How to maintain the steel wire rope of container quayside bridge?

In the daily use of container quayside bridge, steel wire rope is a key consumable and also an important material for the daily production of the terminal. In order to ensure its safety and economy in use, it has been maintained as a key part, mainly including lubrication and inspection. Since there is no mature automatic lubrication and online monitoring system, the maintenance of steel wire rope has been completed manually at high altitude, and most of the maintenance operations are carried out under the condition of steel wire rope movement. Therefore, there are great risks in the maintenance operations. How to effectively control the risks in the maintenance operations of steel wire rope and avoid accidents has become a subject of our equipment management. (the following descriptions take lubrication and maintenance as an example, and the routine inspection process is the same as that of lubrication and maintenance.)

1. Current operation mode for steel wire rope maintenance of shore bridge

In the container quayside bridge of our company, there are several kinds of main steel wire ropes: pitching steel wire rope, hoisting steel wire rope, main trolley steel wire rope, and bracket trolley steel wire rope. In order to ensure the safe use of steel wire rope, it is necessary to regularly maintain all steel wire ropes in the whole process from the position of maintenance personnel. At present, the main positions of maintenance operations are as follows:

(1) Beside the drum of the three mechanisms of hoisting, pitching and trolley in the machine room, the steel wire rope on the drum can be lubricated when the winding drum is full of rope, and the steel wire rope is in a static state during maintenance.

(2) Beside the trolley pulley of the front and rear maintenance platforms of the shore bridge girder, lubricate the steel wire rope of the main trolley and the steel wire rope of the bracket trolley. The steel wire rope is in motion during maintenance.

(3) Beside the lifting pulley block on the trolley frame, the maintenance personnel shall fasten the safety belt and lubricate the lifting wire rope, main trolley wire rope and bracket trolley wire rope. When maintaining the lifting wire rope, the main trolley shall stop at several fixed positions and the lifting wire rope shall be in motion; When maintaining the steel wire rope of the main trolley and the bracket trolley, the main trolley moves back and forth slowly and the trolley and bracket steel wire rope are in motion. The personnel shall stoop to stand on the trolley frame and pass through the bottom of the machine room, the sea side upper beam, the girder small diagonal brace, etc.

(4) Beside the pulley block of the trapezoidal frame, the pitching wire rope is lubricated, and the wire rope is in motion during maintenance.

(5) On the pitching steel wire rope, when the girder is retracted to about 45 degrees, the maintenance personnel fasten the safety belt, climb up the pitching steel wire rope group from the pulley block of the trapezoidal frame, lubricate the section of the pitching steel wire rope that does not move, and the steel wire rope is in a static state during maintenance, so the personnel need to climb at heights.

2. Risk analysis of current maintenance operation mode

Considering the above factors such as maintenance position, personnel position, mechanism movement, etc., the current wire rope maintenance operation mainly involves the risks of personnel pinch injury, personnel falling from height, personnel impact injury, sling falling too low into the water and machine damage. After preliminary troubleshooting and remediation, a standardized maintenance scheme has been developed to clearly specify the motor vehicle instructions, personnel position, and the movement direction of the wire rope during lubrication, Some risks have been effectively avoided, but the following risks have not been solved:

(1) When lubricating the main trolley and bracket trolley on the trolley frame, the personnel shall bend over to pass through the obstacles while lubricating, and the standing objects and steel wire ropes are in motion. Although the speed of motion is very slow, due to the limited space and the fatigue of personnel during high-intensity operation, the maintenance personnel still have the risk of crushing injury and falling from height (although the safety belt is hung, there is also a hidden danger of secondary injury), The risk of lubrication and maintenance cannot be completely eliminated at present.

(21 when personnel lubricate the moving steel wire rope, the speed of lifting, pitching and trolley mechanism is controlled by the driver through the handle in his hand. The speed depends entirely on the driver's personal feeling. If he is careless, the speed of mechanism movement will suddenly change. In addition, the whole lubrication and maintenance time is relatively tight, and the driver is highly nervous and prone to fatigue, which is very likely to misoperate, resulting in the movement on the trolley frame and near the moving steel wire rope Accidents such as crush injury and pinch injury occurred.

(3) When the main trolley is on the front crossbeam, the hoisting wire rope is lubricated. The driver pays attention to the maintenance personnel of the trolley frame, which may neglect the hoisting height, resulting in excessive lowering of the hoisting mechanism and soaking of the spreader into the sea, resulting in water ingress and damage to the spreader.

3 risk control measures

In order to completely eliminate the above unresolved risks, combined with the maintenance mode, specific measures are proposed as follows:

(1] hardware protection: four sunken maintenance platforms are added at the four corners of the overhead block of the trolley frame. During maintenance, the personnel stand in the platform to effectively increase the safe activity space of the maintenance personnel, reduce the operation intensity of the maintenance personnel, increase the safety factor of the personnel position, and avoid the impact injury and high-altitude fall when the personnel follow the trolley through the obstacles.

(2) Software protection: add a "maintenance mode" program in the PLC program to limit the speed of pitching, trolley and lifting mechanism: when the trolley is at the front girder, limit the minimum height of lifting and lowering. When maintaining the steel wire rope, inform the driver to switch to the "maintenance mode", press the corresponding button, just pull the control handle, the pitching, lifting and trolley can maintain a constant speed, and the size can be adjusted in the program according to the site conditions, which reduces the driver's operation intensity, and will not cause sudden acceleration due to the driver's misoperation, resulting in personal injury or the driver's decreased attention. Put the sling into the sea, The accident of personal injury and sling damage caused by the driver is avoided

4 Conclusion

Through the risk analysis of the steel wire rope maintenance of container quayside bridge, aiming at the risks that cannot be avoided from the system, starting with the technical improvement, the hardware and software are improved to effectively eliminate the risks of personal injury and equipment damage in the steel wire rope maintenance, reduce the operation intensity of the driver, and ensure the safety of the steel wire rope maintenance of container quayside bridge. The above improvement scheme can be used for reference by the maintenance management of port cranes.