Transcript 4440.11.SOLAS 2009x

Paris, March 2011
Probabilistic Damage Stability Rules for cargo ships
and SPS (Part B – SOLAS 2009)
Marine Technical Department
Stability Section (DT5)
CONTENTS
 Probabilistic concept
 Stability criteria to be satisfied
 Parameters to be considered
 Concepts for simplified analysis
 Openings, controls & escape routes
 Bottom damage
 Minimum required GM
 SOLAS 92 and SOLAS 2009
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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APPLICATION
 SOLAS PART B – 1
 MSC.281(85) : Explanatory notes to SOLAS CH II-1
 Dry cargo ships with type B freeboard
L > 80 m, if constructed on or after 1 January 2009
L is the length as defined in the ICLL in force
 For SPS : MSC.266(84) : application depending on
flag requirements.
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PROBABILISTIC CONCEPT
What is the basis of the probabilistic concept?
 The probabilistic concept is based on the probability of survival after
collision (damaged ship condition)
 This probability of survival is expressed by the attained index A
 The attained index A is obtained from the summation of the partial
indices As, Ap, Al
For which values of attained index A do we consider a ship as
surviving?
 The requirement for the survivability of the ship is set by the required
index R
 Therefore, the attained index A is to be compared with the required
index R
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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STABILITY CRITERIA TO BE SATISFIED
Four criteria need to satisfied for cargo ships/SPS
1. As ≥ 0.5R/0.9R, and
2. Ap ≥ 0.5R/0.9R, and
3. Al ≥ 0.5R/0.9R, and
4. A ≥ R
Partial attained index
 As : corresponds to the deepest subdivision draught ds
 Ap :corresponds to the partial subdivision draught dp
 Al : corresponds to the lightest subdivision draught dl
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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REQUIRED INDEX R FOR CARGO SHIPS
128
R 1
, if Ls  100 m
Ls  152


1
R 1 
1  Ls Ro
 100 1  Ro


 , if 80 m  Ls  100 m


Where:
Ro = R as calculated for Ls > 100 m
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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REQUIRED INDEX R FOR PASSENGER SHIPS/SPS
5,000
R  1
Ls  2.5 N  15,225
N= N1+ 2 N2 with
N1, number of persons for whom lifeboats are provided and
N2, number of persons the ship is permitted to carry in excess
of N1
N can be reduced to a minimum of N1+N2 subject to the
agreement of the flag
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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ATTAINED INDEX A
A  0.4 As  0.4 Ap  0.2 Al
Each partial attained index is a summation of the contribution from all
damage cases taken into consideration, using the following formula:
i t
Ac   pi ( ri )[ vi si ]
i 1
Where:
i : damaged zone or group of compartments under consideration
c : the considered loading condition
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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FACTORS OF PROBABILITY
Example:
p(j=3) : represents the probability that only zone number 3 will be
flooded taking into account the transverse subdivision (factors r1, r2, r3)
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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FACTORS OF PROBABILITY
Example 1:
Calculation of damage cases
Vertical limit: v1
Penetration: r1
Select the case which
gives the smallest value
for s:
MIN {s3;s32;s321}
Case Nr
Damaged
spaces
Transverse
extent (r)
Vertical
extent (v)
s-factor
1
3
r1
v1
s3
2
3+2
r1
v1
s32
3
3+2+1
r1
v1
s321
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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FACTORS OF PROBABILITY
Example 2:
Calculation of damage cases
Vertical limit: v2 = 1
Penetration: r1
Select the case which
gives the smallest value
for s:
MIN{s34;s342;s3421}
Case Nr
Damaged
spaces
Transverse
extent (r)
Vertical
extent (v)
s-factor
4
3+4
r1
1 - v1
s34
5
3+4+2
r1
1 - v1
s342
6
3+4+2+1
r1
1 - v1
s3421
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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FACTORS OF PROBABILITY
Example 3:
Calculation of damage cases
Vertical limit: v1
Penetration: r2
Case 6a or 6b depending on
B/2 exceeding the CL or not
Select the case which
gives the smallest value
for s:
MIN{s36;s3625;s36251/s362518}
Case Nr
Damaged
spaces
Transverse
extent (r)
Vertical
extent (v)
s-factor
4
3+6
1 - r1
v1
s36
5
3+6+2+5
1 - r1
v1
s3625
6a
3+6+2+5+1
1 - r1
v1
s36251
6b
3+6+2+5+1+8
1 - r1
v1
s362518
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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PARAMETERS TO BE CONSIDERED
 Watertight bulkheads and decks
 Weathertight bulkheads and decks
 Doors (watertight, weathertight of sufficient tightness and strength to
restrict the flow
 Air pipes
 Ventilators
 Piping systems
 Horizontal evacuation routes
 Vertical escape hatches
 Controls: operation of watertight doors, equalisation arrangements,
valves on piping or ventilation ducts, etc.)
 Permeability of spaces
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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PARAMETERS TO BE CONSIDERED
Spaces
Permeability
Permeability
Permeability
at draught ds
Appropriated to stores
0.60
Occupied by accommodation 0.95
Occupied by machinery
0.85
at draught dp
0.60
0.95
0.85
at draught dl
0.60
0.95
0.85
Void spaces
Intended for liquids
Dry cargo spaces
Container spaces
Ro-ro spaces
0.95
0 or 0.95 *
0.70
0.70
0.90
0.95
0 or 0.95 *
0.80
0.80
0.90
0.95
0 or 0.95 *
0.95
0.95
0.95
Cargo liquids
0.70
0.80
0.95
* whichever results in the more severe
Other figures for permeability may be used if substantiated by calculation
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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Specific requirements for SPS
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CONCEPTS FOR SIMPLIFYING THE ANALYSIS
V-lines concept
Important factors for the calculation of the s-value:
θe : Equilibrium heel angle
θv : Angle where GZ < 0 or submersion of unprotected openings
(downflooding point: openings cannot be closed weathertight)
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CONCEPTS FOR SIMPLIFYING THE ANALYSIS
V-lines concept
The envelope curve of worst waterlines after damage for all the
damage cases giving positive contribution to the attained index A
Type of V-lines
 “Watertight V-lines” derived from equilibrium heel angle (final or
intermediate stages of flooding)
 “Weathertight V-lines” derived from positive range (of GZ-curve)
Input for the calculation of the V-lines
 Bulkheads limiting the boundary of damage under consideration
 Decks limiting the boundary of damage under consideration
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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CONCEPTS FOR SIMPLIFYING THE ANALYSIS
Construction
V-lines concept
Scantling calculation (sufficient
strength to resist flooding loads)
Machinery
No immersion of
Weathertight
openings
openings
Watertight openings
Position of ventilators, air pipes
Electricity
Control of watertight doors, valves,
etc.
Safety
Horizontal evacuation routes
Vertical escape hatch
Escape routes, etc.
V-lines from equilibrium
V-lines from positive range
Stability
Verification of progressive flooding
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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CONCEPTS FOR SIMPLIFYING THE ANALYSIS
Safe Area concept
 Area far away from side shell (damage)
 Probability (r-factor) to have damage to area close to CL is very small
 Piping system as much as possible positioned close to the CL
 Maximum penetration is the boundary of the safe area (r2) instead of
CL
 Way to simplify the investigation of progressive flooding
 Negligible impact on attained index A: r3 = 1 – r2 is very small
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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CONCEPTS FOR SIMPLIFYING THE ANALYSIS
No Safe Area
 Investigation on progressive flooding for each damage case giving
positive contribution to the attained index A
 Fitting of valves to prevent progressive flooding
 Maximum penetration is CL (or B/2)
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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CONCEPTS FOR SIMPLIFYING THE ANALYSIS
Shadow of Tank concept
CL
CL
Damage case:
Damage in zone 1
3
Consequences:
Damage in space 1
1
2
Damage of pipe
Progressive flooding of
space 3
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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CONCEPTS FOR SIMPLIFYING THE ANALYSIS
Shadow of Tank concept
Damage case:
CL
CL
Damage in zone 1
Consequences:
3
1
2
Damage in space 1
(No damage of pipe)
(No progressive flooding
of space 3)
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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CONCEPTS FOR SIMPLIFYING THE ANALYSIS
Shadow of Tank concept
CL
CL
Damage case:
Damage in zone 2, up to r
Consequences:
3
1
r
Damage in space 2
2
Damage of pipe
Progressive flooding of
space 3
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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CONCEPTS FOR SIMPLIFYING THE ANALYSIS
Shadow of Tank concept
CL
CL
Damage case:
Damage in zone 2
Consequences:
1
3
rr11
r2
2
up to r1: damage in
space 2 (no damage of
pipe, no progressive
flooding of space 3)
up to r2: damage in
space 2, space 3 and pipe
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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OPENINGS, CONTROLS AND ESCAPE ROUTES
s = 0 (means: ship is not surviving), if position of
 Air pipes, ventilators and openings closed by means of weathertight
doors or hatch covers through which progressive flooding may take
place
 Horizontal evacuation route
is below the waterline at final equilibrium
 Vertical escape hatch
 Controls for the operation of watertight doors, equalisation devices,
valves on piping or on ventilation ducts intended to maintain the
integrity of watertight bulkheads above the bulkhead deck
 Any part of piping or ventilation ducts not fitted with watertight means
of closure, carried through a watertight boundary
is below the waterline in intermediate stages or at final
equilibrium
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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OPENINGS, CONTROLS AND ESCAPE ROUTES
s not automatically 0 if position of
 Air pipes, ventilators and openings closed by means of weathertight
doors or hatch covers through which progressive flooding may take
place
 Horizontal evacuation route and vertical escape hatch
 Controls for the operation of watertight doors, equalisation devices,
valves on piping or on ventilation ducts intended to maintain the
integrity of watertight bulkheads above the bulkhead deck
is above the V-lines
 Any part of piping or ventilation ducts carried through a watertight
boundary is fitted with valves able to prevent progressive flooding
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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SIMPLIFIED ANALYSIS – SUMMARY
 V-lines concept
 Safe Area concept
 Shadow of Tank concept
 Pipes and valves are adjacent to a bulkhead (longitudinal/transverse)
or deck
Provision: the separation distance is of the same order as the stiffening
structure
 Total cross sectional area of pipe < 710 mm2 (where possible)
Otherwise:
 Investigation on progressive flooding for each damage case
 If pipes and valves are outside the order of the stiffening structure,
introduction of a gap or additional zone and investigation of
progressive flooding
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LOCATION OF VALVES AT BULKHEADS
Example:
or
or
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SURVIVABILITY FACTORS
si  MIN{sintermediate,i or s final,i  smom ,i }
sintermediate and smom not applicable to cargo ships but to passenger ships/SPS
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S intermediate and S mom
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S intermediate and S mom
→ S intermediate to be calculated for passenger ships only if :
► progressive flooding / equalization before cross flooding
greater than > 60 s
►Non watertight bulkheads restricting the immediate flow of
water such as A class fire bulkheads, incenerator room,
refrigerated spaces.
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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S intermediate and S mom
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S intermediate and S mom
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S intermediate and S mom
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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S intermediate and S mom
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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BOTTOM DAMAGE
Double bottom height [m]
h ≥ MIN{B/20,2}
hmin = 0.76
Bottom damage
NO
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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MINIMUM REQUIRED GM
pr, v-factors
s-factor
Trim
Geometry of
watertight
arrangement
Loading
condition
VCG
Operational
trim range ≤
0.5% Ls
Operational trim
range ≥ 0.5% Ls
p: longitudinal
direction
Light
draught
(dl)
VCGl
Actual
Actual
Partial
draught
(dp)
VCGp
0
0
≠0 with steps
≤1% Ls
Deepest
draught
(ds)
VCGs
0
0
≠0 with steps
≤1% Ls
r: transverse
direction
v: vertical
direction
If the attained index A = pr  v  s satisfies the stability criteria of
SOLAS 2009, the minimum GM-curve is drawn based on the
chosen VCGs
SOLAS 2009– New Probabilistic Damage Stability Rules – Copyright Bureau Veritas, March 2011
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MINIMUM REQUIRED GM
Minimum GM-curve = envelope GM-curve covering calculations
for different trim values
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2. SOLAS 92 and SOLAS 2009
► SOLAS 1992
► SOLAS 2009
(cargo ships)





Calculations for 2 draughts
(deepest & partial)
No partial index requirements
Permeability for cargo holds is
constant and equal to 0.70
Damage extent is up to CL
Calculations are performed at even
keel (trim = 0)
(cargo and passenger ships)





Calculation for 3 draughts
(deepest, light service & partial)
Partial indices Ai ≥ 0.5R
Permeability of cargo holds is
function of draughts and cargo type
Damage extent is up to B/2
Calculations are performed for
several trims if range of operational
trims exceed +/- 0.5% Ls
(subdivision length)
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Thank you for your attention