Since the beginning of 2025, IACS has launched a campaign to monitor the results of emergency power supply tests on ships. The campaign began on January 1 and will continue until December 31, 2025.
This follows a warning from the Tokyo MoU about potential risks in how emergency power systems are tested, particularly with a method called the “simulated blackout.”
There have been numerous observations by PSCOs where the “simulated blackout” testing of the Emergency Generator is demonstrated as fully functional, but during an actual power blackout, the system does not meet the requirements of SOLAS Ch. II-1, Reg. 42 / 43.
PSCOs have observed an alarming number of ships that were able to demonstrate a satisfactory test of the emergency generator utilizing 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.
As such, these 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 an emergency. This may endanger life, ship, and the environment.
Items to be checked during focus inspection
Focus inspection will be conducted based the following 11 items featured in the checklist :
Q1 Has a risk assessment or similar measures in the Safety Management System (SMS) for the emergency generator test
Q2 Has the controlled blackout test been successfully performed?
Q3 If “No” is ticked in Q2, select the reason for the same (More than one options may be selected, if applicable).
a. Malfunction of control unit/circuit (i.e, Printed Circuit Boards or control relay unit, etc.)
b. Malfunctioned Air Circuit Breaker
c. Miss-selection of engine starting selection switch mode in emergency generator room
d. Closing Quick-closing valve
e. Malfunction of starting arrangement
f. Malfunction of engine
g. No power supply to the services essential for safety in an emergency
h. Port restriction/regulation
i. Others (please describe them in the below note)
Note: If “Yes” is selected for item “i” marked with an asterisk “*”, the reason may be described below.
Inspections
IACS recommends for Flag State Authorities, Classification Societies, and ISM Recognized Organizations the following:
- During routine inspections, surveys, and ISM audits, ensure the emergency generator functionality is tested using both the “simulated blackout” routine/sequential test switch and a controlled blackout . If a discrepancy is found—e.g., satisfactory results with the test switch but unsatisfactory results with the controlled blackout—appropriate actions should be taken to amend the emergency generator test procedure or ensure the test switch circuit paths allow a full and complete test.
- If modifications to the routine/sequential test switch circuit paths are required, these should be approved by the Classification Society/Recognized Organization. Any changes to the emergency generator testing procedure must be documented in the ship’s safety management and preventive maintenance systems.
- Note that the electrical system design and approval are the responsibility of the Recognized Organization/Classification Society to ensure compliance with SOLAS requirements.
Actions required
#1 Ensure that devices like the “Sequential Test” selector or “Routine Test Switch” (RTS) are designed and wired to use the actual circuit paths required by SOLAS Chapter II-1, Reg. 42.3.1.2 / 43.3.1.2, to fully test the system.
#2 Update the Company Safety Management Procedure (SMS) for emergency generator tests to include periodic ‘Controlled Blackout Tests’ (instead of using the sequence test) to ensure the correct circuit paths as required by SOLAS Chapter II-1, Reg. 42.3.1.2 / 43.3.1.2, are tested safely and practically while maintaining system functionality.
Example: A ‘Controlled Blackout’ can be done by opening the MCR bus-tie (transfer line) circuit breaker while in normal mode and with operation switches in auto, as in a sea-going state.
#3 Be aware that the “Sequential Test” selector and/or “Routine Test Switch” (RTS) may not meet the requirements of SOLAS Chapter II-1 Reg. 42.5.4 / 43.5.4 if it sends a signal to disconnect the inter-connector instead of automatically disconnecting upon loss of the main power source. It also doesn’t meet Chapter II-1 Reg. 42.7 / 43.7 if it doesn’t test the complete system
