The Norwegian Maritime Authority (NMA) has issued a safety notice regarding safety concerns and regulatory requirements related to emergency stop devices on vessels, particularly focusing on issues when emergency stop systems use open circuits.
According to the Norwegian Maritime Authority on certain vessels, emergency stop devices are arranged with so-called open circuits. This means that a cable break or other fault in the emergency stop circuit may prevent activation of the emergency stop when required.
An emergency stop device arranged in an open circuit, where the emergency stop function is out of order, does not prevent the equipment from being started and operated. If the emergency stop does not function correctly, it may lead to serious incidents posing a risk to life and health, as well as harm to the environment or material assets.
Corrective measures
All vessels must have operational and maintenance procedures in place to ensure all equipment and components, such as emergency stop devices, function correctly and reliably. This includes measures to improve the reliability of safety-critical equipment like emergency stops.
The following measures must be implemented or be in place on board:
- Function testing: All vessels must have procedures for regular testing of emergency stops. This is particularly important for systems where the function is based on open circuits.
- Error protection: Where emergency stops are connected in open circuits, an assessment must be made to determine whether technical improvements are necessary – for example, implementing closed circuits or redundant solutions.
- Maintenance and control: The functionality of the emergency stop must be incorporated into the vessel’s maintenance and inspection programme. Any identified faults must be rectified immediately.
Relevant legislation
Regulations on safety management for small cargo ships, passenger ships and fishing vessels, etc. – section 9
Section 9. Maintenance and vital equipment
The company shall develop, follow up and document a maintenance system that is adapted to the mode of operation of the ship. The maintenance system shall ensure that vessel and equipment are maintained in accordance with applicable requirements. The company shall ensure that equipment and technical systems where sudden operational failure may result in dangerous situations, are identified.
The safety management system shall include measures for improving the reliability of such equipment or systems. These measures shall as a minimum include regular testing of back-up systems and equipment or of technical systems that are not in continuous operation.
Regulations on a safety management system for Norwegian ships and mobile offshore units – the Annex to the Regulations (ISM)
10.3 The company should identify equipment and technical systems the sudden operational failure of which may result in hazardous situations. The SMS should provide for specific measures aimed at promoting the reliability of such equipment or systems. These measures should include the regular testing of stand-by arrangements and equipment or technical systems that are not in continuous use.
Regulations on the working environment, health and safety of persons working on board ship – chapters 2 and 4
Section 2-2 Risk assessment
- Hazards on board shall be identified. When the hazard has been identified, an assessment of the risk represented by the hazard shall be made. Such risk assessment shall be made on a regular basis.
- The results of the risk assessment shall be documented in writing.
- If a risk to the safety and health of persons working on board is identified, the necessary measures shall be taken to eliminate or reduce the hazards.
Section 4-4 Inspection and maintenance of work equipment
- If safety is dependent on the installation and assembly of work equipment, an inspection shall be carried out before the equipment is put into service.
- Work equipment exposed to loads which cause deterioration likely to result in hazardous situations shall undergo adequate inspection to identify and counteract such hazards.
- Inspections referred to in the first and second paragraphs shall be documented.
- Work equipment shall undergo maintenance regularly to ensure its proper working condition.
