Probabilistic Damage

Presentation of Probabilistic

Damage Stability regulations,

New SPS Code and MARPOL

Regulation 12A

Jens Peter Baltsersen,

Senior Surveyor in Charge, Naval Architect Henrik Erichsen,

Agenda

• Probabilistic Damage Stability – 45 min By Jens Peter Baltsersen

• The Special Purpose Code (SPS) – 10 min By Henrik Erichsen

• MARPOL Regulation 12A – 15 min By Henrik Erichsen

Probabilistic Damage Stability Regulations

What Does PROBABILISTIC Damage Stability Mean?

Probabilistic Damage Stability Regulations

Short Historical Review

Dry Cargo Ships:

• 1992: Damage Stability regulations for ships > 100 m

• 1998: Damage Stability regulations for ships between 80 m and 100 m included in the

existing regulations Passenger Ships:

• IMO Res. A265 – Probabilistic

Damage Stability regulation (1973) • SOLAS 90 / 98 - Deterministic

Damage Stability regulation • Stockholm Agreement (1998)

Water on Deck

Probabilistic Damage Stability Regulations

Short Historical Review

• Harmonization started in the 1980ties by development of the probabilistic damage stability requirements for dry cargo ships • Passenger ships should have been included in the probabilistic

framework keeping the same level of safety

• 1992-1998: Harmonization process developing probabilistic damage stability regulations for both dry cargo ships and passenger ships • 2001: EU Project HARDER

• ”Back to basic”! • Damage Statistics • Model Tests

• Verification

• New designs using the new frame work

• 2005: The proposed damage stability regulations was adopted by MSC 20 May 2005 at the 80 session (Resolution MSC.194(80))

SLF42-3 Proposal

Probabilistic Damage Stability Regulations

Short Historical Review

1st January 2009

The new probabilistic damage stability requirements (revised SOLAS part B-1) will enter into force

Probabilistic Damage Stability Regulations

Short Historical Review

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Dry Cargo Ships (L>80 m): • Container Ships

• RoRo Cargo ships • Car Carriers

• General Cargo ships

• Bulkcarriers having reduced freeboard and deck cargo

(IACS Unified interpretation no. 65) • (Cable Laying Vessels)

All Passenger Ships: • Pure Passenger Ships • RoRo Passenger Ships • Cruise Vessels

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

• Offshore supply vessels (IMO Resolution MSC.235(82)) • Special Purpose Ships (IMO Resolution A.534(13))* • Special Trade Passenger Ships ”Pilgrim Trade” (1971) • High Speed Crafts (HSC Code 2000)

• Tankers (MARPOL 73/78)

• Ships covered by Reg. 27 of the LL Convention

• Ships Carrying Dangerous Chemicals in Bulk (IBC Code) • Ships Carrying Liquefied Gases in Bulk (ICG Code)

* SPS Code currently under revision and will be linked closely to the new SOLAS

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

A ≥ R

Damage Stability Concept:

Attained Subdivision Index A = Σ pi si

Required Index R

1. Cargo ships L > 100 m

2. Cargo Ships L > 80 m (and below 100 m)

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Calculation now based on 3 draughts • Deepest Subdivision Draught d_s • Light Service Draught d_l

• Partial Subdivision Draught d_p What have changed?

ds dl dp 60% Level trim Level trim Service trim Mean draught dl 100%

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Summation of attained index: A = 0.4A_s + 0.4A_p + 0.2A_l

Assuming that a ship will trade:

40% of it’s time at the deepest subdivision draught 40% of it’s time at the partial subdivision draught 20% of it’s time at the lightest service draught

Minimum attained index on each draught:

Each of the partial indices A_s , A_p and A_l are not to be less than 0.9R for passenger ships and 0.5R for cargo ships!

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Trim: If the operational trim range of a vessel exceeds ±0,5% of L_s then probabilistic damage stability calculations with trim should be supplied

Several GM limit Curves have to be presented !

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

P_i-factor: Probability that only the compartment or group of compartments under consideration may be flooded.

• The parameters used for the determination of p_i have been changed in the revised regulations

• Maximum damage length changed from 48 m to 60 m

• Damages of B/2 should be assumed (allowing penetration of longitudinal centre line bulkheads)

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Subdivision: There are no rules for the subdividing except that the length Ls defines the extremes for the actual hull.

However, it is important to consider a strategy carefully to obtain a good result (large attained index A.)

Z 1 Z 1 Ls Z4 Z 5 Z 6 Z 7 Z8 Z9 Z10 Z11 Z3 Z2 Z 2 Z 3

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Subdivision:

The figure illustrates the possible single and multiple zone damages in a ship with a watertight

arrangement suitable for a seven-zone division.

The triangles at the bottom line indicate single zone damages and the parallelograms indicate

adjacent zones damages.

Ls M a x d a m age le n gt h Ls Z 1 Z2 Z3 Z 4 Z 5 Z 6 Z 7

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Penetration factor r:

• Factor r is the probability that a longitudinal bulkhead will not be breached by the damage. For each longitudinal bulkhead inside the ship’s side, an r-value will be calculated. The sum of all r-values from the shell to the B/2 limit equals unity

• Factor p will be adjusted with factor r to obtain the final joint factor p

Damages of B/2 is now assumed (allowing

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Penetration factor r:

• By default, damages should extend to B/2 • A limit before B/2 can, however, be set

B/2 line _{Not included in the}

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Penetration factor r:

• Grey + Blue for a zone -> Σr = 1 (until B/2) • Blue for a zone not extending to B/2 -> Σr < 1

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Factor v:

• The factor v represents the probability that a watertight deck above the waterline remains intact, or in other words, whether or not the bow of an arbitrary ramming ship will be higher than the deck in question.

The maximum vertical extent of damage above a given waterline have changed from 7 m to 12.5 m!

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Factor v: Individual v-factors: • If H – d ≤ 0 → vi = 0 • If H – d ≤ 7.8 → vi = 0.8(H - d) / 7.8 • If 7.8 < H – d < 12.5 → vi = 0.8 + 0.2((H - d) - 7.8) / 4.7 • If H - d ≥ 12.5 → vi = 1 Accumulated v-factors: • v = v1 + (v2 - v1) +…. + (1 - vn)

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Survivability Factor s_i:

The value of “si” represents the probability of survival after flooding the zone “i" under consideration, and includes the probability of any horizontal subdivision remaining effective.

Passenger ships:

S_i = minimum { S_{intermediate,I} or S_final,i·S_mom,i }

Cargo ships: S_i = S_final,i

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Intermediate Stages of Flooding:

• S_{intermediate,i} is the probability to survive all intermediate stages of flooding until the final equilibrium stage

• Only applicable to passenger ships! S_{intermediate,i} =

Where GZ_max is not to be taken as more than 0.05 m and Range as not more than 7°. S_{intermediate,i} = 0 if the intermediate heel exceeds 15°.

Where cross-flooding fittings are required, the time for equalization shall

4 / 1 max 7 05 . 0 ⎥⎦ ⎤ ⎢⎣ ⎡GZ _⋅ Range

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Heeling Moments:

• S_mom,i is the probability to survive heeling moments • Only applicable to passenger ships!

S_mom,i = ≤ 1

The heeling moments M_heel is to be calculated as follows:

M_heel = maximum { M_passenger or M_wind or M_{survivalcraft} }

heel

M

nt

Displaceme

GZ

−

0

.

04

)

⋅

(

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Openings and evacuation routes:

• It is very important to take into account all weathertight and unprotected openings as they can have a large effect on the attained index!

• The margin line definition is no longer in the regulations • Evacuation routes have been included instead

S_i is to be taken as zero (no survivability) if:

• The lower edge of unprotected or weathertight openings through which progressive flooding may take place, immerses,

• Any part of the bulkhead deck in passenger ship considered a horizontal evacuation route or any vertical escape hatch will be immersed etc.

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Minor Damages for Passenger Ships (Regulation 8):

In order not to capsize due to a very small damage, a minor damage concept for passenger ships have been introduced in the new regulations.

• Deterministic concept stating that a passenger ship have to survive a given damage extent.

• Damage extent depending on the number of passengers. • 2 compartment damages!

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Double Bottom Damages (Regulation 9):

A double bottom shall be fitted extending from the collision bulkhead to the aft peak bulkhead.

Any part of a passenger ship or a cargo ship that is not fitted with a double bottom in accordance with the specifications given in Reg. 9 shall be capable of withstanding bottom damages as specified in the regulation 9, paragraph 8 in that part of the ship!

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Permeability:

The permeability of a compartment intended for cargo is now depending on the draught! 0.95 0.95 0.95 0.95 0.80 0.80 0.90 0.80 0.70 0.70 0.90 0.70 Dry cargo spaces

Container spaces Ro-ro spaces Cargo liquids Permeability at draught d_l Permeability at draught d_p Permeability at draught d_s Spaces

Probabilistic Damage Stability Regulations

Requirements (revised SOLAS Part B-1)

Work currently being carried out at

IMO, SLF Committee

• Explanatory Notes for the new probabilistic regulations – draft submitted to SLF 50 – to be finalized i 2008

• Passenger Ship Safety

- development of criteria for ”safe return to port” either under own power or under tow

- time to flood simulations

- requirements for water ingress detection and flood level monitoring systems

• Inclusion of the Special Purpose Ships in the new SOLAS B-1 • Revision of IMO Res. A.266 ”Cross-flooding”

• MSC/Circ.650 “modification of a major character" • Revision of the Intact Stability Code

Revision of the SPS Code

Code of Safety for Special Purpose

Ships - Resolution A.534(13)

Revision of the SPS Code

Which ships are covered by the SPS Code:

• Ships engaged in research, expeditions and survey; • Ships for training of marine personnel;

• Whale and fish factory ships not engaged in catching;

• Ships processing other living resources of the sea, not engaged in catching;

• Other ships with design features and modes of operation similar to ships referred above which in the opinion of the

Administration may be referred to this group.

Revision of the SPS Code

• “Special personnel” means all persons who are not passengers or members of the crew (or children of under one year of age) and who are carried on board in connection with the special purpose of that ship or because of special work being carried out aboard that ship.

• Wherever in the SPS Code, the number of special personnel appears as a parameter it should include the number of passengers carried on board which may not exceed 12.

The requirements in the SPS Code depends on how many ”special personnel” are carried!

Revision of the SPS Code

The SPS Code, IMO Resolution A.534(13) is currently under revision in IMO.

WHY?

• To update references to

current rules and regulations; • To reflect the new damage

stability requirements in SOLAS, Chapter II-1 coming into force 1 January 2009

Revision of the SPS Code

The draft for the new SPS Code – Damage Stability: • Based on the probabilistic concept A ≥ R

• Based on the revised SOLAS Chapter II-1, Part B-1 • Based on the requirements for passenger ships!

• Still based on the number of ”special personnel” onboard 1. below [50 special personnel] / [60 persons]

2. between [50 and 200 special personnel] / [60 and 240 persons] 3. more than [200 special personnel] / [240 persons]

Revision of the SPS Code

A ≥ R

Damage Stability Concept:

Attained Subdivision Index: A = Σ pi si

Required Index R:

1. More than [200 special personnel] [240 persons] – R value as passenger ship 2. Less than [50 special personnel] [60 persons] – 0.8R (passenger ship)

Revision of the SPS Code

Vessels with more than [200 special personnel] [240 persons]: Revised SOLAS Chapter II-1, reg. 8 and part B-2, B-3 and B-4 applies as though the ship is a passenger ship and the special personnel are passengers.

- Minor damages

- Watertight and Weathertight Subdivision

Revision of the SPS Code

Vessels with less than [200 special personnel] [240 persons]:

Revised SOLAS Chapter II-1, part B-2, B-3 and B-4 applies as

though the ship is a cargo ship and the special personnel are crew.

HOWEVER!

All SPS vessels must comply with the revised SOLAS Chapter II-1, regulation 9, 13, 19, 20, 21 and 35-1 as a passenger ship!

MARPOL Annex I

Regulation 12A

Regulation 12A - Oil fuel tank protection

• Applies to all vessels delivered on or after 1 August 2010 with an aggregate oil fuel capacity of 600m3 and above:

• Delivered defined as:

Building contract placed on or after 1 August 2007 or; If no contract, keels laid on or after 1 February 2008 or; The delivery of which is on or after 1 August 2010.

• Also applies to vessels which undergo a ‘major conversion’ in accordance with same dates.

Regulation 12A - Oil fuel tank protection

• Applies to all oil fuel tanks except small oil fuel tanks, provided that the aggregate capacity of such excluded tanks is not greater than 600m3

• Oil Fuel means any oil used as fuel oil in connection with the propulsion and auxiliary machinery.

• “Small oil fuel tanks” is an oil fuel tank with a maximum individual capacity not greater than 30m3

Regulation 12A - Oil fuel tank protection

Tanks to be located above the bottom shell plating at a distance of ‘h’ where:

h = B/20 m or 2.0 m whichever is less

Regulation 12A - Oil fuel tank protection

Tanks to be located inboard of the side shell plating at least distance ‘w’ where:

1. Ships with oil fuel capacity of 600m3 _{to 5000m}3_:

w = 0.4 + 2.4C / 20,000 m where C = total oil fuel volume

Minimum w = 1.0 m (except for individual tanks with a capacity < 500m3 _{minimum w = 0.76m.)}

2. Ships with oil fuel capacity of 5000m3 _{and over:}

w = 0.5 + C / 20,000 m or,

w = 2.0 m whichever is the lesser. Minimum w = 1.0 m.

Regulation 12A - Oil fuel tank protection

• Tanks with oil fuel piping located within ‘h’ and ‘w’ distances from the ship’s bottom and side shell to have special valve arrangements fitted.

• Suction wells in oil fuel tanks may protrude into the double bottom below ‘h’ provided such wells are as small as practicable and that the distance between the well bottom and the bottom shell plating is not less than 0.5h.

ALTERNATIVE to side and bottom protection requirements

• Comply with the accidental oil fuel outflow performance standard in regulation12A

Regulation 12A - Oil fuel tank protection

The Accidental Oil Fuel Outflow Performance Standard: • Probabilistic Concept!

• Mean Oil Outflow Parameter O_M

O_M ≤ 0.0157 – 1.14E-6_{C for 600 m}3 ≤ C < 5000 m3

O_M ≤ 0.010 for C ≥ 5000 m3

Regulation 12A - Oil fuel tank protection

Assumptions for the Mean Oil Outflow Calculation: • Ship assumed loaded to the partial loadline d_p

• All oil fuel tanks assumed loaded to 98% of their volumetric capacity • Nominal density of fuel oil taken as 1000 kg/m3

• For the purpose of the outflow calculations, the permeability of each oil fuel tank shall be taken as 0.99, unless proved otherwise.

• The calculation of the Mean Oil Outflow Parameter is based on a combination of side damages and bottom damages:

O_M = (0.4O_MS + 0.6O_MB)/C

O_MS = Mean outflow for side damage [m3_]

Regulation 12A - Oil fuel tank protection

Mean outflow for side damage O_MS: • O_MS =

P_S(i) = The probability of penetrating oil fuel tank i from side damage O_S(i) = The outflow, in m3_{, from side damage to oil fuel tank i, which is}

assumed equal to the total volume in oil fuel tank i at 98% filling. i = each oil fuel tank under consideration

n = total number of oil fuel tanks

) ( ) ( S i n i i S O P

∑

Regulation 12A - Oil fuel tank protection

Mean outflow for bottom damage O_MB:

• O_MB = 0.7O_MB(0) + 0.3O_MB(2.5) where:

O_MB(0) = Mean outflow for 0 m tide condition; O_MB(2.5) = Mean outflow for -2.5 m tide condition.

The mean outflow for bottom damage shall be calculated for each tidel condition as follows: • O_Mb(0) = , 0 m tide condition_{( ) B(i) DB(i)} n i i B O C P

∑

Regulation 12A - Oil fuel tank protection

Mean outflow for bottom damage O_MB:

• O_Mb(2.5) = , -2.5 m tide condition where:

P_B(i) = The probability of penetrating oil fuel tank i from bottom damage O_B(i)= The outflow, in m3_{, from bottom damage to oil fuel tank i.}

C_DB(i) = Factor to account for oil capture in other tanks i = each oil fuel tank under consideration

n = total number of oil fuel tanks

) ( ) ( ) ( B i DB i n i i B O C P

∑

Regulation 12A - Oil fuel tank protection

Practical Experience:

• Regulation 12A is a MAJOR design driver for newbuildings as should be taken seriously in the early design fase.

• In some ship types, it is difficult to find enough space for the protected fuel oil tanks.

• Will have a major impact on conversions in the future.

• The probabilistic oil outflow performance standard in Regulation 12A is difficult to fulfil.

The Lloyd’s Register Group works to enhance safety and approve assets and systems at sea, on land and in the air – because life matters.

Services are provided by members of the Lloyd’s Register Group

For more information, please contact: Lloyd’s Register EMEA

Statutory Section Strandvejen 104A DK-2900 Hellerup Denmark T +45 32 96 18 00 F +45 32 96 18 81 E jens.baltsersen@lr.org E henrik.erichsen@lr.org