The coupling clamp of a hanging chain breaks and falls while a wire rope
is being wound up during bridge construction work
[Description of the Accident]
During work to remove a wire rope that was used to diagonally mount the
upper suspension cable to a steel tower in the re-construction work of
a bridge, the coupling clamp of the hanging chain broke and the wire rope
fell and collided with the head of the worker who was carrying out the
work to wind up the wire rope.
In order to remove the wire rope that was used for hanging the upper suspension cable in the center of the bridge, the hanging chain was wrapped three-times around the wire rope and supported from the hook of a mobile crane while it was being rewound onto the drum of the winch.
The victim was aligning the wire rope by hand to make sure it was rewound on the winch drum in an orderly manner, and also giving signals to the mobile crane.
However, when the coupling clamp of the chain on which the wire rope was
hanging broke, the wire rope fell and collided with the head of the victim
who was working below.
1. The coupling clamp (high-coupling) of the hanging chain broke.
2. The worker had been allowed to enter the area below the wire, which
was hanging from the mobile crane.
3. The hanging chain was not strong enough to hang the wire rope.
4. Appropriate instructions were not given concerning the worker deployment
in the case of work to be carried out by using a mobile crane.