Deck Safety - Principles of Stability Questions

Which action will best increase the transverse stability of a merchant vessel at sea? A. Ballasting the double bottom tanks B. Deballasting the deep tanks C. Positioning a heavy lift cargo on the main deck D. Raising the cargo booms to the upright position

A. Ballasting the double bottom tanks

Initial stability is indicated by __________: A. GM B. KM C. Deck load D. Maximum allowed KG

A. GM

What is used as an indicator of initial stability? A. GM B. KG C. KM D. GZ

A. GM

Which statement is TRUE about metacentric height? A. It is a measure of initial stability B. It is located above the center of buoyancy C. It is measured vertically above the center of buoyancy D. It's determination is the objective of the inclining experiment

A. It is a measure of initial stability

Deballasting a double bottom has what affect on KG? A. KG is increased B. KG is decreased C. KG is not affected D. KG increases at light drafts and decreases at deep drafts

A. KG is increased

For a given displacement, the righting arm has its maximum value when __________: A. KG is minimum B. angle of inclination is maximum C. small-angle stability applies D. KM is a minimum

A. KG is minimum

What will happen when cargo is shifted from the main deck into the lower hold of a vessel? A. The GM will increase B. The metacenter will move upward C. The center of buoyancy will move upward D. All of the above

A. The GM will increase

Vertical moments are obtained by multiplying a vessel's weight and its __________: A. VCG or KG B. LCB C. LCG D. TCG

A. VCG or KG

Buoyancy is a measure of the ship's __________: A. ability to float B. deadweight C. freeboard D. midships strength

A. ability to float

Initial stability refers to stability __________: A. at small angles of inclination B. when loaded with minimum deck load C. when at transit draft D. when GZ is zero

A. at small angles of inclination

The upward pressure of displaced water is called __________: A. buoyancy B. deadweight C. draft D. freeboard

A. buoyancy

The center of the underwater volume of a floating vessel is the __________: A. center of buoyancy B. center of flotation C. uncorrected height of the center of gravity of the vessel D. center of gravity of the vessel corrected for free surface effects

A. center of buoyancy

The center of volume of the immersed portion of the hull is called the __________: A. center of buoyancy B. center of flotation C. center of gravity D. tipping center

A. center of buoyancy

A floating vessel will behave as if all of its weight is acting downward through the __________: A. center of gravity B. center of buoyancy C. center of flotation D. metacenter

A. center of gravity

When cargo is shifted from the lower hold to the main deck the __________: A. center of gravity will move upwards B. GM will increase C. center of buoyancy will move downward D. All of the above

A. center of gravity will move upwards

If the vertical center of gravity (VCG) of a ship rises, the righting arm (GZ) for the various angles of inclination will __________: A. decrease B. increase C. remain unchanged D. be changed by the amount of GG' x cosine of the angle

A. decrease

Aboard a vessel, dividing the sum of the vertical moments by the total weight yield the vessel's __________: A. height of the center of gravity B. vertical moments C. righting moments D. inclining moments

A. height of the center of gravity

Metacentric height is a measure of __________: A. initial stability only B. stability through all angles C. maximum righting arm D. All of the above

A. initial stability only

The purpose of the inclining experiment on a vessel is to determine the __________: A. location of the center of gravity of the light ship B. position of the center of buoyancy C. position of the metacenter D. maximum load line

A. location of the center of gravity of the light ship

The difference between the height of the metacenter and the height of the center of gravity is known as the __________: A. metacentric height B. height of the righting arm C. fore and aft perpendicular D. height of the center of buoyancy

A. metacentric height

The important initial stability parameter, GM, is the __________: A. metacentric height B. height of the metacenter above the keel C. height of the center of buoyancy above the keel D. height of the center of gravity above the keel

A. metacentric height

What is the stability term for the distance from the center of gravity (G) to the Metacenter (M), when small-angle stability applies? A. metacentric height B. metacentric radius C. height of the metacenter D. righting arm

A. metacentric height

The result of multiplying a weight by a distance is a __________: A. moment B. force C. couple D. center of gravity location

A. moment

If a vessel lists to port, the center of buoyancy will __________: A. move to port B. move to starboard C. move directly down D. stay in the same position

A. move to port

Addition of weight above the center of gravity of a vessel will ALWAYS __________: A. reduce initial stability B. increase righting moments C. increase GM D. All of the above

A. reduce initial stability

Addition of weight to a vessel will ALWAYS __________: A. reduce reserve buoyancy B. increase righting moments C. increase GM D. All of the above

A. reduce reserve buoyancy

The horizontal distance between the vertical lines of action of gravity and the buoyant forces is called the __________: A. righting arm B. metacentric height C. metacentric radius D. height of the center of buoyancy

A. righting arm

For a vessel inclined by the wind, multiplying the buoyant force by the horizontal distance between the lines of action of the buoyant and gravity forces gives the __________: A. righting moment B. vertical moment C. longitudinal moment D. transverse moment

A. righting moment

A slow and easy motion of a vessel in a seaway is an indication of a __________: A. small GM B. low center of gravity C. stiff vessel D. large GZ

A. small GM

Reserve buoyancy is __________: A. the watertight part of a vessel above the waterline B. the void portion of the ship below the waterline which is enclosed and watertight C. transverse watertight bulkheads D. a measure of metacentric height

A. the watertight part of a vessel above the waterline

The moment of a force is a measure of the __________: A. turning effect of the force about a point B. instantaneous value of the force C. stability characteristics of the vessel D. center of gravity location

A. turning effect of the force about a point

At all angles of inclination, the metacenter is __________: A. vertically above the center of buoyancy B. vertically above the center of gravity C. at the intersection of the upright vertical centerline and the line of action of the buoyant force D. at the geometric center of the underwater volume

A. vertically above the center of buoyancy

Subtracting KG from KM yields __________: A. BL B. GM C. FS D. KG

B. GM

Subtracting KG from KM yields __________: A. BM B. GM C. GZ D. KG

B. GM

What is not usually a concern when loading a single-hulled tanker? A. Bending moments B. Initial stability C. Draft D. Trim

B. Initial stability

What abbreviation represents the height of the center of buoyancy? A. BK B. KB C. CB D. BM

B. KB

Which will be a result of removing on-deck containers? A. KG will increase B. Metacentric height will increase C. KB will increase D. Reserve buoyancy will decrease

B. Metacentric height will increase

What is the definition of transverse metacenter? A. The distance between the actual center of gravity and the maximum center of gravity that will still allow a positive stability B. The point to which G may rise and still permit the vessel to possess positive stability C. The sum of the center of buoyancy and the center of gravity D. The transverse shift of the center of buoyancy as a vessel rolls

B. The point to which G may rise and still permit the vessel to possess positive stability

Intact buoyancy is a term used to describe __________: A. the volume of all intact spaces above the waterline B. an intact space below the surface of a flooded area C. an intact space which can be flooded without causing a ship to sink D. the space at which all the vertical upward forces of buoyancy are considered to be concentrated

B. an intact space below the surface of a flooded area

A vessel behaves as if all of its weight is acting downward through the center of gravity, and all its support is acting upward through the __________: A. keel B. center of buoyancy C. tipping center D. amidships section

B. center of buoyancy

Stability is determined principally by the location of the center of gravity and the __________: A. aft perpendicular B. center of buoyancy C. keel D. center of flotation

B. center of buoyancy

A vertical shift of weight to a position above the vessel's center of gravity will __________: A. increase reserve buoyancy B. decrease the righting moments C. decrease KG D. increase KM

B. decrease the righting moments

The purpose of the inclining experiment is to __________: A. determine the location of the metacenter B. determine the lightweight center of gravity location C. verify the hydrostatic data D. verify data in the vessel's operating manual

B. determine the lightweight center of gravity location

A vessel's KG is determined by __________: A. dividing the total longitudinal moment summation by displacement B. dividing the total vertical moment summation by displacement C. multiplying the MTI by the longitudinal moments D. subtracting LCF from LCB

B. dividing the total vertical moment summation by displacement

Stability is determined principally by the location of the point of application of two forces: the upward-acting buoyant force and the __________: A. upward-acting weight force B. downward-acting weight force C. downward-acting buoyant force D. environmental force

B. downward-acting weight force

Transverse stability calculations require the use of __________: A. hog or sag calculations or tables B. hydrostatic curves C. general arrangement plans D. cross-sectional views of the vessel

B. hydrostatic curves

Topside icing decreases vessel stability because it is usually off-center and __________: A. increases displacement B. increases the height of the center of gravity C. increases draft D. reduces the pocketing of free surface

B. increases the height of the center of gravity

The vertical distance between G and M is used as a measure of __________: A. stability at all angles of inclination B. initial stability C. stability at angles less than the limit of positive stability D. stability at angles less than the downflooding angle

B. initial stability

A moment is obtained by multiplying a force by its __________: A. couple B. lever arm C. moment of inertia D. point of application

B. lever arm

The magnitude of a moment is the product of the force and __________: A. time B. lever arm C. displacement D. angle of inclination

B. lever arm

You must shift a weight from the upper 'tween deck to the lower hold. This shift will __________: A. make the vessel more tender B. make the vessel stiffer C. increase the rolling period D. decrease the metacentric height

B. make the vessel stiffer

The point to which your vessel's center of gravity (G) may rise and still permit the vessel to have positive stability is called the __________: A. metacentric point B. metacenter C. metacentric radius D. tipping center

B. metacenter

When a vessel is inclined at a small angle the center of buoyancy will __________: A. remain stationary B. move toward the low side C. move toward the high side D. move to the height of the metacenter

B. move toward the low side

When a vessel has positive stability, the distance between the line of force through B and the line of force through G is called the __________: A. metacentric height B. righting arm C. righting moment D. metacentric radius

B. righting arm

The KG of a vessel is found by dividing the displacement into the __________: A. height of the center of gravity of the vessel B. sum of the vertical moments of the vessel C. sum of the free surface moments of the vessel D. sum of the longitudinal moments of the vessel

B. sum of the vertical moments of the vessel

The weight of the liquid displaced by a vessel floating in sea water is equal to the __________: A. weight required to sink the vessel B. total weight of the vessel C. displaced volume D. reserve buoyancy

B. total weight of the vessel

Aboard a vessel, dividing the sum of the transverse moments by the total weight yields the vessel's __________: A. vertical moments B. transverse position of the center of gravity C. inclining moments D. righting moments

B. transverse position of the center of gravity

A virtual rise in the center of gravity may be caused by __________: A. filling a partially filled tank B. using an on board crane to lift a freely swinging heavy object C. emptying a partially filled tank D. transferring ballast from the forepeak to the after peak

B. using an on board crane to lift a freely swinging heavy object

On a vessel, multiplying a load's weight by the distance of the load's center of gravity above the baseline results in a(n) __________: A. transverse moment B. vertical moment C. righting moment D. inclining moment

B. vertical moment

Reserve buoyancy is the __________: A. unoccupied space below the waterline B. volume of intact space above the waterline C. excess of the buoyant force over the gravity force D. difference in the buoyant force in salt and fresh waters

B. volume of intact space above the waterline

Its small angle stability theory, the metacenter is located at the intersection of the inclined vertical centerline and a vertical line through __________: A. G B. F C. B D. K

C. B

Which formula can be used to calculate metacentric height? A. KM + GM B. KM - GM C. KM - KG D. KB + BM

C. KM - KG

Stability is determined principally by the location of two points in a vessel: the center of buoyancy and the __________: A. metacenter B. geometric center of the waterplane area C. center of gravity D. center of flotation

C. center of gravity

Metacentric height is an indication of a vessel's stability __________: A. for all angles of inclination B. for large angles of inclination C. for small angles of inclination D. in no case

C. for small angles of inclination

When a vessel is floating upright, the distance from the keel to the metacenter is called the __________: A. metacentric radius B. height of the baseline C. height of the metacenter D. righting arm

C. height of the metacenter

When initial stability applies, the height of the center of gravity plus the metacentric height equals the __________: A. free surface moments B. righting arm C. height of the metacenter D. corrected height of the center of gravity

C. height of the metacenter

The waterplane area is described as the intersection of the surface of the water in which a vessel floats and the __________: A. baseline B. vertical reference plane C. hull D. horizontal reference plane

C. hull

In small-angle stability, when external forces exist, the buoyant force is assumed to act vertically upwards through the center of buoyancy and through the __________: A. center of gravity B. center of flotation C. metacenter D. metacentric height

C. metacenter

The volume of a vessel's intact watertight space above the waterline is its __________: A. free surface B. marginal stability C. reserve buoyancy D. freeboard

C. reserve buoyancy

When positive stability exists, GZ represents the __________: A. righting moment B. center of gravity C. righting arm D. metacentric height

C. righting arm

The righting moment can be determined by multiplying the displacement by the __________: A. vertical center of gravity (KG) B. longitudinal center of gravity (LCG) C. righting arm (GZ) D. center of gravity (CG)

C. righting arm (GZ)

At al angles of inclination, the true measure of a vessel's stability is the __________: A. metacentric height B. displacement C. righting moment D. inclining moment

C. righting moment

The TCG of a vessel may be found by dividing the displacement of the vessel into the __________: A. transverse center of gravity of the vessel B. sum of the vertical moments of the vessel C. sum of the transverse moments of the vessel D. transverse baseline of the vessel

C. sum of the transverse moments of the vessel

Stability is determined principally by the location of the point of application of two forces: the downward-acting gravity force and the __________: A. upward-acting weight force B. downward-acting weight force C. upward-acting buoyant force D. environmental force

C. upward-acting buoyant force

When a vessel is inclined by an external force, the __________: A. shape of the vessel's underwater hull remains the same B. vessel's center of gravity shifts to the center of the vessel's underwater hull C. vessel's center of buoyancy shifts to the center of the vessel's underwater hull D. vessel's mean draft increases

C. vessel's center of buoyancy shifts to the center of the vessel's underwater hull

Initial stability of a vessel may be improved by __________: A. removing loose water B. adding weight low in the vessel C. closing crossover valves between partly filled double bottom tanks D. All of the above

D. All of the above

Which is an indication of reserve buoyancy? A. Metacentric height B. Righting moment C. Rolling period D. Freeboard

D. Freeboard

The difference between the height of the metacenter and the height of the center of gravity is __________: A. KB B. KG C. KM D. GM

D. GM

Which would NOT provide extra buoyancy for a vessel with no sheer? A. Lighter draft B. Raised fo'c'sle head C. Raised poop D. Higher bulwark

D. Higher bulwark

Subtracting GM from KM yields __________: A. BL B. GM C. FS D. KG

D. KG

Topside icing decreases vessel stability because it increases __________: A. displacement B. free surface C. draft D. KG

D. KG

What will NOT decrease the stability of a vessel? A. Topside icing B. Running with a following sea C. Using 35% of the fuel in a full tank D. Lowering a weight suspended by a boom onto the deck

D. Lowering a weight suspended by a boom onto the deck

The center of buoyancy and the metacenter are in the line of action of the buoyant force __________: A. only when there is positive stability B. only when there is negative stability C. only when there is neutral stability D. at all times

D. at all times

The geometric center of the underwater volume of a floating vessel is the center of __________: A. hydrodynamic forces B. flotation C. gravity D. buoyancy

D. buoyancy

The water in which a vessel floats provides vertical upward support. The point through which this support is assumed to act is known as the center of __________: A. effort B. flotation C. gravity D. buoyancy

D. buoyancy

Stability is determined by the relationship of the center of gravity and the __________: A. water depth B. keel C. center of flotation D. center of buoyancy

D. center of buoyancy

The geometric center of the underwater volume is known as the __________: A. center of flotation B. tipping center C. center of gravity D. center of buoyancy

D. center of buoyancy

In the absence of external forces, the center of gravity of a floating vessel is located directly above the __________: A. metacenter B. amidships C. center of flotation D. geometric center of the displaced volume

D. geometric center of the displaced volume

The center of buoyancy is located at the __________: A. geometric center of the waterplane area B. intersection of the vertical centerline and line of action of the buoyant force C. center of gravity of the vessel corrected for free surface effects D. geometric center of the displaced volume

D. geometric center of the displaced volume

Your vessel rolls slowly and sluggishly. This indicates that the vessel __________: A. has off-center weights B. is taking on water C. has a greater draft forward than aft D. has poor stability

D. has poor stability

The difference between the height of the metacenter and the metacentric height is known as __________: A. righting arm B. metacentric radius C. height of the center of buoyancy D. height of the center of gravity

D. height of the center of gravity

The important stability parameter, KG, is defined as the __________: A. metacentric height B. height of the metacenter above the keel C. height of the center of buoyancy above the keel D. height of the center of gravity above the keel

D. height of the center of gravity above the keel

In small angle stability, the metacentric height __________: A. is found in the hydrostatic tables for a level vessel B. multiplied by the displacement yields the righting moment C. is always positive D. is calculated by subtracting KG from KM

D. is calculated by subtracting KG from KM

The principal danger from ice collecting on a vessel is the __________: A. decrease in capabilities of radar B. decrease in displacement C. adverse effect on trim D. loss of stability

D. loss of stability

For a floating vessel, the result of subtracting KG from KM is the __________: A. height of the metacenter B. height of the righting arm C. height of the center of buoyancy D. metacentric height

D. metacentric height

The abbreviation GM is used to represent the __________: A. height of the metacenter B. righting arm C. righting moment D. metacentric height

D. metacentric height

Reserve buoyancy is __________: A. also called GM B. the void portion of the ship below the waterline which is enclosed and watertight C. affected by the number of transverse watertight bulkheads D. the watertight portion of a vessel above the waterline

D. the watertight portion of a vessel above the waterline

The value of the maximum righting arm depends on the position of the center of buoyancy and the __________: A. longitudinal center of gravity B. transverse center of gravity C. downflooding angle D. vertical location of the center of gravity

D. vertical location of the center of gravity

If the result of loading a vessel is an increase in the height of the center of gravity, there will always be an increase in the __________: A. metacentric height B. righting arm C. righting moment D. vertical moments

D. vertical moments

The enclosed area defined as the intersection of the surface of the water and the hull of a vessel is the __________: A. amidships plane B. longitudinal reference plane C. baseline D. waterplane

D. waterplane