Ship Construction and Stability test 1
in small angle stability theory, the metacenter is located at the intersection of the inclined vertical centerline and a vertical line through
B
initial stability is indicated by
GM
subtracting KG from KM yields
GM
the difference between the height of the metacenter and the height of the center of gravity is
GM
what is used as an indicator of initial stability
GM
what abbreviation represents the height of the center of buoyancy
KB
subtracting GM from KM yields
KG
topside icing decreases vessel stability because it increases
KG
deballasting a double bottom has what affect on KG
KG is increased
for a given displacement, the righting arm has its maximum value when
KG is minimum
which formula can be used to calculate metacentric height
KM-KG
vertical moments are obtained by multiplying a vessel's weight and its
VCG or KG
buoyancy is a measure of the ship's
ability to float
initial stability of a vessel may be improved by
all of the above
intact bulwark is a term used to describe
an intact space below the surface of a flooded area
the center of buoyancy and the metacenter are in the line of action of the buoyant force
at all times
initial stability refers to stability
at small angles of inclination
which action will best increase the transverse stability of a merchant vessel at sea
ballasting the double bottom tanks
if the metacentric height is small, a vessel will
be tender
the geometric center of the underwater volume of a floating vessel is the center of
buoyancy
the upward pressure of a displaced water is called
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
buoyancy
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
center of buoyancy
stability is determined by the relationship of the center of gravity and the
center of buoyancy
the center of the underwater volume of a floating vessel is the
center of buoyancy
the center of volume of the immersed portion of the hull is called the
center of buoyancy
a floating vessel will behave as if all its weight is acting downward through the
center of gravity
stability is determined principally by the location of two points in a vessel: the center of buoyancy and the
center of gravity
when cargo is shifted from the lower hold to the main deck the
center of gravity will move upwards
a vessel would be referred to as "tender" when the weight of the cargo is
concentrated high and the double bottoms are empty
a vessel is tender if cargo weight is
concentrated high and the double bottoms empty
of the vertical center of gravity (VCG) of a ship rises, the righting arm (GZ) for the various angles of inclination will
decrease
a vertical shift of weight to a position above the vessel's center of gravity will
decrease the righting moments
the purpose of the inclining experiment is to
determine the lightweight center of gravity loctation
a vessel's KG is determined by
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
downward-acting gravity force
metacentric height is an indication of a vessel's stability
for small angles of inclination
which is an indication of reserve buoyancy
freeboard
in the absence of external forces, the center of gravity of a floating vessel is located directly above the
geometric center of the displaced volume
the center of buoyancy is located at the
geometric center of the displaced volume
your vessel rolls slowly and sluggishly. this indicated that the vessel
has poor stability
aboard a vessel, dividing the sum of the vertical moments by the total weight yields the vessel's
height of the center of gravity
the difference between the height of the metacenter and the metacentric height is known as
height of the center of gravity
the important stability parameter, KG, is defined as the
height of the center of gravity above the keel
when a vessel is floating upright, the distance from the keel to the metacenter is called the
height of the metacenter
when initial stability applies, the height of the center of gravity plus the metacentric height equals
height of the metacenter
which would NOT provide extra buoyancy for a vessel with no sheer
higher bulwark
the waterplane area is described as the intersection of the surface of the water and the hull of a vessel is the
hull
transverse stability calculations require the use of
hydrostatic curves
topside icing decreases vessel stability because it is usually off-center and
increases the height of the center of gravity
what is not usually a concern when loading a single-hulled tanker
initial stability
metacentric height is a measure of
initial stability only
the vertical distance between G and M is used as a measure of
initial stabilty
in small angle stability, the metacentric height
is calculated by subtracting KG from KM
which statement is TRUE about metacentric height
it is a measure of initial stability
which statement is TRUE of a tender vessel
its period of roll is long
a moment is obtained by multiplying a force by its
lever arm
the magnitude of a moment is the product of the force and
lever arm
the principal danger from ice collecting on a vessel is the
loss of stability
what will NOT decrease the stability of a vessel
lowering a weight suspended by a boom onto the deck
you must shift a weight from the upper 'tween deck to the lower hold. this shift will
make the vessel stiffer
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
metacenter
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
metacenter
for a floating vessel, the result of subtracting KG from KM is the
metacentric height
the abbreviation GM is used to represent the
metacentric height
the difference between the height of the metacenter and the height of the center of gravity is known as the
metacentric height
the important initial stability parameter, GM, is the
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
metacentric height
which will be a result of removing on-deck containers
metacentric height will increase
the result of multiplying a weight by a distance is a
moment
if a vessel lists to port, the center of buoyancy will
move to port
when a vessel is inclined at a small angle the center of buoyancy will
move toward the high side
in order to minimize the effects of a tender vessel, when carrying a cargo of lumber, you should
place the heaviest wood in the lower holds
a vessel with a small GM will
provide a comfortable ride for the crew and passengers
addition of weight above the center of gravity of a vessel will ALWAYS
reduce initial stability
addition of weight to a vessel will ALWAYS
reduce reserve buoyancy
the volume of a vessel's intact watertight space above the waterline is its
reserve buoyancy
the horizontal distance between the vertical lines of action of gravity and the buoyant forces is called the
righting arm
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
righting arm
when positive stability exists, GZ represents the
righting arm
the righting moment can be determined by multiplying the displacement by the
righting arm (GZ)
at all angles of inclination, the true measure of a vessel's stability is the
righting moment
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
righting moment
a slow and easy motion of a vessel in a seaway is an indication of a
small GM
vessels "A" and "B" are identical; however "A" is more tender than "B". this means that "A" relative to "B" has a
smaller GM
the TCG of a vessel may be found by dividing the displacement of the vessel into the
sum of the transverse moments of the vessel
the KG of a vessel is found by dividing the displacement into the
sum of the vertical moments of the vessel
what will happen when cargo is shifted from the main deck into the lower hold of a vessel
the GM will increase
what is the definition of transverse metacenter
the point to which G may rise and still permit the vessel to possess positive stability
reserve buoyancy is
the watertight part of the vessel above the waterline/ volume of intact space above the waterline
the weight of the liquid displaces by a vessel floating in sea water is equal to the
total weight of the vessel
the moment of a force is a measure of the
turning effect of the force about a point
stability is determined principally by the location of the point of application of two forces: the downward-acting gravity force and the
upward-acting buoyant force
a virtual rise in the center of gravity may be caused by
using an on board object crane to lift a freely swinging heavy object/ using fuel from a pressed fuel tank
the value of the maximum righting arm depends on the position of the center of buoyancy and the
vertical location of the center of gravity
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)
vertical moment
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
vertical moments
at all angles of inclination, the metacenter is
vertically above the center of buoyancy
when a vessel is inclined by an external force, the
vessel's center of buoyancy shifts to the center of the vessel's underwater hull
the enclosed area defined as the intersection of the surface of the water and the hull of a vessel is the
waterplane
