excavators have almost a zero turning radius.” He relies on these machines for most of his digging, grading, and placement of various materials. Maintenance issues have not been a problem, he notes. “They’ve been solid machines. We’ve had the one excavator for a couple seasons now, and just with regular maintenance, we haven’t had any major issues with it.”
As for any contractor, ease of maintenance is an important factor in Anderson’s business. “We deal with a lot of sensitive areas. You have to be careful with everything, right down to diapering your equipment, making sure that nothing is leaking. That’s the big thing with these machines-you can’t have them sitting drooling oil everywhere. In addition, with all of our projects, erosion control is a big concern. We want to avoid any erosion. And you don’t want to have oil running off from a project into a ditch.”
Asked if he prefers to buy or rent his equipment, Anderson says, “We’ve always purchased it. We’ll rent equipment when we’re in a bind, but usually if we end up having to rent something for too long, we’ll end up buying it.”
Depending on the specific project, he may use a variety of erosion and sediment control products-inlet protection devices, erosion control blankets, silt fence-and he also does a lot of composting work.
“The compost world is moving so rapidly right now; trying to keep up with the ever-changing compost products available and what people are specifying has been a challenge this season,” he says. “It’s all coming down to particle size and what’s going to work best for controlling erosion, but in my experience, there’s really no standard. Every job is different, and you try to find the product that best matches what is needed. That’s been a challenge, working with people designing these projects, to come up with a standard approach that everybody can produce, and that can work well for controlling erosion.
“For our composting work, we usually run through our blower trucks. We’ll reload those with excavators, and we’ve got a couple dump trucks we’ll load. These are multipurpose tools.”
Brackets for Erosion Control Blankets
Enviroscape ECM is a manufacturer of a variety of erosion control products and equipment. To assist in the application of erosion control blankets, the company makes two types of roller brackets.
As Enviroscape’s Mark Dietering explains, “We make a four-wheeler bracket and a three-point bracket. The four-wheeler bracket has a ball hitch on it and is pulled usually by a four-wheeler or gator. It can handle rolls up to 500 square yards. It’s a one-man operation to put a fresh roll on the bracket. A person backs up to the roll and slides the bracket into the tubes.
“The three-point bracket can handle from 4-foot- to 16-foot-wide rolls up to 1,000 square yards. A metal tube is pushed through the core of the blanket. The tractor backs up to the roll with the tube and picks it up. The three-point can also be used on a skid loader with forks.”
Dietering notes that the four-wheeler bracket can be used with either a four-wheel vehicle or a gator, or “anything with a one-and-five-eighth-inch ball,” while the best equipment for the three-point bracket is a front wheel assist tractor or a track loader.
He adds that a four-wheel vehicle can safely travel with the four-wheeler bracket and attached roll at a speed in excess of 30 miles per hour, making remote staging more convenient. In addition, he says, “Depending on the project, the brackets can lay down over an acre of erosion control blankets in a single hour.”
These brackets are best used for slopes less steep than 2:1, or in large, open areas. Typical applications include highway median projects, waterway work, and reservoir and detention pond projects.