To further standardize safety management throughout the entire operational process of drum-driven belt conveyors (hereinafter referred to as “conveyors”), effectively prevent various safety incidents such as belt misalignment, belt tearing, fires, personal injury, and equipment damage, and ensure the continuous, stable, and efficient operation of the mine’s transportation system, these Detailed Rules are formulated in accordance with national and industry mandatory standards, including the Coal Mine Safety Regulations and the Safety Code for Belt Conveyors (GB 10595–2017), while taking into account the actual working conditions of mining, excavation, and transportation operations, equipment characteristics, and operators’ working habits. All lifecycle stages involving conveyor selection, installation, commissioning, operation, maintenance, overhaul, and decommissioning, as well as equipment management, operator practices, and on-site supervision, must strictly comply with the following provisions. The mechanical and electrical management department serves as the lead responsible department for implementing these Detailed Rules, tasked with oversight, enforcement, performance evaluation, and accountability; the user unit is the direct responsible entity, bearing responsibility for on-site operations and daily control; and all personnel at each post shall rigorously fulfill their job responsibilities to ensure that all requirements are effectively implemented.
I. Material Performance Requirements
 
(1) Key components such as conveyor belts, idlers, drum rubber coatings, and connecting fittings (including joint adhesives and bolts) manufactured from non-metallic polymers must meet the Class A flame-retardant performance requirements specified in MT 147–2005 “Flame-Retardant Conveyor Belts for Coal Mines.” Following flame-retardancy testing, there shall be no open-flame combustion or smoldering; the residual burned length must be no less than 250 mm; the afterflame time must not exceed 3 seconds; and the smoldering time must not exceed 10 seconds. The antistatic performance must satisfy the requirements of a surface resistivity of no more than 3 × 10⁸ Ω and a volume resistivity of no more than 1 × 10⁹ Ω, with a grounding resistance not exceeding 4 Ω. Practical operational details: Prior to material receipt, the materials management department shall notify the mechanical and electrical management department and the end-user unit three working days in advance to prepare for inspection. During inspection, on-site verification shall be conducted to ensure consistency between material specifications, batch numbers, and test reports; samples shall be randomly selected and sent to a third-party testing institution accredited for mining-product testing for retesting, with retesting covering all core flame-retardancy and antistatic indicators. Upon entry into storage, materials shall be arranged according to the principles of “material zoning, specification shelving, and usage labeling”; temperature and humidity gauges shall be installed in the warehouse to maintain dry and well-ventilated conditions; mixing with oils, acids, alkalis, or other corrosive substances is strictly prohibited. Accountability requirements: The materials management department bears primary responsibility for material receipt inspection and storage management; if materials fail due to failure to conduct required sampling and retesting or due to improper storage, the warehouse administrator and the head of the department shall be held accountable; the mechanical and electrical management department bears supervisory responsibility for the authenticity of test reports and the accuracy of retest results; if falsification of test reports or acceptance of non-compliant materials into storage is not detected, the inspection officer shall be held accountable; end-users are strictly prohibited from issuing non-compliant materials; any unauthorized issuance shall result in accountability for the issuer and the shift supervisor. The mechanical and electrical management department shall complete a monthly review of the performance of inventory materials by the 5th of each month and prepare a review report for archival purposes; failure to conduct timely reviews or concealment of issues will result in strict accountability.
II. Configuration of Safety Protection Devices
(2) The conveyor must be equipped, in full compliance with standards and in a standardized manner, with the four basic protective devices—anti-slip, anti-deviation, coal-accumulation detection, and tear detection—as well as a pull-cord emergency-stop interlock. Each of these devices must be rigidly linked to the conveyor control system, ensuring that, upon activation, the conveyor power supply is immediately cut off and the conveyor stops within one second, while audible and visual alarm signals are simultaneously issued at the head-end control console and in the underground dispatch room, with an alarm sound level of no less than 85 dB. Practical implementation details: the pull-cord emergency-stop switch shall be of the mine-use flameproof type, mounted along the roadway sidewall in a location that avoids areas where materials may fall or where personnel frequently come into contact with it; the wiring connections shall be sealed with explosion-proof connectors. During the monthly full-stroke pull test, two personnel shall cooperate: one monitors the feedback signal at the head-end control console, while the other pulls the switch section by section from the tail end toward the head end, recording the trigger sensitivity and response time. Prior to installation, the temperature sensor’s mounting surface on the drum shall be thoroughly cleaned of coal dust and oil contamination, and the sensor shall be secured using both high-temperature-resistant adhesive and bolts; monthly calibration with an infrared thermometer shall be performed to check for errors, and any sensor found to be out of tolerance shall be replaced immediately. The smoke sensor shall be installed in a location that avoids water-spraying nozzles and dead zones in the airflow; prior to installation, the piping of the automatic water-spraying system shall undergo a hydrostatic pressure test at 1.5 times the working pressure, with the nozzles oriented at a 45° angle toward the drum contact surface; weekly high-pressure air-blowing shall be used to clean the nozzle apertures and prevent blockage by coal dust. Accountability requirements: electromechanical maintenance personnel bear direct responsibility for the installation, commissioning, and routine verification of the protective devices; if device failure results from non-compliance with the relevant procedures, individual accountability shall be pursued. Shift supervisors at the user unit shall inspect the operating status of the protective devices daily; if they fail to report faults promptly, their responsibility shall be pursued. If on-duty personnel in the underground dispatch room fail to immediately order a shutdown and fault investigation upon receiving an alarm, their responsibility shall be pursued. All test and calibration records shall be signed and confirmed by the responsible party and retained for no less than one year. (3) Conveyors used in main transport roadways (including both main and auxiliary main roadways), in addition to meeting the requirements set forth in paragraph (2) of this article, must also be equipped with a belt-tension-decline protection device and a tension-travel-limit protection device, both of which shall be interlocked with the conveyor start-up circuit. Conveyors shall not be started if these devices are absent or malfunctioning. Practical implementation details: the tension-sensor shall be installed on the tension winch’s traction shaft; after installation, it shall undergo two calibrations—one under no-load conditions and one under full-load conditions—and the threshold values shall be set taking into account the conveyor belt’s rated tension and the specific site conditions, with an appropriate margin built in. For hydraulic tensioning devices, the oil-pressure monitoring protection shall have upper and lower threshold limits (the upper limit being 1.2 times the rated oil pressure and the lower limit 0.8 times the rated oil pressure); during weekly verification, the interlocking shutdown function shall be tested by adjusting the tension winch to simulate fault scenarios. Prior to each quarterly full-load interlock test, coordination shall be made with the mining unit to adjust production to the rated load; during the test, dedicated personnel shall monitor the condition of the conveyor belt joints and the tensioning device to prevent accidents. Accountability requirements: technical personnel in the electromechanical management department are responsible for setting thresholds, performing calibration, and developing test plans; if the thresholds are unreasonable or the test plan contains loopholes, the responsible technicians shall be held accountable. Electromechanical maintenance personnel are responsible for conducting the tests and recording the data; any falsification shall result in strict accountability. The user unit is responsible for on-site coordination and safety supervision during testing; if inadequate supervision leads to an accident, the head of the unit shall be held accountable. (4) Conveyors used in inclined shafts and tunnels must be equipped with braking and protective devices tailored to the direction of transport; all braking devices must be certified as compliant by a third-party agency before being put into service, with certification valid for no more than one year. Practical implementation details: after installing the anti-reverse device on upward-conveying conveyors, manual inspection shall be conducted to verify the meshing clearance and reset flexibility; the braking clearance shall be measured with a feeler gauge and maintained uniformly within the range of 0.3–0.5 mm; during monthly verification of braking torque, the tightening force of the brake bolts shall be checked, and a simulated power-outage scenario shall be conducted to record the braking time and distance. When commissioning the soft-braking device on downward-conveying conveyors, the braking torque adjustment performance shall be tested at three load levels—50%, 80%, and 100% of the rated load; for the overspeed-protection device, monthly verification shall involve simulating overspeed conditions through variable-frequency speed control to test the alarm and shutdown response speed, and any deviations shall prompt a thorough inspection for sensor and control-system malfunctions. Prior to each semi-annual full-load downward-braking test, the wear of the brake pads and the sealing condition of the hydraulic lines shall be inspected; during the test, dedicated personnel shall be stationed at the midsection and tail end of the conveyor to prevent material slippage and belt slip. Accountability requirements: the electromechanical management department is responsible for arranging third-party certification; if certification is not organized on time or if the equipment is put into service despite failing certification, the head of the department shall be held accountable. Electromechanical maintenance personnel are responsible for the daily inspection and commissioning of braking devices; if excessive wear or seal leakage is discovered and not addressed promptly, individual accountability shall be pursued. Operators at the user unit are strictly prohibited from making unauthorized adjustments to braking parameters; any violation shall result in severe accountability and suspension from duty. (5) When conveyors are used in inclined shafts and tunnels with slopes greater than 16°, protective netting must be installed on both the pedestrian side and the material-loading side, along with multiple supplementary safety measures. Practical implementation details: prior to installing the protective netting, the site shall be cleared of debris and loose coal; verticality shall be calibrated using a level; after expansion bolts are tightened, torque wrenches shall be used to verify that the tightening force meets the required standard. Material-deflection plates shall be installed parallel to the belt edge, with a spacing of 0.08–0.1 m; the fixing brackets shall be welded to the conveyor frame and treated with anti-corrosion coating. The spacing between cushion rollers at the loading point shall be halved, and the loading chute shall be adjusted to a 30° incline to prevent materials from striking the belt vertically; monitoring personnel shall record the loading quantity and particle size every hour, and if overloading or excessively large particles are detected, the conveyor shall be immediately stopped for cleaning. Accountability requirements: electromechanical maintenance personnel bear direct responsibility for the quality of protective-facility installation; if installation is insecure or spacing exceeds the specified limits, resulting in materials rolling off, individual accountability shall be pursued. Loading-point monitoring personnel at the user unit bear supervisory responsibility for the loading process; if they fail to promptly stop improper loading, their responsibility shall be pursued. The electromechanical management department shall conduct monthly inspections of the integrity of protective facilities; if the compliance rate falls below 95%, the head of the user unit shall be held accountable.
III. Key Components and Environmental Management
(6) Hydraulic couplings for conveyors must use non-flammable transmission fluids; clean water or mine-specific non-flammable hydraulic oil is preferred, and the use of flammable transmission fluids is strictly prohibited. Practical operating details: Before filling the coupling with transmission fluid, clean the filling port and filter screen; maintain the fluid level at 40%–80% of the coupling’s capacity; after filling, allow the system to stand for 30 minutes and inspect seals for leaks. During operation, monitor oil temperature using both temperature sensors and routine manual inspections; measure housing temperature with an infrared thermometer every hour, and initiate cooling measures in advance when the oil temperature approaches 100°C. Replace the transmission fluid and seals every 2,000 hours of operation; prior to replacement, thoroughly clean the interior of the coupling. Seals must be of the original model; after replacement, conduct a no-load trial run for 30 minutes to check for leaks and abnormal vibration. Accountability requirements: Mechanical and electrical maintenance personnel bear direct responsibility for selecting, filling, and replacing transmission fluid and seals; individuals shall be held accountable for using flammable fluids or substandard seals. The operating driver of the user unit is responsible for monitoring oil temperature during operation; if abnormalities are detected but the machine is not shut down promptly, the driver shall be held accountable. The materials management department is responsible for procuring qualified fluids and seals; if substandard products are supplied, the procurement personnel shall be held accountable. Maintenance records must document all relevant information in detail to ensure full traceability throughout the process.

(7) Sufficient explosion-proof lighting must be installed at the head and tail of the conveyor as well as at all transfer and overlap points to ensure that there are no visual blind spots during operations or emergency response. Practical details: Prior to installation, lighting equipment shall undergo a power-on test to verify that its luminous intensity and explosion-proof performance meet the required standards; installation locations shall avoid rotating parts and areas where materials may fall, and each work station shall be equipped with two lamps to provide overlapping illumination. Before each shift, inspection personnel shall check the lamp shades and wiring conditions of the lighting equipment; any damaged or aged components shall be replaced immediately, and decommissioned equipment shall be uniformly collected and centrally disposed of in the surface warehouse—discarding such equipment underground is strictly prohibited. For temporary operations, portable lighting lamps shall be used; prior to use, their battery level and explosion-proof seals shall be inspected, collisions shall be avoided during operation, and the lamps shall be promptly recharged and stored after use. Accountability requirements: The on-duty inspection personnel bear direct responsibility for the daily inspection and replacement of lighting facilities; failure to detect faults or arbitrary disposal of decommissioned equipment shall result in accountability for the inspection personnel. The user unit is responsible for the safekeeping of lighting facilities; if such facilities are lost or damaged, the head of the unit shall be held accountable. The mechanical and electrical maintenance personnel are responsible for wiring inspections and repairs; if short circuits occur due to untimely replacement of aging wiring, the maintenance personnel shall be held accountable. (8) Protective guardrails and warning signs must be installed at hazardous locations such as the head and tail of the conveyor and the drive drum, and dedicated pedestrian bridges shall be constructed at points where pedestrians cross over the conveyor. Practical details: Guardrails shall be fabricated by mechanical cutting and welding, with welds free of slag inclusion and incomplete fusion; after rust removal, two coats of anti-corrosion paint shall be applied. Warning signs shall be hung along routes that personnel must traverse, with the lettering facing the pedestrians. Prior to installing the pedestrian bridge, the ground in the connecting area shall be leveled, non-slip steel plates shall be securely fastened to the supporting structure, and the anti-skid grooves on the surface shall be regularly cleaned of coal dust. During monthly inspections, the horizontal load-bearing capacity of the guardrails and the load-carrying capacity of the pedestrian bridge shall be tested; if deformation or loosening is detected, the conveyor shall be immediately shut down for reinforcement, and a safety cordon shall be established during the reinforcement period to prohibit passage. Accountability requirements: The mechanical and electrical maintenance personnel bear direct responsibility for the fabrication, installation, and maintenance of guardrails and pedestrian bridges; if quality fails to meet standards or maintenance is not performed in a timely manner, individual accountability shall be pursued. The user unit is responsible for on-site safety cordon management; if no cordon is set up during reinforcement, the team leader shall be held accountable. Pedestrians are strictly prohibited from climbing over guardrails or using the pedestrian bridge in violation of regulations; any accidents resulting from such violations shall be subject to enhanced penalties.
IV. Safety Factor Standards for Conveyor Belts
(9) The design safety factor for conveyor belts shall be determined in conjunction with the carcass material and operating conditions, and shall be subject to a dedicated verification by the mechanical and electrical design department; unauthorized reduction of the design safety factor or use thereof is strictly prohibited. Practical details: During verification, the mechanical and electrical design department shall collect parameters such as conveyor transport length, incline angle, and conveying capacity, perform calculations using specialized software, and prepare a verification report that clearly specifies the conveyor belt model, the basis for selecting the safety factor, and an analysis of operational condition suitability. Prior to adjusting the safety factor for steel-cord-reinforced and aramid-reinforced conveyor belts, on-site measurements of tension distribution and splice strength must be conducted, and a special report incorporating the operating status of soft-start and braking devices must be prepared and submitted to the mine’s chief engineer for approval. Monthly inspections using a portable tension meter shall be carried out at the midsection and both ends of the conveyor belt; if the measured data deviates by more than ±10%, the tensioning device shall be adjusted and the safety factor recalculated. Accountability requirements: Technical personnel in the mechanical and electrical design department bear direct responsibility for verifying and adjusting the safety factor; any errors in verification or unauthorized adjustments shall result in accountability for the relevant technical staff. The mine’s chief engineer bears leadership responsibility for approving adjustment reports; failure to exercise strict oversight shall result in accountability for the chief engineer. Mechanical and electrical maintenance personnel are responsible for tension measurements and data recording; any falsification shall be subject to serious disciplinary action. If the user unit fails to promptly report abnormal wear or splice cracking in the conveyor belt, the shift foreman shall be held accountable. Verification reports and tension measurement records shall be archived for no less than two years. Cotton-fabric-carcass conveyor belts: the safety factor shall be set at 8–9 and are applicable only to auxiliary transport roadways with horizontal or incline angles ≤8°, conveying capacities ≤100 t/h, and materials consisting of small lump raw coal (particle size ≤100 mm); they shall not be used in main transport systems or in roadways with steep inclines. Nylon- and polyester-fabric-carcass conveyor belts: the safety factor shall be set at 10–12 and are suitable for transport roadways with incline angles ≤12° and conveying capacities of 100–500 t/h; among these, polyester-carcass belts are preferred for medium- to long-distance transport applications (length >500 m), while nylon-carcass belts are suited to short-distance operations involving frequent starts and stops. Steel-cord-reinforced conveyor belts: the safety factor shall be set at 7–9 and are suitable for main transport roadways with incline angles ≤16° and conveying capacities of 500–2000 t/h; provided that controlled soft-start and soft-braking are employed and operating conditions remain stable, and following successful specialized verification, the safety factor may be adjusted down to 5–7; after such adjustment, tension shall be monitored monthly and the safety factor reviewed quarterly. Aramid-reinforced conveyor belts: the safety factor shall be set at 8–10 and are suitable for underground environments with limited space and where lightweight equipment is required, with conveying capacities ≤800 t/h and incline angles ≤12°; provided that controlled soft-start and braking are implemented and tension is regularly monitored, the safety factor may be adjusted down to 7–8; following such adjustment, tension data shall be recorded daily, and the conveyor shall be immediately shut down and inspected upon detection of any abnormalities.
V. Daily Maintenance, Inspection, and Management
(10) Establish and improve the daily maintenance and inspection management system for conveyors, designating the mechanical and electrical management department as the lead unit and the user unit as the responsible party, and detailing the inspection checklist, maintenance standards, and performance evaluation methods. Practical implementation: Dedicated inspection personnel shall follow the “pre-shift cleanup, in-operation inspection, and post-shift review” procedure: 30 minutes before shift start, they shall clean the underside of the conveyor belt and the surrounding loose coal, and check the tightness of bolts on rotating components; during operation, they shall conduct inspections every hour, carrying specialized tools to measure bearing temperature, equipment vibration, and belt condition, and immediately record and report any abnormalities. A comprehensive daily inspection shall be carried out using a “two-person mutual inspection” model, with each inspector conducting one inspection before and after shift handover; the inspection checklist shall be checked off item by item, and any identified hazards must be marked with their location, severity, and recommended corrective actions. Prior to weekly protective-performance tests, a detailed plan shall be formulated specifying task assignments and safety precautions, and the dispatch room and nearby personnel shall be notified; following the test, the site shall be cleaned up and equipment conditions restored. Accountability requirements: Dedicated inspection personnel bear direct responsibility for the quality of inspections; failure to detect or concealment of hazards shall result in individual accountability; the head of the user unit bears leadership responsibility for the timeliness of hazard rectification; failure to rectify routine hazards on time or to immediately report major hazards shall result in accountability of the responsible person; mechanical and electrical maintenance personnel bear direct responsibility for the quality of rectification; if inadequate rectification leads to recurrence of hazards, maintenance personnel shall be held accountable. The performance evaluation method shall be formulated by the mechanical and electrical management department, with monthly assessments based on inspection records, rectification status, and test results, and assessment outcomes linked to job performance. Strict control over conveyor operating conditions is required; frictional operation of the conveyor belt and jamming of rotating components are strictly prohibited. Thirty minutes before work begins, dedicated inspection personnel shall thoroughly clean the surrounding area and the underside of the belt, ensuring that the clearance between both sides of the belt and the side guards is no less than 0.5 meters, that the amount of accumulated coal at the bottom does not exceed the centerline of the idler shaft, and that no foreign objects are entangled in rotating parts. During operation, inspections shall be conducted once per hour; if friction or jamming is detected, the nearest pull-wire emergency stop switch shall be activated immediately to shut down the equipment, followed by troubleshooting, rectification, and re-inspection until compliance is confirmed before operation can resume. A daily inspection regime shall be implemented, with dedicated inspectors conducting at least two comprehensive inspections per day (one before and one after shift handover); inspection criteria include: uniform operating sound and normal vibration; drive drum bearing temperature not exceeding 75°C and motor temperature not exceeding 80°C; belt misalignment not exceeding 5% of the belt width, wear not exceeding 20% of the original thickness, and splices free from cracking or lifting; idlers rotating smoothly with a damage rate not exceeding 1%; protective devices and lighting facilities functioning sensitively and effectively; and no leakage at lubricated points. Routine hazards must be rectified within no more than 2 hours; major hazards require immediate shutdown and reporting, and operation may resume only after passing acceptance inspection by the mechanical and electrical management department. The protective-performance testing regime shall be strictly enforced: once a week, mechanical and electrical maintenance personnel shall lead a dedicated underground test, with each device undergoing no fewer than three tests, and passing results documented with signatures and archived; temperature and smoke monitoring devices shall be brought to the surface for inspection quarterly, and any non-compliant equipment shall be replaced immediately, with proper records maintained.
VI. Supplementary Management Requirements
 
(11) Strengthen management of operational personnel: conveyor operators and maintenance staff must be certified before taking up their posts; unauthorized or non-compliant operation is strictly prohibited. Practical implementation details: The using unit shall organize pre-job training following a “theory-plus-practice” model. Theoretical training shall cover these detailed rules, operating procedures, and emergency response protocols, while practical training shall be conducted under the guidance of senior technicians, with particular emphasis on equipment operation, hazard identification, and emergency shutdown skills. Pre-job practical assessments shall be carried out under actual working conditions; only those who pass may perform independent operations. During annual refresher training, new regulations, new equipment operation procedures, and case studies of accidents shall be added to the curriculum. Following refresher training, both theoretical and practical assessments shall be administered; those who fail the assessments shall be temporarily barred from duty and may resume work only after passing a special remedial examination; if they still fail the remedial exam, they shall be reassigned to other positions. When commencing work, all personnel must wear prescribed personal protective equipment, including safety helmets, miner’s lamps, and self-rescuers, and must strictly adhere to operating procedures; unauthorized modification of equipment parameters or removal of protective devices is strictly forbidden. Accountability requirements: The using unit bears direct responsibility for personnel training, assessment, and on-the-job management. If pre-job training is not organized or unqualified personnel are allowed to work, the head of the unit shall be held accountable; if operational personnel violate procedures, strict accountability shall be imposed, and in the event of an accident, relevant parties shall be prosecuted in accordance with the law. The mechanical and electrical management department shall oversee training content and assessment standards; failure to fulfill supervisory duties shall result in accountability for the relevant department heads. Records of training, assessment, and on-the-job placement shall be fully traceable and retained for no less than three years. (12) Improve the configuration and management of fire-fighting facilities: sufficient quantities of fire-extinguishing equipment and fire-sand must be provided at the head and tail of the conveyor. Practical implementation details: Fire-extinguishing equipment shall consist of mine-use explosion-proof dry-powder extinguishers, with at least four units per location, each with a capacity of no less than 8 kg; the reserve of fire-sand shall be no less than 0.5 m³, stored in dedicated fire-resistant sandboxes placed within 10 meters of the head and tail of the conveyor in easily accessible locations and clearly marked. Along the conveyor roadway, a fire hydrant, gate valve, and quick-connect coupling shall be installed every 50 meters; the hydrant diameter shall be no less than 50 mm, and water pressure shall be maintained at 0.6–1.0 MPa. Daily inspection personnel shall check the integrity and effectiveness of fire-fighting facilities; monthly, mechanical and electrical maintenance personnel shall conduct a comprehensive inspection of extinguisher pressure and expiration dates, promptly replacing expired or malfunctioning equipment and replenishing fire-sand supplies. Accountability requirements: The using unit bears direct responsibility for the custody and routine inspection of fire-fighting facilities; if facilities are lost, damaged, or fire-sand supplies are insufficient, the shift foreman shall be held accountable; if inspection personnel fail to detect malfunctions in fire-fighting facilities, individual responsibility shall be pursued; if mechanical and electrical maintenance personnel fail to inspect and replace equipment on schedule, the maintenance personnel shall be held accountable. (13) Standardize maintenance and repair procedures: during maintenance, the five-step procedure of “shutdown—power disconnection—lockout—tagging—voltage verification” must be strictly followed. Practical implementation details: A designated person shall be responsible for power disconnection and lockout; warning signs reading “Equipment under maintenance—Do Not Close Switch” shall be hung on the power switch and the head-end control panel; work may commence only after voltage verification confirms that no electricity is present; running equipment while performing maintenance or cleaning is strictly prohibited. During maintenance, for inclined shaft conveyors, anti-sliding stoppers must be installed at both ends of the belt, and the belt must also be secured with manual hoists; removed components shall be placed in stable, safe locations, and small parts shall be stored in dedicated tool bags; random placement is strictly forbidden. Upon completion of maintenance, all debris and waste oil shall be cleared from the site, lockout devices and protective measures shall be removed, personnel shall be notified to evacuate to a safe area, and the maintenance supervisor shall confirm that everything is in order before conducting a no-load trial run lasting at least 30 minutes, with particular attention paid to equipment operating sounds, vibration, temperature, and the sensitivity of protective devices; only after confirming that no hazards remain may normal transportation be resumed. Accountability requirements: The maintenance supervisor bears overall responsibility for the maintenance procedure, operational safety, and quality of corrective actions; failure to follow the maintenance procedure or inadequate safety measures shall result in accountability for the maintenance supervisor; the using unit is responsible for on-site safety supervision during maintenance; if supervision is inadequate, the shift foreman shall be held accountable; if operational personnel engage in non-compliant maintenance, strict accountability shall be imposed, and if equipment is damaged or personnel are injured, relevant parties shall be held accountable. Maintenance and trial-run records shall be signed and confirmed by the responsible party and retained for no less than one year.