Special Purpose Ships and Offshore Supply Vessels comparison with respect to subdivision and damage stability

Antje Fleischhauer 2009-07-14

Revised Code of Safety forSpecial Purpose Ships (2008 SPS Code)

Comparision between OSV-Guidelines and SPS-Code No. 3

2008 SPS Code

adopted by IMO, Resolution MSC. 266(84)

supersedes the SPS Code adopted by IMO, Res. A.534(13) for special purpose ships certified on or after 13 May 2008

applicable to all new ships carrying more than 12 specialised personnel

who are specially needed for particular operational duties

who are carried in addition to the crew

also applicable to ships less than 500 GT tonnage

Comparision between OSV-Guidelines and SPS-Code No. 4

2008 SPS Code: Chapter 2 Stability & Subdivision

intact stability according to the 2008 Intact Stability Code

subdivision and damage stability should be in accordance with SOLAS 2009, chapter II-1 (probabilistic calculation) special personnel are considered as

passengers

the ship is considered as passenger ship => R value will be calculated as per SPS Code 2008 Chapter 2, 2.2

required index R depends on number of persons

Comparision between OSV-Guidelines and SPS-Code No. 5

2008 SPS Code: R-value

R-value will be calculated in accordance with SOLAS Reg. II-1/6.2.3

240 persons*: R is assigned as R

< 60 persons*: R is assigned as 0.8R

60 persons* (

Comparision between OSV-Guidelines and SPS-Code No. 6

2008 SPS Code: Requirements

< 60 persons and between 60 and 240 persons: SOLAS Chapter II-1, parts B-2, B-3 and B-4

240 persons: SOLAS Chapter II-1, parts B-2, B-3 and B-4

SOLAS Chapter II-1, Regulation 8 (minor damage) and 8-1

Comparision between OSV-Guidelines and SPS-Code No. 7

2008 SPS Code

all special purpose ships should comply with following SOLAS regulations:

II-1/9: Double bottom requirements

II-1/13: Openings in watertight bulkheads below the bulkhead deck

II-1/19: Damage control information

2006 OSV Guidelines for the Design and Construction of Offshore Supply Vessels

Comparision between OSV-Guidelines and SPS-Code No. 9

OSV Guidelines

adopted by IMO, Resolution MSC.235(82)

supersedes the IMO-Res. A.469(12)

Comparision between OSV-Guidelines and SPS-Code No. 10

OSV Guidelines

applicable to new offshore supply vessels of 24 m but not more than 100 m in length

provisions for OSV carrying more than 12 personnel are not included in the guidelines (-> Application of SPS-Code)

Comparision between OSV-Guidelines and SPS-Code No. 11

OSV-Guidelines: Intact and damage stability

intact stability according to the 2008 Intact Stability Code

damage stability deterministic calculation two-compartment-status: if the distance between two transverse

watertight bulkheads is less than the longitudinal damage extent, only one bulkhead should be considered as effective

damage assumptions:

longitudinal extent of damage: length of the vessel L > 43 m -> damage length = 3 m + 0.3 L

length of the vessel L 43 m -> damage length = 0.1 L

transverse extent: 760 mm

vertical extent: up to underside of cargo deck or the continuation thereof

Comparision between OSV-Guidelines and SPS-Code No. 12

OSV-Guidelines: Intact and damage stability

damage stability: stability criteria in the final stage of flooding:

angle of heel 15

minimum range of stability 20

GZmax = 0.1 m

final waterline should be below the lower edge of unprotected openings

unprotected openings should not become immersed at an angle of heel within the prescribed minimum range of residual stability.

sufficient stability within intermediate stage of flooding should be proven.

Comparision between OSV-Guidelines and SPS-Code No. 13

OSV Guidelines: Intact and damage stability

damage stability: damage extent in way of a stepped bulkhead

Comparision between OSV-Guidelines and SPS-Code No. 14

GL-Support for SOLAS 2009

GL has issued a Leaflet for damage stability calculation according to SOLAS 2009

Available for down load from http://www.gl-group.com/pdf/Leaflet_SOLAS_2009_-_Damage_Stability_-_V12_.pdf

Thank you for your attention