In modern dredging projects, soil conditions can vary significantly, ranging from soft clay and mud to dense fine sand and hard clay. Selecting the right drag head is essential for maintaining dredging efficiency, reducing energy consumption, and ensuring stable operation of trailing suction hopper dredgers (TSHDs).

As the key excavation equipment of a trailing suction hopper dredger, the drag head directly affects the dredger’s cutting performance, soil intake efficiency, and overall production capacity.

Hansel Marine develops and manufactures a wide range of drag head solutions designed for different dredging environments, providing reliable excavation performance for both new dredger construction and existing vessel upgrades.

During dredging operations, a trailing suction hopper dredger moves forward at a low speed while the drag head travels along the seabed.

Through the combined effects of negative pressure suction, high-pressure water jetting, and tooth cutting, the drag head breaks and loosens the seabed soil beneath the suction opening.

The loosened soil is mixed with water to form a slurry. Driven by the pressure difference generated by the dredge pump, the slurry enters the drag head and is transported through the suction pipe system into the hopper, completing the dredging process.

Different soil conditions require different excavation strategies. To improve drag head adaptability, Hansel Marine has carried out extensive research on:

• High-pressure water jet systems
• Nozzle arrangement and configuration
• Tooth design and cutting angle adjustment
• Internal flow optimization
• Slurry transportation performance

By combining numerical simulation analysis, flow field optimization, and dredging system matching technology, we have optimized the internal structure, hydraulic performance, and slurry flow characteristics of drag heads.

The general sand/clay drag head series is our most standardized and widely applicable drag head solution.

This series adopts modular and standardized components, including:

• Replaceable teeth
• Wear-resistant blocks
• Optimized water jet nozzles

It is suitable for common dredging conditions such as:

• Fine sand
• Coarse sand
• Mud
• Soft clay

The drag heads are designed for trailing suction hopper dredgers with hopper capacities ranging from 2,000 m³ to 35,000 m³, meeting the requirements of both new vessel construction and retrofit projects.

Dense fine sand is one of the challenging soil conditions for trailing suction hopper dredgers due to its high cutting resistance and reduced intake efficiency.

To overcome these challenges, Hansel Marine developed a specialized dense fine sand drag head equipped with:

• Adjustable tooth angle design
• A movable hood with a maximum opening angle of 50°
• Multiple high-pressure water jet systems
• Special cutting teeth with integrated cutting edges

The optimized structure effectively reduces soil cutting resistance and improves excavation efficiency in dense fine sand conditions.

This drag head can be directly installed on trailing suction hopper dredgers for demanding fine sand dredging projects.

Hard clay presents significant challenges for conventional drag heads due to its high strength and low permeability.

Hansel Marine developed an ultra-high-pressure jet drag head specifically designed for hard clay excavation.

With a maximum water jet pressure of 38 MPa, the system uses high-speed water jets to assist cutting, break down hard clay, and improve soil fluidization.

Compared with conventional drag heads, this solution significantly improves excavation capability under difficult soil conditions.

It is particularly suitable for:

• Navigation channel dredging
• Harbor basin excavation
• Hard clay seabed improvement projects

Hansel Marine has independently designed, manufactured, and supplied various types of drag heads, with applications covering trailing suction hopper dredgers from 2,000 m³ to 35,000 m³ hopper capacity.

Whether dealing with conventional dredging conditions such as sand, mud, and soft clay, or challenging soils including dense fine sand and hard clay, Hansel Marine provides customized drag head solutions based on:

• Soil characteristics
• Vessel specifications
• Dredging requirements
• Project conditions

Through standardized product design combined with customized engineering services, Hansel Marine helps customers improve dredging efficiency, reduce operational costs, and achieve more stable and productive dredging performance throughout the vessel lifecycle.