Compactor and Scraper Operator Tips

Incorrect and unproductive methods of operating earthmoving equipment reduces profit. As an earthmoving equipment operator who usually runs a compactor or a scraper, I have learned techniques that may be helpful to other operators.

Compactor

  1. A consistent pattern and smooth surface are vital for proper compaction.
  2. Always begin a fill by outlining the fill perimeter with the compactor blade, or dirt spreader. This ensures that scrapers or trucks know where & how far to spread material.
  3. When starting a fill slope, always outline the toe with the edge of the compactor blade.
  4. With every lift, compact the edge of the slope to overbuild at least 5 tenths wide. This shows scrapers how wide to build the slope, and gives the dozer something to trim off. Different types of materials and designs require more or less overbuild. When in doubt of how much to overbuild, ask the dozer operator who will be grading the slope, or the grade checker.
  5. Always ensure enough material is spread out to the edge of the slope to build it slightly higher than the rest of the fill. This prevent scrapers from sliding off of the slope, and ensures that the slope is not under-built.
  6. Compact the slope more than the rest of the fill to ensure future stability. Also, it will be solid when the dozer grades it.
  7. Always key into existing slopes that are in the fill.
  8. Examine existing slopes for any obstructions or underground installations. When unsure of what to do, & to ensure no utilities are in danger, contact supervision before proceeding.

Compactor Patterns
Compact each fill using a pattern that is appropriate for each situation.

  1. This is the quickest way to get across the fill for use when:
    1. compaction is attained primarily by scraper travel;
    2. compactor makes u-turn after each pass;
    3. just "knock it down" with dirt spreader as time is short;
    4. small windrow is left between pass lanes;
    5. do not split tracks.
  2. The next quickest way across the fill is for use when:
    1. compaction is easily gained, but dependent upon compactor;
    2. compactor rollers need to travel across entire fill to densify soil, therefore splitting tracks is necessary;
    3. spread dirt on 1st pass, then back up during 2nd pass to split tracks as time is short;
    4. for 3rd & 4th passes, repeat "c" above.
  3. The next quickest way to get across the fill is similar to No. 2 above, and is used when more effort is required to gain a smooth surface:
    1. back drag when backing up;
      OR - ( & this takes more time because the compactor turns around after each pass)
      1. use No. 2 above, but don't back up;
      2. instead, go forward on each pass;
      3. split tracks and spread dirt on each pass.
  4. When there is time more compaction can be achieved by:
    1. spreading material on 1st pass, then backing up in the same tracks just made;
    2. after backing up, split tracks & spread dirt forward, then back up in same tracks again;
    3. for next pass, begin next to edge of last pass;
    4. backdrag as time permits if needed to smooth surface;
    5. if time permits, and more effort is needed to achieve compaction, after backing up move over 1 roller width for each forward pass.
  5. Experiment by discovering patterns not mentioned here.
  6. Mix the material and moisture by tilting the blade. One corner will dig while part of the blade will spread & mix.

Scraper Tips

  1. Be prepared to yield the right-of-way at the cut exit.
  2. Begin a fill by dumping close to the stakes at one side of the fill. Cover the fill's entire length, then width.
  3. Always dump on the edge of the slope so that someone else doesn't have to push the material out farther.
  4. If it takes 3 loads in each lane to cover the length of a fill:
  5. Notice the green loads above were dumped next to & touching the brown loads, not overlapping the brown.
  6. Place material all the way to the end of the fill.
  7. Make sure the corners are filled.
  8. If you see compactor tracks, it wasn't dumped on.
  9. Above, the length of the fill was not covered with just 1 load.
  10. Don't dump on cuts. Look at the stakes and ribbons.
  11. If you are not sure if the end of the fill was dumped, go and see. If it was, dump at the end of the next lane. In large fills, the end is usually not filled because scrapers can't see the end when entering the fill. They assume someone else completed the length of each lane.
  12. Don't dump in the lane the compactor is working in. He/she needs to see where the compactor has last been, just as the scrapers need to see where the last scraper dumped.
  13. In a rock fill, occasionally relocate large rocks to the correct location to help the compactor.
  14. Expect the compactor to smooth the fill as much as possible.
  15. When dumping with a slope edge or keyway wall on your right side, use existing compactor & tire tracks, with your right-side mirror, to judge your distance from the right-side edge or wall. Also, look through the gooseneck to see how close the right side of the cutting edge is to the edge, stakes, or wall.
  16. When stopped, open your cab door and look down to see where your tire is in relation to where you thought it was. You will probably be surprised.
  17. Help the compactor elevate the edge of the fill slope above the rest of the fill so that you don't slide off.
  18. Ask a grade checker or compactor operator when unsure about the fill. A well managed fill largely owes its success to conscientious scraper operators.
  19. If a scraper dumps with their can (bowl) too low, the material will be dragged, not spread. That creates a low spot in a lane that appears to have been filled, but has not. Watch for this & spread material in those areas.
  20. When a scraper dumps with the can too high, it leaves piles that are difficult for a compactor to spread. This usually makes bumps in the fill.
  21. Responsibility for each scraper stops at the steering wheel. Each operator is responsible for their machine & what it does. Travel at the appropriate speed for current conditions (haul road, cut, fill, and water).
  22. Dump your load in the fill, not on the haul road.
  23. Before shutting off the engine(s), cool it down by idling for at least 5 minutes, longer on hot days. This will keep the turbocharger, head, & exhaust manifold from breaking.
  24. When entering the fill, always glance at the grade checker & compactor operator for possible directions. In the cut, glance at the grade checker.
  25. Cut the edges of the cut first. Resist the urge to hog out the middle of the cut first. Build stockpiles the same way: edges first to raise them up.
  26. Depending on the situation, create a downhill cut by loading at the end of the cut first. Use gravity to get larger & faster loads. Then load in the midway area, while working back to load at the beginning of the cut.
  27. When loading, overlap the previous cut pass by a foot or two. This eliminates ridges.
  28. Or, "Straddle Load": cut 5 or 6 feet to the side of the last cut lane to create a ridge, which will be centered on every 3rd pass for a fast load. Share the easy loads.

Common mistakes

  1. Not dumping at the beginning of the fill. Open your apron a couple of feet before the edge of the beginning of the fill, not after you are several feet past it.
  2. Don't dump so far from the stakes on the sides of the fill that someone else has to push the material to the edge of the fill. Place the material accurately.
  3. Not dumping in corners, especially when entering the fill while turning.
  4. Looking at the fill to the right, notice the common mistakes:
  5. When the edge of the fill is lower than the rest of the fill, dump on the edge when you are within a scraper width of it. Elevate the edge, then fill next to the loads you just dumped on the edge. This keeps the edge from tilting the wrong way.
  6. When traveling, lower the bowl to about ½ ft. above the ground, or just enough to clear obstacles.
  7. Keep the apron closed when not loading or dumping. This lowers the scraper's center of gravity & helps keep the haul roads smooth.
  8. When loading, open the apron just far enough to keep material from falling back out of the bowl.
  9. When traveling back to the cut, keep the apron closed to avoid dust drafting through the can to the rear engine. This will prevent premature filter clogging and power loss. It also reduces wear on the apron hinge pins.

Not a mistake, just a note: turning with a loaded scraper increases wear on the hitch, as does duck-walking.

Pat Cook has 27 years experience since 1966 as an earthmoving equipment operator. Specializing in scrapers & compactors, he now operates a GPS compactor preparing pads for a GPS blade and teaches a GPS class.

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