🔍 Key Concepts
• Astern propulsion requirements in SOLAS Ch. II-1 (Construction – Subdivision and stability, machinery and electrical installations)
• How non-reversible diesel engines achieve astern thrust (e.g., controllable pitch propellers, reversing gears, electric drive)
• Difference between maneuvering capability and continuous rated power when going astern
💭 Think About
• Ask yourself: Which option sounds like a regulatory design requirement to prevent damage or unsafe operation, rather than a general performance wish or claim?
• Look at each choice and decide whether it describes a mandatory minimum capability, an unrealistic guarantee, or a misunderstanding of how astern power compares to ahead power.
• For ships without reversing gears or CPP, what is the main concern when operating astern: matching ahead RPM, ensuring equal power, or avoiding a particular engine or shaft condition?
✅ Before You Answer
• Check which answers talk about continuous operation versus just having “sufficient” control – does SOLAS specify an exact percentage of ahead rpm?
• Verify whether regulations ever guarantee equal ahead and astern power, especially for controllable pitch propellers, or if they focus on safe operating limits instead.
• For systems without reversing gears/CPP/electric drive, consider whether the rule would more likely emphasize avoiding overload or achieving a specific fraction of ahead speed.