Hotel Service Unit 16 Stabilizer Quiz

Correct Answer:
A) They require no power to operate

Explanation:
Bilge keels are passive stabilization devices, meaning they work without any external power source, making them low-maintenance and cost-effective.

Correct Answer:
C) To enhance stability by increasing resistance to roll at the vessel's widest point

Explanation:
The bilge area is the widest point on the hull, and locating the keels here ensures effective roll reduction as they provide maximum hydrodynamic resistance.

Correct Answer:
B) Cost and maintenance requirements

Explanation:
Bilge keels are cost-effective and low-maintenance, which can make them a preferable choice for vessels where budget and maintenance simplicity are priorities.

Correct Answer:
C) They are less effective at stabilizing than fin stabilizers

Explanation:
Bilge keels reduce roll but do not provide the same level of stabilization as active systems like fin stabilizers, which adjust in real-time to roll conditions.

Correct Answer:
B) By welding along their entire length to the hull

Explanation:
Bilge keels are welded to the hull along their length to ensure a secure, permanent attachment that withstands hydrodynamic forces and provides effective roll damping.

Correct Answer:
B) They are generally maintenance-free

Explanation:
Bilge keels are passive and fixed structures, so they require minimal maintenance compared to active stabilization systems with moving parts.

Correct Answer:
A) The vertical up and down movement of the vessel

Explanation:
Heave refers to the vertical motion caused by waves, where the vessel moves up and down relative to the water surface.

Correct Answer:
D) Rotation about the transverse axis

Explanation:
Pitch is the up-and-down tilting motion at the bow and stern, which occurs around the transverse (side-to-side) axis of the vessel.

Correct Answer:
B) Pitch involves movement along the longitudinal axis, not the transverse

Explanation:
Bilge keels are positioned to reduce roll along the transverse axis. Pitch, on the other hand, occurs around the vessel's transverse axis, where bilge keels have limited effect.

Correct Answer:
C) Surge

Explanation:
Surge is the forward or backward motion of the vessel, usually caused by the propulsion system or the influence of waves pushing the vessel in the direction of travel.

Correct Answer:
C) Roll

Explanation:
Roll is the rotational movement around the vessel’s longitudinal (front-to-back) axis, where the vessel tilts from side to side, influenced by waves and stabilization systems.

Correct Answer:
C) Along the bilge, at the turn of the hull

Explanation:
Bilge keels are placed along the bilge, where the hull turns from the bottom to the side, maximizing their effect in reducing rolling motions by increasing resistance to side-to-side movements.

Correct Answer:
B) By increasing resistance to roll through hydrodynamic drag

Explanation:
Bilge keels reduce roll by adding hydrodynamic resistance as the vessel rolls from side to side, dampening the rolling motion and increasing stability.

Correct Answer:
C) Yaw

Explanation:
Yaw refers to the vessel’s rotation around its vertical axis, causing the bow and stern to move to the left or right, typically influenced by rudder action or current.

Correct Answer:
B) The sideways movement to port and starboard

Explanation:
Sway is the lateral movement of the vessel across the water, often due to currents, winds, or wave impact from the side.

Correct Answer:
C) Free surface anti-roll tanks

Explanation:
Free surface anti-roll tanks are designed to use the movement of water within the tank to counteract rolling motion, providing stability to the vessel.

Correct Answer:
B) Stabilizing tanks generally require less maintenance as they are passive systems

Explanation:
Since stabilizing tanks lack the complex moving parts of fin stabilizers, they tend to require less maintenance, making them a low-maintenance option for roll reduction.

Correct Answer:
B) It reduces the vessel’s fuel efficiency

Explanation:
Stabilizing tank systems add weight and increase resistance due to the water movement within the tank, potentially reducing the vessel’s fuel efficiency compared to fin stabilizers.

Correct Answer:
C) U-tube anti-roll tanks

Explanation:
U-tube anti-roll tanks consist of two tanks connected by a channel, allowing water to flow in response to rolling, creating a counteracting force to reduce roll.

Correct Answer:
C) They are less effective at low speeds and increase drag at high speeds

Explanation:
Fin stabilizers rely on water flow for effectiveness and are less efficient at low speeds. Additionally, they create drag, which can impact fuel efficiency at higher speeds.

Correct Answer:
A) It is effective at all vessel speeds, including low and stationary speeds

Explanation:
Stabilizing tank systems work based on the movement of water within the tank and can be effective even at low or stationary speeds, unlike fin stabilizers, which are less effective when the vessel is stationary or moving slowly.

Correct Answer:
C) Fin stabilizers are generally more efficient at higher speeds

Explanation:
Fin stabilizers are most effective at higher speeds, as they generate lift through water flow, making them a preferred choice for vessels that operate mainly at cruising speeds.

Correct Answer:
B) Gyroscope or accelerometer

Explanation:
A gyroscope or accelerometer detects vessel roll and provides data to the control system, which adjusts water flow in the tanks to counteract the roll.

Correct Answer:
B) It increases fuel consumption due to the weight of water and operational pumps

Explanation:
The weight of water in the tanks and the energy used by pumps may slightly increase fuel consumption, especially if the system operates continuously in rough seas.

Correct Answer:
B) Water ballast tanks with controlled water flow

Explanation:
An ACT roll damping system relies on ballast tanks filled with water. The water flow within these tanks is controlled to counteract vessel roll, providing stability.

Correct Answer:
B) Through an automated control system with pumps and valves

Explanation:
The ACT system uses an automated control system to adjust water flow via pumps and valves, allowing real-time response to vessel movement and maximizing stability.

Correct Answer:
B) By creating a counterweight that resists the roll motion

Explanation:
The controlled water movement in the tank generates a counter-force to the roll, balancing the vessel’s movement and reducing roll amplitude.

Correct Answer:
B) To automatically adjust water flow based on real-time roll data

Explanation:
The control system receives data on roll angles and automatically adjusts the flow of water in the tanks to provide an opposing force, reducing roll.

Correct Answer:
B) Through continuous adjustments made by the automated control system in response to sensor data

Explanation:
The control system continuously adapts to changing sea conditions, adjusting water movement to maintain optimal roll stability.

Correct Answer:
A) It is effective at all speeds, including low and stationary conditions

Explanation:
An ACT system is beneficial because it actively adjusts water flow, providing stability even at low speeds or when the vessel is stationary, unlike bilge keels, which require movement.

Correct Answer:
B) Amidships, on both port and starboard sides

Explanation:
Placing ACT tanks amidships on both sides allows for effective roll reduction, as this is the area with the greatest impact on roll stability.

Correct Answer:
A) It operates effectively at all speeds, including when the vessel is stationary

Explanation:
Unlike passive stabilizers, which depend on vessel speed, an active system can stabilize the vessel even when stationary, as it actively controls water flow to reduce roll.

Correct Answer:
A) It increases fuel consumption due to the pumps required for operation

Explanation:
The pumps used to circulate water in response to vessel roll consume additional energy, which can slightly increase fuel consumption.

Correct Answer:
B) By minimizing vessel roll, resulting in a smoother experience during rough sea conditions

Explanation:
Reducing vessel roll enhances onboard comfort, particularly in rough seas, by stabilizing the vessel and providing a steadier environment for crew and passengers.

Correct Answer:
C) Gyroscope or inclinometer

Explanation:
A gyroscope or inclinometer senses roll angles and provides data to the control system, allowing it to adjust the water movement within the tanks to counteract roll.

Correct Answer:
B) To circulate water within the tanks to create a counteracting force against roll

Explanation:
Pumps and valves in the system control the water flow between tanks, using water movement to counteract and dampen roll.

Correct Answer:
C) It can actively adjust water movement in the tanks to counteract any rolling motion

Explanation:
The system’s active control allows it to respond to roll even when the vessel is stationary, unlike passive systems that rely on external water movement.

Correct Answer:
C) Amidships on either side of the vessel

Explanation:
Positioning the tanks amidships ensures effective roll reduction, as this location allows the water movement to counterbalance rolling forces across the vessel’s beam.

Correct Answer:
B) To reduce vessel roll and improve stability in rough seas

Explanation:
An active tank stabilization system helps counteract rolling by adjusting the movement of water within tanks, thereby enhancing stability.

Correct Answer:
B) It automatically adjusts water flow based on real-time sensor data on vessel roll

Explanation:
The control system responds instantly to roll sensor data, adjusting water flow to counteract roll by directing water movement within the tanks.

Correct Answer:
B) Automatic control system with gyroscope sensors

Explanation:
Gyroscope sensors detect roll and send signals to an automatic control system, which adjusts the fin angle to generate the necessary counteracting lift.

Correct Answer:
B) To reduce vessel roll by generating lift forces

Explanation:
Active fin stabilizers are designed to counteract vessel roll by creating lift forces, which oppose the rolling motion and help stabilize the vessel.

Correct Answer:
A) It controls the lift generated by the fins to counteract rolling

Explanation:
The angle of attack determines the lift force produced by the fins. By adjusting this angle, the stabilizers can generate sufficient force to reduce rolling.

Correct Answer:
B) It senses vessel roll and signals the control system to adjust fin angles

Explanation:
The gyroscope detects the vessel’s roll and communicates with the control system, which then adjusts the fin angles to generate counteracting lift.

Correct Answer:
B) By adjusting fin angles to generate more lift

Explanation:
The control system increases the fin angle to create more lift, countering the additional roll caused by the larger waves.

Correct Answer:
A) By adjusting the angle of the fins relative to water flow

Explanation:
Active fin stabilizers operate by altering the angle of the fins, creating lift forces that counteract roll when the vessel moves through water.

Correct Answer:
A) At high vessel speeds

Explanation:
Active fin stabilizers rely on the flow of water over the fins to generate lift; therefore, they are most effective at higher speeds when there is sufficient water flow.

Correct Answer:
B) They increase fuel consumption due to added drag

Explanation:
The fins create additional drag when deployed, which can increase fuel consumption, especially over long distances.

Correct Answer:
B) They actively counter roll at higher speeds, providing dynamic stabilization

Explanation:
Active fin stabilizers are effective at higher speeds, where they generate lift in response to water flow, unlike passive systems that rely on vessel inertia.