What is the function of the bus tie breaker, and how does its state define open bus versus closed bus operation?

A. The bus tie breaker only controls shore power connections in port

B. The bus tie breaker electrically connects (closes) or separates (opens) sections of the switchboard; in closed bus configuration it is shut, allowing power flow between sections, whereas in open bus configuration it is open, isolating sections so a fault on one cannot propagate to the other

C. It has no relevance to DP redundancy, only to cargo systems

D. Closed bus means the breaker is open; open bus means it is closed — the naming is the reverse of switchboard state

A. It is a manual logbook system maintained by the engineering officer

B. It exists solely to control hotel load (accommodation power), separate from DP thrust power

C. It only logs fuel consumption for reporting purposes

D. It automatically manages generator start/stop, load sharing, bus configuration, and load shedding to ensure sufficient power is always available for DP thrust demand, while protecting against blackout from overload

A. It refers to manually unloading cargo to reduce vessel draft

B. It is an automatic PMS function that disconnects pre-defined non-essential loads (or de-rates thruster demand) when generation capacity is at risk of being exceeded, preventing a generator overload trip that could cascade into a full blackout

C. It means switching all power to the emergency generator during normal operations

D. It is a planned maintenance activity to rotate generator running hours