Tokyo MoU – Emergency Power Supply Testing

Notice to: Ship Owners / Managers/ Operators / Surveyors / Auditors / DPAs / Masters :

C24038 | 01 August 2024

The Tokyo MoU has issued a Safety Bulletin – 04/2024 regarding testing the automatic start of emergency electrical power and connection to the emergency switchboard using the simulated blackout method.

Port State Control Officers have observed that an alarming number of ships were able to demonstrate a satisfactory test of the emergency generator using a Sequence Test or RTS, but when tested by opening the Main Switch Board (MSB) Bus Tie (controlled blackout), the emergency generator was unable to:

1. automatically start; or
2. provide transitional power; or
3. automatically connect to the emergency switchboard.

Simulated blackout tests of the emergency generator may not meet the requirements of SOLAS Ch. II-1, Reg. 43.7, and more importantly, give ships’ engineers a false sense of readiness of the ship’s emergency systems in the case of an emergency. This may endanger life, ship, and the environment.

The Tokyo MoU recommends :

ISM Management companies should:

1. Ensure that any devices such as a “Sequential test” selector or “Routine Test Switch” (RTS), used for simulating blackouts are designed and wired to use the actual circuit paths as per SOLAS Chapter II-1, Reg 42.3.1.2 / 43.3.1.2;
2. Update the Company Safety Management System (SMS) emergency generator test procedures to include periodic ‘controlled blackout tests’ (i.e. not using a sequence test.). This ensures the actual circuit paths required by SOLAS Chapter II-1, Reg 42.3.1.2 / 43.3.1.2, are safely and practically tested.This may include opening the MCR bus-tie (aka transfer line) circuit breaker, while the switch is in normal mode, and operation switches set to auto for a sea-going state.
3. Be aware that the “Sequential test” selector and/or “Routine Test Switch” (RTS), may not comply with the requirements of SOLAS Chapter II-1 Reg. 42.5.4 / 43.5.4 if they send a signal to disconnect the inter-connector instead of automatically disconnecting on the loss of the main source of power. They may also not comply with Chapter II-1 Reg. 42.7 / 43.7 if the complete system is not tested.

Flag State Authorities, Classification Societies, and ISM Recognized Organizations should:

1. During routine inspections, surveys, and/or ISM audits, carried out as recommended ROs should ensure that the emergency generator functionality is tested both by using any “simulated blackout” routine/sequential test switch and a controlled blackout.
2. If there is any discrepancy between the tests, then appropriate actions should be taken either through amending the emergency generator test procedure or assuring the test switch circuit paths allow for a complete test of the emergency generator.
3. Any required modifications to the routine/sequential test switch circuit paths must be approved by the Recognized Organization. Any amendments to the emergency generator testing procedure should be documented through the ship’s safety management system and preventative maintenance system.
4. It is the responsibility of the RO to ensure that at a minimum electrical system design and approval comply with the requirements of SOLAS.

Act now

Ship Owners, Managers, Operators, Surveyors, Auditors, DPAs, and vessel Masters should take note of the above and ensure that testing of emergency generators startup is performed under periodical controlled blackouts to ensure compliance with SOLAS requirements, that any necessary amendments to the ship’s SMS are made, and that any necessary modifications to the electrical systems are approved by the RO.