CN72-1.pdf

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CLASSIFICATION NOTES

DETNORSKEVERITASAS

The content of this service document is the subject of inteectu! "ro"ert# ri$hts reserved b# Det Nors%e Verit!s AS &DNV'( The user!cce"ts th!t it is "rohibited b# !n#one ese but DNV !nd)or its icensees to offer !nd)or "erform c!ssific!tion* certific!tion !nd)orverific!tion services* incudin$ the issu!nce of certific!tes !nd)or dec!r!tions of conformit#* +ho# or "!rt#* on the b!sis of !nd)or"ursu!nt to this document +hether free of ch!r$e or ch!r$e!be* +ithout DNV,s "rior +ritten consent( DNV is not res"onsibe for theconse-uences !risin$ from !n# use of this document b# others(

The electronic pdf version of this document found through http://www.dnv.com is the officially binding version

No( ./(0

Ao+!be Thic%ness Diminutionfor 1u Structure

23L4 /506

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FOREWORD

DNV is ! $ob! "rovider of %no+ed$e for m!n!$in$ ris%( Tod!#* s!fe !nd res"onsibe business conduct is both ! icenseto o"er!te !nd ! com"etitive !dv!nt!$e( Our core com"etence is to identif#* !ssess* !nd !dvise on ris% m!n!$ement( Fromour e!din$ "osition in certific!tion* c!ssific!tion* verific!tion* !nd tr!inin$* +e deveo" !nd !""# st!nd!rds !nd best

"r!ctices( This he"s our customers s!fe# !nd res"onsib# im"rove their business "erform!nce( DNV is !n inde"endentor$!nis!tion +ith dedic!ted ris% "rofession!s in more th!n 055 countries* +ith the "ur"ose of s!fe$u!rdin$ ife* "ro"ert#!nd the environment(

Classification Notes

C!ssific!tion Notes !re "ubic!tions th!t $ive "r!ctic! inform!tion on c!ssific!tion of shi"s !nd other objects( E7!m"esof desi$n soutions* c!cu!tion methods* s"ecific!tions of test "rocedures* !s +e !s !cce"t!be re"!ir methods for somecom"onents !re $iven !s inter"ret!tions of the more $ener! rue re-uirements(

8 Det Nors%e Verit!s AS 2u# /506

An# comments m!# be sent b# e9m!i to [email protected]

If any person suffers loss or damage which is proved to have been caused by any negligent act or omission of Det Norske Veritas, then Det Norske Veritas shall pay compensation tosuch person for his proved direct loss or damage. However, the compensation shall not exceed an amount eual to ten times the fee charged for the service in uestion, provided thatthe maximum compensation shall never exceed !"D # million.In this provision $Det Norske Veritas$ shall mean the %oundation Det Norske Veritas as well as all its subsidiaries, directors, officers, employees, agents and any other acting on behalfof Det Norske Veritas.

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&lassification Notes ' No.(#.), *uly #+)

&hanges - age

DETNORSKEVERITAS AS

CHANGES CURRENT

General

This document su"ersedes C!ssific!tion Note No( ./(0* 2!nu!r# /506(

Te7t !ffected b# the m!in ch!n$es in this edition is hi$hi$hted in red coour( 1o+ever* if the ch!n$es invove

! +hoe ch!"ter* section or sub9section* norm!# on# the tite +i be in red coour(

Main changes

Sec! General

: ;0(/u% h!s been !dded(

A""A

: ? Anne7 h!s been ch!n$ed to A""endi7 A(

A""#

: A""endi7 A h!s been ch!n$ed to A""endi7 >( A""C

: This is ! ne+ !""endi7(

In !ddition to the !bove st!ted m!in ch!n$es* editori! corrections m!# h!ve been m!de(

E$itorial Corrections

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&ontents - age /

DETNORSKEVERITAS AS

CONTENTS

C1AN@ES C3RRENT ((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((( 6

! General %0(0 Introduction(((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((B0(/ A""ic!biit# (((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((B

0(6 Definitions(((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((B

& Categories of Corrosion '

( Allo)a*le Material Di+in,tion for General Corrosion '6(0 @ener!((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((.6(/ Assum"tions((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((.6(6 Vesses +ith en$th* L 055 m ((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((6( Vesses +ith en$th* L 055 m ((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((6(B Refined minimum thic%ness c!cu!tions (((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((066(? Re"!ir ((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((0

- .itting/ Groo0e an$ E$ge Corrosion !-(0 ittin$((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((0(/ @roove !nd ed$e corrosion (((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((0B

% References !'

A""en$i1 A

G,i$elines for the s,r0e2 of 0o2age re"airs !3

A""en$i1 #

Calc,lation of h,ll gir$er ,lti+ate ca"acit2 !4

A""en$i1 C

Co++on Str,ct,ral R,les 5essels 6 CSR &7

C1AN@ES 1ISTORIC ((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((( /0

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"ec.) 0eneral - age 1

DETNORSKEVERITAS AS

! General

!! 8ntro$,ctionThe "ur"ose of the "resent C!ssific!tion Notes is to "rovide the user +ith $ener! inform!tion !nd ! too for!ssessin$ the !cce"t!nce eve of deterior!tion in hu structures(

A shi",s ori$in! sc!ntin$s !re norm!# b!sed on minimum re-uirements !ccordin$ to the Rues for

C!ssific!tion of Shi"s !""ic!be !t the time of construction but m!# !so incude !dditions due to the initi!o+ner,s re-uirements or s"eci! buidin$ "r!ctices( 1o+ever* there h!s been !n e7tensive deveo"ment in shi"desi$n !nd o"timiG!tion of sc!ntin$s durin$ the !st /5965 #e!rs* !nd this deveo"ment h!s in $ener!contributed to reduced corrosion m!r$ins( rovision of ! $ood corrosion "rotection s#stem is* therefore* no+more im"ort!nt th!n ever( As not ! desi$ns or circumst!nces c!n be covered* the instructions herein shoud

be used +ith "!rticu!r c!ution( Acce"t!nce of re"!ir e7tent !nd method must be $iven b# the Societ#(

!& A""lica*ilit2The C!ss Note !""ies in $ener! to shi"s of norm! desi$n buit of stee( Further it does not !""# to vesses+ith c!ss not!tion CSR for +hich the Rues h!ve s"ecific re-uirements to shi"s in service( See A""endi7 Cfor inform!tion of CSR vesses(

!( Definitions

!(! Definitions

!(& Ter+inolog2The structur! terminoo$# !""ied in the s"ecific!tion of minimum thic%ness is iustr!ted in Fi$ure 090HT#"ic! doube hu t!n%er !nd Fi$ure 09/HT#"ic! bu% c!rrier* sho+in$ ! t#"ic! midshi" !re! of ! doubehu t!n%er !nd ! bu% c!rrier(

L rue en$th in m* see t(6 Ch(0 Sec(0

torig ori$in! H!s buit thic%ness in mm

tmin minimum thic%ness in mm incudin$ ! m!r$in for further corrosion unti ne7t hu surve#(

TM thic%ness me!surements

ult !ne utim!te c!"!cit#

y 4ied stress

3LS H!ne 3tim!te Limit Stren$th is ! DNV com"uter "ro$r!m usin$ non9ine!r "!te theor# to c!cu!te ! stiff9ened "!te fied,s utim!te buc%in$ stren$th( It tre!ts the entire* stiffened "!te fied !s !n inte$r!ted unit* !o+9in$ for intern! redistribution of the stresses(

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"ec.) 0eneral - age 2

DETNORSKEVERITAS AS

Fig,re !6!T2"ical $o,*le h,ll tan9er

Fig,re !6&

T2"ical *,l9 carrier

"trength deckplating "trength deck

longitudinal3opside decktransverse

"ide shell frame

3opside tank platingvertical stake

3opside tanksloping plating

3opside tank slopingplating longitudinal

3opside

tank

"ide shelllongitudinal

Hatch coaming

Hopper tanksloping plating

Hopper tank slopingplating longitudinal

Inner bottomplating

Doublebottomtank

4ottom sidegirder

Inner bottomlongitudinal

"ide shellplating

"ide shelllongitudinal

Hopper sidetransverse

4ilgelongitudinal

5eel plate 4ottom shell Hopper tank

4ilgeplating

4ottomlongitudinal

Double bottomtank floor

&6708 H89D

&ross deck structure

&ross deck

structuretransverse beam

&ross deckstructure cantileversupport bracket

&argo hatchwayand roaming

&argo hatchway

!pper shelfplate

!pper stool

&orrugatedtransverse

bulkhead

"hedder plate9ower shelterplate

Inner bottom

9ower stool

'

&orrugated

transverse

bulkhead

9ower stool

side plating

9ower stool side plating

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"ec.# &ategories of &orrosion - age (

DETNORSKEVERITAS AS

& Categories of Corrosion

Corrosion m!# be divided into the foo+in$ c!te$ories=

Fig,re &6!T2"ical groo0ing corrosion in stiffener connection

General:Jhere uniform reductions of m!teri! !re found( Criteri! for minimum thic%ness of hu structur!eements m!# be !""ied in order to determine !ver!$e diminution v!ues* see 6( T#"ic!#* re"!irs +i incudestee re"!cement to ori$in! sc!ntin$s !nd)or reinforcement u"on s"eci! consider!tion(

.itting:R!ndom sc!ttered corrosion s"ots)!re!s +ith oc! m!teri! reductions( The intensit# of the "ittin$must first be estim!ted before !""#in$ criteri!* see Sec((0( T#"ic!#* re"!irs +i incude rene+! of "!tes*

buidin$ u" "its b# +edin$ or !""ic!tion of "!stic fier com"ounds(

Groo0ing:Loc! ine m!teri! oss norm!# !dj!cent to +edin$ joints !on$ !buttin$ stiffeners !nd !t stiffener

or "!te butts or se!ms( Due to the com"e7it# !nd effects of $roove corrosion* diminution criteri! !re imited!nd s"eci! re"!ir consider!tions !re re-uired(

E$ges: Loc! m!teri! +!st!$e !t the free ed$es of "!tes !nd stiffeners* see Sec((/( T#"ic!#* if not rene+ed*re"!irs m!# be c!rried out b# me!ns of ed$e stiffeners)doubers(

For e!ch of the corrosion c!te$ories se"!r!te !ssum"tions* criteri! !nd t#"ic! re"!irs shoud be !""ied !s$iven in reev!nt ch!"ters* !nd to the surve#ors s!tisf!ction(

( Allo)a*le Material Di+in,tion for General Corrosion

(! General

Criteri! for !o+!be diminution on ori$in! sc!ntin$ is b!sed on the rue "hioso"h# deveo"ed forne+buidin$ !""rov!* !nd the difference is m!in# re!ted to !djustment of "rob!biit# eve since ne+ vesses!re considered for ! /5 #e!r "eriod(

The corrosion m!r$ins m!# ho+ever v!r# in siGe de"endin$ on the decisive stren$th criteri!( The m!r$insre!ted to #ied stren$th do* for e7!m"e* norm!# !o+ !r$er diminution th!n the m!r$ins for buc%in$( Itshoud be noted th!t due to v!r#in$ stress eves !nd different stiffenin$ !rr!n$ements sim"e criteri! m!# not!+!#s be $ener!# !""ied !nd other consider!tions mi$ht be re-uired( For the m!in structures of vesses +ithL 055 m ! ist $ivin$ !cce"t!be diminution !nd ori$in! thic%ness is norm!# su""ied b# DNV(

(& Ass,+"tions

The foo+in$ !ssum"tions !""# for criteri! $iven in this C!ssific!tion Note=

: The criteri! m!# be !""ied to norm! !nd hi$h tensie stee i(e( not !uminium or st!iness stee uness

es"eci!# st!ted(: S"eci! consider!tions !re c!rried out if the vesse h!s under$one m!jor conversions e($( h!s been

en$thened(: For vesses buit +ith reduced corrosion m!r$ins* i(e( re$ister not!tion corr&see Rues for Shi"s 2!nu!r#

05'* the minimum v!ues $iven beo+ c!n not be $ener!# !""ied(

%I99:3 ;:9D

98N0I3!DIN69

D:&5 .963IN0

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"ec. 6llowable

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"ec. 6llowable

DETNORSKEVERITAS AS

1o+ever in c!se of o+ buc%in$ c!"!cit# in dec% or bottom* BM of the !s buit section moduus m!# be used&5(B M) 5(B$'(

Se"arate .anels

A se"!r!te "!nes +ithin 5(0B D from the to" or bottom &Ref( Fi$ure 696' shoud be chec%ed* +ith ! Hse"!r!te"!ne defined !s ! "!te fied +ith simi!r sc!ntin$s !nd s"!cin$ for ! the "!tes !nd stiffeners incuded( E($(the m!in dec% bet+een t+o m!in structur! eements* such !s the shi",s side !nd the on$itudin! bu%he!d*

coud be defined !s ! se"!r!te "!ne(

If there !re !re!s +ith different sc!ntin$s !nd)or s"!cin$ bet+een t+o m!in structur! eements* one shoudmode e!ch of the different !re!s !s se"!r!te "!nes* but use !n !rtifici! "!ne bre!dth e-u! to the bre!dth ofthe +hoe "!te fied( E($( if the m!in dec% bet+een the shi",s side !nd the on$itudin! bu%he!d m!# be dividedinto t+o !re!s* A !nd >* +ith different thic%ness of the m!in dec% "!tin$* one shoud chec% one "!ne +ith thesc!ntin$s of !re! A !nd one +ith the sc!ntin$s of !re! >* +here both "!nes chec%ed shoud be $iven !n!rtifici! bre!dth e-u! to the tot! bre!dth of !re! A >* i(e( the entire dist!nce bet+een the shi",s side !nd theon$itudin! bu%he!d(

Fig,re (6!Consi$eration to $ifferent scantlings in calc,lation +o$elling

#,c9ling control of trans0ersall2 stiffene$ si$e

Vesses +here the side is tr!nsvers!# stiffened +ithin 5(0B D from dec% or bottom shoud be modeed in3LS !s foo+s=

L0 hei$ht from bottom)dec% to the neutr! !7is or to the first dec% or strin$er eve(S tr!nsverse stiffener s"!cin$(

The stress shoud be v!ried ine!r# from bottom)dec% to neutr! !7is or to the first dec% or strin$er eve(

Re$,ce$ Efficienc2

Loc! "!nes e($( "!rt of the structure such !s on$itudin! $irder* "!rt of shi" side )on$itudin! bu%he!d* to"+in$ t!n% "!tin$ etc( +ith buc%in$ c!"!cit# beo+ re-uirement m!# be s"eci!# considered "rovidin$surroundin$ "!nes h!ve sufficient stren$th to c!rr# the !ddition! o!d( This is not !""ic!be for m!in stren$thdec% "!nes or bottom she "!nes(

The "rocedure is to reduce the efficienc# of the "!ne to ! f!ctor e-u! to=

Note:

ultis the m!7imum c!"!cit# of the "!ne* found in HDet!ied Resuts in 3LS(

y

ult

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"ec. 6llowable u% C!rriers +ith c!ss not!tions BC-B* BC-Aor BC-B*&the od HC* HC/Eor HC-EA'* doube hu t!n%ers

+ithout ! on$itudin! bu%he!d !nd $!s c!rriers +hich in desi$n !re simi!r to ordin!r# sin$e hu bu% c!rriers

!re shi" t#"es +here doube bottom stresses m!# be critic!(

For such vesses +here the bottom "!tin$ is buit +ith incre!sed thic%ness in midde of the em"t# hods in

!tern!te o!din$ conditions* the foo+in$ "rocedure shoud be !""ied=

The buc%in$ !n!#sis is to be c!rried out for the bottom "!ne bet+een the ho""er t!n% $irder &m!r$in $irder'

!nd the first doube bottom $irder inbo!rd( The !o+!be reduction &in mm' found b# this !n!#sis is to be

!""ied for the other bottom "!tes !s +e(

Fig,re (6&.roce$,re of critical shi" t2"es

If stiffener dimension or s"!cin$ bet+een on$itudin!s v!ries* this +i be subject to s"eci! consider!tion( For

vesses +here the bottom "!tin$ is not buit +ith incre!sed thic%ness in the midde of the em"t# hods in

!tern!te o!din$ conditions* the !o+!be reduction for the bottom "!tin$ !nd stiffeners is m!7imum 05M(

If !""#in$ tr!nsverse stresses direct# to the bottom "!nes* the oc! o!ds !nd o!d c!ses !re to be b!sed on

the rues for ne+buidin$ for the !ctu! shi" t#"e(

3.4.1.4 ull girder section modulus

In order to com"# +ith $ob! on$itudin! stren$th re-uirements* the reduced section moduus of the vesse

is norm!# not to be ess th!n 5M of the re-uired section moduus b!sed on desi$n bendin$ moments(

In !n# c!se the reduced section moduus is not to be ess th!n 5M of the minimum rue section moduus $iven

in the rues t(6 Ch(0 Sec(B(

As ! conse-uence of buc%in$ criteri! the !o+!be reduction of section moduus m!# be ess th!n $iven !bove(

T!be 69/Section moduus reduction contro "rovides ! too for !ssessment of hu $irder section moduus

reduction* conserv!tive# !ssumin$ ! reduction f!ctor for !n !re! e-uiv!ent to the reduction f!ctor for section

moduus( In the subject cross section of dec% or bottom ! structur! eements contributin$ to on$itudin!

stren$th beo+ 5(0B D or !bove 5(B D shoud be incuded(

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"ec. 6llowable uc%in$ contro !ccordin$ to 6((0(/

Si$e an$ longit,$inal *,l9hea$ *et)een 7!% D an$ 73% D fro+ *otto+

!tin$ &/'L 0B5 m 5(5

L Q 0B5 m 5(5

Stiffeners 5(.B

Other longit,$inal str,ct,re *et)een 7!% D an$ 73% D fro+ *otto+

!tin$ 5(5

Stiffeners 5(.B

@irders !nd strin$ers 5(5

Notes:

0' >ottom $irders=

: For sin$e side s%in bu% c!rriers +ith en$th L"" Q 0B5 m c!rr#in$ c!r$o +ith densit# of 0(. t)m6or more* theshe!r stren$th of the $irders in hod no(0 !re !ddition!# to be chec%ed !ccordin$ to IACS 3R S//* !s!""ic!be(

/' Side !nd on$itudin! bu%he!d=

: For corru$!ted bu%he!ds see T!be 69/HTr!nsverse bu%he!ds(

Deck

+.)

1D

+.)

1D

4ottom

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"ec. 6llowable u%he!ds desi$ned +ith t+o "!te f!n$es connected +ith vertic! +ebs &Hdoube s%in bu%he!ds' shoud h!ve !

diminution coefficient* ! 5(5(

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"ec. 6llowable

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"ec./ itting, 0roove and :dge &orrosion - age )/

DETNORSKEVERITAS AS

(= Re"air

Reference is m!de to the IACS "ubic!tion Shi"buidin$ !nd Re"!ir u!it# St!nd!rd* !rt >* !nd A""endi7A concernin$ vo#!$e re"!irs(

Det!is of hu re"!irs incudin$ "rocedures !re to be !$reed +ith the Societ# "rior to commencement of there"!ir(

Are!s found +ith diminution in e7cess of !cce"t!be imits !re norm!# to be re"!ired +ith inserted m!teri!

of s!me $r!de !nd sc!ntin$s !s ori$in!( Atern!tive dimensions m!teri!s !nd re"!ir methods m!#* ho+ever*be !cce"ted "rovided the# !re s"eci!# considered !nd !""roved* t#"ic!# in connection +ith refinedminimum thic%ness c!cu!tions(

Jhere inserts !re !rr!n$ed the rem!inin$ thic%ness of e7istin$ !re!s* !dj!cent to re"!cement m!teri!* shoudnorm!# be !t e!st 0 mm in e7cess of the minimum thic%ness(

- .itting/ Groo0e an$ E$ge Corrosion

-! .itting

-!! Ass,+"tions

The foo+in$ !ssum"tions !""#=

: ittin$ re"!ired b# "!stic com"ound fier m!teri! is on# considered !s ! method to "revent furthercorrosion !nd does not contribute to the stren$th(

: 1!rd co!tin$s !re norm!# to be !""ied !fter re"!ir(

-!& Mini+,+ acce"ta*le re+aining thic9ness )itho,t re"air

!' For "!tes +ith "ittin$ intensit# ess th!n /5M* the minimum rem!inin$ thic%ness in "ittin$ is to be !t e!st=

tmin 5(? torigbut* not ess th!n ? mm(

b' For "!tes +ith H055M "ittin$ intensit# &i(e( $ener! corrosion' the !ver!$e rem!inin$ thic%ness* in the+orst cross section throu$h the "ittin$ in ! "!te fied shoud not be ess th!n minimum thic%ness for $ener!

corrosion $iven in 6(c' For intermedi!te "ittin$ intensities* !cce"t!nce of !ver!$e rem!inin$ thic%ness m!# be decided b!sed on

ine!r inter"o!tion bet+een i' !nd ii'(

-!( A0erage re+aining thic9ness for "itte$ areas

As ! rou$h $uide for estim!tin$ the !ver!$e rem!inin$ thic%ness for "itted !re!s the foo+in$ m!# be !""ied=tact tplate&09nt)055' tpitnt)055tact corrected !ver!$e rem!inin$ thic%nesstplate !ver!$e rem!inin$ thic%ness outside "ittin$tpit !ver!$e rem!inin$ thic%ness in "ittin$

nt estim!ted "ittin$ intensit# in M

Further* in order to !ssist in the !ssessment of estim!ted "ittin$ intensit#* see Fi$ure 90(

-!- Re"air

!' For +ide# sc!ttered "ittin$* i(e( intensit# BM* !nd +here the rem!inin$ thic%ness in "ittin$ is not ess th!n? mm* then the foo+in$ m!# !""#=

i' The use of fier m!teri!)"!stic com"ound of ! suit!be e!stic t#"e !ccordin$ to the m!nuf!cturersinstructions !nd incudin$ the foo+in$=

: "ittin$ to be thorou$h# ce!ned &s!nd)$rit b!sted' !nd dried "rior to !""ic!tion: "ittin$ to be com"ete# fied: ! to" !#er of co!tin$ to be !""ied(

ii' Jedin$* m!# be c!rried out !fo!t* in !ccord!nce +ith the foo+in$=

: "ittin$ is to be thorou$h# ce!ned* $round !nd dried "rior to +edin$

: o+ h#dro$en eectrodes !""roved for the m!teri! in -uestion !re to be used( Jed to st!rt outside"ittin$ !nd direction reversed for e!ch !#er(

b' For hi$h intensit# "ittin$ !nd)or +here the rem!inin$ thic%ness is beo+ the !cce"t!be imits "!tes)stiffeners !re to be rene+ed b# inserts(

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"ec./ itting, 0roove and :dge &orrosion - age )1

DETNORSKEVERITAS AS

Fig,re -6!.itting

-& Groo0e an$ e$ge corrosion

-&! General

@roovin$ corrosion norm!# t!%es "!ce !dj!cent to +eds !nd is of "!rticu!r concern for the connection ofside fr!mes to she "!te in sin$e s%in bu% c!rriers( 1o+ever* $roovin$ m!# be ! "robem for v!rious shi"t#"es( Other common# !ffected !re!s !re=

: +eb fr!me connections to dec%)stiffeners &b!!st t!n%s': +ebs of side)dec% on$itudin!s &b!!st t!n%s': e7tern! she "!tes in the for+!rd "!rt of the vesse(

Ed$e corrosion is m!in# found !round cutouts in +eb structures !nd !t the free ed$es of f!t b!r dec%on$itudin!s(

-&& Ass,+"tions

The foo+in$ !ssum"tions !""#=

: $rooves !nd ed$es !re smooth !nd +ithout sh!r" ed$es or notches: +edin$ is int!ct !nd +ith !cce"t!be rem!inin$ thro!t thic%ness: continuous tr!nsverse $rooves in dec%* bottom* on$itudin! bu%he!d !nd side "!tin$ +ithin the c!r$o !re!

to be s"eci!# considered(

-&( Groo0e corrosion of internal str,ct,res

The m!7imum e7tent of $roovin$ !nd the !cce"t!be minimum thic%ness of stiffeners !nd "!tes m!# be t!%en!s foo+s=

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"ec./ itting, 0roove and :dge &orrosion - age )2

DETNORSKEVERITAS AS

Jhere the $roove bre!dth is ! m!7imum of 0BM of the +eb hei$ht* but not more th!n 055 mm* the rem!inin$!o+!be thic%ness in the $rooved !re! m!# be t!%en !s=

tmin 5(. torigbut* not ess th!n ?(5 mm(

Fig,re -6&Groo0e corrosion

@roovin$ corrosion of stiffeners +ith !n$e "rofie is considered to be serious* !nd shoud be c!refu#considered +hen reve!ed( L!c% of fi7!tion to the "!te +i c!use the stiffener to tit* !nd over time the$roovin$ +i incre!se due to stress corrosion( Jhen the stiffener is titin$ the efficienc# of the stiffener isreduced* !nd this m!# c!use second!r# "robems to the "!te "!ne(

A c!cu!tion +ith res"ect to the she!r stren$th !nd tri""in$ is to be c!rried out if the !bove criteri! !ree7ceeded* but the minimum thic%ness in continuous $roovin$ shoud not be ess th!n ? mm(

-&- Corro$e$ )el$e$ sea+s in shell "lating

Pinimum thic%ness !t the +ed or "!te=

tmin= 5(. torig

-&% E$ge corrosion

4.".).1 0lat bar dec! longitudinals

For !cce"t!be e7tent of corrosion of the free ed$e of the on$itudin!s the foo+in$ m!# be !""ied=

!' The over! hei$ht of the corroded "!rt of the ed$e is ess th!n /BM of the stiffener +eb hei$ht(

b' The ed$e thic%ness is not ess th!n 0)6 tori$!nd +e rounded(

c' The thic%ness of the rem!inin$ "!rt of the on$itudin! is !bove the minimum !o+!be !ccordin$ to 6(

Fig,re -6(E1tent of free e$ge corrosion

4.".)." Manholes lightening holes etc.

!te ed$es !t o"enin$s for m!nhoes* i$htenin$ hoes* etc( m!# be reduced beo+ the minimum thic%ness"rovided criteri! for she!r !re! !re chec%ed !nd the foo+in$ !""#=

!' The m!7imum e7tent of the reduced "!te thic%ness* beo+ the minimum $iven in Sec(* from the o"enin$ed$e is not to be more th!n /5M of the sm!est dimension of the o"enin$ but shoud not e7ceed 055 mm(

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6 0uidelines for the survey of voyage repairs - age )=

DETNORSKEVERITAS AS

A""en$i1 A

G,i$elines for the s,r0e2 of 0o2age re"airs

A! GeneralThe "ur"ose of these notes is to "rovide $uid!nce to the fied surve#ors !nd o+ners de!in$ +ith vo#!$e hure"!irs !nd is to be considered in !ddition to the rues(

A!! 8nitial +eeting

A meetin$ is to be hed +ith the c!ss surve#or !nd o+ner "rior to commencement of hu re"!irs durin$ !vesses vo#!$e to discuss !nd confirm the foo+in$=

!' It is the o+ners res"onsibiit# to ensure continued effectiveness of the structure* incudin$ the on$itudin!stren$th !nd the +!terti$ht)+e!therti$ht inte$rit# of the vesse(

b' E7tent of intended re"!irs( A re"!irs !re to be b!sed on the c!ssific!tion societ#s recommend!tions !nd)or concurrence(

c' Av!i!biit# of "ertinent dr!+in$s(

d' Verific!tion of ne+ m!teri!s re$!rdin$ certific!tion* $r!de !nd sc!ntin$s( Verified mi sheets to rem!inon bo!rd !nd to be "rovided to !ttendin$ surve#or e7!minin$ com"eted re"!irs(

e' Verific!tion of +edin$ consum!bes re$!rdin$ certific!tion !nd suit!biit# for m!teri!s invoved( Chec%on !v!i!biit# of dr#in$ ovens* hodin$ cont!iners* etc(

f' Verific!tion of the -u!ific!tion of +eders !nd su"ervisor# "ersonne* -u!ific!tion records to rem!in onbo!rd !nd to be "rovided to !ttendin$ surve#or e7!minin$ com"eted re"!irs(

$' Revie+ of intended re"!ir(

h' Revie+ of the intended "rovisions to f!ciit!te sound +edments* i(e( ce!nin$* "rehe!tin$ &if !""ic!be'!dherence to +edin$ se-uence "rinci"es( Further* it mi$ht be necess!r# to restrict +edin$ to cert!in

"ositions !nd "rohibit +edin$ in more difficut "ositions +hen the shi"s motions mi$ht infuence the-u!it# of the +edin$(

i' Revie+ of intended +or%in$ conditions* i(e( st!$in$* i$htin$* venti!tion* etc(

j' Revie+ of intended su"ervision !nd -u!it# contro(

%' Com"eted re"!irs !re to be e7!mined !nd tested !s re-uired to the s!tisf!ction of the !ttendin$ surve#or(

Note:

A det!is !nd resuts of subject meetin$ to be covered b# ! memor!ndum( A co"# of this memor!ndum is to be "!cedon bo!rd !nd to be "rovided to the !ttendin$ surve#or e7!minin$ the re"!irs( In !ddition* ! co"# is to be sent or f!7edto the !rriv! "ort +here com"eted re"!irs +i be e7!mined(

999e9n9d999of999N9o9t9e999

A!& Conte+"late$ re"airs

Descri"tions of !n# contem"!ted re"!irs to "rim!r# hu structures* i(e( m!in on$itudin! !nd tr!nsversemembers !nd their !tt!chments* !re to be submitted to the c!ssific!tion societ# for revie+ "rior to commencin$vo#!$e re"!irs( An# re"!irs to "rim!r# hu structures sh! re-uire !ttend!nce b# ! surve#or ridin$9shi" surve#or !t re$u!r interv!s to confirm fit9u"* !i$nment* $ener! +or%m!nshi" !nd com"i!nce +ithrecommend!tions( NDT of com"eted re"!irs to "rim!r# structure to be c!rried out to !ttendin$ surve#orss!tisf!ction( Re"!irs to other hu structur! "!rts m!# be !cce"ted b!sed on e7!min!tion u"on com"etion ofre"!irs(

A!( .rere>,isites for re"airs

No hu re"!irs c!rried out b# ! ridin$ cre+ shoud be !cce"ted uness=

!' The initi! meetin$ h!d been c!rried out !nd conditions found s!tisf!ctor#(

b' A fin! s!tisf!ctor# e7!min!tion u"on com"etion +!s c!rried out(

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4 &alculation of hull girder ultimate capacity - age )>

DETNORSKEVERITAS AS

A""en$i1 #

Calc,lation of h,ll gir$er ,lti+ate ca"acit2

P3 3tim!te hu $irder ho$$in$ bendin$ moment for ! section in ! "ure vertic! bendin$ modus(

3tim!te hu $irder ho$$in$ bendin$ moment for ! section in ! "ure vertic! bendin$ modus(

TheM5is c!cu!ted !s summin$ u" the on$itudin! o!ds c!rried b# e!ch eement in section !t hu $irder

co!"se( An !cce"t!be method for !ssessin$ theM5v!ue is to !""# the DNV 13LS mode=

!ne 3tim!te Limit Stren$th &3LS' is used for individu! eement utim!te c!"!cit# !nd stiffness!ssessments( 3LS is ! DNV com"uter "ro$r!m usin$ non9ine!r "!te theor# to c!cu!te ! stiffened "!tefied,s utim!te buc%in$ stren$th( It tre!ts the entire* stiffened "!te fied !s !n inte$r!ted unit* !o+in$ forintern! redistribution of the stresses(

An e7"icit c!"!cit# chec% &Mtension6yield' of the tension "!rt of the hu $irder is !so to be c!rried out( E($(* forho$$in$ o!din$ conditions the tot! c!"!cit# is imited b# #ied !t the stren$th dec%(

Mcap% min 7M5 Mtension6yield8

Atern!tive !dv!nced methods* i(e( such !s non9ine!r FE mode !n!#ses or e-uiv!ent for !ssessin$ theutim!te hu $irder c!"!citiesM5+i be considered b# the Societ# on ! c!se b# c!se b!sis(

9i A7i! o!d in eement no( i !t hu $irder co!"se *9i% *;+eff

i

ii5 =;=9d;=M '&sec 0

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& &ommon "tructural 7ules Vessels ' &"7 - age #+

DETNORSKEVERITAS AS

A""en$i1 C

Co++on Str,ct,ral R,les 5essels 6 CSR

C! General

There !re t+o different t#"es of Common Structur! Rues &CSR' vesses( E!ch t#"e h!s their se"!r!te Rues(

: CSR9T!n%= Rues for Shi"s t( Ch(0 Common Structur! Rues for Doube 1u Oi T!n%er +ith Len$th0B5 metres !nd !bove(

: CSR9>u%= Rues for Shi"s t( Ch(/ Common Structur! Rues for >u% C!rriers +ith Len$th 5 metres

!nd !bove(

CSR vesses !re buit +ith the Common Structur! Rues Hnet sc!ntin$ !""ro!ch( The ne+buidin$

re-uirements +ithin the Rues incor"or!te defined corrosion !dditions( The minimum thic%ness to$ether +ith

"ossibe Ho+ners e7tr!* Hvount!r# !ddition* or simi!r is st!ted on the !""roved dr!+in$s from desi$ner or

ne+ buidin$ #!rd(

In c!se documents)dr!+in$s +ith inform!tion of minimum thic%ness is not !v!i!be then the beo+ references

m!# be used( For CSR vesses the Hsubst!nti! corrosion imit is e-uiv!ent to H!nnu! ins"ection imit( In

c!se there is !n# discre"!nc# bet+een the res"ective rues !nd this C!ssific!tion Note* then the Rues "rev!i(

Note th!t the CSR9T!n% rues !nd CSR9>u% rues !so h!ve different criteri! for oc! corrosion(

C& CSR6Tan9

In $ener! see Rues for Shi"s t( Ch(0 Common Structur! Rues for Doube 1u Oi T!n%er +ith Len$th

0B5 metres !nd !bove(

For minimum thic%ness in connection +ith thic%ness me!surements* see &ec.1". &hip in ?peration enewal

riteria and sub item 1".1.4 enewal riteria of ocal &tructure for Aeneral orrosion. The beo+ is for

$uid!nce(

C&! Mini+,+ thic9ness for rene)al

tren Rene+! thic%nessU Pinimum !o+!be thic%ness* in mm* beo+ +hich rene+! of structur!

members is to be c!rried out tren t!s9buit tcorr to+n

+here=

tas

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&H6N0:" - HI"387I& - age #)

CHANGES H8STOR8C

Note th!t historic ch!n$es oder th!n the editions sho+n beo+ &if !n#'* h!ve not been incuded(

?an,ar2 &7!( e$ition

Main Changes

: ;6((0(

CN72-1.pdf

Documents