Clamshell buckets Manufacturers online

Clamshell buckets are gripping tools that are often used on cranes or excavators to pick up and move bulk materials, scrap, wood or other loose materials.

They consist of two movable shells that close against each other to enclose the material.

Below you will find a description of how clamshell buckets work, their design and variants, and how they are used, as well as a brief overview of their advantages:

Functional principle of clamshell buckets:

When the open gripper is lowered into the bulk material, the shells penetrate the material due to their own weight or additional closing.
When the shells are closed, the particles are enclosed by the concave shape.
To empty, the gripper is opened and the material falls out.

Structure of clamshell buckets:

1. Gripper shells: Two half-shell-shaped shells that can be moved via joints.
2. Support frame / grapple bracket: Connects the shells to the attachment, e.g. crane hook or hydraulic boom.
3. Drive mechanism: Moves the shells to open or close them. This can be done by:
   Rope pull control: Common in cranes. One or more ropes control the opening and closing.
   Hydraulic drive: Via cylinders, mostly in excavator applications.
   Mechanical lever mechanisms: Rarer, mostly for special purposes.

Variants of clamshell buckets:

Depending on the requirements, clamshell buckets differ in:

1. Open or closed shells: open clamshell buckets for coarse materials, and closed clamshell buckets for fine-grained bulk materials to prevent material loss.
2. With or without teeth: Teeth improve penetration into solidified material.
3. Hydraulically or mechanically operated: Hydraulic systems allow for higher closing forces and more control.
4. Rotatable design: With integrated rotator for precise positioning.

Areas of application for clamshell buckets:

The most important areas of application for clamshell buckets can be summarized as follows:

1. Bulk material handling:
Transportation and loading of sand, gravel, coal, ore, grain and similar materials in ports, transshipment points or silos.

2. Scrap and recycling management:
Receiving and handling scrap metal, construction waste and bulky waste materials.

3. Waste management:
Grabbing and moving household and industrial waste to sorting facilities or incinerators.

4. Wood and forestry:
Handling tree trunks, logs and wood chips.

5. Construction and civil engineering:
Excavation and dredging work, especially for soil material, gravel or underwater dredging.

6. Port and ship handling:
Loading and unloading ships with bulk or recycling material.

Advantages of clamshell buckets:

• Efficient handling of large quantities of material.
• Adaptable to different materials and operating conditions.
• Relatively simple design and robust construction.

Clamshell buckets are versatile tools for handling bulk materials, scrap, wood and waste. They offer an efficient way of moving large quantities of material safely and quickly, particularly in areas such as port handling, recycling, construction and forestry. Their adaptability - for example through different shell shapes or drive types - makes them an indispensable part of modern handling and material flow systems.

Here you will find an overview of the most important criteria to look out for when buying clamshell buckets:

When purchasing clamshell buckets, there are several technical, economic and application-specific factors to consider in order to ensure efficiency, safety and cost-effectiveness of use.

• The area of application and the properties of the material to be moved determine the requirements for the gripper:
• Type of material to be moved: bulk material, scrap, wood or waste. Fine-grained materials such as sand or grain require closed shells, while coarse materials allow open shells.
• Material density and weight: The grab size and load capacity must be matched to the density of the material in order to avoid overloading.
• Abrasiveness and wear behavior: Highly abrasive materials such as ore, scrap require highly wear-resistant materials or additional wear bars.
• Nominal load and grab volume: The grab must not exceed the load capacity of the crane or excavator.
• Optimum filling ratio: The grab should be designed so that it is loaded as full as possible for each pick-up in order to achieve a high handling capacity.
• The choice of drive type and the type of control depends on the design of the crane or excavator on which the grab is to be operated:
• Hydraulic drive: Provides high closing force, precise operation and is standard for excavator applications.
• Cable pull operation (mechanical or electro-hydraulic): More common on harbor cranes, requires a suitable crane control system.
• Compatibility: The grab must be compatible with the existing hoist: Pressure, oil quantity or rope guide.
• Slewing gear: 360° endless rotation is advantageous for precise positioning, especially in tight spaces.
• Additional functions: Quick-change systems, wear protection plates or integrated weighing devices can increase efficiency.
• The purchasing department should keep an eye on the material quality and any necessary wear protection:
• High-strength steels are required for durability and high loads.
• Teeth, cutting edges and shells should be easy to replace in order to reduce maintenance costs.
• Lubrication points, hydraulic lines and bearings should be easily accessible for simple maintenance.
• The manufacturer should ensure fast spare parts supply to minimize downtime.
• An overload protection device offers protection against damage in the event of incorrect loading.
• A sturdy locking mechanism prevents unintentional opening during transportation.
• When purchasing, look for CE marking and compliance with relevant standards such as EN 13155.
• Purchasing should also take into account cost-effectiveness and life cycle costs:
• Inexpensive models can result in higher maintenance and repair costs.
• Lower hydraulic consumption or optimized controls reduce operating costs.
• High-quality materials and design pay off in the long term.
• Maintenance contracts, on-site service and training are a plus.
• Longer warranty periods indicate the manufacturer's confidence in the product quality.

When purchasing clamshell buckets, it is crucial that the bucket is precisely matched to the area of application and the material. Important criteria include the right shell shape and size, sufficient load capacity in conjunction with the existing crane or excavator and the choice of drive type (hydraulic or cable-operated). Additional equipment such as slewing gears or wear protection increase efficiency and service life.

Clamshell buckets can be purchased from various suppliers. You will find comprehensive information on manufacturers and suppliers of Clamshell buckets around the world on Exportpages.