System Components & Functions Flashcards
7 cards from real DPO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 System Components & Functions flashcards as text
In a DP power plant, what is the purpose of bus-tie breakers?
Answer: Connect different power distribution busbars together or isolate them
Bus-tie breakers allow operators to connect or isolate separate power busbars, enabling flexible power distribution configurations that support redundancy requirements.
What is the primary advantage of a Voith-Schneider Propeller (VSP) in DP operations?
Answer: Ability to produce thrust in any direction without rotation delay
The VSP can instantaneously redirect thrust through 360 degrees by adjusting blade pitch, providing extremely fast and precise force vectoring ideal for DP applications.
Which reference system uses acoustic transponders placed on the seabed to determine vessel position?
Answer: Hydroacoustic Position Reference (HPR)
Hydroacoustic Position Reference systems such as USBL, SBL, and LBL use acoustic transponders on the seabed and transducers on the hull to calculate the vessel's position relative to the seabed.
What does the term 'capability plot' represent in DP system assessment?
Answer: A diagram showing maximum environmental conditions the vessel can hold position in
A capability plot is a polar diagram showing the maximum wind, current, and wave conditions from each direction in which the vessel can maintain DP position with its available thrusters.
In DP terminology, what is 'environmental feedforward' used for?
Answer: Pre-compensating thruster forces based on measured environmental loads
Environmental feedforward uses measured wind and current forces to proactively apply counteracting thruster forces before the vessel is displaced, reducing position excursions.
What is the consequence of operating a tunnel thruster at very low RPM for extended periods?
Answer: Poor cooling of the motor windings leading to overheating
Many tunnel thruster motors rely on adequate flow through the tunnel for cooling; operating at very low speed reduces this flow and can cause motor windings to overheat.
Which component prevents reverse power flow from the busbars back into a generator when it trips offline?
Answer: Reverse Power Relay
A reverse power relay detects when a generator starts absorbing power from the busbar rather than supplying it, and trips the generator circuit breaker to protect the prime mover.