GB/T 31052.1-2014 Crane Inspection and Maintenance Standards

GB/T 31052, Lifting Appliances—Code of Inspection and Maintenance, is a multi-part series standard. Part 1, published in 2014, sets out the general requirements for crane inspection and maintenance. It applies to overhead, gantry, tower, and mobile cranes, and serves as the core basis for user units to establish their equipment inspection and maintenance systems. Kelude Heavy Industry develops custom inspection and maintenance programs in accordance with this standard to ensure compliant equipment operation.

Three-Tier Inspection Framework Explained

The standard defines a three-tier system comprising daily inspection, periodic inspection, and thorough examination. Daily inspection is performed by the operator at the start of each shift, covering brake working condition, wire rope wear and lubrication, limit switch reliability, and running sounds of all mechanisms. Any abnormality found requires immediate shutdown and reporting for repair. Periodic inspection intervals are determined according to working class—quarterly for grades A3 to A5, and monthly for grades A6 to A8—and is carried out by maintenance personnel covering crane wheel wear, gearbox oil quality, coupling shaft alignment, and electrical insulation. Thorough examination is conducted annually by an equipment engineer or a third-party inspection body, focusing on main girder camber, cracks in the metal structure, wheel skew, and load testing.

Each tier has a clearly defined role: the operator handles day-to-day safety checks, the maintenance technician performs scheduled technical servicing, and the engineer oversees the annual comprehensive assessment. Results from each tier are recorded separately in the operation log, inspection checklists, and thorough examination report, building a complete equipment health record. The tiers are interlinked—issues found during daily inspection should be incorporated into the periodic inspection plan, and structural concerns identified during periodic inspection should be re-examined in detail during the thorough examination. If any tier uncovers a major hazard, the crane must be taken out of service immediately; operation under faulty conditions is not permitted.

The key advantages of the three-tier system are comprehensive coverage and layered accountability. Daily inspection serves as the safety baseline, periodic inspection provides preventive maintenance, and thorough examination delivers an in-depth health assessment. All three are indispensable and mutually reinforcing. User units should develop inspection plans and procedures tailored to their equipment types and working classes, defining the specific items, acceptance criteria, and record formats for each tier. For newly installed or overhauled cranes, a thorough examination must be carried out before the crane is put into operation to establish the baseline technical condition.

Inspection Item Classification and Criteria

The standard classifies inspection items into three categories: Category A (safety devices), Category B (primary load-bearing structural components and mechanisms), and Category C (general items). Category A items must be checked at every inspection and include the Lifting Height Limit Switch, trolley travel limit switch, Overload Limiter, Wind Protection Device / Rail Clamp, and emergency stop switch. Category B items are covered during periodic and thorough inspections and include the main girder, end carriage, outrigger, crane wheel, brake, gearbox, and wire rope. Category C items cover general checks such as lubrication, fasteners, lighting, and signaling devices.

Any non-conformance in Category A safety devices requires immediate shutdown and rectification, as these defects directly endanger personnel. Defects found in Category B items must be rectified—through repair welding, replacement, or reinforcement—before the crane is returned to service. Category C items may be corrected before the next scheduled inspection, but they must still be recorded and assigned a maintenance work order. The standard specifies clear inspection methods, acceptance criteria, and corrective actions for each category, and inspectors must follow these requirements strictly rather than relying on experience or lowering the bar.

The specific acceptance criteria for Category A safety devices are as follows: limit switches must actuate accurately and reliably, with the hook or trolley coming to an automatic stop no less than 200 mm from the end limit position after the switch is tripped. The Overload Limiter must reliably trigger an alarm and cut hoisting power at 110% of rated load. The Wind Rail Clamp or anchor device must operate smoothly and, once engaged, withstand the wind load generated by the local maximum wind speed. The emergency stop switch must interrupt the crane's main power supply and latch in the off position, requiring manual reset. The Undervoltage Protection device must prevent the crane from restarting automatically after a power supply interruption; the start button must be pressed again to resume operation.

Inspection Records and Retention Requirements

Daily inspection records must be entered in the equipment operation log and retained for at least one year. Periodic inspection records are archived in checklist form and kept for at least three years. Thorough examination results must be documented in a formal inspection report, filed in the equipment technical documentation, and retained until the crane is scrapped. Records must include the inspection item, inspection results, issues identified, corrective actions taken, and the inspector's signature. Records must be truthful, complete, and legible, with no alterations; any correction must be made with a correction stamp and signature.

User units must maintain a technical documentation file for each crane, containing manufacturing documentation (Factory Certificate, drawings, Manual, etc.), Installation Acceptance documentation, daily operation records, periodic inspection records, Maintenance records, retrofit records, and accident records. The equipment file must be transferred with the crane. File administrators should periodically verify the completeness of the records to prevent loss. Digitalized equipment management systems are encouraged, with all inspection records archived electronically and searchable by date, item, and personnel.

Inspection records are critical evidence for accident investigation and liability determination. In the event of a safety incident, complete inspection records enable investigators to trace the crane's technical condition prior to the accident and determine whether potential hazards were identified and addressed in a timely manner. Record completeness, authenticity, and traceability are therefore essential. It is recommended that standard-format inspection checklists be used, with inspectors signing off after completion and supervisors or safety managers conducting a secondary review and countersignature to establish a complete audit trail.

Inspector Qualifications and Training Requirements

The standard specifies different qualification levels for the three tiers of inspection. Daily inspections are carried out by crane operators, who must hold a valid special equipment operator certificate (Q2) and be familiar with the equipment's structure, performance, and safe operating procedures. Periodic inspections are performed by maintenance personnel, who must have proven experience in mechanical and electrical maintenance, hold the relevant special operations certificate, and be proficient in the adjustment and replacement procedures for various crane mechanisms. Thorough examinations must be conducted by equipment engineers or delegated to a qualified third-party inspection agency. Personnel performing these examinations must hold an intermediate or higher professional technical title and have completed specialized training in crane inspection.

User units are responsible for providing regular training and assessment for their inspection personnel. The training curriculum covers standard procedures, hands-on inspection methods, the use of detection instruments, fault diagnosis, and safety guarding practices. Training for operators on daily inspection procedures should be organized quarterly by the equipment management department. Training for maintenance personnel on periodic inspections should be conducted semi-annually. Inspectors performing thorough examinations must complete no less than 24 hours of professional training annually. Personnel who fail the training assessment are not permitted to conduct inspections independently. User units must maintain training records for all inspectors, documenting the training date, content, and assessment results.

Three-Tier Inspection System Comparison

The following comparison table summarizes the key differences between daily, periodic, and thorough inspections regarding frequency, responsible personnel, inspection items, and record-keeping requirements. It serves as a practical reference for equipment management departments when planning inspection schedules and training programs.

Frequently Asked Questions