March-April 2005

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Excavators Do Much More Than Just Dig Holes

But it still takes the right machine, a savvy operator, and the right tools to ensure the project is finished on time and within budget.

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By Joseph Lynn Tilton

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When it comes to earthmoving versatility in tight surroundings or wide open spaces—whether topsoil or solid rock—excavators lead the pack. However, smart contractors know that good operators and the right tools for the job make a big difference in those machines’ overall cost and performance—and in finishing the job on time and within bid.

But excavators aren’t cheap. Ask Dan Baker, owner of Blue Iron Inc. of Stockton, CA. He says, “I sold my ski boat 19 years ago for $7,000 and rented a Komatsu excavator because I knew if I was going to be in excavation I couldn’t get a job without an excavator.” After just one month of renting he became an owner/operator. It took nearly five years to pay for the machine, but by then he was prepared to hire his first employee. He took on another employee three years later. Today, Blue Iron has eight Kobelco excavators and 17 employees, and last year completed more than $10 million in digging contracts in the Stockton area.

Photo: Movax

In regard to what prompted his brand selection, Baker comments, “Excellent dealer support. Tri-West Tractors in Livermore, which is just 30 miles from headquarters, is a real good dealer, very knowledgeable and helpful. When there’s a problem, all it takes is a call and he has someone there who can help, someone who knows the machine.”

On the other side of the equation are the right tools. Since shoring is necessary to prevent walls from collapsing, his company has the largest pile driver mounted on an excavator on the West Coast. “It’s a 100-ton Movax, which can drive piles in pairs, not singly. I had a 50-ton, but took on the larger machine and the time it saves is absolutely incredible.”

After commenting that excavations can be as much as 45 feet, with large excavations removing as much as 300,000 cubic yards as well as dealing in tight spaces, Baker reports the 70-foot-long excavator boom and arm makes it possible for his operators to reach deeply. “Last year, one of our jobs involved an underground addition to a campus center at a hospital. There were a lot of fiber optics and shoring was very difficult because of tight quarters between additions. For shoring, we soil-nailed to avoid caving in. Then we used a Rototilt so we could drill within 1 degree of whatever angle was needed for permanent shoring. That tool made the difference between being able to do the job and not being able to do it.”

He adds that there was some digging by hand and they used a vacuum truck to help remove solids. But it took operators just a day or two to become comfortable with the rotating device. “It’s a user-friendly tool,” he comments. “It’s taken a little bit of luck and a lot of hard work to get this big, but I really enjoy what I do.”

Mike Meehan, Movax product manager for Hercules Machinery Corp. in Ft. Wayne, IN, adds that using the vibratory hammer to start pile placement eliminates the need for a lot of overhead space. “The vibratory hammer holds the pile by its side and can stick the pile into the ground until it stops. By then it’s deep enough that the operator can easily switch to the hammer of choice and finish driving it home.” This includes placing piles approaching 100 feet long within 1 degree of plumb.

He points out, “One contractor used a small excavator on a waterfront project on residential property, versus a crane which takes a lot of support equipment. In Miami, where there are a lot of canals, another contractor had a project dredging sediment buildup. After dredging, the sides of the canal started to cave in, and those sides were right next to the road.” That’s when the contractor used sheet pile and backfilled the whole length of the road. It took three months to install 1,000 feet of sheet pile 25 feet deep. “They used the Movax 100% of the time and no conventional hammering was needed. While you get noise from vibration when interlocking sheet steel columns, you don’t have the intense noise associated with conventional hammering.”

Meehan agrees with Baker regarding the advantage of getting as much size as possible. “Movax was imported to the US in May 1998, and we’ve since bought the manufacturing rights for the Western Hemisphere. Since 1999, we’ve sold and manufactured over 100 units for the domestic market. It’s in a constant state of improvement. We’ve taken it from a 50-ton machine up to 100 tons. We’re making it bigger, stronger, and harder so it can provide more and more energy to accommodate a wider variety of projects.”

Other New Tools
Baker’s latest tool addition came from Sweden, through North American Hydraulics Inc. of Baton Rouge, LA. Dennis Buquet, Rototilt manager for the US market, reports that while the Swedish-built Rototilt has been in the European excavation market since 1987, it has been in the US a mere three years. He also reports, “It’s used in many applications, from railway maintenance to golf courses, foundation work, underpinnings, inner city projects, and in places where you’re dealing with transportation, people, and traffic issues. It makes it possible for an excavator of any brand to work more closely to itself.”

He adds that, most of the time, an order can be filled within two weeks. “The absolute worst case is six weeks on an oddball, ancient machine that’s not a big player in the market.” As for ease of operation, he says learning may take as few as four hours. “With continuous rotation and side-to-side tilt, the operator can use it as an extension of his wrist. And with the attached hydraulic quick coupler, he can quickly and safely change from one bucket to another without having to get out of the cab and put in a safety pin.”

Photo: Link-Belt

Enhanced Excavators
Today’s excavators are more comfortable, more economical, and more versatile than earlier versions. When you consider the added versatility, they’re easier to operate than ever before. “The biggest change in the last decade has been in auxiliary hydraulics,” says Chad Bixby, underground utility product specialist for Caterpillar Inc. in Peoria, IL. “That change allows machines to have different flows and pressures for different attachments. Hammers have different requirements than shears, thumps, or rotators. When you design auxiliary hydraulics you want to make sure the combination of booms and sticks will have the proper structure designed to handle the different tools. For instance, you don’t want to design the stick and boom so it’s too heavy when using a hammer, because of possible problems with the machine tipping.

“Excavators are doing many more functions and the integrated hydraulics and electronics allow the operator to switch between widths of attachments automatically and pick up different attachments without getting out of the cab.”

Bixby then gives the example of digging a trench with a wider bucket, switching to a toothed one to get through hard surfaces, then using a smaller one where the pipe will lie, and finally, once the pipe is bedded properly, using a clamshell bucket to fill in the trench. “Depending on application, versatility of today’s machines has boosted excavator productivity 30% to 40%. Contractors need fewer machines on the job site. You want the job site running efficiently because there are narrower and narrower margins on bids, yet contractors need to make each job profitable.”

One way to do that is to avoid getting out of the cab, yet know where the bucket really is. Kristjan Ingvarsson, founder and president of Ocala Instruments in Orlando, FL, says that excavator depth monitors can now be connected to a GPS system to display the exact position of the bucket, whether digging a basement, a trench, or a perfect embankment slope. “However, using a rotating laser and inclinometer-based depth monitor gives the highest precision in depth measurement and minimizes calibration drift. So if precise depth is the job’s main issue, the instrument of choice is a depth monitor rather than a GPS-based system, at a fraction of the cost.”

Ingvarsson reports the newest enhancement of Ocala’s product line is the Ocalaser. It is a laser receiver that mounts on the dipper stick and automatically relays the laser height to the depth monitor inside the operator’s cab. This makes the reference level exact to within 0.02 feet. He comments that not only can the instrument measure depth, but embankment slopes, distances around the excavator, heights, etc. “One of the nice things is that it will indicate the bucket opening when digging under water. This ensures a full load in every scoop. Some very difficult measuring tasks are easily accomplished with an excavator depth monitor, such as digging a perfectly vertical wall, or a perfect slope under water.”

Is Your Excavator Ready for 2006?
Matt Hendry, product consultant for excavators and articulated dump trucks for John Deere in Moline, IL, adds that manufacturers have been prepping their machines so they will meet federal Tier 3 emissions standards coming out in 2006. “That’s going to drive a lot of end users to replace existing machines,” he predicts. He also notes that operator comfort plays a larger and larger role in excavator design. “It needs to be comfortable and it needs to be simple.”

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Add efficient electronics, efficient hydraulic oil flow, and even higher performance engines, and an operator is able to move more dirt in less time. “That’s because today’s excavator lets the operator work deeper into the rpm curve before the hydraulic pumps destroke, which means more oil flow. More flow means more productivity. Today, using very efficient pilot controls requires much less operator input and efficiently manipulates the hydraulic pump. Operator movement is greatly reduced.”

He reports that—compared with a decade ago—excavators are 10%–20% more efficient, and can expect more than 8,500 hours of use before any major component problems. This will vary greatly depending on how the machine is cared for.

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