Stability Flashcards
Negative stability.
Will not right itself but fall over.
Stability.
Ability to return to its upright position being healed by an external force.
Positive stability.
Returns to position after force.
Range of stability.
Tall narrow vs low wide shape.
Center of gravity. G
Geometric center of an object.
Point where all the gravity is said to be from.
Height of center of gravity.
Distance from G to K.
Weight added to a form …
Changes range of stability.
Center of buoyancy. B
Geometric center of the underwater shape of hull.
Just below G.
Metacenter. M
Pivot point when a vessel is inclined.
Positive metacenter height or positive GM.
Distance between metacenter and G.
Righting arm.
A vector of horizontal force that rights a boat.
GZ.
Tender vessel.
Metacentric height is low causing a long rolling period.
Like Abby.
Stiff vessel.
Meta centric height is high causing vessel to have a short rolling period.
Quick righting. Snappy.
Rolling period.
Time it takes to roll From side to side.
Free surface effect.
When vessel heels, load shifts.
Baffles lessens this effect.
Cargo must be tied in place.
List.
Vessel inclined by an internal force.
E.g., when cargo shifts.
Loll.
State of unstable equilibrium. Inclined by an external force and stays. Can lurch from state to state.
Longitudinal center of gravity. LCG
Center of flotation.
Tipping center.
Draft line.
Numbers are 6” and 6” between.
Load lines on bow and stern should equal.
Table can tell a captain the load weight.
Draft.
Distance between waterline and keel.
Freeboard.
Indicator of reserve buoyancy.
Volume of a vessels watertight space above the waterlines.
Load lines.
Plimsoll marks. Circle with horizontal line. Maximum weight of cargo.
TF: tropical fresh
F: fresh.
T: tropical
S: salt
W: winter
WNA: winter North Atlantic.
Exceptions to load line rules include.
War vessels, fishing, and pleasure.
Great Lakes load lines.
Has own scale with time of year. Midsummer: MS Summer: S Intermediate: I Winter: W
