Difference Between a Rubber-Tired Gantry Crane (RTG) and a Mobile Crane

These are two fundamentally different types of lifting equipment designed for distinct applications.

1. Rubber-Tired Gantry Crane (RTG)

Purpose: Primarily installed in production workshops and outdoor yards for the lifting and transport of large workpieces.

Structural and Operational Characteristics:

• Structural Design: Typically employs a double main girder structure. Each girder has two movable trolley lifting points. The distance between these two points on a girder is connected by an adjustable linkage, controlled by a single hydraulic cylinder. This creates a total of four lifting points across the two girders.
• Lifting Mechanism: These four points connect to four corresponding points on the spreader (or lifting beam). Lifting is achieved through the synchronous extension of four hydraulic outriggers/legs, raising the entire load.
• Full System Composition: Consists of a complete structural gantry, travel mechanism, hoisting mechanism, hydraulic control system, electrical control system, power supply system, and safety devices.
• Undercarriage & Mobility: Uses polyurethane wheels with steel cores, which reduce ground damage during steering while maintaining high friction. Each wheel assembly has its own steering system, allowing for synchronous steering of wheels on the same axis, enabling straight travel, crabbing (sideways movement), and 0–90° steering on-site.
• Hoisting Method: The primary hoisting action is performed by hydraulic cylinders that lift the load.

2. Mobile Crane (Truck-Mounted Crane)

Purpose: A crane mounted on a standard or specially designed truck chassis. The truck cab and the crane operator’s cab are separate.

Key Advantages and Disadvantages:

• Advantages:
  • Excellent Mobility: Can travel quickly on public roads between job sites under its own power.
  • Fast Setup/Teardown: Relatively quick to deploy once on site.
• Disadvantages:
  • Requires Outriggers: Must deploy outriggers for stability during lifting operations. It cannot lift and travel with a load.
  • Terrain Limitations: Unsuitable for soft, muddy, or uneven ground due to stability requirements and ground pressure.

3. Key Comparative Summary