The incident

A crewman received a serious electric shock when his hand brushed two loose wires hanging from the bottom cable entry pop-out of a distribution board.

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The incident happened while he was assessing cable routing from the distribution board during a mobilisation. He was about to run a power supply from the dive system machinery van (MAV) to an ROV LARS. The MAV had 415v three-phase power supplied and was switched on. The crewman ran the LARS cable to the distribution board (DB) located at the back wall of the MAV. He looked at the bottom cable entry pop-out on the DB for a suitable entry point prior to any installation of the wire and noticed two disconnected wires hanging.

He pushed them out of the way with his left hand to provide a better view of the bottom pop-out. When he touched them, he received an electric shock to his hand. He was able to make the DB safe by opening the main breaker. He then went to the diving office and reported the injury. First aid was given, and he returned to work some 90 minutes after the shock.

The two wires were wires that were normally attached to a stepdown transformer connected to a volt meter. The transformer had been removed before the mobilization. It is not clear why the transformer was removed. Though some maintenance records were available, there was no documentation of this particular maintenance in the system.

The crew man was not wearing gloves at the time of the incident, as he was working with small wires in confined spaces and had removed them to improve manual dexterity.

Probable cause

IMCA identified two factors that contributed to the accident:

  • The immediate cause was that the crewman was not wearing personal protective equipment (PPE) and contacted the live wiring which had been left exposed.
  • The root causes were human procedural errors: the exposed live wires were not proven dead before touching; and the crewman was not properly informed about these wires.

Lessons learned

As a result of the accident, the following lessons were learned:

  • Keep and maintain a maintenance log;
  • Better communication and hand-over is vital.