Main engine safety systems are critical for protecting the engine and ensuring safe operation of ships. They typically include:

Safety Devices

• Crankcase relief doors
• Scavenge space relief doors
• Cylinder head relief valves
• Starting air relief valves
• Oil mist detectors
• Overspeed trip devices

Alarms

• Low lube oil pressure
• High cooling water temperature
• High exhaust gas temperature
• Low fuel pressure
• High oil mist concentration

Trips and Shutdowns

Trips and shutdowns automatically stop the engine in dangerous conditions:

• Very low lube oil pressure (< 1 bar)
• Very high jacket water temperature (> 95°C)
• Overspeed (typically 107% of max continuous rating)
• Oil mist detector activation
• Manual emergency shutdown

Interlocks:

Interlocks prevent starting the engine in unsafe conditions:

• Turning gear engaged
• Wrong running direction
• Low starting air pressure