１９７４年国际海上人命安全公约１９９０年修正案(附英文)

【颁布日期】：1990-05-25【题 目】１９７４年国际海上人命安全公约１９９０年修正案(附英文)
【颁布日期】1990.05.25
【生效日期】1990.05.25
【时 效 性】有效

目 录
第Ⅱ－１章 构造——分舱与稳性、机电设备
增加新的Ｂ－１部分 货船分舱和破舱稳性
增加新的第２５－１条 适用范围
增加新的第２５－２条 定义
增加新的第２５－３条 要求的分舱指数“Ｒ”
增加新的第２５－４条 达到的分舱指数“Ａ”
增加新的第２５－５条 因数“Ｐｉ”的计算
增加新的第２５－６条 因数“Ｓｉ”的计算
增加新的第２５－７条 渗透率
增加新的第２５－８条 稳性资料
增加新的第２５－９条 在货船水密舱壁和内部甲板上的开口
增加新的第２５－１０条 货船上的外部开口

１９７４年国际海上人命安全公约修正案〔海安会以决议ＭＳＣ．１９（５８）于１９９０年５月２５日通过〕

第Ⅱ－１章 构造——分舱与稳性、机电设备

以下新的Ｂ－１部分包括第２５－１条至第２５－１０条，加在现有的Ｂ部分之后：“Ｂ－１部分 货船分舱和破舱稳性①
① 在采用包含在Ｂ－１部分的各条规则时，本海上安全委员会请各主管机关注意到，这些规则应与由本组织制订
的有关解释性文件一起使用，以确保应用的一致性。（本部分适用于１９９２年２月１日或以后建造的船舶）
第２５－１条 适用范围１ 本部份的要求适用于船长（“Ｌｓ”）超过１００ｍ的货船，但不包括被证明是符合本组织公布的其它文件②中分舱和破舱稳性规则的那些船舶。② 符合以下规定的船舶可以不适用于Ｂ－１部分：

．１ 《ＭＡＲＰＯＬ７３／７８》附则Ｉ；
．２ 经修订的《国际散化规则》（ＭＳＣ．４（４８）和ＭＳＣ．１０（５４）决议）；
．３ 《国际液化气船规则》（ＭＳＣ．５（４８）决议）；
．４ 《近海供应船设计和建造指导性文件》（Ａ．４６９（ＸＩＩ）决议）；
．５ 《特殊用途船安全规则》（Ａ．５３４（１３）决议）；
．６ 采用《１９６６年国际载重线公约》第２７条的破舱稳性要求且同时符合Ａ．３２０（ＩＸ）和Ａ．５１４（１３）决议的规定，但对适用于该公约第２７（９）条的船舶而言，其被认为是有效的主横水密舱壁应按Ａ．３２０（ＩＸ）决议第（１２）（ｆ）款的规定分隔。２ 下文提到的规则包含本部份的整套规则。３ 对某一特定船舶或一组船舶，如果确信至少能达到与本规则同等的安全程度，主管机关可以接受变通的布置。凡允许采取这一变通布置的任何主管机关均应将其详细情况通报本组织。
第２５－２条 定 义
除另有规定外，本规则定义如下：１．１ “分舱载重线”是用以决定船舶分舱的水线；１．２ “最深分舱载重线”是相应于船舶核定的夏季吃水的分舱载重线；１．３ “部分载重线”是空船吃水加上空船吃水与最深分舱载重线之间差值的６０％。２．１ “船舶分舱长度”（“Ｌｓ”）是船舶处于最深分舱载重时限制垂向浸水范围的甲板及其以下部份最大投影型长度；２．２ “船长中点”是船舶分舱长度的中点；２．３ “后端点”是分舱长度的最后一点；２．４ “前端点”是分舱长度的最前一点；３ “船宽（Ｂ）是在最深分舱载重线或其下的船舶最大型宽；４ “吃水”（ｄ）是在船长中点处从船型基线至所述水线间的垂直距离；５ “渗透率”（μ）某一处所的渗透率是指该处所浸水容积与浸没容积之比。
第２５－３条 要求的分舱指数“Ｒ”１ 本条给船舶规定了一个最低的分舱标准。２ 船舶的分舱程度由下式所要求的分舱指数“Ｒ”来确定：
１／３
Ｒ＝（０．００２＋０．０００９Ｌｓ）
式中：
“Ｌｓ”——船舶分舱长度，ｍ。
第２５－４条 达到的分舱指数“Ａ”１ 按本条计算所得的达到的分舱指数“Ａ”应不小于按第２５－３．２条计算所得的要求的分舱指数“Ｒ”。２ 船舶达到的分舱指数“Ａ”应按下式计算：
Ａ＝∑Ｐi Ｓi
式中：
ｉ——表示所考虑的每一个舱或舱组；
Ｐi ——表示所考虑的舱或舱组可能浸水的概率，不考虑任何水平分隔；
Ｓi ——表示考虑的舱或舱组浸水后的生存概率，包括任何水平分隔的影响。３ 在计算“Ａ”时应采用水平纵倾。４ 该总和仅包括那些有助于增加达到的分舱指数“Ａ”值的浸水情况。５ 上述公式所表示的总和应计及整个船长范围内单个舱或两个或更多相邻舱的所有浸水情况。６ 若设有边舱，边舱浸水的所有情况应加入公式所表示的总和中；此外，边舱和其相邻的内侧舱间同时浸水的所有情况也应加入总和，此时假定一垂直穿透扩展至船中心线但不包括中心线处舱壁的破损。７ 破损的垂向范围假定为从基线向上扩展至水线以上或更高的任一水密水平分隔。然而，如果一个较小范围的破损会产生更为严重的后果，则应假定为该范围。８ 如在假定浸水舱范围内设有管子、管弄或隧道，其装置应做到保证继续浸水不会扩展到那些假定浸水的舱室以外的其他舱室。然而，如果证实继续浸水的影响能被容易地控制并且不损害船舶的安全，则主管机关可以允许较小的继续浸水。９ 在根据本规则进行浸水计算时需要假定船壳只有一个破洞。
第２５－５条 因数“Ｐi ”的计算１ 采用下列表示法，根据不同的情况按本条之１．１计算因数“Ｐi ”；
Ｘ1 ＝从“Ｌｓ”的后端点到所考虑的舱室后端最前部位的距离；
Ｘ2 ＝从“Ｌｓ”的后端点到所考虑的舱室前端最后部位的距离；
Ｅ1 ＝Ｘ1 ／Ｌ
Ｅ2 ＝Ｘ2 ／Ｌ
Ｅ＝Ｅ1 ＋Ｅ2 －１
Ｊ＝Ｅ2 －Ｅ1
Ｊ′＝Ｊ－Ｅ，如Ｅ≥０
Ｊ′＝Ｊ＋Ｅ，如Ｅ＜０
最大无因次破损长度：
Ｊmax ＝４８／Ｌｓ，但不大于０．２４。
破损位置沿船长的假定分布密度
ａ＝１．２＋０．８Ｅ，，但不大于１．２。
破损位置沿船长的假定分布函数
Ｆ＝０．４＋０．２５Ｅ（１．２＋ａ）
ｙ＝Ｊ／Ｊmax
Ｐ＝Ｆ１Ｊmax

| ２
| ｑ＝０．４Ｅ2 （Ｊmax ）
|
| ２ １ ３
| Ｆ１＝ｙ －－ｙ ，如ｙ＜１，
| ３
|
| １
| Ｆ１＝ｙ－－ ，其它情况；
| ３
|
| １ ３ １ ４
| Ｆ２＝－ｙ －－－－ｙ ，如ｙ＜１，
| ３ １２
|
| １ ２ １ １
| Ｆ２＝－ｙ －－ｙ＋－－－，其它情况。
| ２ ３ １２
１．１ 每一单个舱的因数“Ｐi ”按以下各条规定：１．１．１ 当所考虑的舱延伸至整个船长“Ｌｓ”：
Ｐi ＝１１．１．２ 当所考虑的舱的后端点与“Ｌｓ”的后端点重合时：
Ｐi ＝Ｆ＋０．５ａｐ＋ｑ１．１．３ 当所考虑的舱的前端点与“Ｌｓ”的前端点重合时：
Ｐi ＝１－Ｆ＋０．５ａｐ１．１．４ 当所考虑的舱的两端位于船长“Ｌｓ”的前后端点以内时：
Ｐi ＝ａｐ１．１．５ 在应用本条之１．１．２、１．１．３和１．１．４的公式时，当所考虑的舱室跨越“船长中点”时，这些公式的值应减去一个按公式“ｑ”求得的值，在此公式中取ｙ＝Ｊ′／Ｊmax 计算Ｆ２。
２ 若设有边舱，某一边舱的“Ｐi ”值应以按本条之３得到的值乘以本条之２．２表示内侧处所不致浸水的概率的缩减因数“γ”求得。２．１ 某一边舱和其相邻的内侧舱室同时浸水的情况，其“Ｐi ”值应用本条之３各公式所得的值乘以因数（１－ｒ）求得。２．２ 缩减因数“ｒ”应按下列公式求得：
当Ｊ≥０．２ｂ／Ｂ时：

ｂ ０．０８
ｒ＝－（２．３＋－－－－－－－）＋０．１，如ｂ／Ｂ≤０．２
Ｂ Ｊ＋０．０２

０．０１６ ｂ
ｒ＝（－－－－－－＋－＋０．３６），如ｂ／Ｂ＞０．２
Ｊ＋０．０２ Ｂ

当Ｊ＜０．２ｂ/Ｂ－时，缩减因数“ｒ”应在Ｊ＝０时的ｒ＝１，
和Ｊ＝０．２ｂ／Ｂ时，ｒ按上述公式所得值用线性内插法求得：
式中：
ｂ＝计算因数“Ｐi ”所用的纵向限界之间的平均横向距离，ｍ。该距离在最深分舱载重线处由船壳板至通过纵舱壁最外部份，并与其平行的平面之间向中心线垂直量计。３ 对几个舱作为一个舱的“Ｐi ”值，可直接应用本条之１和２的公式计算。３．１ 各舱组的“Ｐi ”值，可直接用下列各式求得：
对取两个舱的舱组：
Ｐi ＝Ｐ12－Ｐ1 －Ｐ2
Ｐi ＝Ｐ23－Ｐ2 －Ｐ3 ，等
对取三个舱为一组的舱组：
Ｐi ＝Ｐ123 －Ｐ12－Ｐ23＋Ｐ2
Ｐi ＝Ｐ234 －Ｐ23－Ｐ34＋Ｐ3 ，等。
对取四个舱为一组的舱组：
Ｐi ＝Ｐ1234－Ｐ123 －Ｐ234 ＋Ｐ23
Ｐi ＝Ｐ2345－Ｐ234 －Ｐ345 ＋Ｐ34等。式中：
Ｐ12，Ｐ23，Ｐ34，等，
Ｐ123 ，Ｐ234 ，Ｐ345 ，等，
Ｐ1234，Ｐ2345，Ｐ3456等
应按本条之１和２对单个舱的公式计算，其无因次长度Ｊ取Ｐ的下标所标明的舱组的无因次长度。３．２ 对三个或更多相邻舱室为一组的舱组，如果该舱组的无因次长度减去该舱组最前和最后舱室的无因次长度大于Ｊmax ，则其因数“Ｐi ”等于零。
第２５－６条 因数“Ｓi ”的计算１ 对每一舱或舱组因数“Ｓi ”应按下述步骤求得：１．１ 通常对任一初始装载情况的任一浸水情况的“Ｓ”应按下式计算：

＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
Ｓ＝Ｃ√０．５（ＧＺmax ）（ｒａｎｇｅ）

式中： Ｃ＝１，如θｅ≤２５°

Ｃ＝０，如θｅ＞３０°

＿＿＿＿＿＿＿
／３０－θｅ
Ｃ＝√－－－－－－－－，其他情况
５

ＧＺmax ＝以下所给范围内的最大正复原力臂（ｍ）但不大于０．１ｍ；
ｒａｎｇｅ＝超出平衡角的正复原力臂的范围（°）但不大于２０°；而且此范围应在不能风雨密
地关闭的开口被淹没的角度处中止。
θｅ＝横倾的最终平衡角（°）。１．２ 如考虑下沉，横倾和纵倾后的最终水线浸没某些开口的下缘，且通过该开口可能发生继续浸水时取Ｓ＝０。这些开口应包括空气管、通风筒和以风雨密门或舱口盖关闭的开口，但可以不包括那些用水密入孔盖或平面舱盖关闭的开口，保持甲板高度完整性的小型水密舱口盖，遥控的水密滑动门，在海上正常关闭的水密完整的出入门或出入舱口盖和永闭型舷窗。然而，如果在计算中计入那些继续浸水的舱室，则本条件的要求也应适用。１．３ 对每一舱或舱组的“Ｓi ”应根据所考虑的吃水按下式计算：
Ｓi ＝０．５Ｓi ＋０．５Ｓp 式中：
Ｓi 是在最深分舱载重线处的Ｓ因数
Ｓp 是在部分载重线处的Ｓ因数２ 对于防撞舱壁前面的所有舱室计算所得的“Ｓi ”值应等于１，此时假定船舶位于最深分舱载重线并且不限制垂向破损范围。３ 如在所考虑的水线以上设有一水平分隔应用以下方法处理：３．１ 对水平分隔以下的舱或舱组其“Ｓ”值应以按本条之１．１所得的值乘以按本条之３．３表示该水平分隔以上处所不浸水的概率的缩减因数“Ｖi ”求得。３．２ 如果由于水平分隔以上处所同时浸水能使指数Ａ增加一个正值，该舱或舱组的Ｓ值应由按本条之３．１所得的值增加一个因同时浸水按本条之１．１得到的Ｓ值乘以因数（１－Ｖi ）求得的值。３．３ 概率因数“Ｖi ”应按下式计算：
Ｈ－ｄ
Ｖi ＝－－－－－－－
Ｈmax －ｄ
为假定浸水至分舱载重线以上的水平分隔，式中“Ｈ”是受“Ｈmax ”限制的一个高度，
Ｖi ＝１，如果假定破损范围的最上层水平分隔是在“Ｈmax ”以下时，

式中：
“Ｈ”是假定限制垂向破损范围的水平分隔在基线以上的高度，ｍ；
“Ｈmax ”是在基线以上破损的最大可能的垂向范围，ｍ，或
Ｌｓ
Ｈmax ＝ｄ＋０．０５６Ｌs （１－－－－），如Ｌs ≤２５０ｍ；
５００
Ｈmax ＝ｄ＋７，如Ｌs ＞２５０ｍ
取其小者。
第２５－７条 渗透率
本规则的分舱和破舱稳性计算中，每一处所或某处所的一部份的渗透率应按以下规定：
处 所 渗透率
贮物处所 ０．６０
起居处所 ０．９５
机器处所 ０．８５
空舱处所 ０．９５
干货处所 ０．７０
液体处所 ０或０．９５①
① 视何者导致较严重的后果而定。
第２５－８条 稳性资料１ 应向船长提供可靠的资料，该资料必须能使船长在各种营运情况下通过迅速而简便的方法，准确了解船舶稳性。这些资料包括：
．１ 确证符合有关完整稳性要求和第２５－１至２５－７条要求的最小营运稳心高度（ＧＭ）对吃水的关系曲线，也可选择相应的最大许用重心高度（ＫＧ）对吃水的曲线，或与这些曲线等效的其他形式；
．２ 有关横贯注水装置的操作说明；
．３ 为保持破损后稳性所必须的其他资料和辅助措施。２ 为了指导高级船员，船上应有永久性张贴的或在驾驶室随时备用的图纸，该图应清晰标明各层甲板及货舱的水密舱室的边界，这些边界上的开口及其关闭方法与控制装置的位置，以及用来校正由于浸水而倾斜的装置。此外，还应给船上高级船员提供载有上述资料的小册子。３ 为了提供上述１．１的资料，所用的极限ＧＭ（或ＫＧ）值，如果它们是从有关分舱指数的估算中求得，则此极限ＧＭ应在最深分舱载重线和部分载重线之间呈线性变化。在此情况下，如部分载重线吃水的最小ＧＭ值是由分舱指数的计算结果求得，则此ＧＭ值也可假定作为对低于部分载重线的各较小吃水时的ＧＭ值，否则应用完整稳性的要求。
第２５－９条 在货船水密舱壁和内部甲板上的开口１ 水密分隔上的开口数量为适应船舶设计和船舶正常作业应保持最少。凡是为了出入、管路、通风、电缆等需要贯通水密舱壁和内部甲板时，应设有保持水密完整性的装置。如果表明任何继续浸水能易于控制并且不损害船舶安全，则主管机关可以允许放宽对于舷甲板以上的开口的水密性要求。２ 为确保在海上使用的内部开口的水密完整性而设置的门应是滑动式水密门，并能从驾驶室遥控关闭，也能从舱壁的每一边就地操纵。在控制位置应装设显示门是开启或关闭的指示器，并且在门关闭时应发出音响报警。在主动力失灵时，动力、控制和指示器应能工作。特别应注意减少控制系统失灵的影响。每一个动力操纵的滑动式水密门应有一个独立的手动机械操纵装置，该装置应能从门的任一边用手开启和关闭该门。３ 用以保证内部开口的水密完整性且通常在航行时关闭的出入口的门和舱盖，应在该处和驾驶室装设指明这些门或舱盖是开启还是关闭的设施。每一个此类门或舱盖必须附贴一个通告牌，说明不能让它开着。这类门或舱盖的使用须经值班驾驶员批准。４ 可以装设结构良好的水密门或坡道用作内部分隔大型货物处所，但以主管机关对此种门或坡道满意为条件。这些门或坡道可以是铰链的、滚动的或滑动的，但不应是遥控操纵的。此类门或坡道应在开航前关妥，并应在航行中保持关闭；此类门或坡道在港内开启的时间和船舶离港前关闭的时间应记入航海日志中。如果在航程中需要通过任何此类门或坡道，则应设有防止未经授权开启的装置。５ 为保证内部开口的水密完整性，在海上保持永久关闭的其它关闭装置应有一个通告牌附贴于每一个此类关闭装置上，说明必须保持关闭。对于装有紧密螺栓盖子的入孔，不需要这种通告牌。
第２５－１０条 货船上的外部开口１ 所有通向在破损分析中假定为完整的且位于最终水线以下的舱室的外部开口，应要求是水密的。２ 根据本条之１要求的水密的外部开口应有足够的强度，除货舱盖外，在驾驶室应设有指示器。３ 在限制垂向破损范围的甲板以下的船壳外板上的开口，在海上应保持永久关闭。如果在航程中需要通过任何这类开口，则应设有防止未经授权开启的装置。４ 尽管本条之３有要求，如为了船舶的操纵需要并且不损害船舶的安全，主管机关可以授权船长根据需要可以打开某些特殊的门。５ 为保证外部开口的水密完整性，在海上保持永久关闭的其它装置应有一个通告牌附贴在每一个装置上，说明必须保持关闭。对于装有紧密螺栓盖子的入孔，不需要这种通告牌。

AMENDMENTS TO THE INTERNATIONAL CONVENTION FOR THE SAFETY OF LIFEAT SEA, 1974

【注】 [Adopted on 25 May 1990 by Resolution MSC. 19(58)]

Whole document


TABLE OF CONTENTS

CHAPTER II-1 CONSTRUCTION-SUBDIVISION AND STABILITY, MACHINERY AND
ELECTRICAL INSTALLATIONS
Addition of new Part B-1
PART B-1 SUBDIVISION AND DAMAGE STABILITY OF CARGO SHIPS
25-1 Application
25-2 Definitions
25-3 Required subdivision index "R"
25-4 Attained subdivision index "A"
25-5 Calculation of the factor "P "
i
25-6 Calculation of the factor "S "
i
25-7 Permeability
25-8 Stability information
25-9 Openings in watertight bulkheads and internal decks in cargo
ships.
25-10 External openings in cargo ships

AMENDMENTS TO THE INTERNATIONAL CONVENTION FOR THE SAFETY OF LIFE AT SEA,
1974
[Adopted on 25 May 1990 by Resolution MSC ·19(58)]

CHAPTER II-1 CONSTRUCTION-SUBDIVISION AND STABILITY, MACHINERY ANDELECTRICAL INSTALLATIONS

Insert the following new part B-1, comprising Regulations 25-1 to
25-10, after existing part B: "PART B-1 SUBDIVISION AND DAMAGE STABILITY
OF CARGO SHIPS *
[* The Maritime Safety Committee, in adopting the Regulations
contained in part B-1, invited Administrations to note that the
Regulations should be applied in conjunction with the explanatory notes
developed by the Organization in order to ensure their uniform
application.] (This part applies to cargo ships constructed on or after 1
February 1992)


Regulation 25-1 Application

1 The requirements in this part shall apply to cargo ships over 100 m
in length ("Ls") but shall exclude those ships which are shown to comply
with subdivision and damage stability regulations in other instruments **
developed by the Organization.
[** Ships shown to comply with the following Regulations may be
excluded from the application of part B-1:
.1 annex 1 to MARPOL 73/78;
.2 International Bulk Chemical Code (resolutions MSC. 4(48) and
MSC. 10(54)), as amended;
.3 International Gas Carrier Code (resolution MSC. 5(48));
.4 Guidelines for the Design and Construction of Offshore Supply
Vessels (resolution A. 469 (XII));
.5 Code of Safety for Special Purpose Ships (resolution A. 534
(13));
.6 damage stability requirements of Regulation 27 of the 1966 Load
Line Convention as applied in compliance with resolutions A. 320(IX) and
A. 514(13), provided that in the case of ships to which Regulation 27(9)
apply, main transverse watertight bulkheads, to be considered effective,
are spaced according to paragraph (12) (f) of resolution A. 320(IX).]
2 Any reference hereinafter to Regulations refers to the set of
Regulations contained in this part.
3 The Administration may for a particular ship or group of ships
accept alternative arrangements, if it is satisfied that at least the
same degree of safety as represented by these Regulations is achieved. Any
Administration which allows such alternative arrangements shall
communicate to the Organization particulars there of.


Regulation 25-2 Definitions

For the purpose of these Regulations, unless expressly provided
otherwise:
1.1 Subdivision load line is a waterline used in determining the
subdivision of the ship.
1.2 Deepest subdivision load line is the subdivision load line which
corresponds to the summer draught to be assigned to the ship.
1.3 Partial load line is the light ship draught plus 60% of the
difference between the light ship draught and deepest subdivision load
line.
2.1 Subdivision length of the ship ("Ls") is the greatest projected
moulded length of that part of the ship at or below deck or decks limiting
the vertical extent of flooding with the ship at the deepest subdivision
load line.
2.2 Mid-length is the mid point of the subdivision length of the ship.
2.3 Aft terminal is the aft limit of the subdivision length.
2.4 Forward terminal is the forward limit of the subdivision length.
3 Breadth ("B") is the greatest moulded breadth of the ship at or
below the deepest subdivision load line.
4 Draught ("d") is the vertical distance from the moulded baseline at
mid-length to the waterline in question.
5 Permeability (" μ") of a space is the proportion of the immersed
volume of that space which can be occupied by water.


Regulation 25-3 Required subdivision index "R"

1 These Regulations are intended to provide ships with a minimum
standard of subdivision.

2 The degree of subdivision to be provided shall be determined by the
required subdivision index "R", as follows:
|-------------------------|
| 1/3 |
| R=(0.002+0.0009Ls) | where "Ls" is in metres.
|-------------------------|


Regulation 25-4 Attained subdivision index "A"

1 The attained subdivision index "A", calculated in accordance with
this Regulation, shall not be less than the required subdivision index
"R", calculated in accordance with paragraph 2 of Regulation 25-3.
2 The attained subdivision index "A" shall be calculated for the ship
by the following formula:
|----------------|
| A=∑p s |
| i i |
|----------------|
where:
"i" represents each compartment or group of compartments under
consideration,

"p " accounts for the probability that only the compartment or group
i of compartments under consideration may be flooded, disregarding
any horizontal subdivision,

"s " accounts for the probability of survival after flooding the
i compartment or group of compartments under consideration,
including the effects of any horizontal subdivision.
3 In calculating "A", level trim shall be used.
4 This summation covers only those cases of flooding which contribute
to the value of the attained subdivision index "A".
5 The summation indicated by the above formula shall be taken over the
ship's length for all cases of flooding in which a single compartment or
two or more adjacent compartments are involved.
6 wherever wing compartments are fitted, contribution to the summation
indicated by the formula shall be taken for all cases of flooding in which
wing compartments are involved; and additionally, for all cases of
simultaneous flooding of a wing compartment or compartments and the
adjacent inboard compartment or compartments, assuming a rectangular
penetration which extends to the ship's centreline, but excludes damage to
any centreline bulkhead.

7 The assumed vertical extent of damage is to extend from the baseline
upwards to any watertight horizontal subdivision above the waterline or
higher. However, if a lesser extent will give a more severe result, such
extent is to be assumed.
8 If pipes, ducts or tunnels are situated within assumed flooded
compartments, arrangements are to be made to ensure that progressive
flooding cannot there by extend to compartments other than those assumed
flood. However, the Administration may permit minor progressive flooding
if it is demonstrated that its effects can be easily controlled and the
safety of the ship is not impaired.
9 In the flooding calculations carried out according to the
Regulations, only one breach of the hull need be assumed.


Regulation 25-5 Calculation of the Factor "Pi "

1 The factor "p " shall be calculated according to paragraph 1.1 as
i
appropriate, using the following notations:
X =the distance from the aft terminal of "L " to the foremost
1 s
portion of the aft end of the compartment being considered;

X =the distance from the aft terminal of "L " to the aftermost
2 s
portion of the forward end of the compartment being considered;

E =X /L
1 1 s

|------------|
| E =X /L |
| 2 2 s |
|------------|

E=E +E -1
1 2
|------------|
| J=E - E |
| 2 1 |
|------------|

J'=J-E, if E≥0

J'=J+E, if E＜0

The maximum nondimensional damage length
|--------------------------------------|
| J =48/L , but not more than 0.24. |
| max s |
|--------------------------------------|

The assumed distribution density of damage location along the
ship's length
a=1.2+0.8E, but not more than 1.2.
The assumed distribution function of damage location along the
ship's length
F=0.4+0.25E(1.2+a)
|--------------|
| y=J/J |
| max |
|--------------|

P=F * J
1 max

|-------------------|
| 2 |
| q=0.4F (J ) |
| 2 max |
|-------------------|
|---------------------------|
| 3 |
| 2 y |
| F = y - ---, if y＜1, |
| 1 3 |
|---------------------------|
1
F =y- ---, otherwise;
1 3
|---------------------------|
| 3 4 |
| y y |
| F =--- - ---, if y＜1, |
| 2 3 12 |
|---------------------------|
2
y y 1
F =--- - --- + ---, otherwise.
2 2 3 12

1.1 The factor "p " is determined for each single compartment:
i
1.1.1 Where the compartment considered extends over the entire ship
length, "L ":
s

p =1
i
1.1.2 Where the aft limit of the compartment considered coincides with
the aft terminal:

p =F+0.5ap+q
i
1.1.3 Where the forward limit of the compartment considered coincides
with the forward terminal:

p =1-F+0.5ap
i
1.1.4 When both ends of the compartment considered are inside the aft
and forward terminals of the ship length, "L ":
s


p =ap
i

1.1.5 In applying the formulae of paragraphs 1.1.2, 1.1.3 and 1.1.4,
where the compartment considered extends over the "mid-length", these
formulae values shall be reduced by an amount determined according to the
formula for "q", in which "F " is calculated taking "y" to be J'/J
2 max

2 Wherever wing compartments are fitted, the "p " -value for a wing
i
compartment shall be obtained by multiplying the value, as determined in
paragraph 3, by the reduction factor "r" according to subparagraph 2.2,
which represents the probability that the inboard spaces will not be
flooded.
2.1 The "P "-value for the case of simultaneous flooding of a wing and
i adjacent inboard compartment shall be obtained by using
the formulae of paragraph 3, multiplied by the factor (1-r).
2.2 The reduction factor "r" shall be determined by the following
formulae:
For J ≥0.2b/B:

b 0.08
r=--(2.3 + -------) + 0.1, if b/B ≤0.2
B J+0.02

0.016 b
r=(------ + -- + 0.36), if b/B＞0.2
J+0.02 B

For J ＜0.2 b/B the reduction factor "r" shall be determined by linear
interpolation between
r=1, for J=0
and
r=as for the case where J ≥0.2b/B, for J=0.2b/B,
where:
b=the mean transverse distance in metres measured at right
angles to the centreline at the deepest subdivision load line between the
shell and a plane through the outermost portion of and parallel to that
part of the longitudinal bulkhead which extends
between the longitudinal limits used in calculating the factor "p ".
i
3 To evaluate "p" for compartments taken singly the formulae in
paragraphs 1 and 2 shall be applied directly.
3.1 To evaluate the "p"-values attributable to groups of compartments
the following applies:


for compartments taken by pairs:
|---------------|
| p =p -p -p |
| i 12 1 2 |
|---------------|

p =p -p -p , etc.
i 23 2 3

for compartments taken by groups of three:
p =p -p -p +p
i 123 12 23 2

p =p -p -p +p , etc.
i 234 23 34 3

for compartments taken by groups of four:
p =p -p -p +p
i 1234 123 234 23

p =p -p -p +p , etc.
i 2345 234 345 34

Where:
p , p , p , etc.,
12 23 34

p , p , p , etc. and
123 234 345

p , p , p , etc.
1234 2345 3456
shall be calculated according to the formulae in paragraphs 1 and 2
for a single compartment whose nondimensional length "J" corresponds to
that of a group consisting of the compartments indicated by the indices
assigned to "p".
3.2 The factor "P " for a group of three or more adjacent compartments
i equals zero if the nondimensional length of such a
group nines the nondimensional length of the aftermost and foremost
compartments in the group is greater than "J ".
max


Regulation 25-6 Calculation of Factor "Si"

1 The factor "s ", shall be determined for each compartment or group
i
of compartments ac cording to the following:
1.1 in general for any condition of flooding from any initial loading
condition "s" shall be
_________________
s=C √0.5(GZ )(range)
max

with C=1, if θe ≤25°
C=0, if θe ＞30°

_______
C= √ 30-θe
------- otherwise
5
GZ =maximum positive righting lever (in metres) within the
max range as given below but not more than 0.1 m;
range=range of positive righting levers beyond the angle of
equilibrium (in degrees) but not more than 20 °; however, the range shall
be terminated at the angle where openings not capable of being closed
weathertight are immersed;
θe=final equilibrium angle of heel (in degrees);
1.2 s=0 where the final waterline taking into account sinkage, heel
and trim, immerses the lower edge of openings through which progressive
flooding may take place. Such opening shall include air-pipes, ventilators
and openings which are closed by means of weathertight doors or hatch
covers, and may exclude those openings closed by means of watertight
manhole covers and flush scuttles, small watertight hatch covers which
maintain the high integrity of the deck, remotely operated sliding
watertight doors, access doors and access hatch covers, of watertight
integrity, normally closed at sea and sidescuttles of the non-opening
type. However, if the compartments so flooded are taken into account in
the calculations the requirements of this Regulation shall be applied.
1.3 For each compartment or group of compartments "s " shall be
i
weighted according to draught consideration as follows:

s =0.5s +0.5s
i l p

where

"s " is the "s"-factor at the deepest subdivision load line;
l


"s " is the "s"-factor at the partial load line.
p

2 For all compartments forward of the collision bulkhead, the
"s"-value, calculated assuming the ship to be at its deepest subdivision
load line and with assumed unlimited vertical extent of damage is to be
equal to 1.
3 Wherever a horizontal subdivision is fitted above the waterline in
question the following applies.
3.1 The "s"-value for the lower compartment or group of compartments
shall be obtained by multiplying the value as determined in subparagraph
1.1 by the reduction factor "v " ac cording to subparagraph 3.3, which
i
represents the probability that the spaces above the horizontal
subdivision will not be flooded.
3.2 In cases of positive contribution to index "A" due to simultaneous
flooding of the spaces above the horizontal subdivision, the resulting
"s"-value for such a compartment or group of compartments shall be
obtained by an increase of the value as determined by subparagraph 3.1 by
the "s"-value for simultaneous flooding according to subparagraph 1.1,
multiplied by the factor (1-v ).
i
3.3 The probability factor "v " shall be calculated according to:
i

H-d
v = ------, for the assumed flooding up to the horizontal
i H -d
max
subdivision above the subdivision load line, where "H" is to be restricted
to a height of
"H ",
max

v =1, if the uppermost horizontal subdivision in way of the
i
assumed dam aged region is below "H ",
max

where:
"H" is the height of the horizontal subdivision above the baseline (in
metres) which is assumed to limit the vertical extent of damage,
"H " is the maximum possible vertical extent of damage above the
max

baseline (in metres), or
|----------------------------------------|
| L |
| s |
| H =d+0.056L (1- ---), if L ≤250m; |
| max s 500 s |
| H =d+7, if L ＞250m |
| max s |
|----------------------------------------|
whichever is less.


Regulation 25-7 Permeability

For the purpose of the subdivision and damage stability calculations
of the Regulations, the permeability of each space or part of a space
shall be as follows:
Spaces Permeability
Appropriated to stores 0.60
Occupied by accommodation 0.95
Occupied by machinery 0.85
Void spaces 0.95
Dry cargo spaces 0.7
Intended for liquid 0 or 0.95*
[* whichever results in the more severe requirements.]


Regulation 25-8 Stability Information

1 The master of the ship shall be supplied with such reliable
information as is necessary to enable him by rapid and simple means to
obtain accurate guidance as to the stability of the ship under varying
conditions of service. The information shall include:
.1 a curve of minimum operational metacentric height (GM) versus
draught which assures compliance with the relevant intact stability
requirements and the requirements of Regulations 25-1 to 25-6,
alternatively a corresponding curve of the maximum allowable vertical
centre of gravity (KG) versus draught, or with the equivalents of either
of these curves;
.2 instructions concerning the operation of cross-flooding
arrangements; and
.3 all other date and aids which might be necessary to maintain
stability after damage.
2 There shall be permanently exhibited, or readily available on the
navigating bridge, for the guidance of the officer in charge of the ship,
plans showing clearly for each deck and hold the boundaries of the
watertight compartments, the openings therein with the means of closure
and position of any controls thereof, and the arrangements for the
correction of any list due to flooding. In addition, booklets containing
the aforementioned information shall be made available to the officers of
the ship.
3 In order to provide the information referred to in 1.1, the limiting
GM (or KG) values to be used, if they have been determined from
considerations related to the subdivision index, the limiting GM shall be
varied linearly between the deepest subdivision load line and the partial
load line. In such cases, for draughts below the partial load line if the
minimum GM requirement at this draught results from the calculation of the
subdivision index, then this GM value shall be assumed for lesser
draughts, unless the intact stability requirements apply.


Regulation 25-9 Openings in watertight bulkheads and internaldecks in cargo ships

1 The number of openings in watertight subdivision is to be kept to a
minimum compatible with the design and proper working of the ship. Where
penetrations of watertight bulkheads and internal decks are necessary for
access, piping, ventilation, electrical cables, etc., arrangements are to
be made to maintain the watertight integrity. The Administration may
permit relaxation in the water-tightness of openings above the freeboard
deck, provided that it is demonstrated that any progressive flooding can
be easily controlled and that the safety of the ship is not impaired.
2 Doors provided to ensure the watertight integrity of internal
openings which are used while at sea are to be sliding watertight doors
capable of being remotely closed from the bridge and are also to be
operable locally from each side of the bulkhead. Indicators are to be
provided at the control position showing whether the doors are open or
closed, and an audible alarm is to be provided at the door closure. The
power, control and indicators are to be operable in the event of main
power failure. Particular attention is to be paid to minimize the effect
of control system failure. Each power-operated sliding watertight door
shall be provided with an individual hand-operated mechanism. It shall be
possible to open and close the door by hand at the door itself from both
sides.
3 Access doors and access hatch covers normally closed at sea,
intended to ensure the watertight integrity of internal openings, shall be
provided with means of indication locally and on the bridge showing
whether these doors or hatch covers are open or closed. A notice is to be
affixed to each such door or hatch cover to the effect that it is not to
be left open. The use of such doors and hatch cover shall be authorized by
the officer of the watch.
4 Watertight doors or ramps of satisfactory construction may be fitted
to internally subdivide large cargo spaces, provided that the
Administration is satisfied that such doors or ramps are essential. These
doors or ramps may be hinged, rolling or sliding doors or ramps, but
shall not be remotely controlled. Such doors or ramps shall be closed
before the voyage commences and shall be kept closed during navigation;
the time of opening such doors or ramps in port and of closing them before
the ship leaves port shall be entered in the logbook. Should any of the
doors or ramps be accessible during the voyage, they shall be fitted with
a device which prevents unauthorized opening.
5 Other closing appliances which are kept permanently closed at sea to
ensure the watertight integrity of internal openings shall be provided
with a notice which is to be affixed to each such closing appliance to the
effect that it is to be kept closed. Manholes fitted with closely bolted
covers need not be so marked.


Regulation 25-10 External openings in cargo ships

1 All external openings leading to compartments assumed intact in the
damage analysis, which are below the final damage waterline, are required
to be watertight.
2 External openings required to be watertight in accordance with
paragraph 1 shall be of sufficient strength and, except for cargo hatch
covers, shall be fitted with indicators on the bridge.
3 Openings in the shell plating below the deck limiting the vertical
extent of damage shall be kept permanently closed while at sea. Should any
of these openings be accessible during the voyage, they shall be fitted
with a device which prevents unauthorized opening.
4 Notwithstanding the requirements of paragraph 3, the Administration
may authorize that particular doors may be opened at the discretion of the
master, if necessary for the operation of the ship and provided that the
safety of the ship is not impaired.
5 Other closing appliances which are kept permanently closed at sea to
ensure the watertight integrity of external openings shall be provided
with a notice affixed to each appliance to the effect that it is to be
kept closed. Manholes fitted with closely bolted covers need not be so
marked.

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