Electrocution: Shock Tactics to Stay Safe

An electric shock can lead to serious life-changing injuries and in extreme cases can kill. It can result in cardiac arrest, multiple organ failure, severe burns or cause a fall from height.

As electrical systems on modern vessels increasingly operate on high voltages, the severity of the consequences from an electric shock increases.

Common Shock Factors

Injury claims resulting from electrocution on board vessels continue to occur. The circumstances and the severity of the outcomes may vary, but there are two common factors:

• A failure to properly plan the task.
• Using defective or unsuitable equipment.

A notable proportion of the electrocution claims reported to North involve either engineer officers or dedicated electrical officers. All too often the incident occurs when they are working on a live electrical system.

A number of injuries concern refrigerated containers (reefers).  Electrical faults and damaged cabling have resulted in the electrocution of crew and stevedores. The use of electrical power tools and welding equipment in wet and humid conditions is another repeat finding.

Safe Shock-Free Working

Persons working on electrical systems must be trained and competent. But as many of the electrocution incidents reported to North show, this is no guarantee of safety. The safety precautions are well-known but they need to be followed every time and properly enforced.

It is abundantly clear that the safest condition for working on electrical systems is when it is dead. A simple set of guidelines for ensuring this include:

• Assess the risks and plan the work.
• Identify the correct isolation point. This might be the local breaker, starter panel or substation. Make sure the right one is identified!
• Shut down and isolate the circuit.
• Confirm the circuit is dead – usually by means of a multimeter
• Lock out (padlock) the breaker and tag out (post notices) to prevent accidental reconnection.
• Record the isolation.

In some cases a formal permit to work will be appropriate in order to bring a higher level of control over the task.

On high voltage (HV) systems – where voltages are greater than 1,000kV (and up to 12kV on some vessels) – working must be strictly controlled. Extra precautions will be necessary, such as a more robust isolation method, earthing and discharging residual energy.

It will of course be necessary sometimes to work on live low-voltage systems, where the voltage may be 440V or has been transformed down to 220V or 110V. This work should be subject to a risk assessment and the necessary precautions taken. Avoid working alone and extra care must be taken to prevent accidental contact with live circuits by the person carrying out the work or by others in the vicinity. This can consist of positioning barriers to restrict access, wearing the right clothing (and removing jewellery) and taking care with tools. Avoid leaving live circuitry exposed when unattended.

To prevent shocks from defective or unsuitable electrical equipment, these simple steps can help:

• Check that the tool, machine or equipment is suitable for the intended use and the conditions it will be exposed to.
• Carry out a visual check on the equipment before every use, paying particular attention to:
  • the plug or connector is free from damage
  • the cable is in good condition and has not been repaired with tape, with no exposed internal wires and glands are in place
  • free from tell-tale signs of overheating or sparking such as burn marks or stains

• If a defect is found, don’t just put it back in the locker. Report it and remove the equipment from use.
• Be vigilant when handling reefer power cables. If you have concerns on their condition, don’t touch them until the power is dead.

Repairs should only be carried out by a competent person (someone who has the necessary skills, knowledge and experience to carry out the work safely).

Are Friends Electric? How to React if a Fellow Crew Member is Electrocuted

• If they are still attached to the source of electricity, do not touch them.  If you touch them, you are likely to receive a shock too and will risk your life
• Turn off the source of power
• If you are unable to switch off the power and the crew member is still attached to the electricity source, stand on something non-conductive and move them away using a wooden pole or a similar non-metallic item
• But if they are in contact with a high voltage system (> 1kV), do not touch them. Even if the power has been isolated, high voltage systems store energy
• Raise the alarm and seek urgent medical attention
• Apply first aid

Further information can be found in Chapter 20 of the UK Code of Safe Working Practices for Merchant Seafarers which can be downloaded for free from the UK Maritime and Coastguard Agency website.