Maxsurf Webinar 5 – Damage Stability
Philip Christensen
FormSys
Damage Stability Topics ?Effect of Damage
?Set Up Damage Cases
?Set Up Damage Key Points ?General Damage Stability Analysis Tips
?Criteria for Damage Stability
Analysis
?Damaged Limiting KG Analysis Tips
?Floodable Length
?MARPOL Oil Outflow Calculation
Effect of Damage
?Applicable to all Analysis types except;
–Tank calibrations
–Floodable length
?Lost Buoyancy method
–As per IMO requirements
–Deducts the buoyancy of the flooded
tanks/compartments from the model
–All tank contents are emptied entirely ?Flooding is considered instantaneous to sea level
? E.g. Longitudinal Strength buoyancy curve
Set Up Damage Cases
?Define tanks & compartments
?Set damage permeability of all damaged spaces ?Create damage cases & Select which T/C?s to damage
?Extent of damage command damages all T/C?s within a zone
?Display damaged tanks & compartments ?Damaged tanks are labelled “Damaged” in loadcase tables
?Permanently flooded spaces should be defined using Non-Buoyant Volume, not damage
Set Up Damage Key Points & Margin Line
?Key points
–Downflooding points
–Potential downflooding points,
embarkation points & immersion points
–Note that key points are not symmetrical
?Can be “Linked To” tank to compartment
–DF point is ignored if T/C is damaged
–DF point immersion does not mean T/C is
automatically flooded
?“Floods From” option
–By default from the sea
–Or from a damaged T/C
–Opposite of “Linked To”
?Use for intact or damage or both
?Adjust margin line points if necessary
General Damage Stability Analysis Tips
?Check the model doesn?t sink or exceed
excessive trim by running equilibrium
analysis
?Analysis heel to port or starboard?
–Worst case scenario from damage
–Check by running equilibrium or large angle
stability analysis
–Run to both port and starboard (batch
analysis)
?Insert Damage Definition table in your report
template
Criteria for Damage Stability Analysis
?Custom criteria
–SOLAS, US, NSCV, Navy and more
?User specified criteria
–From complete set of generic parent criteria
–GZ curve and equilibrium based criteria
?Set criteria to Intact or Damage or
Both
?Criteria to DOwnflooding points,
Potential downflooding points, Margin
line, Deck edge, Embarkation points &
Immersion points
Damaged Limiting KG Analysis Tips
?Need to run both directions to determine worst
case heel from damage (port or starboard)
?Limiting KG …Current loadcase specifies initial
loading of damage tanks? option
–For damage conditions where an initially
loaded tank with a considerable amount
of liquid is damaged and the contents
are …lost to the sea?
?Check limiting KG results by running large
angle stability analysis for same conditions and
check just pass/fail criteria
Floodable Length
?Input
–Criteria
–Displacement range
–Average Tank permeabilities
–Proposed locations of bulkheads ?Calculates
–Maximum length of compartments at each longitudinal position, so that the
vessel passes the selected criterion ?Overlays proposed bulkhead spacing
MARPOL Oil Outflow Calculation
?MARPOL Resolution MEPC.141(54), Regulation 12A: Oil fuel tank protection
– all ships with an aggregate oil fuel capacity of 600m3 and above and which are delivered on or after 1 August 2010
?MARPOL Resolution MEPC.117(52), Regulation 23: Accidental oil cargo outflow performance
Thank You
?Next Webinar 6 Tuesday May 24th 2011 ?Topic: Probabilistic Damage Stability
?Have a suggestion for a future webinar topic?
–Email me: philc@https://www.doczj.com/doc/7a5908231.html,
?See you next time…