Implementing a good maintenance program and operational best practices go hand in hand when it comes to increasing densities and getting the most production out of landfill equipment.
By Clay Layne
Waste industry applications are some of the harshest for operators and the equipment they run. For the past 20 years, we have been working closely with customers to understand those applications and help them meet their goals while lowering costs. During site visits and evaluations, we are often asked: “What are some best practices that you have seen and trained?” The following best practices are a high-level start on improving your maintenance program and operations while lowering overall costs.
A Good Maintenance Program
Before any landfill operations begin, you need to have a good maintenance program. In a busy landfill, transfer station or material recovery facility, no one wants to sacrifice machine availability for maintenance. We get it—production matters, and you have got deadlines and financial goals to meet. But try looking at it another way: instead of sacrificing availability for maintenance, you are ensuring availability through maintenance.
Operations managers who have put the focus on these three basic maintenance practices tell us they are reaping the bottom-line benefits in terms of eliminating excessive wear and maximizing machine and component life.
#1: Performing Daily Walkarounds
This one is easy to overlook in the rush of shift changes or busy workdays. But daily equipment walkarounds may be the single best way to identify potential problems before they turn into costly repairs and downtime. That is because your operators know their machines better than anyone and, if they are paying attention, are likely to notice when something feels “off.”
Make pre- and post-shift walkarounds a requirement. Encourage your operators to perform a quick visual inspection anytime they are off the equipment. And remind them to use their senses—sight, smell, sound and touch—to reveal clues about a machine’s status.
#2: Completing Regular Maintenance on Time
Oil and filter changes. Fluid sampling. Periodic inspections of undercarriage or wheels and tips. They are all things you know you should do on a regular schedule. But again, the pressures of the job can make it tempting to put off these tasks. Do not fall victim to that way of thinking.
Extending maintenance intervals puts component life at risk, impairs machine performance and raises service costs—all of which hurt your bottom line. It costs a lot less to shut down a machine for a few hours of regular maintenance than to have it in the shop for days or weeks following an otherwise preventable breakdown.
To keep maintenance on track, take advantage of technology. A Product Link™ “box” on your machines sends hours and event/diagnostic codes to VisionLink®, where you can schedule and monitor PM activities automatically anytime, you are online.
#3: Training Personnel to Know What to Look For
Finally, do not overlook the importance of training when it comes to keeping your equipment operating at peak performance. Your operators need to know how to run machines right, of course, but they also need to recognize when something is wrong. That requires:
• A basic understanding of how machine systems work and wear
• The ability to conduct a proper walkaround inspection
• Knowing the different levels of machine warnings and how to respond
A well-trained operator is your best line of defense against expensive repairs and downtime, and that makes the investment in training well worth the upfront cost. Check out the options available1—you will find in-person and online classes that fit into your schedule.
When it comes to maintenance, the adage is true: “Pay me now or pay me later.” Spend a little time and money upfront and you are likely to see big savings down the road. And remember, if you need help establishing a maintenance plan, putting your technology to work or accessing training, we are here to help.
Once you have established a good maintenance program that will prolong the life of your landfill equipment, you will need to establish good operational best practices. Using proper techniques on the working face will not only prolong the life of your equipment, but it will also increase your densities in the landfill. The following Best Practices will help you increase your densities and extend the life of your landfill as well.
Plan for safety, production and efficiency. Keep working distances short enough to have good production while not jeopardizing safety and ability to layer and compact the waste. As an example: adding 25 feet of push distance to a D8T due to not cleaning the floor correctly, which keeps inbound from backing up to the working face will decrease production approximately 16 percent. Customers tell us that increased distance due to inefficient work face operations affect safety, density, fuel, and wear on machines and overall maintenance.
Nothing robs airspace and density more quickly than improper layer height. Compaction density is affected by many variables. A large majority of landfills are primarily MSW. Add enough of MSW into a layer and no matter whose compactor or what size compactor is used, density will diminish rapidly. In basic definition, landfill density is achieved by the ability of the compactor to compress and shred material. There will be arguments about moisture, tips, wheel width, etc., but these are the basics.
What we have found during past “Best Practice” testing is that no matter what size compactor with more than a 2-foot layer of MSW, the top of the layer will compact but below a certain compression and shredding level; the rest will stay untouched and will act like a sponge or shock absorber. During the testing, we found that the difference between a 1-foot layer of MSW with four passes and a 4-foot layer of MSW with four passes could be as much as 1,000 lbs./yd3 density loss. (Again, it depends on many variables, but this was the average). Fuel consumption on the machines increased between 10 to 15 percent depending on the thickness of the layer of waste as it got deeper. When we train Best Practices, we always tell our attendees that ‘thin layers’ are best. One last addition, once a layer is added to a compacted area, that layer needs to be compacted prior to adding any more waste. This seems simple and actually redundant, however, approximately 90 percent of the landfills we have performed site/machine assessments on in the past few years, have a tendency during peak times, to not only thick layer, but double layer just to get the tip floor cleared. For example, the dozer layers an area properly, a peak time starts, the compactor is running passes, but the dozer trying to keep up with inflow moves and layers more waste on top of an area that had previously been layered before the compactor reaches that area. The waste layer now could be 4-foot deep or more. Communication between machines (compactors/dozers, etc.) is paramount when trying to achieve good compaction densities.
Consensus is that the minimum number of passes for best density is three to five.2 What we see is normally one to two passes maximum. More to the point, when we ask the compactor operator how many passes, they have on the waste, they tell us “about four,” when they only have one to two. The discrepancy is due to not running a proper pattern. A pattern is defined as “a logical sequence of doing things.” For example: if the dozer/compactor starts on one side of the working face and they work across the face together, then that is an efficient pattern. Layering and compacting from left to right or right to left is a ‘logical sequence.’ Knowing that inbound haul vehicles do not always adhere to that logic, then the dozer/compactor operators need to plan, communicate and stay with a logical sequence so that they cover the whole area without under/over compacting and/or thick layering of material. This is not easy to do during peak times. Again, when helping customers with the best practice of planning and maintaining a pattern, we have seen increases of from 50 to 200 lbs./yd3 increase in density.
In today’s waste, making enough passes to compress and shred the material properly is imperative to achieving higher densities. As I said in “pattern efficiency”, a minimum of three to five passes are needed to obtain the highest densities. And, as I mentioned, the norm is two passes on most landfills. The machine wheels compress, and the tips give traction and shred the material. The more passes, the higher the density. Having said that, most operators that achieve higher densities start on one side and go forward to the end of the waste and back in the same tracks achieving two machine passes over the waste. Continual moving over one-wheel width will eventually achieve four passes. They continue that ‘pattern’ all the way across the waste and then start over. Someone is probably saying, “What about the edges that only achieve two machine passes?” Most operators will perform four machine passes (twice up and back) on the edges until they get to the point that their pattern starts to achieve four passes (repeat the four passes on the far side edge). As per the statement in “pattern efficiency”, as the number of passes goes up, so too does substantial growth in the density achieved.
Finishing the Face
Customers have said, “How you leave the working face at the end of the day, prepares the working face for the amount of work performed during opening the following morning.” How many times have we looked across the working face as they prepare to cover and instead of flat and level, it looks like meteors have impacted the working face? Or, there is big ugly material sticking up? Simply put, the time it takes to run down, track in or perform 45 degree passes to the working face prior to cover or ADCs, the less time it takes to open the following morning and the less cover soil or problem with ADCs you will have. Tracking in or running 45-degree passes, “knit or blend” the working face materials together. The result is: less voids, harder surface, less big/ugly materials jutting up. Thus, the working face is easier to cover, easier to close, easier to open the next day, which translates to less time and money.
At the End of the Day
In conclusion, these best practices on the working face and a good maintenance program will ensure you are getting the most out of your landfill equipment.
Safety first. Include the whole team. Make everyone accountable.
Plan working distances to be efficient and productive. Work with your team and help them understand the areas that add or decrease productive distances that can hurt efficiencies.
Improper layer heights will be your biggest loss of density. Talk with your team stressing and managing proper layer heights for your waste and machine size.
Run patterns so that you achieve maximum passes. Keep your team communicating. Do not allow them to settle for anything less.
At the end of the day, leave the working face so that cover soil can be added easily and efficiently. This also allows a quick start the next shift/morning.
Track the use of your cover soil wherever it goes. This will allow you to cut down on ‘overuse’ of cover soil and help you manage cover soil usage.
“Mine or recover” soil when opening the next day. Use it as the “base” layer of the next day’s cover. Customers have told us this can save them 20 to 40+ percent on their cover soil use.
Chart your working face tonnage to understand peak times. Do not fuel or clean machines during peak times nor take breaks or lunch during peak times unless you have another crew to take their place. Super peaks will take place at the worst time possible. Observe and understand possible super peaks to help your operators cope.
Implementing a good maintenance program and operational best practices go hand in hand when it comes to increasing densities and getting the most production out of landfill equipment. The bottom line is if machines are not moving, required densities are not met. A good maintenance program starting with your operators and daily walkaround inspections will keep your machines moving and lower your overall maintenance cost. | WA
Clay Layne is the Waste Application Specialist with Caterpillar (Peoria, IL). He started working for Caterpillar in 2008 as an operator at the Peoria Proving Grounds working with Engineers on Research and Development of Caterpillar Machinery. In 2011, Clay moved to the Edwards Demonstration and Learning Center. It was here that Clay started working in the Waste Industry, conducting onsite operator training for Caterpillar customers all over the world. Clay can be reached at (309) 675-8486 or e-mail email@example.com.
According to Caterpillar, SWANA and other reliable waste sources.