kettingbaggers

Kettingbaggers, known in English as bucket chain dredgers, are a class of dredging equipment designed to excavate sediment from the seabed, riverbeds, or other underwater deposits using a continuous chain of buckets arranged along a ladder. The bucket chain is driven around a circulation loop by surface-mounted or submersible drive gear. Buckets on the chain scoop material as they move downward, then discharge it as they rise, transferring the sediment to a discharge point on the vessel or to an adjacent hopper or conveyor. The equipment is typically mounted on a barge or spud-supported platform and can be fixed in position with spuds or anchors; a winch-and-pump system then moves the material to its destination. A bucket chain dredger may be self-propelled or towed and is operated by trained crews.

Use: They are employed in maintenance dredging to deepen or widen navigation channels and berths, harbor approaches, and coastlines; they are also used in land reclamation projects and mining operations for sand and gravel.

Advantages and limitations: Bucket chain dredgers offer high production rates in soft substrata and can reach work areas that are difficult for other equipment. They can operate with limited space and under variable weather. Limitations include limited effectiveness in hard or rocky deposits, generation of turbidity and seabed disturbance, and high capital and operating costs.

History: Bucket chain dredgers have a long history dating to the 19th century and were widely developed in Europe and North America, with ongoing modernization in materials and hydraulics. They remain in use in large dredging projects and specialized applications.