Why Does Machinery Failure Still Cause More Than Half of Shipping Incidents? 

Shipping is becoming safer, but machinery damage and failure remain the industry’s largest operational problem.

The Allianz Safety and Shipping Review 2026 recorded 2,818 incidents involving vessels over 100GT during 2025. This was a 16% improvement from the previous year, but machinery damage or failure still accounted for 1,505 incidents, or 53% of the total. By comparison, there were 260 collisions and 218 fires or explosions.

The overall reduction is encouraging. Better vessel design, stronger regulations, improved technology and more developed safety systems are having an effect. However, the continued dominance of machinery failure raises an important question: if operators have more maintenance systems and data than ever before, why does machinery failure remain such a persistent problem?

Most vessels rely on planned maintenance built around time or running hours. An engine receives a service every 1,000 hours, a pump is inspected every six months, and a component is replaced according to the manufacturer’s recommended interval.

This provides an essential maintenance baseline, but it does not necessarily show the actual condition of the machinery.

Two identical engines can deteriorate at very different rates. One may operate at a consistent load in relatively clean conditions. The other may experience frequent load changes, high temperatures, vibration, contamination or operating practices that accelerate wear. Both engines may have the same scheduled service interval, but they do not necessarily carry the same level of risk.

Scheduled maintenance tells an operator when work is due. It does not always reveal what is beginning to change between services.

Many machinery failures appear sudden because the warning signs were not identified or connected in time. A gradual increase in exhaust temperature, a small pressure change, rising vibration, an unusual current draw or increasing fuel consumption may not be serious by itself. When several changes occur together, however, they can indicate that a component is moving away from its normal operating condition.

The problem is often not a complete lack of data. The problem is that the information is scattered.

Running hours may sit inside the planned maintenance system. Temperatures and pressures may be recorded in an engine-room log. Fuel use may be held in a spreadsheet. Alarm history may remain within the vessel’s monitoring system, while maintenance observations are written in individual job notes.

Each record has some value. The greater value comes from connecting them. Without that context, the crew may only recognise the pattern once an alarm activates or the machinery can no longer perform as expected.

Modern vessel technology has improved significantly, but it has also introduced more interconnected systems. A commercial vessel may combine diesel engines, battery storage, power-management systems, emissions equipment, automated controls, sensors and shore-based communications. A superyacht may add hotel loads, stabilisers, watermakers, chilled-water systems, hydraulic equipment and a growing number of electronically controlled systems.

A failure does not need to begin with a major mechanical component. It may start with a sensor, electrical connection, cooling restriction, communication fault or incorrect control response.

Because these systems depend on one another, a relatively small issue can affect several parts of the vessel. A cooling problem can reduce machinery performance. A sensor fault can create incorrect control decisions. A generator problem can affect propulsion, navigation and hotel services.

This makes it increasingly important to understand not only individual components, but also the relationships between them.

Planned maintenance remains necessary. The opportunity is to strengthen it with condition monitoring and better use of operational data. This does not require every vessel to install hundreds of new sensors immediately. A practical approach is to begin with the systems whose failure would create the greatest safety, operational or financial consequences.

Operators can identify critical machinery, establish normal operating ranges and monitor the parameters most likely to indicate deterioration. Existing data from engine-room checks, vessel monitoring systems, fuel records and maintenance history can often provide a useful starting point.

The objective is not to predict every possible failure. It is to identify meaningful changes early enough for the crew or shore team to investigate. That extra warning can allow an operator to order parts, arrange technical support and plan the repair around the vessel’s schedule. The alternative may be an emergency callout, cancelled sailings or an extended period of unplanned downtime.

More data does not automatically improve reliability. Poor-quality readings, excessive alarms and systems that generate warnings without explaining their significance can create more work for the crew. If every small variation becomes an alert, important information can disappear among the noise.

Effective condition monitoring should help people make decisions. It should show what changed, how significant the change is and what should be checked next.

Crew knowledge remains essential. Engineers understand how the vessel sounds, feels and responds under different conditions. The strongest approach combines that practical experience with consistent records and analysis across longer periods. Technology should support engineering judgement, not attempt to replace it.

Machinery failures are also becoming more expensive to resolve. Allianz notes that machinery repair costs remain elevated, with the cost and availability of parts, labour and specialist support adding to the financial impact.

The repair itself may be only one part of the cost. Operators can face cancelled services, disrupted charter programmes, replacement transport, unhappy customers and reputational damage.

Detecting a developing problem does not eliminate every failure, but it gives the operator more control over when and how the problem is addressed. That is the real value of moving towards condition-based and predictive maintenance. It turns maintenance from a calendar-driven process into a more informed way of managing operational risk.

Shipping’s overall safety record is improving, but machinery failure still accounts for more than half of reported incidents. Closing that gap will require more than completing scheduled tasks. It will require operators to make better use of the information their vessels are already producing.