| Case Name |
The fall accident of a net to prevent scattering. |
| Pictograph |
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| Date |
July 2000 |
| Place |
Kagawa Prefecture |
| Location |
The construction site of the viaduct substructure in the project of the driveway construction. |
| Overview |
On the construction site of the viaduct substructure, while workers were moving the scattering prevention net set on the side of the roadside, they were going to lift the net by the crane. Then, the scattering prevention net fell on the side of the road, and it broke the front and back windscreens and the roof of the car of general public. |
| Incident |
On the construction site of the viaduct substructure, workers intended to move the splash prevention net by the crawler crane after they finished driving in stakes.The net (single cylinder pipe frame, width:4m, height:6m) was set up to prevent mud scattering. The splash prevention net had been lifted because the `fuzz' of the edge of the wire rope complementary roll was entangled with the upper stringer. It happened when the support hook was moved up and down near the stringer to lift the splash prevention net. The splash prevention net was pulled out from the base in which the net was fixed. And, it fell on the side of the roadway, then, broke the front and the back windscreens and the roof of a car on the street. |
| Sequence |
* `The slinging worker' and `the person to sign' were new attendances. They were educated as a new attendants for 30 minutes and started the work.
* It was the construction on the national road with heavy traffic. The splash prevention net (width:4m, height:6m) was set to not splash mud and concrete of the pulling work on general cars on the roadway.
* The splash prevention net was inserted in the hole of the basic H steel and fixed with the duplicate material.
* After workers finished the pile construction at the spot where the accident happened, they moved the splash prevention net to the next spot by the crane. Then, they pulled out the duplicate material fixed in the base before the slinging work was to be finished.
* The splash prevention net had been lifted because the `fuzz' of the edge of the complementary wire rope was entangled with the frame (the single cylinder pipe) of the net. It happened when the support hook of the crane was moved up and down in order to carry out the slinging.
* The splash prevention net was lifted up and was pulled out from the basic H steel because the duplicate material had been removed before.
* The splash prevention net was pulled out from the base and fell on the side of the road. It directly hit a general car on the road. |
| Cause |
* They carried out the work differed from the operational procedure.
* The end of the complementary roll wire had fluffed. (It was insufficient to carry out the inspection and maintenance of materials and equipments before the work.)
* The crane operator concentrated on the wire rope, and didn't watch the movement of the hook. |
| Response |
1.The owner stopped the construction, and had the contractor operate the modification treatment about the content shown in the following.
* The arrangement of the site.
* The review of a manual of the operational procedure.
* Placing the specialist in safety person.
* Placing the technician of construction management.
2.The contractor reported countermeasures to prevent accidents in future to the owner and attempted to have everyone in the company understand them completely.
* In the previous arrangement before the works the workers have to confirm their work and the operational procedure, and work according to the defined procedure.
* It is important to remove the `fuzz' of complementary roll wire edge of the crane hook thoroughly.
* A worker doing the crane work has to follow the signalled indications of the worker.
* There must be at least 1 person such as an agent or a boss or a person in charge of a site. The work director (who manages the construction site) must be permanently stationed at the site. |
| Knowledge Comment |
* Dangers lurk in various places. `Fuzz' of the wire rope may cause the accident.
* The accident is caused by an unexpected factor, if workers neglect daily inspections and the maintenance of materials and equipment.
* The work director has to be permanently stationed and should confirm whether the work is safe on the site. |
| Background |
1.The safety management situation of the construction site
* There was no director or manager of the contractor when the accident happened because they attended the meeting. The foreman was not on the site.
2.The background on the operational procedure
* The falling single cylinder of the splash prevention net frame had been welded to the basic H steel. But, they change the weld into the push-in-system that was proposed by the subcontractor in order to advance the work efficiently.
* The subcontractor had proposed the mannual of the operational procedure first. Next, the contractor corrected it with the subcontractor in the meeting.
* The operational procedure was explained to workers before the work started. They attempted to have all workers understand the procedure completely.
* The contractor observed the work involving moving the splash prevention net many times.
3.Contractors and workers
* `The worker to sling' and `the person to sign' had been actually crane operators. But they experienced the work in hand much. |
| Sequel |
In the verification after the accident, `fuzz' of the complementary roll wire was not entangled with the single cylinder pipe (upper stringer of the splash prevention net frame) at all. |
| Incidental Discussion |
It depends on the way to fix the hook with the wire. But, `fuzz' of the edge of the wire resulted from strikings of a complementary roll and a main roll even if they were maintenanced many times. So, it is desired that inspections and maintenances are done everyday. |
| Account of Concerned Parties |
1.The situation of the work
* They mistook the operational procedure. Because they intended to load them into the truck had come to transfer and carry.
2.About `Fuzz' of the edge of the complementary roll wire rope.
* He had noticed `fuzz', but thought it ways safe and didn't care about it.
* `Fuzz' seemed to happen because of the repetition of the work.
* The periphery of the hook of the main roll has fluffed even if `fuzz' is collected many times. |
| Reason for Adding to DB |
In order to recognize `the danger hidden in the work' by this case, we want similar construction companies and workers to utilize this case as an the activity to forecast dangers. |
| Scenario |
| Primary Scenario
|
Poor Value Perception, Poor Safety Awareness, Ignorance of Procedure, Disregard of Procedure, Organizational Problems, Poor Management, Regular Movement, Careless Movement, Regular Movement, Dangerous Movement, Failure, Deformation, Failure, Fracture/Damage, Loss to Organization, Social Loss
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| Number of Deaths |
0 |
| Number of Injuries |
0 |
| Physical Damage |
A car of the general public was broken by the accident. |
| Field |
Civil Engineering
|
| Author |
MIZOGUCHI, Hiroki (National Institute for Land and Infrastructure Management)
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