Inspections conducted on over 36,000 ships during 2025, and recommendations made to improve emergency power supply tests

IACS, the membership organisation for the world’s leading classification societies, has published the results of its Concentrated Inspection Campaign on Emergency Power Supply Tests on ships, conducted during 2025, and made a number of recommendations that will improve compliance with SOLAS requirements.

The campaign was launched in response to concerns raised by the Tokyo MoU over risks in the testing procedures, following observations raised by Port State Control officers over the reliability of ‘simulated blackout’ tests as demonstrating SOLAS compliance.

The Concentrated Inspection Campaign commenced on 1 January 2025 and ended on 31 December 2025. During this 12-month period, emergency power supply inspections were conducted on a total of 36,723 ships. No issues were identified in the vast majority of cases, but a range of deficiencies were found on 853 inspected ships (2.32%).

Based on an analysis of the data gathered during this inspection campaign, the survey panel reached a number of conclusions.

A number of critical and recurring equipment failure points were identified, including the closing quick-closing valve, control unit/circuit (PCB/relay), and Emergency Diesel Generator (EDG) starting arrangement. These failures indicate industry-wide issues with equipment maintenance, installation quality, or component durability, and directly compromise SOLAS Ch. II-1 Reg. 42/43 compliance for automatic Emergency Power Supply (EPS) activation.

The campaign also identified non-equipment deficiencies, the most notable of which is the lack of controlled blackout test procedures in company and shipboard Safety Management Systems (SMS). This is contrary to SOLAS Ch. II-1 Reg. 42.7/43.7 (periodic full system testing). Simulated blackout tests are widely used, but do not test the actual circuit paths required for real blackouts, which gives ships’ engineers a false sense of readiness of the ship’s emergency systems.

From an operational perspective, the campaign also identified crew unfamiliarity with Emergency Diesel Generator (EDG) operation and the mis-selection of starting switch modes. This highlighted the role of human error as a contributor to malfunctions during emergencies. Including gaps in crew training, competency, and safety culture.

The report also set out a number of recommendations:

• During ISM audits, focus should be on ensuring that a procedure exists in the necessary detail for conducting a controlled blackout test for emergency diesel generators and may pay more attention to whether the testing arrangements and procedures for emergency diesel generators adequately demonstrate the functionality of the emergency power supply system as a whole, including by means of controlled blackout testing where appropriate.
• IACS will consider a further analysis to clarify the inspection and testing cycles and requirements for high-frequency malfunctional components such as quick-closing valves, control units and starting devices.
• IACS will consider further studies to standardize the design standards for emergency generator simulation tests to ensure that the design complies with the requirements .

Commenting on the findings of the campaign, Robert Ashdown, IACS Secretary General,said: “We are grateful to our members for their close engagement and support for this Concentrated Inspection Campaign, which was prompted by a warning from the Tokyo MoU about potential risks in the testing of emergency power systems that may not meet SOLAS standards. Their rapid response has enabled us to conduct over 36,000 inspections in this 12-month period. This in turn has delivered robust and detailed data insights into this critical issue across the global fleet.”

“Over 97% of ships inspected had no deficiencies, but a range of issues were identified in the remaining cases. Based on these findings, the IACS panel set out a number of conclusions and recommendations on inspection and testing procedures, requirements, and crew training for emergency power system tests. These will play an important role in ensuring that emergency systems operate as intended, comply with SOLAS requirements, and enhance safety at sea.”

In the 853 inspections where deficiencies were found, the deficiencies are categorised as follows:

• Malfunction of control unit/circuit: 16%
• Malfunctioned Air Circuit Breaker (ACB): 12%
• Mis-selection of engine starting selection switch mode in emergency generator room: 12%
• Closing quick-closing valve: 22%
• Malfunction of starting arrangement: 14%
• Malfunction of engine: 8%
• No power supply to the services essential for safety in an emergency: 10%
• Other: 7%

The consolidated report of the concentrated inspection campaign is available on the IACS website here.