Aux 2 Unit 16 Stress on hull Flashcards

Aux 2 Unit 16 Stress on hull

What is one method to reduce vibration caused by machinery on a vessel?

B) Using vibration dampeners or isolators on machinery

Why are deck beams important in resisting transverse stresses?

C) They provide horizontal support and prevent deck deformation

Which of the following is an example of dynamic stress?

B) Pressure from waves impacting the side of the ship during rough seas

How might a vessel's hull experience sheer stress while floating in still water?

B) From internal forces such as uneven cargo distribution or structural irregularities

Which of the following is NOT an effect of severe vibration on a vessel?

B) Improved passenger comfort

Which of the following can contribute to vibration due to hydrodynamic forces?

B) Water flow around the hull and propeller cavitation

What is the best definition of sheer stress in the context of a vessel's hull?

B) A stress that acts parallel to the surface, causing one layer of material to slide over another

What is meant by "static stress" in the context of a vessel's hull?

B) A constant, unchanging load on the hull, such as the weight of the cargo and the structure of the ship itself

Where is longitudinal stress most likely to be at its maximum on a vessel?

B) The midship section

Which of the following best describes how sheer stress might be distributed in a vessel at rest in still water?

C) Varying along the hull, particularly where there are structural changes or weight imbalances

Which of the following conditions is most likely to increase the occurrence of racking?

B) The vessel moving through rough seas with significant rolling motion

What does the term "dynamic stress" mean when referring to a vessel’s hull?

B) Stress that results from constantly changing external forces such as waves, wind, and vessel motion

Why might panting occur at the same time as pounding in heavy seas?

B) The rapid movement of the bow through waves causes both slamming impacts (pounding) and pressure fluctuations (panting)

What is the meaning of the term "racking" as it applies to a vessel’s hull?

B) The side-to-side distortion of the ship’s hull caused by external forces

What structural feature helps to distribute the stress from pounding more evenly across the hull?

B) Reinforced deck beams and bulkheads near the bow

Which situation would likely increase static stress on a vessel's hull?

B) Loading heavy cargo evenly throughout the ship

What does "pounding" refer to when applied to a vessel in rough seas?

C) The forceful impact of the bow slamming against the water when the vessel moves over waves

Which of the following structures primarily resists longitudinal stress in a vessel?

B) The ship’s longitudinal girders and deck plating

Which part of the vessel’s structure contributes to both longitudinal strength and watertight integrity?

C) Longitudinal bulkheads

What are the main functions that a protective coating should perform on a vessel’s hull?

B) Protect against corrosion, prevent fouling, and improve fuel efficiency

Which structures in a vessel help resist racking?

C) Transverse bulkheads and side frames

How do longitudinal stringers assist in resisting transverse stresses?

C) By providing lateral support to reduce flexing of the hull

What certification is required for compliance with regulations on protective coatings?

B) An International Anti-fouling System Certificate

What is meant by "panting" in the context of a vessel’s hull?

B) The repetitive in-and-out movement of the hull plating due to varying pressure when the vessel pitches in waves

What is the primary cause of longitudinal stress in a vessel’s hull?

B) The vessel's own weight and the distribution of buoyant forces along the length of the hull

Which of the following best describes "racking" in a vessel?

B) The twisting or lateral deformation of the vessel due to side-to-side forces, such as rolling in heavy seas

What causes transverse stress on a vessel when it is being acted on by waves?

B) Wave impact and varying water pressure along the hull

What is the role of transverse bulkheads in preventing racking?

C) They divide the ship into compartments and add lateral strength to resist distortion

How does racking occur in a vessel’s hull?

C) Through the side-to-side force exerted on the hull by waves, causing distortion in the transverse bulkheads

What legislation applies to the use of certain protective coatings on a vessel’s hull?

B) The International Maritime Organization (IMO) regulations, specifically the International Convention on the Control of Harmful Anti-fouling Systems on Ships

How is a vessel's hull reinforced to resist pounding?

B) By reinforcing the forward bottom plating with thicker steel or additional frames

Where is transverse stress typically at its maximum when a vessel is floating in still water?

B) At the midship section

What is meant by the term "pounding" as applied to a vessel being driven hard in a seaway?

B) The impact of the vessel's bow slamming into the water when it rises and falls forcefully

Which of the following methods is commonly used to strengthen a vessel’s hull to resist panting?

B) Installing longitudinal girders and panting stringers at the bow

What is one possible effect of excessive vibration on a vessel?

B) Structural fatigue leading to potential cracks

What is the primary cause of transverse stress when a vessel is floating in still water?

C) The vessel's own weight acting on the hull

Where is transverse stress at its maximum when a vessel is drydocked?

C) At the points where the keel blocks and side supports contact the hull

In which scenario would a vessel experience significant longitudinal stress?

C) When the bow and stern are supported by wave crests with the midship section unsupported

What is the cause of transverse stress when a vessel is drydocked?

C) The vessel's weight being supported by keel blocks and side supports

Why is it important to check humidity and temperature before applying the coating?

C) To ensure proper adhesion and curing of the coating

Which additional structure complements transverse bulkheads to enhance resistance to racking?

B) Longitudinal stringers

What is "hogging" in the context of ship stresses?

A) When the bow and stern are unsupported and the midship section is supported by a wave, causing upward bending

What is panting, and how does it relate to a vessel in heavy seas?

B) The expansion and contraction of the hull plating due to pressure changes as the vessel moves through waves

What type of movement in a seaway is most likely to increase sheer stress on the vessel's hull?

B) Pitching, where the bow and stern move up and down due to waves

Which part of the ship helps resist transverse stress by increasing the vessel’s overall rigidity?

B) Deck beams and transverse bulkheads

What does "sagging" mean when referring to the hull of a vessel?

A) The downward bending of the vessel when the midsection is not supported by water and the bow and stern are supported by waves

Which of the following is NOT an example of static stress?

C) The fluctuating load from passengers moving on board

Which part of the vessel is most affected by pounding?

C) The bow

Which of the following combinations correctly identifies both a dynamic and static stress on a vessel?

 

B) Dynamic: Wind pressure on the mast; Static: Hydrostatic pressure on the hull

How can a vessel’s hull be subject to sheer stress when it is in a seaway?

B) From the alternating crests and troughs of waves, causing bending and differential forces along the hull

What is the first step in the process of re-coating a vessel’s hull in drydock?

B) Pressure washing and removing the existing coating and marine growth

How can propeller cavitation be reduced to lower vibration levels on a vessel?

B) Ensuring the propeller design is optimized for the vessel’s operating conditions

What structural feature of a vessel primarily resists transverse stress?

C) Transverse bulkheads and frames

Which of the following is a critical step in the re-coating process of a vessel’s hull?

B) Applying a primer coat before the final protective coating

What is the role of the keel in resisting longitudinal stress?

C) It acts as the backbone of the vessel, resisting bending forces along the hull

Which of the following is NOT a function of a protective coating on a vessel’s hull?

C) Adding buoyancy to the vessel

What is one common cause of vibration in a vessel?

B) Machinery operation, such as engines and propellers
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