Cutterhead / Cutter Wheel Dredger
High-Performance Dredging Technology for Demanding Deposits
Cutter wheel dredgers and cutter suction dredgers belong to the category of mechanical cutter suction dredgers. They combine the mechanical excavation of in-situ material with hydraulic transport, making them particularly suitable for deposits where conventional suction dredging reaches its limits due to compacted or cohesive layers.
The basic design of both dredger types is similar: A vertically adjustable ladder supports the cutting equipment and guides the suction pipe directly to the excavation area. The mechanically excavated material is collected together with water and transported as a solid-water slurry by a high-performance dredge pump. The dredge pump, main drive system, and generally the required auxiliary equipment are housed within the central pontoon, where they are protected from external influences. Additional flotation pontoons arranged along the sides provide the necessary buoyancy and stability.
The key difference between the two dredger types lies in the cutting equipment and the resulting excavation method.
Cutter Wheel Dredgers – Controlled Excavation at Great Depths
In a cutter wheel dredger, a large rotating cutter wheel is installed at the lower end of the ladder. The axially oriented wheel body is equipped with robust, wear-resistant cutting edges or excavation tools. As the wheel rotates, these tools continuously engage with the in-situ material, mechanically excavating it from the deposit.
The suction pipe extends laterally into the cutter wheel housing, allowing freshly excavated material to be collected directly within the cutting area. The dredge pump generates the required flow and transports the solid-water slurry through the connected pipeline to a processing facility or designated discharge location.
During excavation, the entire ladder and rotating cutter wheel are lowered in a controlled manner. Unlike a conventional cutter suction dredger, this configuration does not perform a lateral swinging cutting movement. Instead, the cutter wheel advances into the deposit through the downward movement of the ladder.
Thanks to this operating principle and the robust design of the cutting equipment, cutter wheel dredgers are particularly suitable for continuous raw material extraction. Depending on the cutter wheel configuration and the cutting tools used, materials such as sand, gravel, silt, clay and other cohesive materials, as well as more heavily compacted deposits, can be excavated.
Cutter wheel and bucket wheel systems are also used in underwater mining operations, including the extraction of mineral resources.
A major advantage of our cutter wheel dredgers is their ability to operate at considerable depths: Depending on the project-specific configuration, dredging depths of up to approximately 40 metres can be achieved.
Cutter Suction Dredgers – High-Performance Excavation Through Swinging Movement
In a cutter suction dredger, an approximately hemispherical, rotating cutter head is mounted at the front of the lower end of the ladder. Replaceable, wear-resistant cutting teeth are installed on its cutter arms. As the cutter head rotates, these teeth penetrate the in-situ material and mechanically excavate it.
The suction pipe extends into the cutter head from behind, collecting the freshly excavated material directly at the cutting face. In combination with the dredge pump, this creates a continuous process of mechanical excavation, suction, and hydraulic transport.
Cutter heads can be specifically adapted to the geological conditions of each deposit through their geometry and the selection of cutting tools. Suitable systems are used across a wide range of materials, from loose sand to compacted sand, gravel, and clay, as well as soft rock and, with appropriately powerful equipment, hard rock.
The defining characteristic of a cutter suction dredger is its swinging excavation method. Initially, the cutter head is lowered into the deposit to a predetermined cutting depth. At the stern of the dredger, a spud is lowered into the ground to anchor the vessel and simultaneously provide the pivot point for the excavation movement.
Using laterally arranged cables and winches, the entire dredger, including the ladder and rotating cutter head, is then swung around this pivot point. The cutter head follows an arc-shaped cutting path through the deposit. Once a swing has been completed, the cutter head is advanced by a defined increment. The swinging movement is then repeated in the opposite direction. This method enables controlled, precise excavation in successive layers.
To advance across the excavation area, the dredger is equipped with a second spud. This spud is used alternately with the first, establishing a new, offset pivot point. By switching between the two spud positions, the dredger gradually advances across the deposit in a step-by-step movement.
This spud system is a characteristic feature of cutter suction dredger operations.
Depending on the project-specific configuration, our cutter suction dredgers can achieve dredging depths of up to approximately 20 metres.
For a Wide Range of Materials and Applications
By combining mechanical excavation with hydraulic transport, cutterhead and bucket wheel dredgers can also extract materials that are difficult or uneconomical to recover using conventional suction dredgers.
Typical applications include:
- Extraction of Sand and Gravel
- Excavation of Clay and Cohesive Soils
- Extraction from Compacted Deposits
- Extraction of Mineral Raw Materials
- Underwater Mining and Resource Extraction
- Deepening and Creation of Excavation Lakes
- Port, Canal, and Hydraulic Engineering
- Land Reclamation and Infrastructure Projects
- Cleaning and Desilting of Reservoirs
Custom-Engineered for the Deposit and Dredging Requirements
Cutterhead and cutter wheel dredgers are built using a pontoon-based design and dimensioned to meet the specific requirements of each project. The size and geometry of the main pontoon, dredge pump capacity, drive power, pipe diameter, ladder length, as well as the type and dimensions of the cutting equipment, are tailored to the characteristics of the deposit, the required dredging depth, and the desired production capacity.
The result is not a standardized solution, but a custom-engineered dredging system designed to match the material characteristics, dredging depth, and production requirements. The key to achieving optimal performance lies in the interaction between the cutting technology, suction system, pump capacity, and hydraulic solids transport. Only when these components are precisely matched can efficient, high-performance, and cost-effective dredging operations be achieved.
Pictures of a Cutter Suction Dredger
Pictures of a Bucket-Wheel Excavator
