Double-girder rubber-tyred gantry crane

Structure and operating principle

A double-girder mobile gantry lifts and transfers heavy fabricated structures, precast components, tanks and machinery.

A portal frame combines overhead lifting with rubber-tyred ground travel. Wheel reactions, steering geometry and load position jointly affect stability; the power and lifting arrangements remain specific to the selected model.

• Double main girders provide the lifting-unit support arrangement.
• Diesel or electric configurations for different site power conditions.
• Model-specific portal width and lifting height accommodate different load envelopes.

Application and selection

Serves heavy fabrication and yard transfer where fixed rails are unsuitable. A route survey must check floor strength, slopes, joints, overhead clearance and turning space for the complete machine and load.

Working method

1. Before work, authorised personnel confirm the load and its centre of gravity, the permitted machine configuration, the route and receiving position. Complete the checks specified for the equipment, verify protective functions by the approved method and stop if a defect affects safe operation.

2. Establish the permitted lift-and-travel mode, centre the load within its approved support geometry, and make a controlled lift. Travel only at the load height, steering mode and speed allowed by the machine instructions, then set down at the prepared position.

3. After the task, place the load on stable supports and leave the equipment in its prescribed safe state. Record faults and abnormal events. Maintenance or jam clearance requires secure isolation of relevant energy, including stored hydraulic, pneumatic and gravitational energy.

Precautions and maintenance

Do not assume every model permits travel with a suspended load on any slope. Protect the swept path from pedestrians and stop for tyre, steering, brake or hydraulic faults; never bypass levelling or motion interlocks.

Inspection frequency, wear/discard criteria, lubrication, brake adjustment and replacement parts follow the supplied instructions and applicable local requirements. Only competent personnel may maintain the equipment; return to service follows the prescribed checks.

Configuration and standards

This is an equipment-selection and operating-principle overview, not a complete operator manual, lift plan or certificate. Verify rated load, duty, geometry, environment and protective functions against the nameplate, approved drawings and delivered instructions. Do not combine separate series maxima into one promised configuration.

Requirements follow the destination and installation, not the website language. China: determine the applicable GB/T references and statutory equipment obligations. EAEU destinations: check the applicable TR CU/EAEU regulations, amendments and conformity documents. English-speaking markets: select the relevant national rules; US OSHA and UK HSE references are not universal law. EU projects require their own applicable conformity assessment.