Among the challenges a landfill environment can pose to a compactor is unpredictable and uneven terrain. The circumstances at Bees Ferry are no different. This can cause modified wheel loaders and other machines to experience situations where only three wheels are making contact with the ground below. The inability to keep all four wheels on the ground not only hurts the machine's efforts to maintain traction, but also results in a lower percentage of waste that is actually compacted.

The scrapers keep the wheels clean so we can get full penetration into the material we're compacting.

Dukes pointed out that this issue hasn't been a concern with the BOMAG units, thanks to their center articulation joints and hydrostatic drive systems. "They have an independent motor on all four wheels, so they all pull," said Dukes. "And the articulation pivot keeps all the wheels on the ground, unlike other machines I've seen."

Maintaining full ground contact with the wheels is obviously beneficial, but it only makes a real difference if the wheels can also stay free of debris and properly compact waste as they roll over it. "When we've run over refrigerators, pieces of tin and other things with some of the other machines we've used, that stuff will just stick to the wheel and stay there," said Dukes. "But with the wheel scrapers in place on the BOMAG machines, it isn't a problem. That's a big thing because we use a sticky clay as cover material, which causes a lot of dirt accumulation on regular wheels. The scrapers keep the wheels clean so we can get full penetration into the material we're compacting."