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Once deemed a toy, these smaller machines are helping users meet excavation challenges in a big, big way. By Joseph Lynn Tilton |
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When mini-excavators first came on the American market, they didn’t get much respect. Many considered them a toy. But this machine’s reputation has grown up. Today they’re known for their ability to work in tight places yet be easy on surfaces traveled. In addition, they’re much easier on the company budget than their big brothers are. Now the mini-, or compact, excavator is used for every kind of task imaginable, including utility trenching, concrete removal, tree harvesting, repair digs, swimming pool excavation, tree transport and planting, grave digging, and even orange harvesting. "If I’ve heard it called a toy once, I’ve heard it called a toy a hundred times," remarks Mike Smith, president of IHI in Elizabethtown, KY. IHI has been in the equipment business since 1952 and entered the mini-excavation business in 1975. These machines typically retail for $20,000-$90,000. "Big ones start at about $130,000 and can go up to $500,000," he says. "The mini-excavator was developed in Japan in the mid-’70s. The first machines came to the United States in the early ’80s. I got into the mini-excavator industry in 1985, and over the years I’ve seen it evolve into a very, very productive machine," Smith observes. He points out that manufacturers took the technology from the large machines and downsized it. "As the technology changed and companies moved to different pump systems and different control valves, the mini became easier to use. Our latest pump system, for example, involves a combination of piston and gear pumps. Different pumps are responsible for different functions." Two main pumps take care of the boom arm and bucket; a third takes care of the cab swing. As a result, the operator is able to use every function at the same time and at full power. "Piston-pump technology also allows machines to use smaller engines because piston pumps need about 20% less horsepower," Smith explains. Another advantage with the mini is that it has an independent boom swing, which allows the operator to offset the boom to dig around existing utilities, buildings, walls, and so on and still have the capability with the 360° rotation to put dirt precisely where he wants it. The mini is an alternative to a rearloader, a tractor-backhoe, a skid-steer, or a trenching machine. "Ninety percent of utility digging is less than 5 feet deep," Smith notes. "You don’t need a 14-foot backhoe to do that job. The smaller machine can do the job with lower hauling costs for a truck or trailer. For the most part, you can pull a mini behind a one-ton truck, even a three-quarter-ton pickup with smaller models. There’s no need for a commercial driver’s license." Another advantage is that many models come with zero tail swing or with zero turning radius. "We’re the only manufacturer I know of that offers both zero turning and zero tail swing," Smith claims. "With a conventional excavator, when you swing the cab 45 degrees, the back of the excavator extends over the trucks, so the operator has to keep aware of objects behind him. With zero tail, the whole back never gets outside of the tracks. If you can pull the mini in an area, you can dig and turn and not have to worry about swinging into any structure." Best of all, the learning curve for a mini is minimal. "The controls are human engineered. You push the boom lever down to bring it down and pull the lever up to bring it up. Same with left and right motions. The controls are like an extension of the arm. Furthermore, minis come with both ISO and SAE operating patterns. It’s generally a matter of flicking a switch to choose which operating pattern to use." Maintenance is also much less of a problem with mini-excavators, which have a design life of 8,000-10,000 hours. They’ve been particularly popular with the rental industry because of their low maintenance and short learning curve. When asked about attachment popularity, Smith replies, "Most popular attachments include a thumb, a hydraulic demolition hammer, an auger, and a wide range of buckets." In Madison, CT, Doug Larson, owner of Colonial Stone Works, is pleased with his minis. "Right now I have a 40JX and a 70Z by IHI. I had a midsize 28 from IHI before I got my first mini two years ago. When they offered me a machine with zero tail swing, no overhang, and no risk of hitting the building I’m working next to, I had to have it. Now if I can get my tracks in there, I can safely turn my machine around." Larson is his own operator. "I don’t let anyone else run my machine. I’m in masonry about 50% of the time and going toward excavating rather than doing any construction. I’ll probably be doing a lot more concrete footings as well." He adds that he has done many things with his minis. "Up here we do a lot of stone laying; we turn hillsides into stone steps. We also do a lot of tree moving. With my 70Z I was able to move a bunch of mountain laurel, including a clump of three. Each tree was about 5 inches in diameter, with the clump maybe 12 feet in diameter. It was rugged terrain, but I was able to put them on a trailer with the machine and move them 5 miles. A neighbor had built a house and wanted privacy. Since laurel is an evergreen, it provided the needed privacy." Colonial Stone Works keeps its focus on a 30-mi. radius. Larson notes that the mini is a stable piece of equipment, ideal for working slopes. "We do a lot of drainage work for existing buildings, dealing with shrubbery, the structure, the power lines. On one job, the owner wanted a crawl space under the first floor, and we dug a 14-foot-deep full basement." What features does Larsen like about his machines? "Rubber tracks. They’re quiet, and I have them on both machines. The life of the machine is good too. I expect 5,000 hours from the tracks alone. These machines are rugged, although a lot of people actually look at the machine and wonder what I can possibly do with a small blade or a quarter-yard excavator bucket. "Frankly, if you take a 25-ton machine to dig a water line, that’s crazy. You’ll have a 4-foot-wide trench. You’re better off digging the water line with a smaller machine, only moving a quarter of the earth - with a lot less impact on the customer’s yard." One such contract included 9,000 ft. of trenching by the prison in Suffield, CT, working on the far side of the guard rails and next to a swamp. "A big machine wouldn’t have been able to get in there. I could have done the job in two, two and a half weeks, but I had to wait on the other subs, so I found other jobs to do while waiting."
Bill Brown, owner of Specialty Equipment rental in Lawrenceville, GA, reports that his minis are popular. He has 15 of them and has been renting out minis for the past 15 years. "Mechanical contractors are learning that they can run their residential and commercial sewer and water lines and save a lot of hand digging in confined areas. In addition, they don’t need a big, rubber-tired machine." Users make believers. "Quite a few go from renting to owning. I’m a dealer, so I sell them. They learn that while they’ll pay $45,000 to $60,000 for a backhoe or other big, rubber-tired machine, they can buy a mini to do a lot of the same work for between $30,000 and $35,000." Brown is particularly pleased with the engineering. "They’re strong and powerful enough to do the job, but not so strong that they can break the boom or other pieces. Rubber tracks are also a big advantage as far as loading on asphalt or crossing curbs." Just how popular are minis today? "In the last five years, the growth in mini rentals has quadrupled. Besides plumbers, customers include masons doing their own footings or modular walls. Even some of the pipeline guys use them instead of a huge excavator for service heads. They’re digging graves, and they even have them on the golf course - they’re that environmentally friendly," Brown notes. "Skid-steers have done well with attachments," he adds, "but productivity is a lot better with mini-excavators than with skid-steers, just by the nature of the operation. You can get more downward force on an auger run by an excavator than with a skid-steer. But skid-steers will never go away; they have a different usage." What should new users look for in a mini-excavator? Brown suggests bucket size, depth of dig, and weight of the machine. "Renting is a great way to get a sample, to test the mini before you actually buy it." For the mini, the attachment makes the difference. "You can do amazing things with buckets alone," reports Keith Rohrbacker, product manager for construction equipment for Kubota in Torrance, CA. He notes his company’s line of minis offers six models from 2,000 lb. to more than 12,000 lb., with prices ranging from $19,000 to $65,000. "One dealer will sell only the bucket, usually a 24-inch, general-purpose trenching bucket. Yet other dealers sell every machine with a thumb. "The thumb is particularly popular with landscapers because it gives them a gripping device. Back east, some use our 5-ton machine for carrying logs or use the thumb to grasp a tree and load it onto a waiting truck. Landscapers also want to place boulders, and they use the thumb for that." Other attachments include augers and hydraulic breakers. Uses are limited by the imagination of the operator. "I saw our little K008 - only 1,980 pounds - being lifted into the bottom of an orchestra pit for demolition work. And I have photos of a helicopter transporting another around to remote transmission-tower locations. A popular use for our larger models is grave digging. Says Frank Parker of All Terrain Backhoe Services Inc. in San Jose, CA, "Put a 36-inch bucket on them and you can reach over obstacles and get into tight areas better than with a little backhoe." Rohrbacker and many others interviewed also note that automatic air-bleeding systems make it easier to restart the machine should an operator run out of fuel. "Just pour in the fuel, turn the key, and it automatically bleeds the air," says Rohrbacker. "But these machines are easier on fuel too. You can get about a day and a half on a tank of diesel." Also popular are antivandalism features. Now it’s possible to leave a small machine in the field and essentially box it up for the night. Many of today’s mini-excavators provide measures preventing unauthorized persons from gaining access to the controls. "Then even the most determined hooligan’s efforts are foiled," says Rohrbacker. Frank Parker partners with Jerry Smith in All Terrain Backhoe Services, which uses one backhoe and four mini-excavators. "We got our first mini in 1994. We saw the need because they’re putting more buildings on less ground here in California, and working space is getting tighter and tighter. But there’s still plenty of work for the backhoe," Parker adds. His first mini job involved reaching over a 6-ft. chainlink fence in South San Francisco and removing the mud brought against it by 11 in. of rain. "What I like is ease of operation. You can put dirt anywhere you want within 360 degrees of the dig, and it takes just two to three days to get fully comfortable - and they are comfortable for operators." The seat and controls make for a comfortable operation, even during a long day. Parker also cites ease of maintenance and long life as two other pluses with the technology. "In 4,500 hours, we’ve only lost a final drive on the tracks. We were pushing dirt with the blade one afternoon when it went, so we had to stop for the day. But that machine was back the next afternoon pushing dirt."
Tightness is his specialty. "We have two Kubota KX101 machines, a Kubota KX008, and a Takeuchi TB145. We have used the KX008 in a school’s bathroom. It was narrow enough to get down the hallway and through the door. Rubber tracks are no problem on a concrete pad, but in this case it was a total remodel. So I first knocked out the exterior walls before digging up the old bathroom floors." This strategy further sped up the process, to the delight of the customer. That’s because all work was done on a time and materials basis. "Without the mini we would have had to dig out those bathrooms by hand." Parker and Smith also use the KX008 and KX101s under buildings, excavating for new foundations during earthquake retrofits. Minis help them take on jobs too big for operators with one backhoe and too small for companies with full-size machines. "It gives us a great working niche." Jeff Stewart, product sales manager for Takeuchi in Atlanta, GA, agrees that minis make a difference. He points out that his company’s focus is on mini-excavators, with seven machines. "We also have two compact track loaders, so we are tightly focused on the mini aspect of moving dirt and debris." He states that earlier models operated with gear hydraulic pumps. "They were tough to operate because they were a little jerky. They’ve been replaced with piston hydraulic pumps on all but the smallest model. We haven’t put a piston pump on that machine because that would add $1,000 to a $20,000 machine, which is just too much for the added benefit." That model, the TB007, is popular in the rental market with homeowners and other one-time users. "It’s only 29 inches wide, and rental yards have a ton of them." Mark Webb, branch manager at United Rentals in Fort Myers, FL, emphasizes, "Homeowners like them because they can walk them through their 3-foot gate in the backyard and it takes just 30 minutes to learn to use them." Stewart points out that the new TB175 includes an automatic step-down travel system. "If you go to turn at high speed, it automatically gears down, providing more torque. Then it automatically gears up when the torque is no longer required." This system increases productivity 15% and doesn’t affect the digging.
Improved ergonomics, such as thumb-operated electrohydraulic push-button controls for auxiliary hydraulics instead of a foot pedal, make it easier to operate a hammer or a thumb. "Now, instead of [fussing with] one pedal with multiple functions requiring bend-and-reach motions to change buttons, the operator is able to focus on the task," Stewart notes. Travel alarms are standard anytime the undercarriage is in motion. "These are tough machines. There are machines out there that are 20 years old and still running. Maintenance costs are the lowest of all comparably sized equipment. Maintenance is probably just half that of skid-steers, for example," he observes. When asked about unusual uses, he gives the following situation: "A couple of guys with tree-harvesting equipment harvest trees 6-10 inches in diameter. The harvesting attachment will cut the tree, lay it sideways, de-limb it, and cut the trunk into 4-foot segments. But another guy uses his mini for harvesting oranges. You can’t shake Valencia orange trees, so the user invented a machine with rotating vinyl fingers at the end of the boom, which he inserts into the tree. The fingers twist the oranges out, and they fall to the ground, where they’re sorted. He says using the mini-excavator gives him a 35% production increase over any other mechanical-type picker."
When it comes to versatility, Kyle Hubert, western district manager for compact equipment for Kobelco America Inc. in Stafford, TX, observes, "Compact excavators are where skid-steers were five, six years ago. The demand is just exploding. Now that everybody else is getting into the game, people want a value-added machine. Before, the concern was just how deep did they dig and how much did they cost. Now they want a machine that feels more like a big excavator. A tight machine; no slack in the boom; and a good, fine feel to the controls, which they get since the machines have gone from linkage to hydraulic controls." "The compact excavator is not just a little machine used to dig anymore," Hubert emphasizes. "Large contractors are using them for prep and cleanup work on the job site. They’ll use them to cut down and haul out the trees, then bring in the big versions for major digs, then go back to the small machine to clean up the site. Also, the compact is ideal for ground too unstable for a 22-ton excavator; a 4.5-ton machine can compete with tractor-loader-backhoes and get over the landscape safely." Fiber-optic repairs are yet another popular use for this handy machine. "Compacts have borrowed from the large machines to better serve the customer, to keep them happy, and the customers are keeping us busy." Des Jarvis, product manager with the construction industrial division of Mitsui in Bridgeport, NJ, agrees. He’s been in this industry 20 years and can remember when the mini was basically a backhoe design given a 360º cab swing. "Now top-of-the-line compact excavators have all the features you’d expect in their $200,000 big brothers. These include a hydraulic swing brake on the slew that smoothes the operation and takes away the shock to the swing motor and swing gear." Rental operator Brown adds, "Travel alarms are the same as with the big brothers, and there’s even a 12-volt power adapter for the operator’s cell phone." Jarvis notes, "You can offset the boom left and right to dig alongside barrier walls and expose existing structures, such as basements. Basically you can dig a perfectly square hole without moving the machine," Jarvis notes. A proportional pressure-control joystick is another feature pointed out by Al Yang of Komatsu in Chicago, IL. He mentions that his company’s current lineup includes eight models with operating weights from 3,400 to 14,130 lb. and optional steel tracks. He remarks, "It’s a quiet machine, and it is becoming popular for use in existing subdivisions for foundations, swimming pool excavation, et cetera. Low noise and low emissions make the mini a good neighbor. Also, Komatsu’s boom is a single piece of steel. There are no welds to flex loose." Contractor John Dougherty, president of Charjon Construction Company in Latrobe, PA, has two mini-excavators helping him handle $1.5 million a year in contracts. "I have a Takeuchi TBO-70 and an IHI J20X. I use the 70 for water-main construction in a tight area, and I just finished a project for the Erie City Water Authority. "Another project is in Brighton Township near the Greater Pittsburgh Airport. There we’re installing 15,800 feet of 12-inch ductile iron 5 feet down in an 18-inch trench. With the mini’s offset boom, I’m able to keep between a 3,000-foot-long wall and the edge of the road." Dougherty first thought he would just rent a machine. "But I did so well when I first tried it that I ended up buying it. I like being able to have the controls with the same pattern used on my big machines." Is there advice he would offer other contractors? "Quick-attach buckets should be standard. It takes 10 minutes for two guys to change buckets. I’m getting serious about buying a quick-attach. Also, my machines have blades on them, and they’re great for backfilling and light grading. These minis are versatile, quick to get into tight spots, and very smooth to operate." Historically, European manufacturers haven’t had nearly the space constraints to consider compared to their Japanese counterparts have. But when it comes to minis, Europeans are getting involved. "We introduced our Nagano mini just a year ago, but Nagano has been a manufacturer of minis for more than 29 years," points out Pieter van den Assum, sales manager with the Lely Corporation in Wilson, NC (Lely has three locations in the US: North Carolina, Texas, and Oregon). "Now we have eight models ranging from $20,000 to $80,000. "Our specialty is the NB30 with no tail swing and an offset boom, which makes it possible to dig alongside the machine for trenches, foundations, pipelines, and even graveyards. But all machines are top of the line. C&P in Ooltewah, Tennessee, supplies us with a range of quick couplers and buckets. The Nagano machines fit nicely in our package, which also contains Furukawa compact wheel loaders and mini bulldozers." In short, the goal of the mini-excavator is to meet the perceived needs of prospective customers, whether that’s excavating in a tight spot while keeping the work quiet, digging a difficult landscape, making repairs in existing utility lines, or even harvesting oranges. Journalist Joseph Lynn Tilton specializes in land and building issues.
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