Patrol inspection of overhead cables is one of the basic contents of operation and maintenance of overhead cables. Through visits and inspections, defects can be identified and preventive measures can be taken to ensure the safe operation of the line. Usually, the inspection of overhead transmission lines should be carried out through the "nine inspections" 1. Check the tower. Check whether the tower has collapsed, tilted, deformed, decayed, damaged, and cracked foundations, and whether the iron components are bent, loose, skewed, or corroded. Check if the length of the iron wire for the tower bolts or nuts is insufficient, if the screws are loose, and if the binding wire is broken or loose. Are there any items such as bird nests on the observation tower 2. Check the cross arm and accessories. Check if the cross arm and accessories are displaced, securely fixed, if the welds are cracked, and if nuts are missing Thirdly, check whether flammable, explosive, and highly corrosive substances are stacked on the ground along the way, whether there are violations along the roads near buildings, and the possibility of damage to facilities such as lines and buildings caused by thunderstorms or strong winds; Check if other power lines, communication lines, wireless wires, speakers, etc. are installed on the tower; Please refer to wiring for unauthorized access to electrical equipment 4. Examination Line. Check the wiring and lightning protection wires for external damage such as broken strands, backdrops, corrosion, scratches, etc; Check whether the close distance, sagging, etc. between the ground line and nearby buildings or trees meet the requirements, and whether there is unbalanced sagging phenomenon in the three-phase conductor; Check if the wire connectors are in good condition and have no signs of heating, severe oxidation, or corrosion 5. Check the insulation. Check the insulation for cracks, dirt, burn marks, and flashover; Check the deflection degree of the insulator string, and the insulator iron is damaged VI. Check the lightning protection device. Check whether the size of gap protection is qualified and whether the auxiliary gap is intact. Check whether the external gap of the lightning arrester has changed and whether the ground wire is intact. Check valve type lightning arrester porcelain for cracks, dirt, flashover marks, and good sealing. Check if the deflector lightning arrester is intact, whether the grounding is corroded by water, and whether the exposed grounding deflector and grounding connection are firm 7. Check the cables. Check the cables for rust, looseness, detachment, and uneven force on the unit wires. Pull out the pile, protect it from decay and damage. Loose anchor cables, insufficient soil quality, and settlement of fill soil. Puller, wedge clamp, UT