Aux 1 Unit 11 Q8

1 / 10

What would be the consequence of not having a complete bush in the aftmost bearing?

D) Enhanced shaft flexibility

B) Increased risk of shaft misalignment and potential damage as the shaft exits the vessel

A) Improved performance

C) Reduced friction

2 / 10

Why does the aftmost bearing in a propulsion shaft system require a complete bush?

A) To provide full circumferential support and prevent any lateral movement, ensuring the shaft remains aligned as it exits the vessel

D) To decrease the amount of lubrication needed

C) To increase the flexibility of the bearing

B) To reduce the bearing's manufacturing cost

3 / 10

How does the complete bush in the aftmost bearing help to prevent misalignment as the shaft exits the vessel?

B) By providing continuous support around the entire shaft circumference, ensuring proper alignment and preventing lateral movement

C) By restricting the shaft's movement entirely

A) By allowing the shaft to move freely

D) By increasing the shaft's rotational speed

4 / 10

Which of the following best explains how a plain bearing system allows for longitudinal movement of the propulsion shaft?

A) By using fixed bearings that do not allow any movement

C) By rigidly fixing the shaft to prevent movement

D) By cooling the shaft to prevent expansion

B) By using axial clearances in the bearings that allow the shaft to slide back and forth slightly

5 / 10

What is the primary reason why intermediate bearings may only have a bush in the lower half?

A) To increase the overall cost of the bearings

D) To improve the shaft's flexibility

B) The weight of the shaft ensures that it maintains contact with the lower half of the bearing, making a full bush unnecessary in intermediate positions

C) To reduce the shaft's load on the bearing

6 / 10

What could happen if the propulsion shaft is not allowed to move longitudinally within the bearings?

B) Excessive stress could build up, leading to bearing failure or damage to the shaft.

A) The shaft would become more efficient.

C) The shaft would operate more smoothly.

D) The bearing would automatically adjust.

7 / 10

How do propulsion shaft intermediate plain bearings accommodate changes in alignment due to varying vessel conditions, such as loading or hull flexing?

D) By reducing the size of the bearing

A) By using fixed, rigid bearing mounts

C) By increasing the size of the bearing housing

B) By incorporating a self-aligning feature that allows the bearing to adjust to minor alignment changes

8 / 10

What design feature is commonly used in plain bearings to allow for alignment changes due to vessel conditions?

A) Fixed, non-movable bearing blocks

B) Spherical bearing housings that allow the bearing to tilt slightly

D) Enlarged bearing surfaces to allow for play

C) Completely rigid and unmovable bearing mounts

9 / 10

Why is it important for the propulsion shaft to be able to move longitudinally within its plain bearings?

B) To accommodate thermal expansion and contraction of the shaft, preventing excessive stress on both the shaft and bearings

D) To reduce the overall weight of the propulsion system

A) To increase the vessel's speed

C) To allow for easier alignment of the shaft

10 / 10

In what scenario would longitudinal movement of the propulsion shaft be most critical?

D) When the shaft is not in use

C) When the vessel is docked

A) When the vessel is stationary

B) During rapid temperature changes, such as when transitioning from cold to warm waters

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