A grab bucket bridge-type unloading crane is an efficient mechanical device specifically designed for handling bulk cargo. With a sophisticated and precise structural design, it aims to meet the demands of fast, safe, and efficient operations.
First, the boom system is one of the core components of the grab-type ship unloader, providing a sufficient working range. The boom is typically made of high-strength steel, offering excellent rigidity and stability to prevent deformation or swaying during large-scale movements. It is connected to the main body via hinges and can be luffed using hydraulic or electric drive systems.
Second, the grab bucket mechanism is the part that directly contacts the cargo. Depending on the type of materials being handled (such as coal, ore, grain, etc.), various types of grabs can be selected, such as double-rope grabs or multi-petal grabs. The design of the grab must ensure efficient loading while preventing spillage during lifting. Grabs are generally equipped with automatic opening and closing mechanisms, controlled by wire ropes or hydraulic cylinders.
Third, the hoisting mechanism is responsible for the lifting and lowering of the grab, including components such as winches, wire ropes, and pulley blocks.
In addition, the travelling mechanism allows the entire machine to move along rails, enabling it to cover the full length of the dock and reach different areas of a ship. This mechanism is typically driven by electric motors in conjunction with a gear transmission system for smooth and rapid movement. To ensure stability and safety on the rails, the system is also equipped with anti-slip devices and limit switches.
Grab bucket ship unloaders are widely used in coal handling operations, enabling the fast and efficient unloading of coal from cargo ships to stockyards or transport vehicles.
For mineral resources such as iron ore and copper ore, which are typically transported by large cargo ships, grab bucket ship unloaders can unload these materials quickly and accurately for further transfer or storage.
Grains, soybeans, and other agricultural products play an important role in international trade. Grab bucket unloaders can complete the loading and unloading tasks swiftly while ensuring the integrity of the cargo.
At major rail freight stations, grab bucket unloaders are used to load and unload bulk goods such as coal and ore transported by rail, ensuring timely transfer of cargo to its destination.
Inland ports and intermodal logistics hubs are also key application scenarios for grab bucket ship unloaders. They effectively connect water, rail, and road transportation to facilitate efficient cargo distribution.
At mine export terminals or transfer points, grab bucket ship unloaders are used to load extracted ores onto vessels or to unload imported machinery and materials for use in the mine.
| Performance Parameters of Bridge-Type Grab Ship Unloader | ||
| Item | Parameter Range | Technical Notes |
| Rated Unloading Capacity | 1000–5000 t/h | Suitable for coal, iron ore, soybeans, and various other materials |
| Grab Bucket Capacity | 8–50 m³ | Wear-resistant teeth (high-chromium cast iron), lifespan ≥ 2 years |
| Working Range | 25–45 m | Max outreach can achieve a grabbing depth of up to 18 m |
| Hoisting Speed | Full load: 60 m/min | Four-drum synchronous control, with acceleration optimization |
| No load: 120 m/min | ||
| Traveling Speed | 20–30 m/min | Rail-type traveling; adaptive to track deviation ±50 mm |
| Duty Class | A8 (ISO 4301 Standard) | Continuous operation ≥ 18 hours/day |
The grab unloader can handle large volumes of bulk materials such as coal, ore, and grain quickly and effectively. Its powerful hoisting system and advanced control technology enable high-speed and stable operations, allowing the processing of thousands of tons of material per hour. This efficiency reduces vessel dwell time at the port and significantly enhances overall logistics throughput.
With various grab types available, the machine can be adjusted or swapped to suit different types of materials—whether bulk, granular, or powdered. For example, double-rope grabs are ideal for loose materials, while multi-petal grabs are suitable for handling fine particles or powders.
The grab ship unloader features an intelligent automated control system with functions such as smart path planning, automatic cargo status detection, and optimized grabbing strategies. These innovations improve operational precision, reduce human error, and support semi-automatic or fully automatic working modes, further enhancing efficiency and safety.
Modern grab unloaders are designed with energy conservation and emission reduction in mind. Efficient drive systems and optimized hydraulic control technologies are employed to significantly lower energy consumption and environmental emissions.
1. Industry Position
Founded in 2006, Dafang Heavy Machinery covers an area of 1,580 acres and employs over 2,600 people. With an annual sales revenue of 3.566 billion RMB, the company focuses on two main business sectors: lifting machinery and steel structures. Major products include single and double girder bridge and gantry cranes, electric hoists, steel structure bridges, prefabricated buildings, and industrial plants. Dafang serves critical sectors such as military industry, aerospace, nuclear power, offshore engineering, metallurgy, and mining. Its products are exported to over 100 countries and regions, including the United States, Russia, and Southeast Asia.
Annually, Dafang manufactures 30,000 single-girder cranes, more than 12,000 double-girder and gantry cranes, and 30,000 electric hoists. Based on production scale, sales volume, and brand recognition, the company ranks among the top three in China’s crane industry.
2. Core Technologies
Dafang’s R&D team consists of over 260 members, including 104 with senior or intermediate engineering qualifications. The company invests 3.8% of its annual sales into technology development. It has obtained 12 international invention patents, 50 national invention patents, 415 utility model patents, and achieved 43 scientific and technological milestones. Dafang was the first in the industry to adopt anti-sway and automatic positioning technologies.
In 2016, Dafang became the first enterprise in Henan Province to implement smart crane applications and to introduce remote monitoring technology. The company also developed the multifunctional brewing crane, filling a domestic market gap. In 2021, Dafang was the first in the industry to be certified for unmanned intelligent cranes. In 2022, it undertook a project for a tower crane at a commercial satellite launch site.
3. Manufacturing Capability
Dafang Heavy Machinery is equipped with advanced in-house designed manufacturing equipment, including 1,500-ton press grooving machines, extrusion machines, and roller machines. The company has established leading domestic workshops, including an electrical assembly line, steel pre-processing line, paint finishing line, and China’s first practical single-girder lean production line. Precision machinery includes imported German NILES CNC gear grinding machines and Japanese MAZAK machining centers.
Dafang strictly follows refined manufacturing processes, adhering to the principle of “doing it right the first time, zero defects.” This commitment to quality is deeply ingrained in every employee, ensuring that every product delivered meets the highest standards.
4. Service Assurance
Dafang upholds a “comprehensive, high-quality” service standard, providing users with fast, attentive, and thorough one-stop services. With 24/7 online support, choosing Dafang means complete peace of mind. Just tell us what you need—we’ll take care of the rest.
It is mainly used for bulk materials like coal, iron ore, and grain, with various grabs such as clamshell or multi-leaf types available.
Yes, we offer optional PLC control systems with intelligent path planning, state recognition, and remote control functions.
The entire system is modular in design, allowing easy installation. On-site guidance or full installation service is available.
The crane is equipped with limit switches, anti-slip devices, and emergency stop systems to ensure operational safety.
