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440V electrical shock incident

A member has reported an incident which a technician received a 440V electric shock. The incident occurred during an investigation of a power distribution unit (PDU) located in the ROV control room onboard a vessel. The purpose of the investigation into the PDU unit was to conclude whether the observation ROV being powered from this PDU was able to provide output data of a certain quality. The person who was shocked was not harmed and did not require any medical follow up.

Our member’s investigation revealed the following:

  • The task was not a planned operation and it was performed by personnel with inadequate training/knowledge of the dangers associated with this work;
  • The PDU was not properly labelled with warning signs, and had no top cover;
  • There were two separate power supplies to the PDU; this was not identified due to the low level of familiarisation of involved personnel;
  • The ROV supervisor was not notified about the operation;
  • There was no job-specific permit to work (PTW) or any management of change. However, a generic PTW was made;
  • There was a risk assessment but it was neither suitable nor sufficient – not according to requirements in regards to details, attendees and quality.

Our member noted the causes:

  • The direct cause of the incident was that the technician touched or came near equipment that was powered to 440 V;
  • The root causes identified were as follows:
    • Rescheduling of work tasks caused personnel to carry out ad-hoc investigations inside the PDU unit – There was poor safety awareness related to ongoing work – The PDU was inadequately labelled as being a place where there was danger of electrical shock
    • There was no detailed PTW completed – There was inadequate risk assessment underpinning the work on the PDU unit. The risk assessment was not performed to such a level of detail that it allowed actual risks to be disclosed
    • The persons doing the work were inadequately trained on this particular ROV system
    • There was inadequate quality and safety verification of equipment received onboard
    • It was not clear to personnel how the organization works offshore.

The following lessons were identified:

  • Stop the job if you feel unsafe;
  • Follow the requirements as defined in management system;
  • Always inform supervisor;
  • Always complete familiarisation;
  • Always make a detailed risk assessment and be compliant with the control of work system;
  • There should be thorough verification and site acceptance of new equipment, particularly with regard to quality, labelling, design and location on board.

Our member took steps to:

  • Revise bridging document with focus on clear communication lines;
  • Ensure control of work system was understood by all crew on board;
  • Revise risk assessment, training matrix and amended procedures to avoid repetition.

Members may wish to refer to the following similar incidents (key words: electric, shock):

Safety Event

Published: 8 September 2014
Download: IMCA SF 15/14

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