The present disclosure provides a dredging device including a body. The body includes a salvaging device salvaging sludge, a crushing device crushing the sludge, a sludge discharging device discharging the sludge, and an adjustiug device adjusting a height of the dredging device and moving. The salvaging device includes a driving wheel, a driven wheel, a transmission belt, salvaging hoppers. The dredging device further includes a second motor, crushing wheels, and a baffle. The second motor is turned on to drive a first gear to engage with second gears, so that rotating shafts drive the crushing wheels to crush sludge and larger stones. The baffle blocks an upper portion of the crushing wheels, which avoids the sludge splashing on a worker.

A trencher that is convertible between first and second trenching configurations so that when the trencher is in the first trenching configuration, a trencher boom includes a first trenching portion at the distal end of the boom and a second trenching portion that extends along a longitudinal axis from the first trenching portion toward the proximal end. The first trenching portion defines a first trench width, and the second trenching portion defines a second trench width. The first trench width is larger than the second trench width. The second trenching portion has a greater length measured along the longitudinal axis as compared to the first trenching portion.