The Traditional Double Girder Electric Crab Hoist is the main lifting mechanism of a double‑girder overhead crane. It travels along the main girder rails and carries either a winch or a fixed electric hoist as its lifting unit. This design makes it an ideal choice for crane maintenance workshops, DIY crane production, and general material handling in heavy industry.
The hoist can be equipped with CD‑type (single‑speed) or MD‑type (dual‑speed) wire‑rope electric hoists. These hoists are also widely used on monorail overhead cranes (straight or curved I‑beam tracks), gantry cranes, and jib cranes. Their compact construction, light weight, and high interchangeability have made them a standard lifting solution in industrial plants, mining, railways, wharves, and warehouses.
The entire crab unit is designed in accordance with Chinese national standard GB/T 3811 – Design Rules for Cranes and refers to European FEM standards, ensuring reliable performance and long service life.
⚠️ important – This equipment is NOT suitable for explosive, flammable, or highly corrosive environments unless special protection is provided.
Compact, lightweight – small building clearance and low wheel load.
Maximum lifting height – optimises workshop headroom.
Rugged crab frame – made of rectangular hollow steel sections for high strength with low weight.
Alloy steel wheels – high wear resistance and long travel life.
Modular design – easy to replace and maintain components.
Smooth travelling with optional variable frequency drive (VFD) .
Stable lifting and lowering, simple and safe operation.
High interchangeability of parts across different capacities.
Conical rotor brake motor – provides high starting torque and positive braking.
Insulation class B or F, protection class IP44 / IP54 (or higher on request).
| Component | Description |
|---|---|
| Lifting motor | Conical‑rotor three‑phase asynchronous brake motor; compact, reliable. |
| Gearbox | Three‑stage fixed‑shaft helical gears, hardened alloy steel – long life, low noise. |
| Rope drum | Seamless steel tube – light, efficient power transmission. |
| Brake system | Asbestos‑free brake linings with cartridge‑type insert pads for easy maintenance. |
| Parameter | Range / Values |
|---|---|
| Lift capacity | 1 – 80 tonnes |
| Lift height | 1 – 120 metres |
| Span (bridge) | 7.5 – 31.5 metres (customisable) |
| Power supply | 220‑440V, 50/60Hz, 1‑phase or 3‑phase |
| Protection class | IP44 – IP55 (optionally higher) |
| Ambient temperature | –20°C to +40°C |
| Duty group | M3 – M4 (higher duty groups available on request) |
| Capacity (t) | Duty Group | Lift Height (m) | Lifting Speed (m/min) | Trolley Travel Speed (m/min) |
|---|---|---|---|---|
| 3.2 | M5 | 6/9/12/15/18 | 0 – 5.0 or 0 – 8.0 | 0 – 20 |
| 5 | M5 | 6/9/12/15/18 | 0 – 5.0 or 0 – 8.0 | 0 – 20 |
| 8 | M5 | 6/9/12/15/18 | 0 – 4.0 or 0 – 4.5 | 0 – 20 |
| 10 | M5 | 6/9/12/15/18 | 0 – 4.0 or 0 – 4.5 | 0 – 20 |
Other speeds, heights, and capacities can be engineered to order.
| Model | Lifting Speed | Best Use Case |
|---|---|---|
| CD‑type | Single fixed speed | General lifting tasks where precision is not critical. |
| MD‑type | Dual speed (normal + slow, ratio 10:1) | Precise positioning, delicate loads, or assembly work requiring smooth and accurate lifting. |
Note: CD models use a ZD‑series single‑speed motor; MD models use a ZDS‑series dual‑speed motor with separate windings for creep speed.
Manufacturing workshops (machinery, metallurgy, textile, food industry – non‑hazardous areas).
Warehouse and logistics centres.
Power stations and maintenance depots.
Railway workshops and container yards.
Assembly lines and crane DIY production.
The crab hoist can also be supplied as a stand‑alone unit for integration into custom gantry, jib, or monorail systems.
The brake motor is self‑braking – power failure automatically engages the brake.
All electrical components are protected against dust and moisture (IP44 standard).
Overload limiter and limit switches are included as standard.
Regular inspection of wire rope, brake linings, and gear oil is recommended.
Do not operate in ambient temperatures below –20°C or above +40°C without special modifications.
Do not use in explosive, flammable, or highly corrosive atmospheres unless specially protected.
To recommend the exact model that best suits your requirements, please provide the following details when enquiring:
Lift capacity (tonnes).
Lift height (metres).
Type of load – what will be lifted (e.g., steel coils, machinery parts, general cargo).
Power supply – voltage, frequency (Hz), and phase (1‑phase or 3‑phase).
Control type – manual (pendant) or electric (radio remote / cabin control).
(Optional) Desired lifting speed, travel speed, duty cycle, or special environmental conditions.
Our technical team will then customise a solution that fits your crane structure and operational needs.
Yuantai Crane reserves the right to modify specifications without prior notice
LINKS : Dongqi Crane