Dredgers usually adopt a multi-layer flat bottomed ship design, which has good stability and load-bearing capacity and can cope with various complex water environments. Sand dredgers, on the other hand, are usually designed with single-layer or double-layer flat bottomed boats, which have a relatively simple hull structure and mainly meet the needs of sand mining in waterways and other water areas. Dredgers are mainly used in water areas with silt accumulation, such as rivers, lakes, etc., with the main purpose of maintaining smooth navigation channels or clearing floating debris. And sand dredgers are mainly used in large-scale construction and earthwork projects, to excavate sand or soil for construction purposes.

The working principle of a dredger is relatively simple and efficient. It mainly utilizes its own excavation equipment, such as grab buckets, suction pipes, etc., to conduct excavation operations underwater. The excavated sediment is transported through pipelines to designated locations, such as the shore, barges, or other treatment facilities. The dredger is also equipped with a powerful power system and positioning system to ensure stable and accurate operation in complex water environments.