Using proper training will not only improve safety in the landfill and prolong the life of the equipment, but it will also increase densities in the landfill.
By Clay Layne
A landfill’s primary objective is to operate at the lowest cost per ton. This is accomplished through:
• Achieving safety goals
• Managing inbound tonnages
• Meeting density requirements
• Achieving the plan
• Working efficiently
• Planning/tracking maintenance on equipment
How does the landfill achieve those operating objectives? One of the best ways to achieve those items is with well-trained, skilled operators for the landfill equipment. Before going to work on any piece of equipment, the operator should take time to read and understand the machine’s operation and maintenance manual (OMM). The OMM contains safety features, operating and maintenance characteristics, capabilities and limitations, location of all controls, indicators and warning lights, and safety devices on the machine—everything an operator needs to know about.
machine. Any deficiencies need to be reported. Photos courtesy of Caterpillar.
Achieving Safety Goals
The skilled operator starts thinking about safety as soon as feet hit the floor in the morning. The safety mindset is still intact when driving to the landfill and arriving. What is the safety mindset? It is a behavior or an attitude, something that a skilled operator chooses to do and lives by each day.
Three main causes of accidents in the landfill include:
- Weather—causing changes in visibility and/or underfoot conditions
- The machine itself—some type of failure such as hydraulic lines or brakes
- The human element—contributing to many accidents
Ninety percent of all landfill accidents can be attributed to:
- Improper maintenance or walkaround
- Slips, trips, and falls
- Running into something or not seeing something
- Not thinking ahead or having the “big” picture in mind
- Not paying attention
These are all things that should be discussed in the pre-shift safety meeting. The objective is to keep everyone in the safety mindset, and a discussion should be held to address how to handle these issues if they arise.
Pre-Shift Walkaround Inspection
Before the start of the shift, make sure the machine is ready to go. Make it a routine, and start in the same place every time, first removing the battery disconnect key. The inspection should include looking up, down, under and all around the machine. Any deficiencies need to be reported, verbally and/or in written form. Items to be on the lookout for include:
• Inspect all systems
• Cracked welds, loose lug nuts or bolts, black marks on the paint
• Built-up debris or waste around heat sources should be removed
• Seatbelt condition and date of install
• Visual scan of the work area as well as your machine
• System checks of the service brake, brake accumulator, park brake
Using the company’s walkaround inspection form, write up all deficiencies. After completing the walkaround inspection, keep in mind that a high percentage of all injuries to an operator are from mounting and dismounting the machine. Therefore, always maintain three points of contact.
Stay Alert
The operator must maintain situational awareness throughout the day. The landfill operating environment poses many special safety challenges the operator should be aware of, including:
• Airborne materials
• Fire hazards
• Other operating machines, so know the machine’s blind spots
• Drivers, co-workers, the public, and other people at the landfill
• Employ a three-point scan technique, looking in mirrors, at the backup camera and to the rear
• Look toward the rear before moving in reverse, remembering that three to five seconds is the average time before the operator can see behind
• Never let cameras or technology contribute to complacency
Working Distances
Plan for safety, production, and efficiency at the landfill. Keep working distances short enough to maintain production, while not jeopardizing safety and the ability to layer and compact the waste. For example, adding 25 feet of push distance to a D8T dozer because the floor is correctly cleaned keeps inbound trucks from backing up to the working face, which will decrease production. Feedback from landfills consistently show an increased distance due to inefficient working face operations, which affects safety, density, fuel, and wear on machines, and overall maintenance.
Layer Height
Nothing robs airspace and density quicker than improper layer height. Compaction density is affected by many variables. A large majority of landfills take in municipal solid waste (MSW). Add enough MSW into a layer, and no matter what compactor or the size used, density will diminish rapidly. In basic definition, landfill density is achieved by the ability of the compactor to compress and shred material. There are differing opinions about moisture, tips, wheel width, etc., but these are the basics.
During past best practice testing, we have found that no matter the compactor’s size, more than a 2-foot layer of MSW will only result in the top of the layer being compacted. However, below a certain compression and shredding level, the rest will stay untouched and will act like a sponge or shock absorber.
Testing shows the difference between a 1-foot layer of MSW with four passes and a 4-foot layer of MSW with four passes can be as much as 1,000 lbs./yd3 density loss. While it depends on many variables, this has been the experienced average.
Fuel consumption on compactors increases between 10 to 15 percent, depending on waste layer thickness as the thickness increases. Best practices training advises thin layers are best. Also, once a layer is added to a compacted area, that layer must be compacted prior to adding more waste.
While it seems simple to follow, a vast majority of the landfills where we have performed site/machine assessments in the past few years have a tendency during peak times, to not only attempt to compact a thick layer, but double that layer just to get the tip floor cleared. For example, consider the dozer that layers an area properly during non-peak times. As a peak time starts, the compactor continues to run its 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 compacts that area. This waste layer can now be 4-feet deep or more. Communication between machines (compactors/dozers, etc.) is paramount when trying to achieve good compaction densities, especially during peak times.
Pattern Efficiency
Consensus in the industry is that the minimum number of passes for best density is three to five. What we see is normally one to two passes maximum. More to the point, in our best practice testing when we ask the compactor operator how many passes they have on the waste, often the response is “about four,” when in reality it has only been 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 instance, if the dozer and compactor start on one side of the working face and 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.
Since inbound haul vehicles do not always adhere to that logic, then the dozer and 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. When assisting customers with the best practice of planning and maintaining a pattern, we have seen from 50 to 200 lbs./yd3 increase in density.
Density Passes
In today’s waste, making enough passes to compress and shred the material properly is imperative to achieving higher densities. A minimum of three to five passes are needed to obtain the highest densities. Unfortunately, as mentioned, the norm is two passes on most landfills.
The compactor’s wheels provide compression, 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.
So, 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, repeating 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
How an operator leaves the working face at the end of the day prepares the working face for the amount of work performed during opening the following morning. Unfortunately, many times the working face looks like meteors have impacted it or there is large material sticking up from the face versus it being the desired flat and level as it is prepared to be covered. Simply put, the time it takes to run down, track in, or perform 45-degree passes to the working face prior to cover or alternative daily covers (ADCs), the less time it takes to open the following morning.
At the end of the day, the operator should conduct a post-shift machine walkaround and:
• Lower all implements to the ground
• Shift to neutral
• Enable hydraulic lockout
• Set parking brake
• Remove all debris from heat sources
Keep in mind that more than half of all landfill fires happen after hours due to not performing a post shift walkaround.
Training for Skilled Operators
A well-trained operator is the best line of defense against expensive repairs and downtime, and that makes the investment in training well worth the upfront cost. Check out all options available and find the one that works best for the operation.
When it comes to training and maintenance, the adage is true: “Pay me now or pay me later.” Spend a little time and money upfront, and the operation will likely see big savings down the road. And remember, if help is needed to establish a training plan, put technology to work, or access training, it is available.
Once a good training program has been established, this will prolong the life of the landfill equipment and increase required densities to establish good operational best practices. Using proper training will not only improve safety in the landfill and prolong the life of the equipment, but it will also increase densities in the landfill. | WA
Clay Layne is the Sales Support Consultant in Waste Applications at Caterpillar Inc. Clay covers landfills, transfer stations, and MRFs. He started working for Caterpillar in 2008 as an operator at the Peoria Proving Grounds working with engineers on the 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. He can be reached at (309) 675-8486 or e-mail [email protected]