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By Daniel C. Brown |
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Contractors are doing more with less these days. They're extending equipment maintenance intervals and pushing machines to their limits. More aggressive preventive maintenance (PM) programs are the order of the day. "We're getting more and more into reliability-based maintenance," says Thad Pirtle, vice president and equipment manager at Traylor Bros. Inc., a heavy/civil contractor based in Evansville, IN. The company runs some 250 million dollars' worth of equipment, a mixture of newer and older machines. Pirtle explains, "We measure the utilization time of equipment‹the uptime in between inspections. First we inspect at eight-hour intervals, and if that's OK, we move it up to 16 hours, then to 24-hour intervals. We find out where the limits are. We get rid of a piece if it needs repairs too often‹or we buy a different brand or type of machine. For example, we found a type of light plant that will go 13,000 or 14,000 hours, where the old ones would only work for 7,000 or 8,000 hours." In other equipment maintenance trends:
Major manufacturers, such as Caterpillar and John Deere, have introduced onboard electronic data loggers. At John Deere, for example, excavators have onboard information centers that capture and record data, such as hours of operation, machine utilization, engine speed, travel time, history of alarms and faults, and more. You can find out how much your machine travels and how hard the engine and hydraulic pump work. "With onboard electronic systems, we have the data to determine what an operator did at a specific time on a particular date, and we can work jointly with project management to reduce costs‹through training, better operations techniques, better maintenance," says Mike Monnot, director of equipment at Zachry Construction Corporation, a large heavy/civil contractor based in San Antonio, TX. "Now, we can make accurate cost predictions based on factual data. We can identify when our operators need more training." With this technology you can download such operating information with a pocket-sized personal digital assistant (PDA). In turn, the data can be transferred to your personal computer, which can display graphs, histograms, and spreadsheets that will summarize machine performance. You can e-mail the performance data to others for evaluation and action. "On Cat scrapers we can plug in the PDA and tell if the engine was over-revved," says Mike Lax, equipment manager for Pavex, which is Graniterock's construction division based in Redwood City, CA. "We lost an engine in a scraper and the word came back that it was over-revved. On truck engines, that onboard data logger can tell you start times, stop times, how fast the engine is going, what gear it's in, what rpms [revolutions per minute] it was shifted at. And you can set the speed on a truck so that it won't go over, say, 65 miles per hour. You can set safety features in the engine." Oil Sampling Pays Off
A good oil sampling program has proved invaluable for Landmark Construction, an Indianapolis, INbased earthmoving contractor that runs in some 15 million dollars' worth of equipment. "We have caught gears and bearings going down before they failed completely," says Kent Field, the firm's equipment manager. "We use Caterpillar's oil lab or DA Lubricant, and we can have a result back in 24 to 30 hours, if we really push for it. "We once had a Cat D6M dozer with about 9,000 hours on it, and the iron count jumped up in the transmission oil. We opted to have a re-bearing and re-seal job done on the transmission. When they tore down the transmission they found one gear that was beginning to pit and erode. So we only had to replace one gear, and that was before failure." Because Landmark practices oil sampling and an aggressive PM program, the firm chooses to run equipment beyond the recommended time for, say, an engine overhaul. "If Cat recommends a certain engine be overhauled at 10,000 hours, we'll go ahead and run it for 12,000 hours," says Field. Would he run it to 14,000 hours? "If it's a larger machine, yes, we would run it out to 14,000 hours," says Field. "But if it's smaller, like a D5M, it would be traded. Even if you rebuild a smaller machine, you can't get your money back. Even though it's cheaper to rebuild the final drives than buy a new dozer, you don't improve the reliability of the electrical system, the hydraulic system, the steering, or the braking." Pavex's Lax is using oil sampling to extend oil-change intervals. "We're actually tripling the oil-change intervals, compared to the manufacturer's recommendation, on some concrete trucks," says Lax. "Oil-change intervals depend on conditions. Scrapers in the dirt require more frequent oil changes. Yet on some machines under favorable conditions, I think we'll get 500 to 750 hours between changes. "Most manufacturers recommend 250-hour changes, but if you can get more hours, it saves money, filters, and labor," says Lax. "We signed some agreements with our oil distributor, to buy from them. They help us extend our oil-change intervals; they're onboard to make it happen." Aggressive PM
Hubbard Construction Company, an Orlando, FL, heavy/civil contractor with 135 million dollars' worth of equipment, has "extensive software systems that allow us to collect detailed cost data, such as cost per hour and uptime," says Andy Agoos, senior vice president and an equipment manager. "Those two things drive us‹cost per hour and uptime. "We use an extensive work-order system at Hubbard," continues Agoos. "It enables us to capture the ongoing costs of any item that has a replacement cost of $5,000 or more. The system is from J.D. Edwards and includes payroll, job costs, inventory, a complete accounting package, and a complete equipment system. We've tailored that system to 'Hubbardize' it. "In that system is a work-order package. You just have to have the discipline and the structure to open work orders to accumulate the costs. If we have a machine that doesn't start, and the technician spends two hours to bleed the fuel system and replace the battery, he'll put in a work order for his labor and for the battery." Downtime matters. "The job [accounting] will recognize that the machine was down for two or three hours that day," says Agoos. "Our jobs report either equipment operated, idle, or down. So we can clearly see the reliability and how the machine is performing." Lax explains that Pavex has placed its equipment (about 10 million dollars' worth) on PM software from J.D. Edwards. "Our PM schedules are automatically reported through our in-house computer system," explains Lax. "We've implemented this system over the past few years, and we're on the learning curve. "We know that at certain intervals of elapsed hours we need to check wear parts‹screed plates on pavers, chains on pavers, and the like. By tracking historical records, we can tell when something's likely to hit a critical wear point. We're switching to a system where we replace by preventive methods, rather than fighting fires. We can hit pretty close to when a wear part is going to fail." Minimal In-House Repairs Many contractors work to minimize their in-house maintenance. "We just try to do the paramedic-type maintenance ourselves," says Todd Peterson of Peterson Contractors Inc. in Reinbeck, IA. The firm is a large contractor with annual revenue that reaches between $50 million and $80 million, and it owns a fleet of some 300 pieces of construction equipment and trucks. "We have 12 full-time mechanics and several small shops," says Peterson. "For high-production machines, we keep the equipment pretty current and aim to take off the top 30% of its productive life and then trade it. That way it never requires major dissection." "We have a philosophy that each category of equipment is different," Peterson says. "Some machines are older and hold up well. Air compressors are an example because they see limited use. Generators for a crushing plant are built to go 30,000 hours or more. We do a lot of heavy demolition, and you don't need expensive machines to knock a building down‹so the 30% rule doesn't apply to everything. We made a conscious decision to fix up our trucks, and they last a long time." Peterson notes that his company doesn't do engine rebuilds. "Our mechanics are too talented to be doing engine rebuilds. They have to diagnose and fix things quickly or send it somewhere else for a more intense repair. "If our equipment gets pneumonia or has a heart attack, we send it to the dealer," Peterson says. "It's expensive to have a lot of capital tied up in a shop. You can't sell shop facilities. We try to stay flexible. It's inflexible to have to fix everything. A big shop is like a big monster. You have to feed it because it's costing you money." The owner of TechniComm, a Des Plaines, IL–based communications business, Daniel C. Brown is a frequent contributor to Forester publications. GEC - July/August 2004
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