A QZ Grab Overhead Crane is a double girder overhead crane fitted with a grab bucket for bulk material handling. It is commonly used for coal, ore, limestone, scrap, sand, clinker, and other loose materials in steel plants, ports, power stations, cement plants, and waste treatment facilities.
The crane uses a four-rope grab bucket to pick up, transport, and discharge bulk materials. Grab bucket type, lifting capacity, span, lifting height, working duty, and control method are selected according to the material characteristics and site conditions. Different configurations are available for indoor, outdoor, and automated handling systems.
QZ Grab Overhead Cranes are divided into single girder and double girder types. Single girder cranes are commonly used for light-duty bulk material handling with smaller grab capacities. Double girder cranes are used for larger grab buckets, higher lifting capacities, and continuous operation in steel plants, mines, power stations, and other heavy industrial facilities. Grab bucket type, span, lifting height, and control method are selected according to the material and operating conditions.
The main girder is a single box-type or I-beam structure. The structure is relatively simple and the manufacturing cost is lower. It is used in applications with lower lifting capacity, shorter span, and limited space requirements, such as small warehouses or workshops.
This is the most common standard QZ-type crane. It uses two parallel main girders with a rigid structure and high stiffness. It handles larger load capacities and spans, with stable operation. It is widely used in heavy industry sectors such as ports, power plants, steel mills, and cement plants for bulk material loading and unloading.
The QZ Grab Overhead Crane consists of the bridge frame, trolley, grab bucket, traveling mechanism, hoisting and opening-closing mechanism, electrical system, and safety and auxiliary devices.
QZ Grab Overhead Crane: each part works together for bulk material handling in ports, steel plants, power plants, and similar industrial sites.
To learn more about the functions of safety devices, read the article: “Overhead Crane Safety Devices: Types, Functions, and Working Principles”
QZ Grab Overhead Crane is used for bulk material loading and unloading. Parameter configuration is directly related to actual working conditions. Lifting capacity, span, lifting height, speed, and grab bucket volume are selected based on material type, bulk density, and on-site operation method. Different application scenarios use different configurations.
| Parameter | Value |
|---|---|
| Rated Capacity | 3–30 t (typical 5–20 t) |
| Span | 7.5–40 m (typical 10.5–31.5 m) |
| Lifting Height | 6–40 m (typical 18–28 m) |
| Duty Class | A5–A8 (mainly A6–A7) |
| Hoisting Speed | 39.2–48.6 m/min |
| Trolley Speed | 43.2–45.9 m/min |
| Crane Travel Speed | 86.5–113.6 m/min |
| Grab Volume | 0.75–10 m³ |
| Power Supply | 3-phase, 380V, 50Hz |
| Operation Mode | Pendant / Cabin / Wireless Remote |
| Working Environment | Indoor / Outdoor |
| Temperature Range | -25°C to +45°C |
The specifications of the QZ-type grab bridge crane are configured based on on-site conditions, including technical parameters such as lifting capacity, span, lifting height, duty cycle, travel speed, and grab volume. WEIHUA can provide customized solutions tailored to different material types and operating frequencies.
The type of grab bucket is selected based on the physical properties of the material being handled, such as particle size, density, and shape, which directly affect grabbing performance.

The most common type, used for general bulk materials such as coal, sand, and grain.

More cutting edges and better penetration into material piles. Suitable for irregular materials such as large ore, scrap steel, and iron chips, as well as sticky materials like sludge.

Equipped with teeth on the bucket edge for handling larger block materials (typically above 200 mm), such as large ore and limestone

Works on a scissor mechanism, with increasing closing force during operation and a wide opening range. Suitable for yard cleanup and ship hold cleaning, but less effective for initial grabbing of large lumps.
Different grab buckets are designed for different bulk materials and operating conditions. The table below compares their structure, suitable materials, working characteristics, and applications.
| Comparison Item | Double Rope Grab | Multi-Tine Grab | Teeth Grab | Clamshell Grab |
|---|---|---|---|---|
| Structure | Two bucket shells connected by four wire ropes and a pulley system. | Multiple curved tines (typically 4–8) are mounted around a central hub. | Two bucket shells with reinforced cutting teeth on the bucket edge. | Two bucket shells with straight or curved edges, hinged at the top. |
| Opening / Closing Method | Opens when lowered and closes when lifted by the wire ropes. | Tines open when lowered and close toward the center when lifted. | Teeth penetrate the material during closing and grip the load. | Opens when lowered and closes when lifted to scoop material. |
| Typical Use | General bulk material handling. | Handling irregular, loose, or mixed bulk materials. | Digging and handling hard or compacted bulk materials. | High-capacity grabbing and dredging operations. |
| Suitable Materials | Coal, sand, gravel, grain, ore powder, and other loose bulk materials. | Scrap steel, municipal waste, sludge, clay, soft ore, and mixed materials. | Rock, limestone, cement clinker, hard ore, and oversized materials. | Large lump materials, dredged sediment, ore, and bulk cargo. |
| Recommended Material Size | Best for particle sizes below 100 mm. | Suitable for mixed particle sizes and irregular materials. | Best for particle sizes above 200 mm or compacted materials. | Suitable for medium to large lump materials and dredging work. |
| Key Features | Simple structure and stable operation. | Multiple tines provide a strong gripping force from different directions. | Reinforced teeth improve penetration into hard materials. | Large bucket capacity with efficient scooping performance. |
| Advantages | Low maintenance, reliable operation, high efficiency for loose materials. | Excellent gripping performance for irregular materials. | Strong digging capability and high wear resistance. | Large payload per cycle with good sealing performance. |
| Limitations | Not suitable for large blocks or compacted materials. | Lower filling efficiency when handling fine powders. | Higher self-weight and increased tooth wear. | Requires a larger opening space and is less suitable for fine materials. |
| Typical Duty Class | A3–A6 | A4–A6 | A5–A8 | A4–A8 |
| Typical Applications | Power plants, cement plants, mines, warehouses, and material yards. | Steel plants, scrap yards, waste treatment plants, ports, and recycling facilities. | Mines, quarries, cement plants, and steel mills. | Dredging projects, ports, shipyards, and bulk cargo terminals. |
The grab bucket directly affects material handling efficiency, filling rate, and service life. Different grab designs are suitable for different bulk materials, particle sizes, and working conditions.
For more information about grab bucket types, selection guidelines, and application differences, read our Crane Grab Bucket.
A QZ Grab Overhead Crane handles bulk materials with a grab bucket suspended from the trolley. During operation, the crane travels along the runway while the trolley moves across the bridge to the loading position. The grab bucket descends into the material pile, closes to collect the material, and is lifted to the required height. The crane then carries the load to the unloading point, where the grab opens to discharge the material before returning for the next operation.

coal, iron ore, clinker, grain, bulk cargo

scrap steel, iron ore, coke, sinter

coal, biomass fuel, and ash handling

limestone, clinker, gypsum, coal powder

ore, stone, tailings

municipal waste, sludge, recyclable bulk materials
QZ Grab Overhead Cranes are built for handling bulk materials such as coal, ore, sand, limestone, clinker, grain, scrap, and industrial waste. They are widely used in steel plants, mines, power stations, cement plants, and material storage yards for continuous loading, unloading, and stacking operations.
QZ Grab Overhead Crane is configured based on site conditions, material type, and working requirements. Design and selection are adjusted according to actual operational needs.
WEIHUA provides customized design and configuration according to project requirements and application conditions. We will configure a suitable double-hook overhead crane for your project.
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WEIHUA supplies QZ grab overhead cranes with full production capability, covering structural design, fabrication, assembly, testing, and delivery. Solutions are configured according to project requirements, including lifting capacity, span, grab type, and working duty class. Each unit is produced under industrial standards for long-term operation in demanding environments. For technical consultation, customization, or quotation, please contact us for detailed support. eeds. For technical support or project inquiries, contact us for a tailored solution.


It is used for loading, unloading, and transferring bulk materials such as coal, ore, sand, grain, and scrap steel.
Common applications include ports, steel mills, power plants, cement plants, mining sites, and waste handling facilities.
Options include rope grab, hydraulic grab, multi-jaw grab, and scissor grab, selected based on material type.
Standard range is 3–30 tons, with customized models available for higher requirements.
Yes. Span, lifting height, grab volume, control mode, and duty class can all be designed according to site conditions.
It is typically designed for A5–A8 working duty, suitable for frequent and heavy operation.
Pendant control, cabin control, and wireless remote control are available depending on application needs.
Overload protection, limit switches, emergency stop, and optional anti-collision and monitoring systems are available.
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