Chain trenchers: the chainsaw of the earthmoving world A chain trencher digs a trench with a continuous loop of chain wrapped around a long steel boom, called the digging bar. Instead of scooping soil in batches like an excavator, it cuts in one uninterrupted pass, producing a narrow trench with straight walls and a consistent depth. How the system works: - A hydraulic motor drives a sprocket at the top of the boom, pulling the chain around the bar - Cutting teeth bolted to the chain bite into the ground as they travel down and forward - The chain carries loosened soil up out of the trench - A spoil auger at the surface pushes that material to the side so it stays out of the cut - A crumber shoe behind the chain scrapes loose debris off the trench floor - The operator lowers or raises the boom angle to set trench depth while the machine creeps forward Why the teeth matter: - Cup-style teeth scoop and carry soft soils and clay - Carbide-tipped rock teeth concentrate force into small ...