🔍 Key Concepts

• Engine orders relating to propeller speed (RPM) and direction of rotation • Steering orders relating to rudder angle and direction • The purpose of an engine-room/bridge order book or bell book and what it is intended to record

💭 Think About

• Think about which orders, if changed, directly affect the ship’s propulsion and movement through the water in a way that engineers must later be able to reconstruct from the log. • Ask yourself whether the record is meant to show only speed changes, only direction changes, or the full picture of what the propeller/engine was doing over time. • Consider whether rudder movements are normally logged in the same record as engine orders, or if they are tracked by separate instruments/records like a rudder angle indicator or VDR.

✅ Before You Answer

• Identify whether RPM (speed) and direction of rotation (ahead/astern) are both important to reconstruct propulsion history. • Decide if rudder orders are typically kept in the same ‘bridge/engine order’ record or handled by different recording systems. • Before choosing, picture what information investigators or engineers would need from that record after an incident: speed only, direction only, or both speed and direction of the shaft.