Tanker Operations

TAN KER OPE R ATION S A Hand book for th e Person -in-Ch arge (PIC) FOURTH EDITI ON

MARK HUBER

Based on earlier editions of Tanker Operations A Ha nd book for the Sh ip's Officer

by G. S. Marton

A~rican Progress, one of the Doubl Shipbuilding. CourtellY Mobil 8hi ,e Eagle-class vessels built at Newport N ews ppmg and Transportation Company.

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CORNELL MARITIME PRESS Centrevi lle. Maryland

Copyright nt on the STeWcert ificate. This endorsement stutes th.t the person is qualified to se rve on tan kships carrying dan gerous oils, che micals. or gas in bulk . The following references sho~ld be consul~ed for details concerning each of th ese endorBements: th.e U n ~ted States Code of F~rol Regulat ions. Title 46 CFR Pa~ l~, ~ertlficatlOn of Ta~kennen; and the Intern ati onal Maritime Orga nlza tlOns STCW Conventlon , 1978, as amended in 1995, Annex 2, Cha pter V, "Special Training Requi rements for Personnel on Tankers" (Regula tion v/n I would like to thank many individu a ls for ass isting me with th is seemingly endless project. In particular, I am !p"at~~ to my wife, Jody, a nd my family for th eir patien ce and support . This edition of th e text ha s also been enhanced throu gh the efforts of severa l contributors , eac h of whom wrot e new chapters: Captain Richard Beadon, Director, Center for Ma ri time Education at Seamen' s Church Institute; Robert Stewart, Professor, Ca lifornia Maritime Academy;John O'Connor, Pr esid ent of In ternati onal Ma rin e Consultants; and Scott Bergeron, Chief Operating Officer , Liberi a n Sh ip and Corporate Registry. The glossary was written by Kelly Curtin , Assistant Professor, State University ofNew York Maritime College. I a lso wish to thank my colleagues at the U.S. Merchant Marine Acad em y: John Hanus, Lt. Rob Smith (USCG>, Paul Zerafa, and Brian Holden for th eir computer expertise , and Captain Douglas A Hard for his ti reless efforts throughout this endeavor, reviewing each cha pte r and offering constructive criticism. Finally , I would like to thank th e following individu als a nd organizations for providing information and many of the illustrat ions: Alaska Tanker Company; Ameri can Petroleum In stitute; Atl a ntic Richfield Company; Avondale Shipyard; Mary J en Bea ch; Ian -Conra d Bergan, Inc.: Bethlehem Steel Corporation; BP Pip elines (Alas ka) Inc.; British Petroleum Company , Ltd.: Butterworth Systems , In c; Calhoon MEBAEngineering School; California Maritime Acad em y; Chevron Shipping Company; Clement Engineering Services ; College of Nautical Studies; Coppus Engineering Corporation; Dixon Valve a nd Coupling Co.; Environmental Protection Agency; ExxonIMobil Corporati on ; Th omas J . Fellei~n; Bill Finhandler; Foster Wheel er Boiler Corpora tion ; Ga mlen Che,:"~cal Company; General Dynamics Corporation; Keith Gill ; Global ~~tIme a~d Transportation Schoo~; Gulf Oil Corporation; Eri c Halbeck; nan HaU, Haywood Manufactunng Company; Howden En gin eeri ng; Lynn Hu~r.; ~udson Engineering Company; IMO Industries, In c., Gems Sensors DIVISion; Ingersoll Dresser Pump; International Association of Independent Tanker Owners UNTERTANKO); International Association of Ports ~nd Harbors (lAPH>; International Chamber of Shipping (ICS l; In~~~~~o~al Ma~ne Consultants; International Maritime Organization Shi : n~matIonal Tanker Owners Pollution Federation; Keyst one I~PLe,"gKiom~any; Keystone Valve Division of Keystone International, Inc., e nceid: Kockumatt AB'L 'M arttime; · · . Law ; LIbrary . lon, aunn Bnan ,

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of Congre ss Photo Duplication Service' Kimberly Lo . Lc ' , '1 P rt (LOOP)' E ' M . ' renzo, Ullllana OfTshore 0 I 0 ', , n c a; MalOe Maritime AO"d"m ' 1/ ' Lo f T h ....,. '" y, .. an ne g; Maritime I n eu ' ,John• , ute I 0 8ec nology' and Grad uate St udiiee :' Caplam Mazza; Metritepe, nc.; teve ~ Miller; Mine Safety Appliances Com an . MMC Intem atlOnal Corporati on; Frank Mohn Services AS· Ron ~r ~~ Nat ional Acad emy Pre ss an d the National Academy ofScien~es' N t?ne I' letvy,r Nat IF' P . , 8I 1~ 0na __ Audu bo n 8 ocre a irona ' N ' 1' \ -Ire rotectton Association', N" a rena ueu8 aphic ociety; a n ona t x antime Union ofAmerica' Nation I D _ h gr , ' 18 1 ',. , a ne searc CounCil; Natr ona tee ~ n d S hl p~U1ldmg Company; National Trensportation Safety ~oard ; Nau~Ical Instlt u~ ; Newport News Shipbuilding; J ohn O'Connor ; Oil Compames Intem atlOnal Marine Forum; Penn-Attransco Corporation; Per:rnea Mari time Protection ; Phillips Petr oleum Company; George Roeanovich ; Saab Electronics; Saab-Seania, Aerospace Division; Sailors Union of the Pacific; Salen & Wica nder AB; Salwicc, Inc.; San Fr an cisco Maritime Museum; E.W, Saybolt& Company, Inc.; Ed Schultz; Seafarers Intern ational Union ;Sea men's Chur ch Institute;SeaRiver Maritim e; Servomex (U .K. ), Ltd .; Shell International Petroleum and Shell Oil Compan y tU.S.A.); Shipbuilders Council of America; Skarpenord Data Systems AS; Southern Oregon State College; Sperry Marine Systems; Sta cey Val ve Co" Inc.: Star Enterprise;State University of NewYork Maritime College; Stolt Nielsen Transport ation Company; Sun Shipbuilding and Dry Dock Company; Texaco, Inc.; Tosco: Transamerica Dclaval, Inc.; TS Tanksyetern SA; Underwriters Laboratories, Inc.; U.S. Coast Guard; U.S, Depa rtmen t of Transportat ion; U,S, Maritime Administration ; U,S. Sal vage Association; Val ve Manufactu rers Association; Viatran Corporation ;Vitronics , Inc.; Rosalie Vita le; West Coast Ship Chandlers, Inc.;Terra White ; J eff Willia ms; William E. Williams Valve Corp.; Wilson Walton Intemati onal ; Worthington Pu mps, Th e last edition of Tanker Operations offered this word of advice to the read er : "You can't learn tankers from a book; don't try to do so, Ships are design ed an d equipped differently, and notwo are exactly alike. In th~ en~. there is no substitute for seeing th e actual equipment and operatmg ~t your self." As a follow-up to that thought , I would add that no on thi s subject ca n ade quately address every vessel design, piece ofeqwpment , or procedure. Ultimately, a thorough working knowledge .of the cargo Syste~ on th e vessel is your best defense aga inst potentlal mishaps. Remem~ , . lized . . . a nd pr actrca . I expenen ' c. gained trammg . as an apprentice t h e specia on tankers is just the beginni ng of a lifetime of Ieammg.

u:xt

Prefa ce t o the First Edition

A

nu mbe r of ye ars ago, when I wua beginning mycareer on oiltank I ofte n felt the lack of a simple, stra ightforward handbook on the basic problems of tanker ?pera tions . Hence, this book. Tanker Operations: A Hand book {or the S hIp's Officer is directed primarily toward the newcomer to t anke rs ; specifically, the new officer. Generally speaking, it is not 8 step-by-ste p manual covering every possible situation. Instead, it is intended as: 1. 2. 3.

An introductory guid e designed to make the new officer's adjustment to tanker life smoother , less perilous. A source of useful infonnation for th e more experienced officer. A refe ren ce book for ot he r ind ividu als interested in the operation of oil tanker s, pa rt icularly tho se as piring to the ratin g of tankerman.

I should point out, h owever, that tanker s cannot be learned entirely from a book . The tankerman'a job is too complex and, in many ways, intuiti ve. Moreover, eac h t anker is unique a nd mus t be learne d individually . Fortunately, the lea rning process is not an entirely lonely tas k. Shipmates-pumpmen, fellow officers , sa ilors-ha ve knowledge to share, an d some make exce lle nt teacher s. In th e end, however , th e way to learn a tanker is to put on a boiler suit and, flashli ght in hand , explore every co.me r ofthe vessel, learning pum pr oom, piping systems, valves.This is a ~e~lOus, sometimes exhausting process , but it must be done. A~ officer unwllhng to make this effor t should forget a bout a car eer , even a bn efone, on tanke rs. Some tankers. old and ru sty. a re relics of a bygone era. Others are so .futuristic, so thoroughly automat ed . th at th eir crewmembers feel more like astronauts than t ankerm en . And, in all likelihood, th e futur e tankerman will need the training and temper ament of an astronau t. xvii

v III

Rl.'gardl('s~of age or equ ipment, however, all tankers perform th e 8a~lle bl~ zmg

basic task-they carry oil. Their voyages span th e globe~ from th e

deserts of Saudi Arabia to the frozen shores of the Ar ctic. 'Throu gh It a ll, tankermen are accompan ied by the pungent smells of ~rude. Oila n d ~a8o­ line, by loneliness, tension , exhaustion .. . and the s8t1~factlOn of d~mg a job well. No individual can adequately describe this unique way of hfe . It

. .. must be experienced firsthand. I would like to take this opportunity to thank the m an y mdlVldual s and organizations who were kind enough to help mein th~seffort. ~ome showed remarkable patience with my repeated requests for mfonnatlOn , resea rch . . ' materials, and illustrations. Special thanks to ; The American Bureau ~f Shipping; ~encan ?ast Iron Pipe Company; American Institute of Manne Unden~ters; Amen can Institute of Merchant Shipping; American Petroleum institute ; the Ansul Company; Apex MarineCorporation ;Atlantic Richfield Company; the Scott Aviation Divisionof ATO, Inc.; Mrs . Gerry Bayless; Bethlehem Stee l Corporation ; Bingham-Willamette Company; British Petroleum Company, Ltd..; Henry Browne & Son, Ltd.; Buttenvorth Systems, Inc .; Chevron Shipping Company; Coppus Engineering Corporation; Exxon Corporation an d Exxon Company ,US.A.); FMC Corporation; Mr. Steve Faulkner; Mr. Bill Finhandler; Gamlen Chemical Company; General Dynamics Corporation; General Fire Extinguisher Corporation; Mr . R.W. Gorman ; Gulf Oil Corporation; Mr. Arthur Handt; Hendy Inte rn ational Company; the Pen ce Division of the Hudson Engineering Company; Mr . John Hunter; Huntin gto n Alloys, Inc.; th e Keystone Valve Division of Keystone Internation al , In c.; ~kumsAutomationAB; Mr. Gene D. Legler; the H arry Lundeberg School; Mine Safety Applian ces Company; Mr . C. Bradford Mitchell; National Audubon Society; National Foam System, In c.; National Maritime Union of America; National Steel an d Shipbuilding Company; Miss Maureen Ott ; t he ~~h M. ~~rson s Company; Paul-Munroe Hydra ul ics , In c.; Mrs . Pi a P~ pp ; Phillips Petro l e ~ Company; Sailors' Union of the Pacific; Sal en & WIt:lJlder AB; S~ Francisco Mari tim e Muse um ; E.W. Saybolt & Compan y, Inc., Mr. W.F. Schill; Seafarers International Union; Shell Intern a tion a l Pe~roleum an~ Shell Oil Company m.S.A); Shi pbuil ders Council of Am erica ; pehITY,Manne Syste ms; Su n Shipbuil ding an d Dry Dock Company' Mr Bob ut er and: Und S ite L ho . ' . United Sta~ Me~~ T8 a. ~aton~s, In c.; Un ited State s Coast Guard; e antime Administration; U.S. Salvage Association ' Valve .. ~ Menur acturers Aeeociati ' p Chan dlers Inc ' Worthingto ' . on,. Wes t C oast Shi n ' ., Pum p Corpora uon. G. 8. MARTON

fi th C l" . Qu inghi s seagoingca rohm e a ifomia Maritime Academy ill 1969. G B. Marton 8r.aduated

reerd' e. serued on all types ofmerchant ships, includ·

ing tan'kerIJ of a1l 1\Jpe8 '1sl

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TANKE R OPERATIONS

C HA PTER 1

Tank Vessel Design and Classification

he first tanker appear~d over a century ago, and sincethat time tanker transport ha s evolved into one ofthe most efficient modes oft ranspor tation in the world . Modem refinements in th e design ofthe se vessels have resul te d in the development of a versatile carrier capable oftransport ing a wide array of bulk liquid cargoes. Today, tank vessels (both ships and bar ges) are responsible for the movement oftremendous volumes of liquid cargoes . This chapter focuses prim aril y on vessels th at are designed to carry cargoes classified as "dang erous liquids." Th e following definitions are provided to eliminate confusion about th e typ es of vessels de scribed in th e te xt. The Unite d St ates Coast Gu ard (USCG) defi nes a tank vessel as "a vesse l th at is constructed or ad apted primarily to carry, or that carries, oil or ha zardous material in bulk as ca rgo or cargo residue." The USCG further categori zes a tank vessel as a t ankship (if it is self-propelled) or a tank ba rge (if it has no mean s of pr opulsion ). Th r oughout the text, efforts have been made to use the term "tank vessel" ift he topic applies to both shi ps and barges.

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OIL TANKER The earliest design of tank vessels involved construction with a single hull . Figure 1-1 shows a cross section ofa traditional single-hull design . In the early part of the twentieth cent ury, th e shift toward longitudinal construction resulted in a unique subdivision of the cargo tank area . A13 seen in figure I-I, the use of twin longitudinal bulkheads divided the vessel athwartehipa into three tanks: a center tank flank ed by a set of wing tanks. A series of oiltight transverse bulkheads completed the subdivision of the cargo area, as required, for the particular trade of the vessel. This method 3

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Figure 1-2. Profile view of a doubl e-bottom ta nker. The double-bottom space serves 8S the s egr egated-ballaet ca pacity for the vessel. Copyright e In terna tional Maritime Organization CIMO), London .

of con struction wa s well s uited for the bulk t rans portatio n of liquid cargoes ; at the same time it virtuall y eliminated the free surface problems experi enced with earlier tanker designs. Free surface is an effect cre at ed wh en liquid s move about in an unrestricted fashion within a compartment such as 8 cargo or ball ast tank. The

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resultant shift of weight has an adverse impa ct on the stability ofthe vessel. so every effort is made to minimize shifting.Typical methods of reducing the free surface effect include keeping the number of slack cargo and ballast tanks to a minimum, constructing smaller compartments (subdivisions). an d utilizing partial bulkheads (swas h plates or swash bulkheads).The success of the single-hull design is evidenced by the fact that it has withstood the test of time and deadweight Idwt) tonnage. Single-hull construction predominated until the late 1960s when political and environmental pressures drove the tanker industry to seek other methods of construction. By the 19708 a number of owners had shifted to double-bottom construction (fig. 1-2) to meet the new segregated-ballast requirements. Th e gr ounding of the Exxon Valdez in 1989 prompted domestic an d international requ iremen ts calling for newly constructed oil ta nkers to be fitted with a doubl e hull. Double-hull tankers had been successfully operated for a number ofyea rs, hence this design took cente r stage as the most likely re sponse to the public 's out cry for height en ed protection of the marine environment. The use of two pieces of stee l (inne r and oute r hull s)to separa te the cargo area from the sea is expected to minimize oil outfl ow from the majority of tanker casualties-grounding, collision, or minor shell dam age-that involve a breach of the hull . The cons truction scenes of the ARGO Endeavour (fig. 1-3) clearly illu strate th e protection afforded the cargo tanks wit hin the double hu ll. The Oil Pollution Act of 1990 called for new tankers contracted after J un e 30, 1990, to be constructed with a double hull. The U.S. construction requirements contained in Title 33 CFR Part 157.10d specify minimum spacing as follows:

6

TANK VESSEL DES IGN AND CLASS IFICATION

OIL TANKER

7

For vessels of 5.000 dwt and abov eFor vessels of less than 5,000 dwtDouble sides 'WI W z 0.5 + dwt 120 ,000 or 2 meters the lesser and in no case lesa t ha n 1 meter Doubl e bottom (In H '" Bre adth / 15 or 2 meters t he lesser an d in no case less than 1 me te r

Dou ble sid es (W ) W . O.4 + / 2.4) (d wt / 20, OOO ) in mete rs , but in no case less than 0 .76 mete Double bottom (II) r H • Breadt h / 15 in meters, but in no cas e lesa th an 0.76 m('ter

Figure 1-4 sho,:",s t he newly ~n 8tructed double-hull tanker American In th e domestic trade by Mobil Shipping a nd 'I'rene portatton Company. Th e.double-hull requirement created tremend ous cont roversy with in t he United ~tate8 and inte~na tional shipping communities. Industry experts questlOn~d the effe:t.lvene~s of th e double-hull design in a h igh energy grounding or collisio n WIth the potential for significant 10s8 of cargo. Th e Oil Pollution Act of 1990 (OPA '90) left th e door open toaltem at ive vessel designs which could offer en vironme ntal protection that was equ al to or better t han the protection provided by the double hull . During the 1990s research into al ternative designs and techno logy was conducted t hroughout th e world . However , in 1993 , a USCG report to the U.S. Congress reaffirmed t he double-hull design 8 S the only method of construction th at s hould be permitted to ope rate in U.S. wate rs . This conclusion placed the United St ates at odds wit h t he rest of th e shipping commun ity as the Inte rn at ional Maritime Or ganization (IMO) had embrace d not only the double-hull method of construc t ion but also the controve rs ial mid-deck design . The Coast Gua rd cited inexper ien ce with th e mid-deck design as one of the re asons for not recommending it as a viable alte rnative to the double hull. In the mid-de ck design (fig. 1-5)an inte rmediate oiltight deck essentially creates an up per an d a lower cargo ta nk. In the event ofmajor bottom damage, thi s design pr even ts sign ificant loss of cargo based on the hydr ostat ic principle . When fully loaded , th e head pressure of th e oil in the bottom tank is less th an the wat er pressure exert ed on the outaid e of the hull . Once the vessel comes to rest, ins tea d of oil gravitating out the bottom of the vess el, water Flows in , pressing up the bottom tank. This simple but effective concept ap pea rs to outperform th e double-hul l design in model tests t hat simulate casualties involving significant bottom damage. The wider doubl e side s in th e mid-deck des ign resemble tr aditi onal wing tanks and provi de better protection against collision dam age than the double hul l. Another des ign closely related to the mid-deck is th e Coulombi Egg shown in figu re 1-6. After seve ral years of evaluation, IMO has also accepted this design as affording a mea sure of protection for the marine environment equivalent to that of the double hull. As in the case of the middeck des ign, however, the U.S. Coast Guard opposes the idea of equivalence and will not perm it eit her design into t he United States. The controversy Pr~gr(,s8 operated

Figure }-3 Conat eli 1 hull at number 1ru on scene oftheARCO EndeolJOur showing th e protective daub e cargo tanks port and starboard. Courtesy ARea Marin e, Inc.

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Ballast

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Figure 1-6. The Coulombi Egg design .

10

TANK VESSE

DESIGN AND CLAS!:l1 1"lL;A' I IU1~

O'It"T aJtemative design s continues in part because ~he U.S . posi t ion ha s er. Iecnve ly closed th e door on ot he r tec h ~ol ogy as evidenced ?y the fact ~hat double-hull orde rs and deliveri es dommate new construction worldwide.

P AR CEL TANKER As cons umer demand for che m icals an d ot her s pecialty products incre ased worldwid e the need for vessels desi gn ed s peci fica lly to transp ort th ese cargoes also expande d. As a qui ck fix, so me owners modified exi sting product carriers into what were te rmed "drugs!ore" ve ssels , carrying lim ited quan tit ies of ma ny differen t pr oducts . tr.ItImatel~, these vessels

paved the way for parcel carrie rs, vesse ls specia lly designed an d constructed from the keel up to accommodate the growing m arket . Figu re 1-7 shows one s uch vessel , the Stolt Innovati on, built and operated by Stolt-Nielsen S.A. Figure 1-8 shows the deck of an externally framed vessel. This method of cons t ru ction allows th e in ternal s urfaces of tanks to be smoot h . Du e to the nature of the ca rgoes transported, parcel tan ke rs a re desi gn ed to maintain a high degree of segregation bet ween ca rg oes . Fi gure 1-9 s h ows t he complexity of deck pipin g on one coastal che mical carrier. Toward th e end of th e t wentieth century, the demand for parcel tankers incr eased as th e tr an sport of th ese ca rgoes by s uch vessels proved to be sa fe and cost-effective while maintaining th e hi gh est stan da rds of qu a lit y assurance. The list of differ ent cargoes ca rri ed by parcel t ankers is exhaustive; however , th e rul es governing t he sa fe t ransport of these cargoes a re well defined in th e international bul k che mical codes. Th e construction and s urvi vability requirem en ts for che mica l vessels ca n be found in Title 46 CFR Part 151 (barges ) and P art 153 (sh ips) as well as in the bulk chemical codes (lBCIBCHl from the Inte rn ational Maritime Organi zat ion (lMO>. nB C is the Internati onal Code for the Cons t ruction a n d Equipment of Ship s Carrying Dangerous Ch emicals in Bulk . BCH is t he Code for the Construction and Equipment of Ships Ca rrying Dan gerous Chemicals.) The marine environment is afforded three levels of protection against an unc~ntrolled r~lease of t he cargo re sulting from a brea ch of the cargo tank. FIgure 1-10 illustrates th e spacing requ iremen ts for Ty pes I II and III containment in the cargo area , as specified in t he bulk chemical codes. 1.

Type I containment provides the maximum level of protecti on possible ~hen transport ing f1ubstances t hat pose th e greatest environmen tal risk I an .uncontrolled release from th e vessel should occur. In addition to the spaCing requirements between th e side and bottom shown in figure 1-B, veuelsconatruetedin . . . eccordance WIththese rul ea must also be capable 0 r SUI"VJVlng a certain prescribed level of damage to th e hull.

Figure 1-7. The St olt Innovation serves in the parcel tra de worldwide. Dourteay Stolt-Nielsen Tran sportation Group Ltd .

Figure I -B. The deck of an externally framed parcel tanker. With thi s design, the cargota nks have smooth internal surfaces. Courtesy International Marine Consulta nts lIMC).

12

TAN K \ 'ESSEL DESI GN AND CLASSIFICATION COMBINATION CARRIE R

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Type II conta inment ill required whe n t ran8por1ing substance/:l t hat pONe a significant ha zard to the environmen t . T he s paci ng require ments and t he aurvt va bihty requirements orthe vessel a re Ieee than those for Type I COn _ tamment .

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T)-pe III containment affords a moderate leve l of protection. No special spacing requi rements a re neces sa ry and the s urvivability cri teria in the

even t of vessel damage are not

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The chemical codes furt her classify cargo tanks according to t he ir con. struction.Independent tank s are cargo tanks not designed as a part of the hull structure. An examp le of an independent tank would be a cylindri cal cargo tank installed above th e deck . An indep endent tank is u sed to eliminate or at lea st minimize the forces or st resses th at may be working on the adjacent hul l structure. An independent tank is in stall ed in such a manner that it can be moved relative to t he vessel. Integral tanks are cargo tanks t hat fonn a n essential part of t he hull structure and contribute to the st rengt h of the vessel. In tegral tanks are subject to the forces and stresses experienced by t he hull structure as a resul t of cargo operations and motion of the vessel. Figu re I- I I illustrate s several cargo tank configurations on parcel tankers .

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Gravity ta nks ar e those tanks ha ving a design pressur e not gre ater th an 10 pounds per square inch gauge and of prism at ic or ot her geomet ric s hape where s tress analysis is neither readily or complete ly determinate. Pressure tanks are independent tanks whose pressu re is above 10 pounds per square inch gauge and fabri cated in accordance with domestic rules.

C OM B I NAT IO N CAR R I E R The USCG defin es a combina tion carrier as a ny vessel designed to carry oil or solid cargoes in bulk. Th ey are s pecially built vessels often referred to as

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relbu1k/oil ca r rie rs (OBOs) capa ble of alte rnat ing betwee n carrying oil oa rgoee a nd bul k comm odities auch 8S ir on ore or coal. Combinat ion ca m : r8 ca n also be ada pted to meet th e s pecia lize d requireme nts of a custome r 8uch 88 alte r nating between the transport of ca ustic and alumina for th e aluminu m indu stry. The advantages of t his design include th e ab ility to carr)' cargo in both directio ns during a voyage a nd to shift t rades ea market conditions and frei ght rate s change . Figure 1-12 illustrate s a typical c r08S section of a n DBO . Th e design is characteri zed by large rai sed h atch openings 8S well 8 S a doubl e-bottom and top side ball ast tanks for t rimming of solid cargoes. Some of the concern s expressed with t his design include damage to t he tank coati ngs a nd high st resses from t he loadin g of dry ca rgoes. Problems also arise in sit uations where m aj or components ofthe ca rgo sys te m (such as pum ps, valves. ine rt ga s systems , and so forth) experie nce extended periods of inac tivity. To combat thes e proble ms. combination carriere requir e frequent in spec tion and on goin g pre ve nti ve maintenance to e nsur e the continued reli ability of ca rgo system equipment.

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BARGES rtation by water ut il' thod of bulk liquid transpo An f.'(me induatrv . Th domesne tank barge 10 ust ry iIS com posed of approIZCllt ' "l.rtk bll.rVs . e an d th ey account for th e transp ort of milli ons afton 8!(!ly

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Ited States d e I"rver produ cts 8th0 ce'iO II T k barges within th e U rute annua y. an . I k h rough inl d waterway system (rivers , a es , aya, and sounds) d ' out th e i an . d Th . . un th shore in the coastWIse tr a e. eee versati le vessels tr ll ey aI.. run 0 ffi k hi F' 8 SPort the full range ofcargoes carried by tan 8 IpS . rgu re 1-13 shows a tYpo I nd profile view of an existing single-hull ba rge. leal p anr~"barge8 are constructed with ' ....., . ' a centerline bu lkh ead and a 8 ene80f transverse bulkheads . This results In a port-and-starboa rd ca rgo tank figuration 8S seen in figur:e }-13. The number of ca rgo compartments fo~~ on a barge is generally dictated .by the trade ?ft he ves ~el . Under the Oil PollutionAct of 1990, the barge industry al so IS fa ced ~th converting the existing single-hull fleet to a double-hull standard. Fi gure 1-14 show new double-hull barge that is being constructed by Ala ba m a Shipyard ~o: the domestic coastwise trade. Barges transporting ca rgoes other than oil must m eet the constructioll requirements outlined in Title 46 eFR Part 151, which ca ll for heig htened pro tionofthe cargo area from side or bottom damage to the ba rge. Barge ,

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2 starboa rd cargo tank

3 port cargo lank

2 pert

cargo tank

1 starboard cargo tank

Ra~e

t pert cargo lank

Tank hatch

0 0 2 starboa rd cargo tank.

0 0 1 starbOard cargo tank

TANK VgSSEL Dc"

re

,

_" t , t_ 'ctuTalstrengt h, collision a nd ground· 0 ,... " hullsare categon"l ed al.'COnung d . bility in the event of floodilog fr om specified iog ."quiremant8. " are cate gorized in th ree wa ys as follow s :

8 ': r;;ySTWS

daInagt>tothehull. The u

r~

'".,.,-'" to ea....... products wh ich req uire the maxi. 'O J urw topl't'Clude the uncontrolled reles se of th e ca rgo. ItIUlii pre"l'ntl\'e m69ll . . Type ll bargt' hull. I re theee designed to ca rry products which require sig. "\'1' measures 10 preclude the u ncont roll ed r ele a se of t he nlfieant pl't'ven... ... '1'....-

'lr

I barge hu It8 are delll.... ()f rel\llel ll'lll

"'~ClWI~l-

BRANCH PIPING

bellmouth connects to athwartship piping kn own a s branch piping . As shown in figure 4-1, the branch piping conn ects the center a nd wing tanks , >::~ti~e, \f\o re.-and-aft main line. For example, the forw ardmost ca rgo ta nksP.Qrt &riter, and starboard, commonly referred to as "1 ac ross"-are

~

M

l!l --0- c,

~

1>--0-

00

•

f--oo-o Bev eled lor welding to suction pipe

I

~

0-

I>- 0-

00 ~

-0----

Radial ribs prevent

vortex lormation and set bell to proper height

c, ~

lil

~

[ [!) Bonom p!atill9

preeent8 the end of the bottom piping in

Curing.

LY

~i-

"

~

[>--0>

-J;Ri G

CARGO PH'I NO SYSTEMS

connected to th e sta rboard main through the bran ch line. Many new f!lE'l!l arE'equipped with two bellmouths that operate through a 8ingle ::.: a!l seen In figure 4· 1. Loop (Ri n g Main ) Another type of bottom piping system commonly se~n on barges and cer, tern d edicated ..........0 carriers is a loop or nng mam. Fi gure 4-3 iIIustr.t ~.. . . . I h ea toop system in which the piping ":lnsln a conunuous eire e t roughout the bottom ofthe vessel. interconnecting the cargo tanks an ~ pumps. A loopar, rangement is s uitable on vessels where cargo se grega tio n ill not a critical factor such 88 cru de-oil carriers . In Iaet, some large r-crude-oil vessels are designed wit h minimal bottom piping in the cargo tanks. Th is a rrangement is common ly referred to as a free-flow vessel. Cargo flows through the bottom ofth.e t~n k s via remotely cont rolled sluice gates in the bulkheads . As t he vessel IS dIsch arged and de. velops a tri m by th e ste rn, cargo is directed to the bellmouths located in the aftermost ta nk. Only a short run of bottom piping is therefore needed to connect th e hellmouths in the after cargo ta nk to t he pumproom. This significantly reduces cons t ruction costs by elim inating a major portio n of the large diam eter piping th at wou ld otherwi se be necessary.

Piping Details The dimen sion of t he piping is usually dictated by the size an d capacity of the eargo pum ps as well as the anticipated loading ra te s of t he vessel. Coastal tankships and ba rges generally have ca rgo piping ra ngin g from10 to 14 inches in dia meter, whe reas the piping on large crude-oil carrie rs can reach 24 to 36 inches in diameter. The proper support and anchoring of the bottom cargo piping can be seen on the vessel under con struction in figure 4-4. The cargo piping is us ua lly constructed of steel or equivalent material (carbon steel) although vessels carrying certain p arcel s may require the use of special material suc h as stainless steel. The schedule of th e piping (thickness of th e pipe wall) va ries wit h the service in whi ch it is employed-cargo, inert gas , or va por . Federal regulation stipulates that cargo piping must be tested eve ry yea r hydrostatically and a record of such tests must be main tained on board . . Cargo piping sections are connected t h roug h the u se of bolted flanges or slip-on (Dresser ) couplings. Bolted flan ges (fig. 4-5 ) a re employed to connect successive lengths of cargo piping; how ev er they do n ot afford the degree of flexibility necessary to handle the bending st resses of t he vessel or the thermal variances of the pipe . Slip-on couplings. on the ot her hand (fig. 4-6). provide a leak·free method of connecting piping without the need for flanges . These couplings accommodate cha nges in te mperature as well as ~he bending of the vessel (te ns ion and compression forces) that occurs dur~ mg cargo operations and at sea. Som e ope ra tors h ave experienced problem:; I

Figure 4·4 . Large-diameter bottom cargo pipingin one vessel un der construction. Courtesy Jeremy Nichols.

.

r• •

'"

--

II • • .

--~. ~: " . p-

-

............- .... . . :I' . . . - ,-

z: :',

'. -

.-. - -- .; ..,;-~='-'- -

'- ., . . .: , • \

Figure 4·5. Cargo piping secticne connected through the use of bolted flanges. CoUrtesy International Marin e Consultants (lMC).

CARGO PIPING SYSTEMS

10

wIth ,dip-on couplings (fig. 4·7) due t? excessive mov ement of t he piping and dt't.t,noration of the gasket matenal cau,sed by t~e cargo. Anot her ap. proach to welded piping connections is t he tn.staliatlOn ~r loop s or bend s that allow the piping to expand a nd contract without causing undue s t rai n or possible fractures .

DE CK PIPING The above-deck piping generally consists of one or more d isch a rge mains eonnecung the cargo pumps to the athwarts~p's ma nifold piping. The cargo manifold is the bitter end of the on-deck piping th at forms the inte r. face between the vessel and the shore facility. The manifold is generally located amidships and equipped with valves and blanks. It is considered sound practice to always close the manifold val ves wh en there is no active transferofcargo. Securing the vessel piping in this manner is a pr ecauties. ary measure against the possibility of cargo movement (gravitation) when the transfer has ceased. The end of the manifold piping is fla nged to pennit ~nnection to the shore facility via flexible cargo hoses or mecha nica l loadmg arms.

Dre sser Style Pipe Couplings 'Oresser" style couplings are widely used lor connecting piping on board company vessels because they provide the fleltibility necessary to withstand stresses caused by Bltpansion and ecetracnon during temperature changes. vesselmotion in a seaway. andvessel vibralion.These ereesareabsorbed without damage to the pipe or leakage at thejoint so long as the Dresser couphngs are property lilted and well maintained. Unlorlunately, Oil spills have occurred on board company vessels in the pastdue10 Dresser couplings rupturing or separating

Many of thesespills happened because nearbypiping was notpropertysUPpOrted.allowing e~ssive

motion at the coupling.

Dresser, style couplings will not maintain an oiltight seal or holdpipesections together it pressunzae Without the pipe being clamped or secured on EACH SIDE of thecoupling. T.herelore,neverpressurize the line it the pipe is nol secured andfirmly su~orted on both siCkls 01 the flexible seal The mas ter should be advised of any repairs requiring the. removal. 01 in.hne supports so that ~pprOPriate precautions can be taken. Dresser couplings Will alsofall ~ thepipe is not straight, so always align the pipe properly when lilting newcouplings. Oil spllls are extremely dangerous and cosily, and everyettortshould be made .to ensure :~~ [hey do nol occur on your vessel. Since Dresser style couplingsare the"w~ak Ilnl( In the . . Proper Inslellallon, support, and maintenance ol lhesecouplings Is essential to sate operations.

con. neeted t h rough t he u se of Blip-on type ing u sections yin temeuonal Ma rin e Cons ultants UMC).

Fi~re 4-7. An important messa ge from one fleet operator concerning Dresser couphng. . Ccurtesy Chevron Shtppmg . . Compa ny, LLC .

CARGO PI PING SYSTEM S 6

Flange s Manifold fla nge s are u su ally const~cted in accor~ance with a national d rd to ensure a s mooth operation when m a k m g the co nnection be s~n ath' vessel and the facility . I n t he United States , t he Ame ri can N . ween hi ' h th .~_." a. tional Standards In !lti t u te (ANSI ) p u I S ~s e criteria lor standardized flanges including suc h items as the following:

l

I.

2. 3.

4.

5. 6. 7.

Inside diametRr rn» Outside diameter tOD) Bolt circle diameter (BCD) Number of bolt holes Thickness of the flange face Raised- or rtueb -fece fla nge Material of ecnetrccnon

Another recognized source dealing with sta n d a r dization of fl anges and manifolds on vessels is Recommendations for Oil Tanker .Uanifolds and Associated Equipment from the Oil Companies Internatio n a l Marine Fo-

e Tightening a bolt cilcls perway to lighlen up a ring is to take the slackup evenly \hen u TNl ~ing baCk and 'onh as shown in the draWing Don't OV8foo'lI R~n:~ilduaIy· .~e~n" can be eaSilycracked by tIghtening the boltCilCle UI'leVllI"tf' ee lhal . eser pressure on the wleoch can stnp the boltthreadsor puI out•....: a~ ....lhal a It1Ie flce SS u'" s,""

Figure 4-8. The correct procedure

for tightening a bolt circle. Courtesy Chevron

Shipping CompanY, LL C .

rum IOCIMFI.

Wh en connections are made using bo lted flange s , t he following require-

ments m ust be met:

1.

2.

Suitable gas ket material must be used in the j oin ts a n d coup lings to make a lea k-free seal . It is not advisable to double up on gaskets or to reuse them. Gaskets are gene rally constructed of a fiber or n eoprene mate rial; however , Teflon may be used with certain cargoes . When ANS I flanges are employed, a bolt must be pl aced in every other hole at a min imum, and in no case should less than four bolts be used in the connection. Be aware that company policy usually specifies that a bolt

be ins talled in every h ole. 3. 4. 5.

When usin g non-ANSI flan ges , a bolt must be placed in ev ery hole. For permanently connecte d flanges , a bolt m ust be placed in every hole. Each nut and bolt sho uld be u niformly tightened to distribute the load and ensure a leak-free se al. Any bolt ex hi biting signs of strain, elongati on, OT deterioration should be rem oved fr om se rvice.

The proper sequence of tightening a typical bolt con nection is shown in go, ii-B. When it's necessary to install a blank (b li n d fl ange ) on t he manifoll:1 ct.1ons can be found in figure 4·9 .

Couplings . ~ f 8ecunng.the . h lll~ hose ormechanica1loading ann ~ t e neet of quick-connect couplings . The t ypical qUlck vacuum relief > maximum design vacuum

The bar graph sh own in figure 5- 12 furth er illustrates the normal ope rfng pressu res and settings for PV reliefdevice s in a va por cont rol syste m, a I It is important to realize that PV val ves , like any mech anical device . canfail when ne eded m os t . Therefor e , routine in~ pection a nd maintenance areessential to en sure p ro pe r st ructural protection ofthe vessel. As part of the regulations, each n ewl y installed PV va lve must ha ve a means of checking that the valve operate s freely and does not remain in the open p0sition. For more details conc ernin g the function of PV va lves, consul t chapter 4.

HIGH /LOW VAPOR PRE SSURE PROTECTION Vapor control systems must be eq ui p pe d wi th a pressure se nsing device that permi ts the per s on-in -ch a r ge to monitor the d eck pres sure in the vessel, High- and low-pres s u r e alarms must gi ve both a ud ible a nd visual warning when a n ex t reme condition exi sts. The a la rm se t ti ngs a r e a s fol lows: High pressure a larm _

Figure. 5-11. On the ve81lel shown here, a ca rgo tank was overp res8urized whenthe ~IC faded to open the appropriate branch lin e valve and the PV valve was inopera' uve. Numerous underdeck framing member s were fra ctured and th e entire deck above the cargo tank was deformed upw ard in to a pro nounced dome. CourtesyLl. Comdr. Douglas B. Cam eron, U.S. COBBt Guard .

not more than 90 percent of the lowest pressu re relief valve sett ing Inerted ta nker

_ not less than 4 in . wg (100 mm w g) 0.144 psi

l-cw preseure alann [ Noninerted tanker _ lowes t vacu um relief va lve setti ng

1

AND VAPOR CONT ROL OPERA TI ONS E" S VENTINGSYST." •

li Z

OP~;IlAT IONS

112"

11 3

mulBling" ca rgo Buch aa jet fuel or ae sottne. the initial loading 1tic accl~ b e lim ited to minimi ze the development of a static electrical U raW tlhO c Expe ri en ce has shown that" agitation , .splallhing, and pipeline friccltllrg , l'bute to charge se pa r at ion In cert ain low-conductivity cargoes. t;On contu r it.is con sid er ed safe pr act ice to limit the velocity to each ta nk to Asa res t , I second u ntil a sufficient cushion ill achieved . A table of flow ter 1 l1\c perpondin g to a lin ea r velocity of 1 meter per second th roug h verit CIl C0 ra . 7: ;pip in g a nd also additional guidance concerning the han dh ngof ous~lze CU m ul a t ing ca rgoes ca n be found in chapter 2.

"8U

995 " Tank test head

". PV brilr. pressure sel DOin t

PV valve pressure se lpo lnl HIgh-p ress ure a larm

stat iC aC

4·

Fi nal Ga u gi n t( trol regula ti ons prohibit th e opening of a cargo tank to at.moVapor c;n . g active ca rgo transfer, The intent of th is requirement IS to sphere un~em vapor-tigh t throughout the operation. In fact, it ehould be keeplly th unnece e eye to open a tank to atmosphere during loading if a ll re. . lOla d qUIre equ ip me nt-is fu nct ioning properly.

Low -press ure alarm

55' ''''

:""':t-';;'c'~' PV valve vacuum se tpoi nt 'Ft-"~'~ 7" PV bril r. vac uum

set pcmt

Vapo r piping pressure

ecc when loading one system

~ -56

« (In of H~O) System pressure and

Figure5-12. Bar graph illustrating the normal operating pressures a nd settingsfor preesure-vacuurn relief devices in a vapor control syste m.

~

1'0 14-- -+-- t--I- -t- i - t;j

OPERATIONS This section addresses a number of th e operational concerns th at a PIC must keep in mind during a closed load in g ope ration .

Loading Rates One critical element that affects th e overall sa fety and success of VB~r control operations is the determination of max im um allowable loadmg rates. The regulations specify that cargo loading ra tes m ust tak e into BCcount the preeeure drop through the vapor piping system as well 88 the venting capacity of the pressure relief valves on the tan k. A graph reflecti?g t~e cargo loading rate versu s the pressure drop for a typical in 8talla· tion 18 shown in figure 5-13.

The maximum allowable loading r ate must be determine d and clearl~ unde~d by both vessel and terminal personnel prior t o commenccm~n ofloadmg. While loading, the vessel PIC sh ou ld clo s el y m onito r t he loa.d,n~ rates and

AAAk p

~

repure to prevent damage to the system .

dol+--+--!- +-+ -t--ti l i t i is 1-l-- -l--i- -+- t-----r- I I l":; i

selpOint bar graph

Wh

en

loadlOg

i

•

o

1,400

2,800 4,200

5,600

84 00 9.800 11,200 12,600 14,000 7.000 . , te (bblsllir)

Ov erall regulated cargo load ing ra le lank) to en vapo r heade r ssm Pr essure drop is lrom no . 1 ce nle r tan k (mos t rsmo d 55% hydrocafbOnvapor, I 0145% Inert gas an I . Pressure drop Is lor a rn xtur e vapo r ma in. 2. All port vapor header IS larthestlrom the

, . beween cargo loading rates and the Figure 5-13. This gra ph sh ows the relab on8hlPh et remote cargo tank. Regulapre811ure drop through t h e vapor pi'ping from . t e rna t the pressure drop th rou gh ,. . that ca rgo loa di109 ra es ta ke IOtaaCC'Oun . Ivee on th e 10nllllpeCify ttv of h sscre rehefva . ,apaclty 0 t e pre t he vapor piping as well as the ven , 109 tank.

1/'

• ANDVAPORCONTROL OPERATIONS VENTINOSYSTEMS

'tted to open tanks for th e pu rpose of veeeet p('r80n n('1n~ pernl! rntures provided th e following criter;ll'aug. ternp ng. 98mpling, and takmg (' II are

' ,._

... Af7l\ •DEcL.AAAnoN OF INS PECTION ADDENDUM t{!!!!f ~OPllU __

et:

2 3.

•

5.

o active transfer to th e tank. .. There,is n tnve prell8ure i8 mai rrtained . rted tank . a POSI . rn an IO~ ~ _..l k the vapor pre88ure ISreduce d to at mo spheri c Viath In a nonlnton0'0lI_

--........-

--

mp'fe cargo (ullage ) report that is completed after each cargotra ns, fep.!!ft p'roVlW an accurate accounting of the cargo on th e vessel for 1111 itA movement . From Manual of Petroleu m MeaJluremrnl art: January 1986, "Guidelines for Marin e Cargo Inspec· the American Petroleum Institute.

139

r to determin e the qu ality of th e IOllded ca r. . I 1 di 1b ,1I am pell m Ul~t be Inor de , d which ar e a na yze m a a oratory. The qUlllity . f lh ' di e cergc te ea Inc . t as the qu an t ity, a n In some cae ea even more I« I obla nllrtan '11 b di 'I ' I . n most cases ilTl...·vcsseI's crew W I not e tr eebly Involved in the sampl'Ing process but• ' the be taken to prevent pr o ems . Flf st unl es8 special ' • ,p8 can h Id b 11 " requirements st the inspector s ou not e a owed to obtain a ss m I r h p eo t e cargo eh d,'cls, te, h eargo tan k , or tan k s, h ave fini ' until t e r h U ntil ed loadin• . Second ' th e mspector OIlid know t~e contents 0 e.ac tank and whe re the liquid level of the sl! 0 faUs withm the tank . ThIS may be accomplished by providing the in. ~arg tor with an ullag~ sheet o.f recorded measurements and an escort from .pe< "ssel's crew. Third , the Inspecto r should properly label each sa 1 thev~ .. ' .. 1 h rnpie tainer. Finally, a r etain sa m p e s ould be obtainad from th e inspecto ':~t can be sealed and re tained on boa rd in case qualit y differences a ' r nse dtne 'ng the voyage or a ft er 11.... com pleti etlan. u~all1ples mu s t ~ repres en ta ti ve ~fthe cargo load ed , a nd th er efore special sampling ~U1pment ~nd techniques o~ procedures have been developed. It is routlOe for the inspector to provid e his or her own equipment . Samplecontainers are usually one-quart glass bottles that can be sealed ."ith a plastic cap or cor k (fig. 6-12 ). Each bottle is held in an assembly that allows it to be lowered into the tank to 8 predetennined level befo re the container is opened and the bottle allowed to fill. There are several diffe re nt types of sa mples. A spot sample i! 8sample that is taken at a specific loca t ion (depth ) in a tank. Uppe r, middle, and lower samples are spot samples take n at the midpoint ofthe upper third, middle third. and low er third of t he ca rgo tank. A gra b or lin e sam ple iss sample that is obtained at the header or manifold at a specific tim e during the load ing or disch arge operation . An all-l evel s sa m ple is obtained by lowering a weighted, stoppered bottle or be ak er to a point 1 foot 10.3 meted above eithe r t he tank bottom or the fre e water level, opening the container, thenraisin g it at a ra te that allows it to emerge from the cargo with the container being about 75 percent full (maxim u m 85 percent). A running sample is obta ine d by lowe ri n g a weighted, unstoppered bottle or beaker to a perm 1 foot I :

. the tank?

15.000 barrels )( 0.9707 z 14.560.5 barrels

E ter t he (volume-to -wei ght) conversion table with the API gravity 3 . n rgc to find t he a ppropria te conversion factor . In thi s case: (If the ca Long tons per b arrel

e

0.15186 or barrels per ton - 6.585 (see table 6-2 )

4 Eit her multiply the standard (ne t ) volume by th e long tons per barrel or di~de t he st a ndard (n et) volume by t he barrel s per ton. Standard (net ) velume x long tons per barrel _ long tons 14,5GO.5 xO.15186 = 2,211.2 long tons Standard (net) volume I barrels per long tc n e long tons 14,560.5 / 6.585 .. 2,211.2 Iong tons

volume correcti on factor(VCY)

The tonnage in a tank is found by e nte ri ng the appropri a te conversion table (a lso found in the API tables ) with the API gra vity of the ca rgo to dennine the stowage factor . There are two wa ys of find ing t he tonn age: Standard (net) volume

143

long tons per barrel ", long tons

TABLE 6-1 Excerpt from API Table 6B-GenE'ralized Produclll Volume Correction Factors for Gen eraliz ed Products API Gravity at 60

Temp. ( F) 135.0 135.5 136.0

13.0 0.9709 0.9707 0.9705

13.5 0.9708 0.9706 0.9704

QF

14.0 0.9707 0.9705 0.9703

14.5 0.9705 0.9703 0.9701

ndard (net) volume I barrels per long ton '" long tons TABLE 6·2 Excerpt from API Conversion Table 11 API Gra vit y

13.8 13.9 14.0 14.1 14.2 14.3 14.4

Long TOilS Per Barrel 0.15207 0.15196 0.16186 0.15175 0.15165 0.16154 0.15144

15.0 0.9704 0.9702 0.9700

1

CARGO M EAS URE ME NT AND CALCULATION

144

TABLE 6·3 Ellcerpt from API Con version Tab le

API Grat'ity 13.8

Barrels PI''' Long Ton 6.576

13.9 14.0 14.1 14,2 14.3 14.4

6.580 6.585 6.590 6.594 6.59 9 6.604

,,

if! ,, ,

-'

T. b!•• 6-1, 6-2. and 6-3 repri nted (XIU rU>By oflhe American Pl'tro leum Il\Stitu~ PrIm/tum MM8/H" rMlit Tobln - Vo/umt Corrtdion FactDnl, volume 2, 19110. '

CARGO PLANNI N G Vessel personn el normally develop a det ai led pla n (prestow)ofthe uPoom. ing load based on tentative orders and a nticip at ed cargo values receiVed from th e owner/operato r and te rminal. Som e of t he factors considered when drawing up th e cargo plan in clud e the following: Num ber of gra des an d quan tity Limiting draft Iseas cna lload line ) Vessel trim

Bending s tresses and shea r forces Tank preparation (clean ing/pipeline flu shing/d rying ) argo segregation argo compatibility Re latory requirements dlng'1pOrt and discharge port seq uence um!!fir of cargo hose 9lanns P.fg r~o handling requirements

ing can be accomplished in a vari ety of ways. Modem tank uently equipped with a cargo ca lculato r or a computer soft· that-contains the hydrostatic da ta an d characteri sticsorthe (these deviceshas improved th e cargo plann ing process by d..by saving time over the lab orious hand celcule' fth-e cargo loading programs in use today ati." rem ut certain key information when perfonmnga on 31erefore,the PIC should have a thorough.un· . process to avoid a ny cIarms · S ,Slllsl c ellIetten .. r f!e stowage of the vessel. As of this wn tl~g, . usingrab !Jthe vessel computers with vane t m r tUl;e, IG deck pressure, oxygen conten , ijj t1y from the cargo system (fig. 6-13).

-

III

j

LOAD l, INl';S AN D ZO NE LIMITAT IO NH

CAllGO MEAS UHEMt: NT AN D CALC UI.NfI(I N

146

147

The reduction cf'crcw s lze a nd th e heighten ed compk'xity or . d II ' d tlYIl!.{'rn modern vC!'Iscl s ha s neccesuetc . fi H' mcrease use of compuU'r.'l and, Hun mated ca rgo systems IHI seen III rgu rcs 6- 14 a nd 6-15 . .I UU).

LOAD LI N E S AN D ZON E LIMI T ATIO NS The load line ora vessel (its "Plimlloll m ark" ) indicates t he maxi mu m missible tonnage that ca n be load ed ba sed on th e zone (location ' per· world ) the vessel will pass th rou gh a nd t he season of the year. From the ea rliest seafaring t ime s, attempts were made to e ns u re th e sa fety the sonnel a nd the vess el by imposing strict limits on the ca rgo ca rried pee. voyage , thereby red ucing the ri sk s from overloading (fig. 6. 16 ). each

07

Figure 6-15. Depend ing on t he vessel , the cargo operat ion may be controlled on dKk, in the cargo cont rol room, or, as shown here, on the bridge. The insta llation sbo\\'11 enables th e PI C to mon ito r cargo ta nk ull ages, tempera tures, stress, draft, trim, and inert gas pressur e on a single screen. Cargo syste m valves can be operated bytouching a light pen to th e screen . Courtesy Seab Marine Electronics.

Figure 6-14. On automated veeaela. the cargo oper at ion is freq uently controlled ~om a console located in the cargo control room (CCR). Courtesy Shell intema -

tional Pet roleum .

Today, inte rnat ional sta ndards governing load lines have been implemented by th e maritime nations of th e world and incorporated into U.S. rules. When a vessel is constructed, th e appropriate load line markings are calculated and permanently etched on th e hull by an authorized classification society. In the United States, th e load lines are usually assigned by the ~erican Bureau of Shipping (fig. 6-17). Each mark corresponds to a given duplacement, or the total tonnage of wate r displaced by the vessel. This tonnage is exactly equa l to the weight of the loaded vessel. The various ~arks are identified as tropical, su mmer, winte r, and winter Nort h Atlanhe zones including sa lt water and fres hwater conditions. Due to the fact t~lltsalt water is more buoyant t ha n fresh , allowance is made for the extra linkage ofthe vesse l in fresh water this is kn own as th e freshwater allowsnce( FWAl. ThiIS sys te m of ma r king . ' permi.t s vessels to loa d more cargom . . ~glO~8 of predomin antly fair wea ther and duri ng seas ons when good se~/r can be expected (refe r to t he load line zones and seasonal chart innear the end of this cha pte r).

.. LOAn LINES ANn ZONE LIMITAT IONS

CARGO M fo~ASUREM ENT AN D CALCULAT ION

148

3 In.

I

21',

10000ard ot eemeeot

~~

I

F

These measurements to be laken trom center oiling 10 top 01eact\ line

l..+L3

uwer edge 01 hOtiZontal irIt kl pass through \he

cen19f of nng

1~

l-

149

in.

TheCllfller 01 the ling is to be placed on each side 01 the vessel at the midl:Ie01 the I&ngthas tlefr«l.-.lhe load Une Regulations. The ling and lines are to be permanelltlymar1 • the ca rgo sys tem of 8 ta nk vessel and explains th eir operation . pumps In

Ce n t ri fu ga l Pumps centrifugal pumps a re often referred to as th e main cargo pumps {MCPl, . the fact that they discharge th e bulk of the cargo from the vessel. ~en pumps have a high-volume out put which makes th em wellsuited 8S rneee . size . consridering their . cargo pumps. Centrif entrt uga I pumps a re small In :~nut and have few moving parts, which generally equate s to greater

., .1

'I I +I

Ii -2 SUbmerged cargo pump located in a sump at the bottom of the cargo Scott R. Bergeron.

162

CA HGO PUM PS

re liability lind lese maintenance, Another ad va nta ge seen wit h th o pump is its adaptability ttl a vari ety of dri ve uni ts , le a ving t he OWlS ~Y P~{)f ime 0of construe"Ion . Cent n""lUgnJ pump, nerWlth man v options at th e nme ' by a steam t urbi' ne , a n e Iectrtc ' rno , or , a hy drau d riven ran l!tc moto r Or may di ~ ' n. r pumproom, t h e d rtve ' Uhlts " afC locBlf'8e] engi ne. On vessels WIth a n a....e te . the e ngi ne room and a re conn ected to t he liqui d en d orthe pUmp via a dd,lll shaft extending th rough the bulkhead. A ga Sl igh t gla nd must be erna lonvf' in the bulk head that separates t he pumproom from t he en gin e rOOm to Yt'd ven t the movement of flammable ca rgo vapo rs or liquids bet wcl' ~~ . spaces. Whe re the cargo pumps are located in ea ch tank, th e dri ve uni t .e placed eit her on deck or i~mediately a~ove th e pump within th e ta nk. T~: mai n drawback in t~e design of a cent~fugal p~mp 18 th e fa ct t ha t it is not se lf-pri ming. Cent nfugal pumps require a continual flow of liq uid (Prim ) to pump . whic~ usually makes them un suitable for ~t~ ppi ng (dra ining): cargo tank . This type of pump does not have the a bility to reprims itselr wh en suction is lost un les s it is outfitted with a s pecial priming fea ture. To facilitate stri pping th e cargo tanks and pipelines , m any vess els are equipped with eithe r a positive-displacement pump or an ed ucto r. In a ce nt ri fugal pump, the impeller is the main r ot ating e lement that imparts e ne rgy by increasing th e velocity of the liquid a nd deliv eri ng the ca rgo to th e s hore facility. Figure 7-3 is a cutaway view of a ce ntrifugal pump showing th e location of t he im peller within the casing. Cargo enters th e eye of th e im peUer a long the axis of rotation and is thrown outward radially th rou gh use of t he swept-back vanes. At th is point the cargo leaves th e impell e r va nes a t a h ig h velocity. Through the design ofthe volute, energy in the liquid is converted from h igh- ve locity to a combination of velocity and di scharge pressure. To assist in the conversion of energy, some centrifugal pumps are a lso e qui pped with diffuser vanes within the casing. The pump impell ers ope r ate a t a hi gh speed (rpm) capable of generating considerable heat if the pump is operated impropy. Oentrifugal pumps require a continual flow of ca rgo for pr oper cooln~ internallubricat.ion, and gland sealing. Op erating thi s typ e of pu mp in e 1'tVERl. condition (insufficient prime) can result in overheating, lea ding nll lh possibility of fire. In a normal di scharge oper a tion, a v a smooth delivery and produce little noi se or vibra tion.

K INETH..: PU M PS

163

ked in suc h a wa y a ll to step up th e energy in the liquid as it ellerllilYst aCh eac h s tage orthe pump. The impelle r assembly is connected glOavell,hroUg . rti I h ft ithi h ' rve un it on deck VIa a ve rca R a Wit In t ~ discha rge pipe. Thi s edn IOWrtgePlen t ta kes a dvantage of the s peed and efficiency or a centrifuga l .rv h the pump a nd. po~ntl a ove~ ea mg. ~ 10 t e previous case, the througult f th is inequit y 18 overheatmgofthe distant pump. Pump manunet res °enera lly recomm end that both pum ps be operated at the same fad urersl speed so cloSely observ ed for a ny difference in te mperatu re. S HORE BOOST ER PUMP

boo ster pu mp is em ployed whe n th e discharge head at the terminal Ashore ' arises , . at for the vessel's cargo pump. Th ire SI'I uanon wh en th e IS too ~\s are loca ted at a considerable elevation above or distance from shore el The shore booster pump operates in series with the vessel's . h d I' the vesse . a dding ene rgy to the system and enabling t e cargo e Ivery cargo pum P, ' . h boo th I to roceed at a re a son ab le ra te . Pnor to sta rt ing t ester, e ves~e p pa typ ically exhibit a high di scharge pressur e and a poor delivcargopurn t: ~ t h uld ery rate (velocity). During the pr et ransfer conrere nce, agreemen so. be reached concerning a dva nce notifi cation of th e booster pump being brought on lin e. It is common pra ct ice for th e vess el PIC to.sta nd by the pump controls when the booster is sta rt ed. Th e sudden dro.pm the loa~ ~~ thevessel's cargo pump could ca use it to overa peed and tn p out. T~ a ~l unnecessary sh utdowns or delay s, it is essential that good communicat ion exist between the PI C of the vessel a nd the facility. Once the shore boostehr , lll b e a d rop to . th e discharge pressure on t e pump is operatmg, there will I. vessel and a corresponding in crea se in th e pumpmg rat e. AUT01\lATIC PRIMING SYSTEMS

.

' IIy emp1oys a vari The PIC of the cargo di scharge tYPICS " ety of operational ' n the tech mques ' . Iy d tacua ' sed to maintain such as those previous lve nhvaia pnrne 1d 0age or centrifugalpump. If performed incorrectly, expensive p yaica am II POtential fire hazard can re sult. I d ectal auto-

With these concerns in mind, manufacturers deve OP~h se a minimal IDatic priming features for centrifugal pumps to e autco . a ystem virflow is always maintained. With certain pumps, t~e au 7-~~~I::trates one t anyeliminales the need for stripping pumps. Figure ,I , e Of autopriming system found on cargo pu mps in marme aervic .

KINETIC PU MPS

173

-/ -- I I I I I I

-POll sa; ; ;S!

Sea Suction vll ives

I I I I I

~nll

a

GrOUP 3

Slraine r Pump suction Main ca rgo pump 3

I I I I I I I I _1- --

--

I

Bulkhead block

crcssovar valves

Crossover valves

Eng;ne room

L'" c:onUolier

eoctcn

Main cargo

Bulkhead blo< k

I I I

pump 2

Crossover valves

Group 1

Strainer

Main cargo pump 1

Pump

Bulkhead

suction

block

Sea suction valves

--

--

Separat or lank

-~~

GfOUp 2

Slrnlner Pump

--

PUITI(l' oom

Starboard

sea chest

I I I L

figutf! 7-12. One

type of autopriming syste m used with a ct'ntrifugal pump.

When th e pump begins to lose suction, a venturi activates a reo eireulation line which returns liq ui d to the st raine r/recirculation tank on the suction side of the pump. The pump is primed by the liquid in the recirculation tank, and the cargo recir culate s until a norma l pumping con-

dition is restored. At the same tim e, gases in the recirculation tank and pump casing are vented throu gh an ext raction line to the discharge side of the pump. These devices m ake it possible to discharge th e cargo tanks more completely without d amaging the pump. The y also protect the pump from damage resulting from operator erro r such as closing a valve on the 8\1ction side of an operating pump. Th ere a re many designs of self-priming ~um~s on the market; therefore the operator should consult the manufec~ !!. man ual for a detailed description of the type and method of operaIi fthe one fou n d on the vessel.

Tro ubles hooting

. umping system the problems that typically arise are rela~d to lac~ or l ack of delivery. The operator must carefully monitor carg

., 174

I>()SITlVI':- DI SI'I ..AC l';M ~;N T I'UM I>s AN\ll'; lll lL'T(lll.' hanical fail ure. A worn or damage d pump, an excessively worn impelMt c ki l d-' I .. o, . h n rauore. lea ng g an ....sea s, or a bad dn ve unit may cause ler. ea

problems.

SUCTION SIDE

1.

2.

3.

4.

S.

6.

175

CARGO PU M PS

Air or vapor bound pump. This condition generall y OCCUI"ll at eta rt_up due to improper pri ming of the pump . Centrifugal pump s must be initially primed by opening a vent at the top of the rasi ng to bleed ofT any gilt tra pped in th e pump. The casing and impeller mu st be filled with liquid at start-up or the pump will not operate. Clogged strainer. When a foreign obstruction becomes lodged in the strai ner, it restri cts the flow ofliquid to the pump, which results in a loss of suction. It is the n necessary to clean the strainer by closing the appropri_ ate valves to isolate it, draining the cargo from the unit, a nd removing the access cover. The strainer is generally composed of cylindri cally 8haped mesh designed to pr event foreign objects in the liquid flowfrom damaging the internals of th e pump . Cavitation. This results from air leaks or vaporization of the cargo in the suction line of th e pump. Refer to th e earlier discussion of cavitati on in this chapter. Insufficient g ravity head. The pump ceases to operate due to a lowcargo level in the tank. Cargo characteristics. The viscosity or specific gravity of the cargo may be grea ter th an the pum p is designed to handle. Pumping problems can also occur when the te mperature of a heated cargo is permi tted to cool to its pour point . In th e worst case scenario, t he cargo actually begins to solidify in th e tanks . Mechanical failure. Mechanical pr oblems inclu ding a worn or damaged pump casing, en excessively worn impeller , bea rin g failu re, leaking gland w's eals, or a bad dri ve uni t may cause discharge pr oblems.

P UMP CO!'oliROLS AND GAUGES

pu mps in marine service have variable spee d control. This alo Mostc arg eater to alter the s peed of the pump ba sed up on changing opIO..... s.thec~~~i tions. The pump spee d is changed e ither by local control of er8t1n~ nit or thr ou gh use of a controller from a r emote location. For the dn~e the spee d ofa d ee pwell pump on a barge is typically a djusted by elsm~ 1', the s peed of t he d ri ve unit on deck. On tank vessels equipped changlngu,o mated cargo control system, the pump speed is remotely adwith an a . Th . d ·ng an a ir cont ro ller , rheostat, or hydr auli c controlle r. I' perf h ' . Juste uet e cargo pump is monito re d through use 0 t I' 10 1\owmg formant e of 'h gauges: I.

2. 3

..

Tachometer (pump rpm) Discharge pre ssure (discha rge side of th e pump) . Compound gau ge (displayin g vacuum and pressure on the suction line ) Man ifold pre ssure (pressure at the vessel's rai\)

The accuracy of the se gauge r e a d outs is vital to an operstor when mak.ingdeeiaiona . . . . opera tion The gauges and .controls concerning t h I' pumping 1 '. arephysically loca ted a t t he pu m p or in a convenie nt central locatlon such 88 the top of the pumpr oom or ca rgo control room . The eme.rge~cy sfh uht. . ge ne ra 1\y 1oca te d a t the midpoint 0 t I' down controlfor the cargo pumps IS . vessel in the vicinity of the m anifold . All personnel in volved m the cargo operation sho ul d be a war e of t he location a n d operation of the e mergency ahutdown for the pumps.

DISCHARGE SIDE 1.

Escessioe dis charge pre ssure. Thi a may occur at a terminal with an exceeslve discharge head . It if! a common problem when the vessel pumps must deliver the cargo a considerable distance or vertical height to the shor~ tank. Check for valve malfunctions in the discharge line such as a sheared . In . t h e pump opera timg a ga inst a close ste rn or dropped gate resultmg valve .

eOSlTIVE.mSPLACEMENT PUMPS AND EDUCTORS

dt

.' di Splacement pumps section describes the different types of postli ve t the end of a el as the use of eductora to drain the tanks an mea a ischarge .

-

roSITM:'-V1SPI.ACEMENT I'UMI'8 ANIl Ent lC'"nlll.'l

•

CARGO P UMPS

176

Au.~illry

slide val\'e

Piston valve

177

. t af t h e piston creates a va cuum , thu!!. drawin, t\ vemc n . tak I F" . te ca r go mto ,"emO e va ve . IguTC 7-13 18a simpl r \." tinder throu gh a n m e· VI ew 0 a rethee)' . gpUnlp. C1 Proca~~g the d isch a r ge st roke, the pi~ton forces tho cargo out of the eylinDo h th e d iKch a r ge va lve, creating a delivery pres sure on th t\ t · tona · 1m · take an d d·I SCh arge valves are usually e ou i e def th" '"h pump. Add tt side of ~~ake these pump~ double-acting. Si~p\y stated, a double.acti'~g stalled. ne in whic h pum pm g actton occurs Simultaneously on both Bides pulllP I~ °tonfor eac h st rok e of the pump .The ne t res ult i8 a smoother delivPlS incr ea sed pum pm . · orthe . and g ca., pa~l. y. Re ciprceating pump s ar e self· t~ . meaning t hey have the ab ility to regain suction whe n suction is pnJ]1l:~ se pumps a re capable of moving the atmosphere (vapors and inert. 1051. ir ) which ma y be drawn from the ca rgo tank with th e liquid during f 31 M1.5 0final • U n.lik e-e stages of st n. ppmg. I ~ ~ntnif ug~ \ pumps, they can develop th eu nece ssa ry t o draw liquid in to the intake when operating in a UIII theva dition. The m ain disadvantage of reciprocating pumps is that they :~l\Y slow. For example. a reciprocating pump on a typical coastal k vessel gen erally h as a capacity of800 to 1,000 barrels per hour tbpb). ~ ncem when ope rati ng a pos itive-displacement pump is that th e disline is open. A positive-~isP~8c~ment pump will de,,:elop a consi~er­ abledischarge pressure if the pipeline 15 blocked or a valve ISclosed agamst

:

Slay rod

ch:

lhe pump. Pomp cylinder

R ota ry Pump Another type of positive-displac ement pump is th.e ro.tary pump : which operatesby physical ly trapping the ca rgo a nd ca rrying It ~m t~e inlet to ~he outlet. Thi s is usually accomplished through the rotatlO.n of mte~eshm~ ~ars, lobes , screws, or vanes. Figures 7-14 through 7-17Illustrate differen typu of rotary pum ps .

,Figure 7-13 . Simple view of a reciprocating pump. From Principles of Naval Engi·

neenng.

Reciprocating Pump poeitive-diaplaeement pump typically used in striPpingllervice 1E~i!ii!~.~m~.,Ia~n~,k vessels is the reciprocating pump . Th e design general1Y Dsists; oftwollislona (duplex pump) that move back and forth in eyle e d i her by steam or air. The flow of liquid to and from the UUlp'i8 ccompliehed through spring-loaded val vee. On the intake stroke, e

sueuco

.ct4. Simple gear pump. From Principl es of Naval Engin«rins·

• Swinging Iype moving venee-".; 8PH(M4')

DISCIIARGOEE~IL wAs H CRU

>",,0 0

TA J'';KS

SECREG" TED BAL LAST

FigtlJ't' 8-16. Tank barge moored at an offshore platform . Courtesy TOSCO River.

D1Rn" BALLAST

NIA

SLOPS

IdA

head .

reasonable dist ribution of weigh t over the length o.f~he vess el , thereb~ mini. mizing stress on th ehulJ an d ens uri ng proper Sla bility (fig. 8- 17). Du ri ng -the discharge of the vessel. th e PIC follows 8 number of soun d tanker pra ct ices: 1. Trim: The discharge of't he ca rgo tanks s ho u ld be arranged t o ge t th e bow up at an early stage in the opera tion. Dischargin g the fonv 8,rd

~anks

increases the trim by the stem , which aids the drai nin g a nd stnppmg of the cargo tanka. On the othe r hand , th e vessel s ho uld not be a llo wed to develop an excessive trim, 8 S thi s can cont ri bute to fal se t a nk le vel a larms,

unacceptable stresses, engine room problems, and und er keel clearsnce problemshull . 2.Pumproom.' Frequent in.pec'ion. ofthe pumproom sho uld be m.Bde

during y the dis charge operation , checking for leaks . The PIC s h ou ld penodicsll check 'he CB'go pump 88Bls, beBrings, and CBsings for When cargo pumps are operating properly, there s hould be minimal norse or vibration. No one is permitted to enter the pumproom unless the ventilatioo evstem t. OpecS'ing and a .tendby ia P'80ent 0' the PIC is notifi ed,.

ov"heBti~g.

~hould be monitored. Any abnonnal fluctuation s or Bu dde n

3. Pump pressure: During the cargo discharge, the pump and mani-

(h~

fold pres8Jltes

chsn,lle/l)m diSChs,ge Preseura WBn-Bnt B .hutdown of the operuticn . 'l'liedischs,ge pre aura of t he vessel CBn be expected to change gradually as the-shore tank are filled or when shifting tanka.

2 s.ll.

Notice of Readiness All r the te rms of a cha rte r party, the master of a vessel must present the notice of readiness (NOR) when the ves s el arrives and is r e a dy in all respects to conduct cargo operations (fig, 9- 1), The s ign ifica nce of this notice is th at , und er normal charter parties , it establishe s when laytime will begin, This simple act can ra ise se rious qu es tions and confli cts. While the NOR may be tend ered , it may not a lways be accepted . The charter pa rty clearly specifies under what condit ions-whe n , whe re , a nd how- t h e NOR is to be tendered . Common clau ses indi ca te how it mus t be sen t ft hecharter par ty clear ly specifies that th e NO R mu st he ' ~ do . ampie, h F id h "'0 C'Tc>d between 0800 a nd 1800 Monday throug nay. t en th ere is no n('ed to waste fuel and expenses to try to meet an ETA of 1900 on F riday U d these conditions, at the direction orthe comm erci al opera tor, it is P~ob:h~r more prudent to run at an economical speed th e la st few days to pi to id U an anY early Monday arriva l. :t'he s~me .1 heory.a ppItea f i es. n.der most char. ter part ies, laytime WIll begin either six hours after a va h d NOR is tendered(in the event that the vessel must anchor du e to bert h un availabil "' " ~'d ft 'yl or once the vessel 18 mooredTi . me watung l or tt es a e r the NOR is te . dered is nonnally n~t considered.as layti~e and, th erefore, is not paid f~r by the charterers. Time used dunng transit from the a nc horage is also not counted as laytime. It is important to note that the NOR should be tendered on ly whe n th vessel has a rrived at the locat ion specified by the charter pa rty Inorm alle the customary anchorage) and when t he vessel is re ad y to load or charge. U~ der most conditions, the vessel is ready to load or discha rge when she IS ready to proceed to berth. Whil e delays caused by s uch thing as port clearan ce formalities ha ve to be accepted, t her e a re no excuses if the c~ rgo tan~ are not properly clea ned or inerted. A fal sely prese nted NOR I~ not ~ah d a nd could cause signi ficant delay a nd monetary loss in the resulting disputes. >

>

As a rule of t h u.m b ,.t h e ve s s e l s ~ ou l d a lw ays pr ovide e nou gh pump,ssure t o malOtaln t h e 100 perg. Normally, t he shipowne r is FinandIngpr ally re sp on sible l'tor t h ~ diI S.Ch a rgmg ti1I1~e exce e d ~n~ twe nty- four hours when 100 paig i s n ot m amt at .ned . Exce~tt~ns to t hia include discharging of rnultiple gr ade s or t~rmtoal. r eetnctton a. A pumping log must be maintained by the ve ss el s cr e w to orde r to defend a ny pcesibl e claime in >

>

>

di;'

Cargo Hoses While ti fhth e NOR nonnall Ysets t h e tim e for la ytime to beein the dis connech . e- , Ion 0 eeea nonnally determi est of the ehipo I rmm ee t e end of laytime. It is in t he best interwner opera tor to ha th h possible after loading di h . ve e oses con n ecte d 8S long as U d or I SC arging ha s sto ppe d n er most charter parties th . nected. and disconnected b th' he ca rgo hoses shall be furnis hed, canpenae. In practical term s. [he ~ c ~rterer at th~ charterer's ri sk and ex. munal hos es WIll be us ed . If it becom es necessary to use vessel ho sumesliability for the cond~:'s, It ;~uld be done only if the charterer assponsibility for the cargo en::tt~e e hos.es. For.a sh ipow:n er/ope rato r, relp the c~go once it ha s pasfled th m.~fold rail . Anythmgthat h appen s e rer should remain the charterer's ren ibHity. >

>

thi s respect. With regard to loading , the normal rule is tha t the vessel will accept cargOat the rates requested by t he chartere r, with du e regard for safet y. The loading rate of t he vessel is normall y determined by th eventingcapacity of either the common vent line, the pressure relief valv e, or the vapor collection (emission ) con t rol syste m , depending upon which venting system is in u se while loading. Suitable reduction s ofthe loading ra te are allowed to safely top ofTt h e vessel's tanks . Prote s ts It is incumbent for the ve ssel's master to protest against violations of the charter party. This is d on e by a letter of protest. The vessel operator normally specifies the format ofthe letter orprctest tsee figures 9-2 and 9·3). Common rea son s for protest include the following: Slowloading rates (an ything less than the vessel can safely accept for loading) Slowdischarge rates (any reduced discharge ra tes ordered by the terminal or when the tenninal will not allow the vessel to maintai n 100 peig at the manifold) Deadfreight (when the terminal does not load the minimum nominated cargo quan tity) Cargo quantity discrepancies (differcnces between the charte rer's ca rgo surveyors' total s and the vessel's own cargo quantities determined by gauging) Shore connections (insufficient number of shore connections provided, or the diam eter of the hcaea is less than tha t of the manifold) Multiple grad es of cargo (multipl e grades of cargo am not loaded or discharged simultaneously)

Jahall ditch arge , u IIcargo, ee defined her eat&thltl'eOf ' respect of part cargo, from the at ill In e:\'eallel8hall maintain a minimum die-

Safe Berth In meat if not all charter parties, it is the charterer's obligation to nominate a safe berth for both loading and discharge. The safe navigation of the vessel remains the responsibility of the ma~t~r. However, if the master feels that the nominated berth is unsafe or If It does not have enough water

/JURI' fIA/IJ1/IIE LETTER OF PROTEST PROTEST OF DIFFERENCE BETWEEN SHIP & SHORE FIGURES TO

MIT

BOLERO I

16-lJ6-{)O

FROM

1ll' Mast e, of MIT Bo~ro I

I. \1'18 Mu tel' 01 MITBolero ' • hereby. on behalf of ine DIme,.. and/or dlartefel'l, protest ag.,st Itle sloW loading rate along Side your terminal ,

T,

PIlI. . . be

~ 1m ltlIl"8 iI' (J11Cf'81)8r!CYbetween ship ancl shore fig l.nts covering the IoId&d It

yOI.I temi/'IIIIlNs

,,"'"

day of

Metric Tonnes

AdU8llo8 dlflg rate was only.

M, lJ1C10£11'18 5

"'.!ric TOnne'

MIT BoleroI can receive

m' I h in Iho tank. loaded

I herebyalso eee ere. on behalf of the (HmeB andfOr charterers, the nght to revert i"llhil On bel'IIH of ltlI Owners and/of cNrtete1'1, I hereby protllSllhis difference hol din g you

matter at a later date.

retponal)le tor any IndiOI' IUclaims \IItidl may occur d ue to this difference

Yoursfa lthfu lly , the Muter of Mlf BoIel'O I

....

Youl1l1aittlflJRy.

Figure 9-3. Sample letter ofprote8t. Courtesy Laurin Maritime.

CHARTERINOAND OPERATIONS

222

n

(the vesse l t he n t he master mu st ad vise t he opera.

available for the d f a 0 tor 8 8 800n as POSSdllble:, .

/JUBINIIIA/IR1ME

'

ecommended t hat one con sult t he In te rt anko For furt her stu y. I 18 r " publicati on: "Tan ker Voyage Cha rters.

TANK INSP ECTION CERT IFICATE

Oth er Cons iderations .~... while not specifically addressed in a charter party The (ollowmg ttem a. ' should be famili ar to vesse l personnel :

.

""n TERMINAl.

cLEAN TANK CERTI FICATE

.

1 di

argo the termi na l representa tive or ca rgo surveyor

mgrt"-fi"" ~ indicating that the tanks are of su itable eleanll. 80U signsce ...... . . h This ness. is part icularl y important when the charterer requi res visual Pri "Idto .

08

tank inspecti on pri or to loadi ng (fig. 9-4).

hours LT on the

and found....". nnep. ara ticn.

• Officera' Licenses • Health Certificates • P&A Manual

• Approved COW Manual • Approved Ballast Manual • Oil!Cargo record book • Oil transfer procedures • Garbage log for compliance with MARPOL Annex V • Proofof cargo hose/piping testing • Proofoffixed and portabl e fire fightin g equipment servicing • Proofof professional servicing of breathing a ppa ratus • Proof of life raft se rvicing • • • • • • • • •

Settings for vessel's PV valves Shipping document and cargo manifest Certificate orinhabitation or stabilization of cargo Declaration of Inspection if transferring bunke rs Cargo Information Cards for the cargo on board Inert GlUI Manual Waiver Letters, if any Yt!II~1 Response Plan Safet Manual

!I!\ll!;'i!,~Operation Manual mpan II policy for upgrading and training

In addi tion, the following items ma y be checked an d should be d . • Firemen's outfits rea y. • Internation al s ho re connection • N a vi ga ti on eq u ipme nt • Charts, publica tions, a nd corrections EPIRB, pyrotechnics a nd hy drostatic releases • Flame screens, bunker tanka • Suitable paint lock er • Marine s a ni tation devic e Reference should also be made to the particular requirements of the oil majo r in specting the ve sse l. The foll owing items are of vital importance as these provide an overall impression of the vessel, and will play an essential part in how the inspection will be con ducted . 1) Gangw a y : Co rrectly a rranged-is the gangway net rigged? Ie there a life ring nearby? 2) Signs : All warning s igns posted I 3 ) Crew: All cre w worki ng on deck s hould ha ve hard ha ts and the nece ssary protection ge ar. . '2 4 ) Deck Watch: Is h e present in the area? Hard-hat, emergency eqwpment handy, necessary for cargo loading/di scharging; walkie-talkie; ask the. ~spec­ tor who he is and who he wants to se e; confirm with Duty Officer that thie is OK. One crew member s ho u ld follow the Inspector to the ship office. 5) Fire Equipment at the Manifold: Correctly rigged and present. 6) Deck: Clean, free of oil/water and obstructions. 7) Scuppers: Blocked, emergency pump in position and discha~geconnected. nnelinvolvedmthecargoopB) Cargo Information: Make su re t h a t a II perao . . . . ' being loaded/discharged, partieeraucn are briefed regarding what cargoes are lit: ularly the deck watch. All MSDS 3 to be up and easily resdable.

ali ty gogglll8 rubber I No visitors, Hazardous cargo ' 2 AA per emergency Inetructicne. This could refer to s e boots, robber gloves. 3 Material Safety Data Sheets

REVIEW

V1:.Tf ING INSPECTIONS

237

236 9) Emergency Equipment : Wor kinR', pre sent ,an d clea rly ma rked. 10 ) Mooring~: In good orde r, no lines on the wm~h ends . II I Accommodation: All doors closed, clean a nd m prope r order. The Inspection Make sure th at the inspector is accompanied on th e vessel d u ri ng the inept;(_ non.The best people to do this would be the Mas ter, Chi ef E ngineer, ChiefOf. fleer an d the First A.'lsistant Engineer (Second Engineer), who can divide the areas of inspection a mongst th emselv es Normally, t he inspector will start by checking all certifica tes" and docu. men tat ion with the Ma ste r. He will then move into the a reas listed below However , it must be reme mbered th at th e order and sched ule ofthe inspec: tion eon be cha nged to ecfueve less dis t urbance to the nonnal ope rationa onboard. The inspector will have a pre·pl a n ned inspection fonna t , which he will wish to follow, th ough th ere is not hin g to stop different sections being done in a different orde r. With the new OCIMF VP Q , much oft he da ta referring to the tanker will hav e been completed in a dvance. Ma ke su re t ha t you have a completed up-to-date copy a vail able for th e ins pector a s this will save

much t ime. I I Bridge and Radio Room 2) Cargo Contro l Room and Tank Deck 3) Engine Room and Sl.et'ring Gear 4 ) Accommodati on I Galle y

& iow an'M mMt common rkfi ciend es found in all areas : Bridge and Radio Room The most common deficiencies encoun te re d in t he B ridg elRadio room areas are related to publicati ons. • Peeeege plan only pilot to pilot. En sure tha t t he filed pas sa ge plan covers berth to berth navigation ,. Mililling publica""", ,r om Id em ditiIOns on boa ni when new publica tions

na,ye; been ieeaed I

• • • • •

Officers and ratings not we arin g hard hats on deck No screens inside the vents for the ballast tanka No ca libration gas for gas detection imtruments Crew not wearing personal proteet ron gear No policy for e ntering tanks

Engine Room and Steering Gear • No proced ures or instructions posted for foam sysu-m Emergency steering pr oced u res not posted properly in steeri ng gear room Hot work pr ocedures not used or not present in the man uals No sa fety guidelint s available for engin e room/workshop welding equipment • No eye pro tection waming noticea posted for engine workshopmschine • No clean goggles by gri nders a nd lathes ry Accomm od ati on/G alley • Untidy • Overhl'ad ventilation greas y-fire hazard • Accommodation ventilaUlrs with no idtntification labels After the In spection

All insp ectors should sit down a nd dtaeuee observations and comments after the inspection is completed. If not , the Mas ter should record 8 writte n objl!Ction that this ha s not taken place an d inform his company immediately. Additi onall y, the inspector will give the Mes ter a written list of th e cbse rvetic ne fou nd. This is a very i mpo rta nt part oftht inspection process. It is 81110 the last cha nce for inpu t before the in sp ector fill'S his re port with the oil major. Be su re to discuss everything thorou ghly. Misunderstandings can be the cause of observations. • Correct all obse rv ations as soon a s possible • Se nd the report to the head efflce or depart ment in charge • Com plete t he In specto r Feedbac k Fonn a nd send it toget her with th e report (8 copy is to be foun d at th e bac k of th is booklet ).

mg:Maliter'1 standing orders and night order book

i.~~re;i'r. gyro error t

f~ition on the navigation chart during trans it of pilota ge to

REVIEW 1. What is vetting? Why i s it n e ce s sary in the present-day transportation of cargo? . . I 2. Describe the SIRE s yst e m established by the all Compenwe ntemational Marine Forum. . . 3 , List the major areas of a vessel that are examined in an mspectlon. 4 . Why is a successful vetting inspection crucial to What are some common deficiencies identifipd ~y vettll~glI~specto~:. 5. Describe the role of vessel personnel 10 a veltmg Inepecu n.

~he vessel~

•

BAl.l.MiT l NG 01 '~; RATI O N !i

239

CHAPTE R 11

Ballasting and Deballasting Opera tions

Tank

vessels generallycarry cargo in only one direction, hence the need carry ~awater ballast on the ret,urn leg ofthe voyage. There are ex. ceptlons . h .to this rule such as parcel earners that often backl oad as th eyare dIIIC argmg cargo and ~nk barges that lack the necessary equipment to ballast. Properlyballasting a v,esse,' is extremely important; it represents a largepercentage oft~e o~rat mg life of a tanker (see figu re 11·1 ). Car eful plannmg and execuncn IS also essential when conducting eimulta db ' neous disch cargo w.tH; arge an alJastmg operations. ,to

BALLASTI NG OPERATIONS A proper ballast plan for the vessel should tak e In . to accoun t a nu mber of Iactcra:

Figure11-1.The ballast Iegofa voyage ecnstituteas largepercentage ofthe eperating lifeof a vessel. Courtesy ChevronShipping, that operators carefully devise a suitable ballast plan forthe vessel, taking into account the anticipated weather en route to the next loading port. Modern ta nke rs a re equi pped with segregated.ballast systems consisting of tanks, piping, pumps, and sea chests used exclusively for ballas t service durin g th e life of the vessel. These systems were mandated as a means of reducin g th e routine operationa l discharges of oil that typically occurre d during the ball ast tri p. Operational discharges at sea included the disposal of dirty ball ast , tank was hings , pipeline flushings, and pumproom bilges, 'The installation of segregated-ballas t syste ms on ta nkers has dram atically reduced th ese dischar ges by simply eliminating contact between oil and water. Th e minimum qu antity of ball ast carried is dictated by the draft and trim requiremen ts that are conta ined in Regulati on 13-2(a), (b), and (c) ofMARPOL 73/78 and Titl e 33 CFR Part 157.10which stipulatethe following: Minimum draft amidships '" 2,0 + .02 (length ofve/lsell in meters Maximumtrim", .015 {lengthofvessell in meters Full propeller immersion The rules further state that a vessel must comply with these requirements during all phases of the ballast passage. The segregated .ballast

240

BALlASTI NG AND

DEBALLAST ING OP ERA TIO NS

, jl.ely located a round th e ca rg o a rea to minimize tanks must also be proft c(Jr : n or grounding. Th e total a mou nt of ba lla 8 t pollution in the even~o~co ISd'".ftand trim requirem en ts is ge nerally co the rnlm mum r d " n, neede d m mee t II t COnditlon. Adver se or etenora t mg Weath ballast trip often necessita t e taking :r stdered a fair-weat her b? 8 S th conditions offshore d~~17:st additional ballast car~ed in one or rnor~ storm ballast. Stonn ._ special handling or dis pos al at recepuon k hich t hen requrre cargo tan 8 W I I term condition. the vessel ma y carry 50 pe rcent or facilities as hore. n as . b II t more of the deadweight tonnage m a as .

i:

BaUs st System Con figurati o ns yetem on a tanker generally fall s under one of The segregated' ballas t 8 d b II . I desi In most case s the segr egate - a ast system con. three possib e esigns . ' . h . 11 < II . f . f ·ng tanks( fig. 11-2a ltha teIt er partta y or ru y com. sists c a senes o W1 d tnm requi ts A I . -

the shadow. PORTABLE WATER.WAS HING

Although pennanently mounted tank cleaning mach ines a re becoming re prevalent in new construction. portable ma chines still pr edominate in smaller vessels. Aportable tank cleaning machine (as shown in fig. 12-4) is used in conjunction with standard 2lh-inch tank clea ni ng hose connected to a hydrant on the supply main . Seawater is delivered to the washing machines from a tank cleaning pump. The temperature oft he wash wate r can range from tha t ofthe ambient seawater to as high as 1 80~F if a heater is employed. Th e supply pressure to be maintained at the machi nes on deck is a critical param eter th at varies considerably fro m one machine to another; therefore. the manu facturer's manual should be consulte d for the correct value. Modern tank cleaning machines operate at lower pressures than their pr edecessors. soa standard value is difficult to assign; it can ran ge from 100 to 180 psi (7 to 13 kgfcm~). The correct supply pressure is cri tical to the success of the wash operation. as it affects thejet length and the cycle time of the machine.The cycletime represents the time necessary for th e machine to rotate thr ough all th~ angles ~t a particul ar location in a tank . Th e cycle time for portab le machines ~anes depending on the manufacturer ; however, cycle time on most machines averages approximately thirty minutes Since most portable machines are driven (powered) by the washing medium. ins ufficient supply preeeure results in slower machine rotation whi ch has a n adverse affectl,on the wash. 1 ,e machinea should be electrically bonded via the hose to th e ta nk -e e8ril ~ supply main. Safe industry practice dictates that the tank clean",,,,,,,!n~g~ ~ted for continuity in a dry condition and visually in spected to use. A meaSured resistance exceeding 6 ohm s per meb'r ejection ofthe hose . The tank cleaning hoses should n"d arecord ofthe test results maintained on th e vessel.

TANK CLEANING OPJo: llATIONS

257

256 . hould be made up pr ior to loweri ng t he m~ch i no in to the All connectIons S t d to th e hose a nd the hos e IS conne ch'd tn hin e is conne e e "' " tank-the mac. I 1 . the machine to t he fir st drop (level ) in thl' the hydrant pncr to. owe~ngld not be broken un t il the operat ion is Corn_ tank . These connec.tIO~S 8 ouved from th e ta nk . To facilitate d raini ng the plete and the m8chl~e IS mer ation is complete, a bleeder va lve s hould he hose after the c1e8~mgl ope;ned to break th e vacu um, t hen resecured g opened or the.coupbdn OO'assembly is lowered into t he tank (fig. 12-51 Th rnachme an h ose d t: . I d e . . th deck' it is typ ically 8upporte on a lair en called a through openin gs In e , saddle . h. rally have a fitt in g to wh ich a ta g line is connected . .. The mac mea gene . II . , .1. . _ han'"ng the position ofthe machine as we a s Setu n ng It This ISC! ILa...,S C eo'

s rtic ulardrop . Some vessels ar e equipped wi . 8" 6P) aSllem bly for por ta ble wa shing cperatir, ith aspecialhose reel (fig. )2h di . 'Ins. The ta nks are was e, m a lien ee of drops with the m ' .. ch level for the s pecified cycle time of the m hi ~chme rema mmg at eS-The numbe r 0 f d rops a nd the amounlof tiac tne orin scma cases 1onh ff me Spent at each drop can ger. vary based on a n um er 0 rectors mcluding the foliowinJl:; 1. 2. 3. 4. 5. 6.

7.

E):perience factor with the cleaning Operation Tank size an d i.ntemal configuration (complexity) Time ela psed since the lallt cleaning operation Previous cargoes carried Coated or mild steel tanka Hot- or cold-water was h Rinsing or full was h

Th e nu mbe r of lan k cle aning ma chines th at can be operated simultaneously is usually dep ende nt on the dime nsion of the supply mai n a nd the ability to maintain the desi gn pr essure at the machine. A typical ta nk cleaning error occurs when per sonnel a ttempt to operate more than th e recommended n umber of m achines simultaneously. As menti oned ea rlier. thi s ca n result in low supply pr essu re leadi ng to slower machine rotat ion and in adequate jet length . Operators should be mindful of t he limitation s of the cleaning system th at can influ ence the effectiveness of

.

ended in a ca rgo ta n k on a fair-

2·5. Tank cleaning hose and machine suep Iffi a saddle .

TANK CLEANING OPERATIONS

258

259 th -dryh ato p the ac cumulated was h water r, de °xe rato r should stop the W~8 ',~n use. • an re Ut e the number arma. du ne . th The use of coa tmg:s on e ta nk RUrfael's (fo ~ t ok bol to m . S hould a buildup occu

. in re d u ci n g the ti m e and effort nece esa r e.: am pie, epoxYJis very ef_ l1ve l fec oat ings also re d u ces t h e qu antity . of scale ry IN Cean a ta d . nk ' Th euaear C sueh k C . an ca rgo Imp d

leel of a tan . oattng manufacturers eh ld be regnate In 'hi' n ' ,>ng lim itat ion s t hat m igh t cont ribute to C~~t' "a:lnsulted for any erea h ..... mg 181 ure Typ> I trietions involve t e te mp erat ure of t he wash wale \' lea reT s d the u se ofch e mica l a d d itiv es . In a ddi tion conlact , ,8,uh PP Y Pressures, an . , . ' WI certai n typesof ~ a-oeS he ating requir em en ts , exceSSIVe stress and vib ti ...... r. ' " • ' " ra Ion can also ......ntrib ute to t he prem a t u re laJiure of the coatt nsa in a ta k 1 ,. k ti be 1 !'>u n . t ts reccm. gs regu arly inspected for evid fr >1 mended t ha t tan coa mdance wt •• ence o a nure and maintamed In a ecor a nce Wit h manufacturers' guidelines. >

>

>

>

FIXED MACHISES

The use af fixed wa shin g sys te ms with permanently mounted machines in the cargo tanks pa r a lleled .t he development of the modem supertanke r. Withth e a dvent ofla rger ships ca me the daunting task ofhow toe ffectively clean the immen se cargo tanks. It soon became apparent that the portable cleaning methods of the pas t were inadequate for the job. A number of equipment manufacturers developed fixed tank washing machines conn ected to fixed s u pply pipin g on deck. Figure 12-7 illustra tes a typical deck -m ounte d tank cleaning machine t hat can be powered with seawate r or crude oil. When com pa red to portable ma chin es, fixed machines have the advantages of grea ter throughput an d jet length , which are more effective when cleaning larger tan ks . The hi gh er out put fixed washing machi~es are ~i­ cally classified accord ing to thei r t hroughput. A high-capacity washing machine (HC WM ) is d efined as any fixed machine with a throughput exceeding 60 cubic m ete rs per h our. Fixed machines in this category were linked to the dev elopment of a significant sta tic charge in the ta nk atmosphere which ultimately le d t o t he inert ing requi remenls (see cha~ter ~~). Other claimed advantages affixe d washing systems are the reduct,~n 0 a ll !XIr and the fact t h a t it is easie r to control th e ta nk atmosphere SIOC,' ti In new construe ton. . . k openings remain close d during th e op~ra IOn. ems in their smaller e owners are now installing fixed was.h~ng syst f rtable washin g duct carriers, a departure from the traditional Ivided ir ~~ two groups: Ii e. F> txed tank washing machitoes can be divi e mro bl submerged . able deck-mounted machines and no~p~=:'n~zZle variety more distinct stages ea. Deck-mounted machines are usual y be programmed to perform th e wash in shbe tween prescribed aniPhe operator Bets the machine to was e 1 a Control unit on deck (fig. 12-8).

-

TANK CLEANING OPERATIONS

260

Twin-nozzle nonprogrsm rnnble machines a re stra te gica lly po8 1itilO n o

e~t

Nou lfJ lingle il'l(licator " \

Manual18ve' se m~ .. "anism

d

(side- or bottom_mounted ltn t he tank to reach the s ha d ow areas who h e missed by the deck.mounte d machin es. Th e shadow are a s r ep re a rc are tank surfaces that are shielded from t he clea ning jets by la rge 1mary the structural members such 88 main girde rs , stringers, tran sver:e: n orweb ma frames , an d so on (fig. 12-9), These ma chi nes a re fa cto ry set to perf

____~In ._

BO~om 8rlg1e adjuster

Bottom angle selector

Manual

raiW\ow&f lilt ing lugs

Nozzle angle indiCator

Seal dra'"

,Ol>mm

.....

Deck flange Manual

reverse Cross Shall

mechanism

Bollom angle adjuster

Impeller

,"'"

in~ G~~box and contro ls for the LavomaticSAdeck-mounted tank clean• 18

model contains a selective an: oontrol for USB with multistage

lIi t The gearbox contains (1) the in-line washing nwd turbine that. ac time and (2) the syatem of gears controlling the speed and directfo n urtesy Butterworth .

.......

CHUIlE.O IL..WASHING (COWl

263

complete wa8hin~ pa tt ern every time, cycling throu ber a nd location of tank cleaning mach' " gh all the an,l .. 10 DUroof the ta n k s u rfaces . Th e lMO rules" Inesl sd eterm· " e_ . Inedbythecov .g'te that " 8 \1hori er on zonta I an d vertical areaslor crude-OIl-washi"ng systems staent or ett «. ti 1 b d n ti are washed by diIrectimpinge_ e c tv e ty y e ec IOn or splashingof th . . m During t he washing opera tion, the machin e ~mplngingiet"" roper rota tion sho~1d be checked by per80nne~ :~t~:gll, ~c1e times, and ~es8eI8, th e smooth mternal surfaces ofthe cargotan';' Withdouble-hull shadow ar eas should mak e the job of cleaning tanks mand th~ absence of rnooth inn er bottom of th e cargo ta nk combined .th ~ch SImpler, The ~el1s or sumps should e.nhance stripping effecti:nes~ e use ofsuction uantity of mu ck and sediments left behind in the tank W~Dhd reduce th,e q · h ' It COJTe!' ~i:Gase8is confirmed, the compart~ Auipment .rJllclesn sample tubes connected if. cording to the Int ernational B (JS,GOTT): "Care should be tion .Qfi. the compartment by

phere in a cargo 13·5. Remote sa mpling of the atm oe an Mark Huber.

tank CourtelY Kelly .

282 " d th e use of resp onse curves when inh 'r prl't i limitations an ~l I " M ' n~ . 13 6 hows n Watchma n j > U t tgus onuor f rolll Mi th e readin gs. Figur e 8 MSA model 260/36 0/36 1) used for tt·"t inl.: .I~' Sa fety Applia nces (rep aces ,I • mosph eres on a ta nk vessel. ,

instr-urnen

t

i

Tox ici ty rt

t has been tested for oxyge n and hydroca r bon con t('111

Afte r th e com P8 men losive limi t ad dition al testing for the p re se nce of nn . I . t the lower exp ' ......

re a~';7 ~ alth threat ening substa nces may be necessa ry . The need to tear

tentta . y e ~ th t m"phere is usually bas ed on the ma keup of th e carforlolClcvapo . 137 I 'ead in th e space . Figure . 8 h OW S th e detecto- tubes " rsIn

goes preVIous y came t icall used to perform thi s test.

yp The ~etector tubes a re chemically treated to rea ct to t he p~esence of a specific gas in th e atmo sph ere. For example. a ca rgo tank pre viously uRCd rt commercial gasoline (regu late d ca rgo) wou ld need to be to transpc h h Th . ibl checked for the presen ceof benzene in t e atmosp ere . e pernu.5sl e ex" it (PEL ) for substa nces such as ben zen e. a known ca rcin ogen. is 'bl . di to ' . posure I tm so low ( 1 ppm)that a conventional corobus h e-gas ~n. lea r IS,not SUitable an d should not be relied upon to measur e the tox icity level In th e atmosphere. The following instrument read ings derived from IS GOTT are considered acceptable for cert ifying a space safe for workers (cold wor k ):

Figure 13·6 . The Watchman "Iultigas Monitor . Courtes y Mine Safety Appliances Compa ny fMSA).

OIygen--21 percent

Combustible-gas indicator-less than 1 percent lower explosive limit (L EL) Toxicity-below recommended/regulatory occupational exposure limits It is necessary to attain th ese readings to permit entry into a compartment without requiring external breathing apparatus . Ba sed on the tes t results of the atmosphere. personnel may be required to wear a respirator or meet other stipulated condition s for entry. There a re two cla ssifica tions jlfI atmosphere generally receives : "safe for workers" and "s a fe for hot 1X,0 k." The rating assigned to a compartment generally indicates the type f ark fua may be conducted in the space. For example, wh en a space is n a af:! for workers rating, it is possible for personnel to ente r and iii no I w k ithout the need for external breathing apparatus.

'n w8tl1ofthcatmOllpherein 3-7. Detector tubes used to performgil&"spt'Cl ~SA) . Courtesy Mine Safety Appliances Company I '

...

ENCWSED SPAC ~: ENTit y

28 4

285

d to revcnt the s pread af fire . In the Un it ed StatcR, a " III p,roperl y tr.ea~ ".Pfi aled by t he Na ti onal Fi re Protecti on AS80ciat" Bnne chemist ce . pectiIOn, a n d lR . sua nce ofe, IOn . . dI' 0rr pn-S'orm t he tes u.ng. rns INF PA) 18 requ ire ""Ihot wor k in or on ca rgo k a, fuueel 011tanks oi ,. ·ng tan and tificates w h en con d u" , . . d ' urn 8 i elin es, heating ( 0 1)S, or fitt mg~ conn ecte. ~ Il~ch spaCes. ~y ~ 1 :'8'i~ :copyofthe ma rine che misl ce rtdicate, which 18188ued afte r gu , S' D and inspecti ons ha ve been con ducted. t h e proper ears . f " . h . t" d ., t i requiri ng th e scrvt cea o a manne r erms a re cscribedin S uu eno ne he servi f . hemi Title 46 CFR Part 35.01· 1. When.t e aervrces 0 8 ma n ne c ermst a re not ll bl ch as at sea the senior officer pre sent frequently determines , d ·1 h . avana e,au the condition of a space . Company manual s etar t e reqUIrem en ts th at must be met prior to perm itt ing per sonnel to en te r a compartm.ent or conduct hot work. Figure 13·9 is a n exam ple ~f a standard checkhst used by one company to assis t senio r per son nel WIth the process of preparing a compartm ent for entry. Vessel pers onnel should also fami1i ~ ze the~selves with t he guidance contained in the Int ernational Safety GUide for Dfl Tan kers a nd Terminals and in the Nati onal Fire pro tect ion Association manual no. 306, Standard for the Control of Gas Hazards on Vessels to be Repaired . concerning entry and work in enclosed spaces.

ENTRY PROCEDURE Once a compartment has been thoroughly tested and a n entry permit issued.th actual entry procedure must be carefully executed . All person ellOv v d m the operation should be properly trained a nd must clearly ' ,. st.B:n th'el duties when it is necessary to enter an enclosed s pace. •.•.'1.:-, : demonstrations should be conducted regularly t o pr eI , , ' sl gency response and procedures regarding rescue • !mJ ~:IJ!l:a t1o IUl y,.

n

~

the minimum dlstan«" offsh ore ell MllXimuJn quantity ofeubst.ances pe rtank wh ich may be d is c h argedto th

M' Muimum concent ra tion ofs u bsta n~es (emu ~nt) in t he s hi p's wak Minimum depth of wate r at sea dunng the d is ch a r ge e

e

CARGO RE CORD BOOK

The cargo and ballast operations perfonned on a ve s se l carryi g . US liquid substances in bulk must be record ed in a n a p prove d ca: ODOlUO book. The cargo record book must be completed for each tank i gh ,record, following occur: n w Ich the L 2

3.

,•.

Loading of cargo Intern al transfer ofcargo Unloading of cargo Cleaning of cargotanks

Mandatoryprewash in accordance with the proced ure s and IP&A1 manual a rrangements

Ballasting of cargotanks ~ sdl4rge of ballas t from the cargo tanks 8_ ~BpoqJ of reeiduee to reception facilities 9. Discharge Into the f 10. Accidental or other ::c;;~::olv~ ° hresidues by ventilation a isc arge of cargo 6. 7.

As in the case of the oil record book . person in charge of the operation ,.entne s mus t be completed by the The cargo record book is subject to .a nd signed by the mas ter of t he vesse l. elate authority. mspechon and review by com petent port

303

III conttliOS d et a ile d iofor~atioo of the vessel's physica l layout a nd • m as well as ope r at IOnal pr ocedures t hat mu st be followed in a n ent :~~ to COlD ply with the requtrerneots of a~nex II of MARPOL 73n B. Th e maoual sho~ld contain ope~atlOnal inst ructions for per sonnel conductin g ca rg o h and hng , tank cleaning , h andling of slops , and the ball ast. g/deballasting of ca r go tanks . In The manua l sh ould contain the followi ng information a nd ope rati ona l \I

instrUctions: 1.

A list of th e NLS cargoes the vessel is certified to transpo rt and cargo spe-

2,

cific information A list of the cargo tanks and the nOxlousliquid substance(s) that may be

earned A descri ption ofthe equi pment and arTangement8 in the cargo system including such ite ms as th e fonowing: Line drawing of th e cargo pumpin g and stripping systems Ca rgo heating and tempera ture control system Identification of tanks to be used for slops Description of the discharg e arTangements 4 . Th e detailed procedures to meet th e stan dards for the specific vessel, in-

3.

cluding such items as: Stripping methods {cargo tanks) Methods of draining cargo pumps and pipelines Prewash programs for the cargo tanks Ballasting and deballasting procedures Procedures for the discharge of cergcwater mixtures Proce du res to be followed when a problem develops involving a deviation from the approved discharge procedure A ta ble of th e qua ntity ofcargo residue ineach tank upon completion of st ri pping opera tions A ta ble indic ating the qu antity in th e tank alte r performing th e water tee t

SURVEYS

,t~e transport of noxi

.. ous l~qu~d substances in bulk on. C tinuin ~s periodic surveys by the na g . f'o g comphanc ith WI h e insyectors ofth e WI the requirements of e port states where the vessel

~a:T.1~""!tl,s u rvey as well

The master of the vessel shall ensure the di scharge of cargo residues is conducted in accordance with the guidance contained in the P&A manual. CERTIFICATES

Upon satisfactory completion of a survey, including approval of the P&A manual, the vessel is issued an International Pollution Prevention Certificate for the Carriage of Noxious Liquid Substances in Bulk or a Certificate of Fttneas for the Carriage of Dangerous Chemicals in Bulk. Both are usually valid for a period not to exceed five years.

,r

POLLUTION REGULATIONS

30'

POLLUTION REDUCTION EFF OR T S . been mad e wit hin t he tanker indust ry to redu . . . " 'l'remendQUS st n desdhave . I ntional pollu tIOn 0f t h e m anne enVIronment both aCCIIde ntal an wn intothee following list , inel u dee coerati operatrona 1 measures ae. ~~t:8e::::;; vessel design and equipme nt: I. 2.

3.

•

5. 6. 7. 6.

C HA P TE R 15

1.£Isd -on·top Segreg9ted -bsll s st design s Shore recepti on facilit ies Crude-oil.""s shi ng sys tems Vapor control sy sle m8 Doublt'-bull const ructio n Efficient cargo st ri pping systems

In ert Ga s Systems

Pr'ewlllIh procedurt"8 and slops disposal

REVIEW 1. List the operational sources ofmarine pollution from the cargo system ofa tank vessel. 2. Describe the methods used in the tanker indus try to reduce sea poilu. tion both operationally and through vessel design. 3 Which of the IMO conventions is consid ered the m ost com pre hensive with respect to pollution or the environment? LI.!It the present pollution regulations governing the dischar ge of a 0 residues from an oil tanker. IS "special area"? nIUl of pollution are addressed in each of the MARPOL anB8..Ubstances (NLS) categorized regarding poiluF:~llb:'i~~,n tained in a "Cargo Record Book"? tafhed in a Procedures and Arrangements

I

n December of 1969 the shipping world was rocked by a series of explosions that occurred aboard three VLCCs, the Marpeesa , the Mactra, and the Kong Haakon VII. Eac h was a newly const ructed supe rtanke r operated by a rep utable company. The ph otogr aph showing the afte nnathofthe explosion aboa rd the Kong Haakon VII (fig. 15-I) is a soberi ng remind er of the potential h azards assoc iated with cleaning ta nks on a cru de-oilcarri er. Shi powne rs launched an extensive investigation to determine th e probable ca use of the explosions. Alth ough it was difficult to pinpoint the exact cause in eac h case, the investi gat ion point ed to a static electrical discharge as the pr obabl e source of ignition. Factors common to ea ch incident includ ed ste a ming cargo tanks a t sea in a ballasted condition, employing fixed tank wa shing m achin es, and tank c1eaning (center tanks) at the time of the expl osion. Th e us e of high- capacity (fixed) washing machines (HCWM ) delivering water-and, in some cases, recirculated oily-water mixtures-e-at high velocity and pressure against the cargo tank surfaces was linked to the de~el­ opment of a significant static charge. The benefits of fixed tank washing had been recognized for some time, and rather than abandon this method of cleaning, the tanker industry decided to vigorously pursue the concept of controlling the atmosphere in the cargo tanks while conducting 8 wash. It was determined that maintaining a low oxygen content in the cargo tank was the key to ensuring the safety ofthe operation. "lnert.gae," ~s it is c?mmanly called, is defined as a gas or mixture of gases contalOmg IOsufficlerft oxygen to support the combustion of hydrocarbons. . . The events in 1969 prompted the development ofmtemaLionaf tions calling for the installation of inert gas (I syswmlJ'on crud "lnerting" then became an industry standerd't il worldwide. The rules goveming..t!te design oJ!Elrati n i:l 81

I NERT GAS SYSTEMS

SOUHCEs OF INEItT GAS

'06

307

S OU RC ES OF I NERT GAS e types ofinert ga s syst ems a re in common use toda '( 11 n ' S )', (21 0 1il • fiIre d linert gaa generate ty . ' "nu ehigae eyeTh, ' stea ms h Ip (elll, ( . w TS m e ter 8 IpS and barges); and (3). nitrog en syste ms (pa rcel la nkeral. On 8tea mS~ l ps l t~e exha us t from, a mari ne boiler burnin g a residu al fuel oHresults In a m ixture of ga ses with the following breakdown (a pproximate values) : Nitrogen Carbon dioxide Oxygen

Sulfu r oxides Water vapor Soot Heat Carbon monoxide Nitri c oxide

,....,.. 1 2-14 ~

2-4 % 0 .3%

.%

300mf)m3 200-3000C 1,000 ppm 400 ppm

Th e exhaus t is dra wn ofT t he uptakes , processed in th e scru bber, and deliver ed via h ea vy -du t y fans to th e ca rgo ta nks . Figure 15·2 shows the typical la you t of a n IG sys tem on a ste a mship.

---

. ."gy

15-1 Theaftennathofth

.

OC uJfi(i durlng!.he te k I e e~plo8lOn aboard the VLCC Kong Haakon V/l n c eanmg P-" . 6a e roceaeon t he balla st pas sage. Courtesy 1 apPeued 8S regul ti . 1 19'7 Th ... a l,on 62 10 the Safety of Life at Sea srge ~de Imh.at merting requirements were obvie earners that were employing fixed wash-

U li!!:@a;'tan ks. The success of theBe Syste ms in the to xpa n810n . . orthe iner'ting requirementB to 8 ele o(amaller tonnage.

Figure 16-2. A block diagram showing the major components of an inert gee eyetern . Courtesy Richard Beedon and Eric Mo.

SYSTEM COMPONENTS

INERTGASSYSTEMS

309

808 ti owners are installing oil-fire d inert ga s gen ron. . d h erato Jn new construe h.n IOwarddie!lel propulsIOn an t e custo mer s' d re ult ofthe s I . k . crnshd as a res • lit ~ inert gaB. On parcel tan era tr ansp ort mg ca tgoes a (or better qua . Y ' .0 0 concerns over quality assurance h ave led to ' h ~n­ euve ttlcontamma I , e in. stallation o( nitrogen syatems.

GENE RAL REQUIREMENT S FOR AN INERT GAS SYSTEM The inert gas system must be designed and ~perated as necessa ry to rnain_ tain the at mosphere in the cargo tanks In a nonfl a mm abl e condition throughout the operating cycle of t he vess~1 unless the tanks a te gas free. Regardless o(th e type ofi nert gas system Installed on th e vessel, it should be capable o(supplying a gas or a mixt ure of gases with an oxygen contt'nt 0(5 percentor less by volume. This enables the operator to mainta in an oxygencontent of8 percent or less by volume in the cargo tanks. Th e onboard IG manual should always be consulte d as some companies and te rmi nals havemore stringent requirements concerning the oxygen lev el to be maintained in the cargo tan ks.The ot her general requirem ent for the IG system relates to the operator's ability to mai nta in a posit ive deck press ure at all times. Thepurpose o(tms requirement is to prevent the ingress of air that couldpotentially compromise th e inert status of t he ca rgo tank or th e en~re vessel. By regulati on, the operator mus t maint ai n a minimum of 4 inches(.100 mm) water gauge (wg) during the oper a ti n g life of the vessel. ~e U~ted States rules concerning inert gas sys te ms h ave been barmoniaed ~th the SOLAS requirements to eliminate t he discrep ancies that onceexisted between t he systems found on international an d domestic vesta r;fer to Title 46 CFR Part 32 .53- 10). It is important to realize that I~ e past twenty years, the ru les governing the de sign and opera tion of m~ have been amended several times as operators gained more exth thes~ eyeteme. To stay abreast of any changes that have been l~temi1,.honaIlY, operato rs sho uld cons ult the appropriate manu-

oiler -uptake va lves or flueGiant wh en it is secured.

These valves a re ~ocated in an ex~re m.e!y host ile environment-hot, dirty , lllld corrosiv e. ThiSca n affect th eir ability to maintai n agastight seal. It is mrnended th ese va lves be operated on a regular bWlis and sootblown to ""'ure proper operati on. Some manufacturers have opted for an ..·••eea1 ellS' . I·ieu c f a tt empt im gto~ atnta i n amechani cal se alattheup• ~ arrangem entm take valves. Th e s~otblowers on th e boiler should never be operated in con'unction with the in ert gas system; the refore, interlock s are installed on ~e uptake valv es to pr event s uch an occurre nce. Fr om the uptake valves, the hot-gas inlet line dir ects t he flue gas to the base ofthe scrubbing tower.

Up take Bell ows Toaccommodate the thermal vari ances (expans ion and contraction) ofthe piping during operation , an expans ion joint generally referred to as the bellows is in stalled in the h ot-gas inlet line . According to surveyors, the bellows repre sents a weak leak in the piping system; it is subject to meta l fstigue and holing ove r time, possibly resulting in air leaks in the system. Sc rubber The scrubber is the primary processing unit that converts the hot, dirty, corrosive flue gas into a usable inert gas which can be safely delivered to the tanks. The scrubbing process has four functions: 1.

2. 3. 4.

Cooling Removing the solids (soot) Removing the corrosives(sulfur oxides! Removing entrained water

Numerou s scrubbe r designs use varying method s to accomplish these functi ons; therefore, the manufacturer's manual must beconsulted for the details of the unit on the vessel. In a typical wet bottom scrubber (fig. 15-3l, the flue gas ente rs t he base of the tower through a wate r seal. AB the. gas bubb les t hrough the water , it is initially cooled and the larger soot particles are removed This initial cooling is very important as It causes the corrosive sulfur oxides to be flush ed out of the gas while it p~es throug~ :: g seal water and seawater sp rays. AB the gas moves vertIcally t hrohu f . fb m t eye tha t clean se t e gas 0 tower it passes t hro ugh a se ries 0 a ea or r . , . ta t of t he gas with t he sea wafi itiee i th the fine r soot particles. Th e cont muous can c . I· t· and removal 0 rmpun res m e ter epraya results 10 further coo 109 ac Ion . I f gas At th e top of the towe r (outle t) th e final process m;ol;es re~ova 0 ph; sical water droplets from the gas . 'ryte first met~~ 0 :m~::;s~; tr ained water is accomplis he d by pesamg th e gas roug ~ I d rewhich ca uses the water to condense on th e cellula r-lik e matena an I main in th e tower. In the second method, th e gas moves through a cyc one .' ti on throwing th e water . . or vortex se parator whi ch imp arts a spmn mg ac ,

SYST EM COMI'ONF:N TS

I N ERT GAS SYSTE M S

310 scrubber-typlcallllYOlll

- ... Hoi 085Inlel

,- - ...... , -- -+

,

,,,

:

r

!

Demister

•,

Gas oullel

,, ,

•

.

- ...'\ -rrr-

.

," .. : .. , ' ,, ,,

,<

.

Ii- , • ' --

seal

.<

.....

....

I

Weir

311

In e rt Gas F an !'! The next. major com po~ent in the system is t he IG fans. Two inert gas fan s are rcqul r~d , the c.ombme d ca pacity of which must be rated at 125 percent ofthe ma ximum discharge ca pacity of all th e cargo pumps that can beoperaled simultaneously. Th e inte nt of thi s requirement is to enable the opera tor to m~in tain a positiv e deck pressure t hroughout the cargo discharge. Installat IOns va ry, but most owne rs opt to exceed thi s requirement by installing two 125-percent-rated fan s. The advanta ge claimed for this arrangement is that if either fan fails, it would not adver sely impact the discharge operat~on of the sh ip. The IG fans are typically driven by heavy-duty el ectric motors and equipped wit h isolation valves on the suction and disch arge sides. The fan s should be visually inspected on a regular basis through ports located in the top of the casing for evidence of deteri oration s uch a s scori n g, acid damage. and carbon buildup . Duri ng operation, the fan should be check ed for excessive heat and vibration . Upon shutdown of the system. a freshwate r rinse of the fan blades is recommended for a period of fifteen to twe nty minutes. On the discharge side of the fans . two sensors a re req uired, one for monitoring t he temperature of the gas an d t he othe r for monitoring oxygen conten t. The alarm sett ings are as follows :

Drain to overboard

Figure 15·3.lntemal viewahowin lh

tesyRidlardtl --d Dell

.

g

onand Ene Ma.

e componenlsofawet bottomscrubber.Cour.

d~plet8outwardintoafunnel_ h

..

.

thia pointthe gas is full II aped catche r where it 18 drain ed away. At important to real,' th y proceased and ready for deli ve ry to t he deck . It is ze et t hescrubb d . or the undesirable elem ts i h er cee not achieve com plete removal Overti . en 10 t e gas . me, detenoration of th pected based upon th ee 1Ii . e components in a n IG syste m ca n be externaI surfaces of th crency of'the ecru bbi109 process. To protect th e 'memployedagainstth. e se~bber. either special coatings or liners are t ureamust be carefullcorrostve elem en 18'In t h e gas. The anticorro sive fee. ber8hell. Uponahutd: 1n8P• to ensure proper protection of the scrubr t hcted flush . seawaterwnc e eyete i recommended the scru bber be fl ed WIth f . m.rit 18 ._ue-gll! SY8tem8hes lIh~wn'• tPhenod of 30 to 60 minutes. Experience with ...,nance 18 · t he key to ... . n and preventive mam. . at rou t m e" me. pectio ~Ia nt . enalln ng aefe, unmterrupted . ope ration of the IG

\lii'i;l;';~l.l":ll. gth (.

Fresh_Air Inlet Which p . P anta have a fresh -air in let on the sue errnita the s yetem lIl1ureorvacuum condl_ ~IOn.

.

f m theoverp l'fllsuriutio n of num ber

Figure 15-12. Damage to th e dl.'Ck resulting ~ilS 8 Cameron. U.S. Coast Guard. 1center cargo tank . Courtesy Lt. Comdr. Doug .

f.

SYST E M COM PONENTS

INERT GASSYsTEMS

320

321

DECK PRESSURE IN PORT 112"

Dl.lring ca rgo ope rations, t he deck pressur e must be carefully monitored by he PIC to prev en t the development of any extreme conditions. Following ~rc some typi cal causes of problems with deck pressur e:

99,S"Tank test head

".

Improper lineup oft he IG/vent system Excessive loading rate Excessive cargo pumping rate Mechan ical malfunctions (i.e., faulty PVvalves) Constricted line [i.e., liquid plug in the line) Cargo polymerizat ion Shore vapor recovery problems Ii.e., restricted line or blower assist)

1. PI/ bfk,r. pressure setpoin l PV valve pressure setpoint H,~pf1ISsure alarm

"

lowilfessure alarm

139'

:~F."~7""'PVvalve vacuum 1 ,

setpoinl

PVbOO.vacuum setpOinl

2. 3. 4. 5. 6. 7.

Alarm and Shutdown Features The inert gas syste m must have several alarm and shut do...."O features to protect the system in the event of a critical fault . The required alarm and shutdown features are as follows: 1.

i

(In d HPI SY51 em pressureand se!pOitlt bar graph

1 ~13

Bar graph aho\lring the typical operating pressur es and setti ngs of etdfilOOl in an inert gas system.

DECK PRESSURE AT SEA

~e l will va ry cons iderably based u pon changes F. r: enrnple. the deck pressure ca n be expected to o n as temp eratures approach t hei r m aximu m; ~ ~ typj cally drop s off becau se of t he cooler ma r Ouctuations in the deck pressure are ater temperature a n d 8S a result of 1 v 1 lfrsonnel monitor the deck pres1n i1 underway . In the eve nt the deck r; a e limi , it is gen erall y n ecessary ~ti . th e other h and . should I c e table limit, it m ay be pr es sure. "Topping S!i1IIii.ll~.~n k already in the in s r prevent any

2. 3. 4. 5. 6.

Low cooling water supply to the BCnlbbing to.....er High wate r level in the scrubber High gas temperature-U.SJIMO: 167°F t75°C) Blower failure alarm Power failure to the autoeontrolfeature Loss of water supply to the deck seal

Sui table in terlocks mus t be in stalled such tha t any fault. condit~n reeulring in a sh u tdown of t he blowers also res~ts in ;h~ clO:l:ft~~ \;:::. pressure regulating valve. The au tomati c shu own ea ure ti tern shoul d be te sted on a regular basis to ensure proper opera ron. lOG" oxYGEN READINGS

. . h PIC may encounter elevated ox· on the discharge side Dunng the operation ofthe IG system, t e l ygen readings as sensed at the fixed oxygen ana ~Z;;tennine the source of u of the fans . Should t his occur. the oper~tor m h• lgh oxygen alann sounds. h l t i action belore te ful it may be necessary t h e oxyge n an d ta k e ccrrec we . a!ity are an succeee • . . r b placing th e system 10 reIf t h e efforts to tmp ro,:e gaa.qu to divert the ofT.s peclficatlO n gas eit he / . al causes of elevate d OXYcircul ation or vent ing to at mosphere. Some yprc gen readings include the following: 1. 2. 3. 4.

Poor combustion control Low boiler load Leaks on the suction side of the fan~ Prolonged recireulation

5. 6.

Failure to secure the ai r lIell ] ll r rangemen t of t he up ta ke vlllv!.'

]acement met hod!'! a re routinely perform d . r~P and di spla ce men t . Whi ch method a pa.,~ Ion inerted vesse ls: dilu• ICU ar vessel I . tlOn emp oys 18 dicted by the su pply (entry) a n d ve nt ing (exit) ta k ar rangements of the cargo tan s.

Faulty oxygen a nalyzer

EMERGENCY PROCED UR E S

Dilu ti on In the event of a tota l failu re of th e inert ga s plant to d elive r the ro . ..,qu1ted . . h d k h

quantityorquahty oflOert gas to t e ec , t eoperator of t he sys te rn take certain actions. Under domest ic ru les, t he operator is prohibited ~ust

allowing t he creati on ofa l1amma ble a tmosphere in the ca rgo tanks ' th ere rom fore, it may be necessary to suspe nd aUcargo operation s a n d hold thO d . . rd e ueek pressure m the vessel. In othe r wo 5 , th e ope rator mus t n ot comp . the inert status ofthe vessel by resuming the ca rgo disch arge wjth:~I:

benefitofthe IGllystem. Several safety concern s, particu la rly in th

U

e

crude tankers, warrant this actio n . Also, local a n d terminal requ i e caSe of hibi h . f remen ta may pro It t e resumption 0 cargo opera tions . The followin g li t •• fth I ti I · .. IS repro. sents some 0 e po en ta igmnon sources t hat may pose a th t h

safetyof the operation: I.

2. 3.

The dilu tion (mixing) method is accompli shed throu h th . . hi h i ' , hievi g e introduction of gas at Ig ve DCI y, a c ievm g maximum penet ratio . to h and cons iderable turbulence within. the ta nk atmo sp nhlnere.' Theecar~o ~k 8.100 IS to .. th e create a h omogeneous .atmosp h .here In the ta nk by thoroughi y rmxrng existing a tmos p.h ere WIt the mcoming gas . Experience with this method has shown tha t It ?enerally takes 3 to 5 volume changes ofthe cargo tank atmosphe re to ac h ieve full gas repl acement. To achieve the he, ul th d h a res te usI utr on me 0 ,t e supplyofgas isgenera Uy directedto a limited ing t h e diluti numbe r of t anks, prefe rabl y one at a time, there by achievingthe maximum velocity to that tank.

rea to t e

Pyropboric iron sulfide ignition Static generation from the IG syste m Static generationfrom the use of high-capaeity washi ng machines

The risk from an intern al Source of i iti . . enoughto warrant the SU8 . f igru Ion IS Ju dged to be significan t .h pension 0 cargo operati Sh Id WlS toresumeeargooperatiODs the . o.ns . ou an operat or ' only VIable options are (1) to fix the inerr g81l system or (2) to co Port state inspectors ~ect ~ an rnal sup ply of IG. n are in compliance with the inrart. om1exte y c?ec k tank ves se ls to ensure th ey e 109 requiremen ts .

gas replacement · I at osphere in the necessary in order to e cargo tanks . Two ga s

Di spla cement In the displaceme nt (layeri ng ) method, th e gas enters th e cargotank at low velocity, forming a stabl e hori zontal interface between the incoming and exiting gases . The gas enters the top of th e ta nk and acts like a piston pushing the exiting gas out via a purge pipe or other suitable arrange ment. To minimi ze turbulence in t he tank a tmos phere, the gas is generally directed to a number oftanks simultaneously, th ereby slowing the velocity.The displacement method u suall y tak es 1Jhto 2 volume changes ofthe tank atmosphe re to ac com plis h full gas replacement. Figure 15-14 illustr ates the typical supply and venting a rr a nge ments and th e methods that should be employe d when performin g gas replacemen t. For detailed guidance concerning t he m ethods and time necessary to perform gas replacement consult t he vessel's in ert gas manua l. There a re ge ne rally two ways to dete rmine th~ success of ~ gas replacement ope ration . One is by a n experience factor With the partl c.ular vessel. th e othe r is by te s ting a nd monitorin g th e tank atmosphere WIth portable instrumen ts . Figure 15-15 illu st rates a typical hydrocarbon analy~er (model lOOT Ga scope or Tankscope from MSAl com~only used. to venfy th at a space has been properly purged prior to gas-freel~. A rea~mg on th e analyzer of 2 percent hydrocarbons or less by volume IS ~eqUired before ventilating with air. Reducing the hydrocarbon conce~tratlOn ofthe space to this level prevents the tank atmosphere from becommgflamma,ble when it is subseq uen tly ventilated with air (gas .freed). An operator s und.er. h d . th k y to successfully controlling . . . . sta ndm g of gas repla cement met 0 S IS e e the cargo tank atmosphere and ens uring th~ ves~ells mamtamed m a nonflammable condition throughout its operatmg life.

INERT GA.'! SYSTEMS

INEHT GAS m :m:RATOH. . .' . d s give off hydrogen s e gas w pyrophorlc OXIdatIOn. Certain sou r ~ e d fi . nt a tmosphere to fonn co m bin es with rus t (iron oxide ) ID an O~ygen- e ~e th recess is reversed . ir on s ul fid e. When oxygen is introduc~ lD~ the de s~rur oxide. and hea t. o: Ir on s ul fide combine s wit h oxygen to o~ I~n 'f a n~mmable atmosphere is This heat may be en ough to cause a n exp oercn 1

·,,· .c

pres ent.

.

ed to connect a valve s ituated some dis. land 'wheel) typi cally on deck. lth n operatmg S . tance from the operator WI a tank(s )capableofreceiving cargoreslreception fa cility. Usually refers to a shore I ps from a ta nk vessel. In the ebdues (oiVnoxious liquid ac bs te ncee' ~r 8 O't can s] so include the use of tank sence of suitable tanks or capacIty uck ore, I uier mobile facilitie s. tank true e. or OUI~ . 1 d barges, railroad tan k ~o.rs, . lacement piston-type pump. Types I.nc u e reciprocating pump. A poslt1Ve-dls~ They are particularly suited as . catlng pumps. simplex and duplex rt'ClP~ riming ability. stripping pumps due to their lIelf·p h QI manifold when the flanges on etu . r. -A fitlllll:coIJlUlonly i~talled onht e ~ the cargo hosesor loading arms. n e a differ in dtmenaron from t oae

reach: rod. A s te e l rod or een ee of rods WI

GLOSSARY GLOSSARY

353

352 evtded by the man ufactu re r of a t mos phere lelllin" Ch a,«> pr nn iulHt ru ml'nt, bl t heuserto convertt h e mere r ree dim g o f an equlpmea t to ena e . to the actual concentra tion of a part icular ga~ III II llpllce: -O n

rt's""n.ff' CUn~s. Y -

.

_mo,·";",

on board" a t th e eompleticn of the disch arge ope ratio n. RO8 , Cargo .., hi h tT . te h' rotary pump. A positive-dis plaCt'ment pump w IC u I rzes m rmes m g lohl's, gealll, vanes, or screws to draw suct ion. . . runaround. A temporary (U·shape dl piece ofplpm g used to crOSHover cargo sye_ terns or groups at t he manifold. . . . R~'P. Re-id vapor pressure. The vapor pressure of a hq wd ~s determined by us ing a stan dard Reid a ppar at us. The test involves m easu~ n~ t~ e re s ulta nt vapo r press ure in a closed contai ner when a sample of t he hqwd IS hea ted to a sta n, dard temperat ure of lOO°F I3S,B'C ). It proVIdes a measure of the volatility of U

. . a liquid. soddl... A fairlead or support used to preve nt a hose from kinki ng and chafing. mg. Bending etrese caus e d by th e unev en distribution of we ight on a ,' e Mel. A sag condition is created when th ere ia a conce nt ra tion of weigh t in the midsect ion of the vessel; the deck is subjecte d to compression and t he keel is und er tension. See also hog. SCM Self-contained brea thing ap paratus. scMdul... Refere to the thickness of th e wall of a pipe . Differ ent sched ules of pipe are used dependin g on the intended use ofthe line (ca rgo, vapo r, hy d raulic, water, bunker). ~ru bbeT. The primary processin g unit in an inert gas system. Its fun ctions in clude cooling the gas, re moving solids (soot). and removing corrosives and physical water droplets from th e gaa. (J€up/Hr!weathurhd:drain . Drain lines leading from the main deck ove r the ves sel's side. These openings must be plugged before ca rgo operations commence. 1M cM, t. The n~me given to the re inforced openi ng in t he h un of a tank vessel th rough which seawater ballast can be loaded or disch a rge d grega::;.baliru/ 6yBte". A system on a ta nke r cons isti ng of ran' ks, piping, and /U' 'c uJ'dl use~_ exclUSIvely for balla st service. A segregated-balla st system hoda...,0 not nav e any mte nnI' CtiIon '0 w t he cargo system of t he ve ssel , j~~:;:he Th tank l' inte,m~ sUrface.sof a ca rgo tank s hielde d from the impi·ngi ng I' eamng ma chm t s. ' Mar f Orrf The result of 0 . f aChn~ at a particula rpo~~ng orcea (such aa buo yant ver eua gravitational) l lop tonh k deei r oca Ion upon th e bull of a vessel. elIlgnated on a vessel for th . f . ~inis aod. Ilopl. e receipt 0 tank wa shings , pipeline . '" /

~

ationaI Con.vention for the Safety of Life at S ea

~;~"" ~~;d~ OII CQD,taining. · ·5 cant amount of .s ulfu r and s ulfur "d etgm o ro

!mAuJ' I e w ) whoreh iIS c haracterized by the obj ectioneg.

s io

f . .a g'lveo volume of a substance at a stan1'1 the weight of an equal volum e of

a fl e

Ous com bustion . The ignit ion of a ma teria l t hat occurs by the genera tion

.' h e mu teri sPOfl / of hea t WlthiD.t annlth rough a n .intern al chemical reaction. The mate -

.81ign ite s Wit h ou t t he need for a n exte rnal source of ignition.

n. ,.., A s hort s ection of fla nged piping. poe!I pieces drench. An open-ended wre nch with a tap ered spike handle used for align .

~ng the bolt holes in two flanges when maki ng a connection.

,pll

t 'c ~ccu mulator oil. A poor cond ucting cargo that ia capable of developing and

sta

I

retaining a sign ifi ca nt electrostatic charge.

tic electricity. The electricity prod uced by dissimilar materials through physical sta contac t and se pa r a ti on such as the flow of cargo throu gh a pipeline. static nOflOccum ulat oT oil . A good conducti~gcargo that read ily gives up anyelectros tati c charge through the shell platin g of the vessel to earth.

STCW. Standards of Training, Certification a nd Watchk eeping for Seafarers. STEL. S hort-term exposure limit . Th e max imum concent ration of a substan ce to wh ich workers ca n be expose d continuously for a 8hort period of time. provided t he daily TLV is not also exceeded. strainer. A fitting installed on the suct ion s ide of a cargo pump to pr:event any ~or­ eign objects or debris from being dr awn into the pump and possibly damaging t he internals. . . stripping. The final dra in in g of the conte nts of a cargo tank o.r PI ~\.Og system" . , ubmerged pump. A pump specifically de signed for inB~ahon 10 a tank. It IS pa rticularly suited for multigrade vessels that requ ire enhanced segrega. rion. The pump and d rive unit are located at the ~:m of the tank . Suez max A tanke r in the range of 120,000 to 200,000 f'· . . I d i ta k todam"nthe mo\'ement o rqswash pla te. Framing member instal e IDa n

uida. 'd . bulk tanker. An y ves se l des ign ed ~ carry Iiq~ ~;~~hat ~r'\'e8 as th e opening for tank ha tch. Th e raised eoarrnng of a hate on access to a ca rgo tank . h t i capabl e of measuring the ccacentank scope A com busti ble-ga s indicator t 8 ~s . ~ _depece It isparti cul . arly . . b olume 10 an lDeI"WU f t h purging operati on pri or to t r ation of hydrocar bon vapors yv u s eful wh en determining t he succesS 0 e ga s-freeing a tank . tank top. S ee tank hatc h. fl water in a cargo tank throu gh th e . ) Th mea surement 0 ree t hl elJage (water cuts. e fi di g paste on a bob. " us e of a n ins trumen t or wate r- ~ n In . hted average- The m8Xlmum err TLV-TWA. Threshold limit value- tl me ':I~hich it is believed that nearly al~ bo rn e conce ntrat ion of a subsumc e rm el g.hour workday or 40·ho u r workers may be rep ea tedl y expose dsfo al: " nu issible eJlposure limits . . h t d ersc effect. eea workweek , WIt ou a v d ' 1016 kg). . f . ht'2 240poun s , ton fong A urnt 0 weig . , d. (1 000 kgs). " . f . ht· 2204 poun ' tall, metric. A unit 0 werg . , und s (907 kg). ecilied ulton, sho rt, A unit of weight; 2,00, 0 ~ the loadingofs ca rgo ta nk to a epee th e . ff. The proce ss of comp eh ng . ' th e transfer of cargo gIVen toppml~;e. ·lt is considered a critical op:r::~o~.~ regulations, a ny critical operaheightened potential for a spII~. ~ fthe peraon-in-charge (PIC). uoo ~ui re8 the direct s upervtSlon 0

GLOSSARY

'54

' rod ' ( 'n,rtgas into a tank alrea dy in the in ert condition Them t uctlono I h ' . ( . . the tank pressure to pre vent t e mgresa of air. with the obJect 0 ralsmg . p ' onGUS to human life. I . ( the concentration of a known or suspecte d tone- 018 . -t t t A measurem en v • 1tuU'1 Y est , . b tance in the atmosphere of a s pace . It I S usually a health.threatenmg tlU s . . gas.specifictest that is ~easured in parts per nulhon (pp m ). TPI Tonaper inch ImmerSIOn. .' . . . tro~I"!"I't bulAheod. A solid bulkhead runnwg m the athwartshl p direct ion uau_ aUy 8eparating cargo tanks. trim arm The numencal difference between ~B and.LeG. . h A fixedcontainment area (coaming eqwpped WIth gratmgs ) permanently troug installed under the cargo manifolds ofthe vessel, design ed to collect any s pill. age that 0C"CW'8 when connecting/~sco nnecti ng ho~es or arms. UEL. Upper eaplceive limit. The maomum concenrrancn of hydroca rbon vapor in air that fonns an ignitable mixture in the presen ce of an extemal scuree of ignition. Above the UEL the concentration of hydroc arbon vapors is too great (rich miJIture) to support combustion. It is also known as t he up pe r fla mma ble limit (UFL). ULCC. Ultra large crude carrie r. tJlo8r. The measurement offree space above the liquid in a tank. It is t he distance from the surface of the liquid in the tank to a reference datum on deck , nor mallythe rim ofthe ullage opening in the hatch. Reference to th e ull age calibretion tables for the vessel will give the volume of liquid in the tank (gross volume). ullage Oprnmg. Small opening in the tank hatc h on deck that serves as th e reference point for measureme nt of liquid (cargo) in the tank. lJQ~ A gsa belowita critical temperature. I!opqr tonJrol I)'Itt m. Pipmg an d equipment on 8 ta nk vessel that is necessary to ~ntrol certem cargo vapor emissions during load ing an d ballasting operatypical Installation includes vessel/shore vapor collection piping, tl !l, 142 eemple, 143--4, 198 terms, ISO uni te of measure, 14 2 volume correction factor, 143-4 Cargo hazan:i9 cotroll ivit y, 5 0 t'~~, 45

fire and explosion, 40 Oxygen defi cien cy, 4 7-8 reactivi ty, 49 toxicity, 35 , 45 Cuga informat ion chemical cedes , 40

CMmical Dala QuUk for B uIll S hipTrn!fl t by Wa ter, 37 CHE MT REC, 37 CHRIS, 37, 39 Goth of FtderoJ Rl'8 ulatio1Ul, 40 Material Safet y Data Shee ts , 37 , 278

Po€ltet Qui rk to Chemical Haz o rW, 40 Tanker Safety Guid e Data Sheets, 37 Cargo measurement. See also Gauging accuracy of, 125, 131-6, 141 calibration tables, 125, 129-31 final gauging, 113, 12. fr,e water, 129, 134, 137, 141 l[I'Oh ohaerved volume, 129 ins~ct(pn company, 122, 133-4 lightering, 137 ne tandard volume, 129, 143 quanjity, 129 ta,219_2Q in onbg IUly 13

a

term S, 125--9 total ca lcu la t ed volu me, 129 tota l obsl'rved volu me, 129 tri m corred;on s , 133 typica l equ ipment u sed , 123 ,.U 8t'l list , 13 1 vl'8111'1 trim , 13 1-3, 136 visco us cargOt's , 136 vola ti le cargoe s , 137 wllt er-in di cat i ng pa ste. 135 wed ge calcula tion , 135, 158 Carg o plan ni ng com pu te r pro gr am , 146 det ermin ation , 144-6 loadin g to rm al draft, 16S-7, 202-3 pre etew , 14., 156 Cargo report, l3 8 sa m ple, 139 Cargo tanks Indepe ndent tanks, 12 integral tanks, 12 gravi ty tanks, 13 pre ssure tanka, 13 Cargo t ransfer agreemen t to begin, 189 bonding cable, 191 cargo hoeee, 183--6 cargo i nfo rmatio n , 19 1, 193 ca rgo pl an , 182-3 cofferde me, 196 com m u nicat io ns, 187 eer mecnen a, 186, 190 cont a inm en t boo m , 196-7 de clarntio n cfinapection, 191- 2 d isch a rg e containment, 186 documen ts, 2 16-7,219-24 doo n an d porta, 196 draft re st ri cti onll, 196 200 emergency sh utd own , 187-8, 199emergency towing wires , 191 federal regulations, 18Z-91 nre-fighting gear, 191. 194 nro safety, 190 name screens, 194--0 7 202 freshwater nllowanctl, 196- , goal, 182 inert Ifns system, 191 194....5 lnaulaung OanjCt!, 191, lighting, 189 londln.ll:lI • a monlti,j _n..d i rn

portahl e elect ric equi pm~ nt, 196 pretro nl fer confe rence , 189 pum proom vi:>nti liltion, 196 repai r work , 190 118fe smoki ng are u , 190-1 n fety matches, 196 ICU Ppel1l, I86--7 lea v IIIVI'S, 191 lIt'grtgated-ballut Ir l tl' m, 196 I pill respollJle equi pment, 196 sufficient penonnel, 188 tranafe r pl'OCl'durn manual, 188 unauthorized craft 194 vapo r contro l opera tions, 191 vessel moorinp, 182, 184 warning signals, 189-90 Cavitat ion. S« alIo Pump . caURll, 168- 9 effect , 168 -ga ss ing",I68 loas oh uct ion, 17. prime tank use, 169 ~ntrifugal pum ps , &t PumPI

CG-38£ See CMm.CGI Data G"j,u for Butt SMprMni by Wall' Charte r party. 5« alto Cha rte,", ATRS (Ame rican Tanlr.tr RaI l'

utel, 227 bill of I. ding, 122 , 222. 2201 cargo h OlIeS , 2 18 cargo quantity, 2 16 cargo Ia Dlple8. 222 d ea n tank certi ficate, 222 dem~,211i

dry tank cert ificate, 222-3 fre igh t rate, 226-8 laytim e, 2 15-6 let ter of indem nity CLOI I, 224 lum psum , 227-8 nonce or re8dine.., 11 15-B pricing,220h5 prote st- , 2 19- 2 1 pumpingclauae , 2 18- 9 rate per ton , 228 role oftankennnn, 211i 811f" berth, 219. 222 terms, 211i--201 time challfl' equiv.lsnt, 228 Worldacal., 22lHl Charteror, 121-2, :l12 Chart...r ing department, 2:M ChllcWDt A..'>BATANKVOY, :1)3

Schtd-

363

INDEX

362 Cbarh'nl ft(}/Itinutdl bil~boal, 212-3 B££PEEVOY. 213

chartl,208-9 ~halll' J'8Uo•. S~ Loading rates

DUlplaremenL Sf'f'Weight Dapl'Cl!'ml"nt m"lbod (lGl S. GaB noplaa>m'nt

1 " . ubI4 hbtlltom 5. S. tJUp e IUrf~. 8ft oUo Stability defin~, 5 red uction, 3, 5 simulta ne-ous c.aTll'O discha rge and bal. Illlit , 207--8 single-h ull tons truct ioo, 3-4 Free water . SN Cargo mealureml'nt Fn' ight rate. Sn 0 1&0 Cha rte r pa rty ATRS, 227 defined,225 lum,",UlD, 227-8 ra te per ton, 228 time cha rte r equivalent, 228 Wor llb caJe, 225-6 World5ca1e CIllcuiation, 226-7 Fn'Shwatu allawance . SH Wa d lines

GM free candili on, 29-.10, 282 flammable rang.. disgram , 28-9 gu-flfting operation, 3 1 purging prior to, 31, 278 safe ",ading, 29-30, 282 Gas flfting. Sn o/s(, Enclosed space entry l'lfP03ures during. 47 fadars aJJl'CIing, 279 rued fans. 278 gas·fIft mode, 278, 310 inert gas faOll, 278-80, 3 10 mechanical Wi sh ing, 278 numbe r of\'illume changl'll, 279 proCl'U, 278 purging prior to, 278 time rl'quired to, 279 Gu ketB, 72, 83. St'l aiI/O Manifold Gaa pre55ure regulating valve lORY>. Srl' alsoInert po a utomati c mode, 3 11 barriee, 311- 2 function of, 311 inert gal genl'rutor, 326 intt'rlocu, 321 location 0(, 307 main to ntrol valve, 311 medea of operation. 311 shutdown, 321 Gal ",placement. ~ oW Inl'rt 11:" dilution [lI"tbod. 323 dilpt.cement ml'thod, 323 p i (rl!t'ing, 31, 27&-80, 310, 322

INm:x

INDEX

366 G ill TfplftCl'P'ltnl t(Onti" udJ

primary inerting. SO, 322 purgi ng. 31. 218. 322

rr irn'rti ng.322 n1PpIyand Vl'Dtlng arT1lllgt'menu , 323-4 Gauging. S« oUo Cargo meB!W't'P'll'n t

bob. 13()-2. 137 d.-d. 124 cut, 130 dip, 126 tquipmenl UM'd. 133 ~1....~r. I29.134 . 137-a, 141

inn'g!!, 126, 130

loxalion of, 131-a, 136

rubber, 78--9 ata in le» steel, 80 lui la bility,78 s upport of, 8D- l Hot work adjaren t speeea. 282 , 284 fire producin g actiona , 282 ma rin e ch em ist, 284 ma rin e (h erniat «>rt incate, 47 , 285 mu cking , 270, 282 preparation for, 270, 282 Hyd roge n sulfide haza rds , 46-7, 277-8 sour crud e, 26, 58

mlJl ual, 130,137, 316

IBC. Se e In tern a tion al Cod e for t h e Const rud~on a nd Eq uipme n t of S hips Ca rr ym g Dan ge ro u s C he m ica ls in Bulk ICS , See I nt ernation a l Ch amber of Shi p pi ng Im m edi a tel y Dangerous to Life an d Hea lt h (ID LH) ,36 IM O. sl~e In ternati on al M a ri ti m e O rga n iza-

ebeerved referenceheight, 126 opE'n. l 24 outaie, 126 reference height, 126 I't'ference point, 126 re peaw bility,13lJ-l 8OUnding, 126 8Wp Il'auge,202 tank i&Olalion riO), 316 Iape., 130-2 th ieving, 137-8 lopping off, 2011-1 u1lac'e. 128. 130,14 1 .'!for CIlt.a, 137-8 Grevi l)' tanka. S« Cargo tanh

""

Hand hOililll:. 270. 8ft aUoTank clean'

HiJb-level -.lann

mg

taUMI, 109

,lf ltiDJ , l09

eempcnenta , 308-22

tank overli1l. 109 tGItilll 115 rh· . 11'111lt \'alV'e 1HVV) S« Vtn tilli . a

~vtJto.. lO l-.1

".1Jl2 10\

Impell er. See Pumps I ndepe nd en t tanks. See Ca rg o ta nka In ert gaa a tmosp he re con t rol , 3 05 avoi dance ofthe flam m a bl e r a nge 29-31, 308, 322-3 ' harrie r, 3 11-2 block di agram , 307 boiler e xh a us t , 307

z.o

crud e-oil -washing requir em en ts 268 deck press ure, 30, 114 , 124, 3 1~2 I 327--8 ' emergency procedures , 3 22 t n lry i nto enclosed spaces , 27 5, 277 e xplo aion a , 305--6 eate rne l eu p ply o f, 322 ll"811 fre eing, 31, 278-8 0, 31 0 , 322 ll"811 quality , 3 08, 32 1, 324, 329 11"811 replacement, 322-3 gauging tanka, 124 general requirementa , 308 ullrrls a ssociated with, 48, 274--6, 277 }n l:rt gae gene rators, 308, 3 24-8, 328 Itroge n eyetema, 326-7 apecification , 311 , 321 content 2 9-30, 114 , 116 , 118 , 91268, 308,321-2

pad dinK With , 49 port s ta ll' in sp edion , 322 pf1"(:Buti on s , 327-29 primary in erting. 30, 32 2 pumping operar icn e, 168, 208 purKi ng , 31 purging proces s, 3 1, 27 8, 322-3 pyrophoric oxidation , 322. 329 ~nerting, 322 ru in , 305--6 &egreglltion of cergoes , 32 8-9 SOLAS, 306, 308 sources of , 307 atearning tanks, 270 ate llms h ipa, 259 ta nk cle ani ng 259 "to ppi ng u p", 320 Inert 11'118 fene. See al so In ert glls d ri ve unit, 3 11 inapection , 3 11 i nte r locks , 32 1 numbe r of, 3 11 positiv e d ec k p ressure, 3 11 ra ted ca pa ci ty , 3 11 rin ain g , 3 11 s h u td ow n , 32 1 Inert gas genera to rs Hoo). Setalso Ine rt gllll a ir b lowers, 32 5--6 a pplica tio n, 308 , 324 combus ti on ch amber, 325-4) contamin ati on , 328-9 ga s qualit y, 308, 324-5 , peaitive pressure sys te m, 326 scrub ber, 325--6 s u rpl us ge e, 326 Inspection company ca rgo meaa urerne nts. 141 eq ui pme n t use d. 133-4 functio n of, 122 aamp lin g, 138--41 , 222 the nnom ett'ra. 13 1 In tegral tanka . Sce CllfllU tank In tern ation a l C h am be r of Shi pping (leBl, 264 Intern ati onal Code for the eonstnacUon an d Equipm ent ofShipll CIlf1YIIIS Dangt'fo ChemicaIa in Bulk f1BCI, 10, 300 Inwma:naJ Maritim" Organir.llu on elMOl harri ..r betw.... n CfltfU llfld noncargtJ

afll ''', III Co ulom bi Ep, 7, 9 d oubl .. bottom tanker, 6 doubl hull ~U1l'1'm ..nl

367 ~IARPOL 7anB, 29B nlld-deck de aign, 7, 9 pollution Iegi"la tion 298

Sa lAS 74, aoe-e, 30s

J typea 1.11,111 containm..nt 10 13 nl "nlGl/.01IIIl Softly Guide for'Oil' TOM ""

orui T..nnlll4ll (/SGOTTJ ~ndoaed

" paDe "ntry, 27., 282. 2&1 llmmabl" range diagram 28 guldelinu for handling ~~t ' ton,44 ICIlCl'llmula·

aBO CTOM section, 15 alf" ru dinp prior to ..nt ry, 282 telItmg tank lltmO!l phefl'8 280 INTERTANKO. Sn alto VettiOll: A Guide to 1M V..llitll Proceu, 232-7 Kindic pump" . Sff Pum pa Kong Hookon V11, 305-6 Layt lme. 2 15--8. Set oUo Cha l1er pal1y Lighteri ng cargo measurement, 137 vapor balan cing, 114, 118- 9 vapor control, 114 VLCCa, 22-3 l one". 204 Line l1ush. S~ DiKbllli" opera tion Loading opera tion checiul 1.1 "tart-up, 197 cloud loading, 191 commencement of, 197 cornminiling,203 critical operati on,197, 200-1 finiahingth e, 201-2 gauge information. 197 heating coil operati on, 198-9 line dUplaceOlent, 202 loadingrste, 167 properl1 ow, 197 proper " enting, 197 .ailing ca rgo, 20 1 8Ilm plin g. 198 secu ring for eel, 202 ehutd cwn of, 199-201 sta tU8 of manifold valv ..", 197 to pping ofT, 200--1 t ran arer fa te at s ta rt- up, 197 va por contro l opera tion, 191 Loading f8 1ea . S N ,d.., Loadini Opl' fllt ion ca lcula tion of, 167, 198 facton influenci ng, 167 pro IMta , 2 19

•

INDEX

INDEX

368 L/Id line' ADS, 141 C'llitroUinll'!(lne .148

definl'd, 145--8

di,pJft~rnent . 141, 160 dock waler ,lJ o,,·an('l'. 153-4 freih", alef _1I0"'8I1re,141, 163-4. 196-7.202 iIIUlllr'8 lcd.l50 Wile allowance, 14S-9 LoadontoplLOTJ

definl'd. 2-45. 304 f.elor1l.lTectin,. 247, 270 pl'OC'f'.S8, 247, 26g..70 Lon,(iludinaJ bulkhead, 3

LOOP. S« OlTMor!! mooringll

Mid·d.'ck tanker. S ee a l flu Cnn ~ truction des ign , 7 cro~a sec tion , 9 Muckin g. Se e cdso Tank dcnninK defin ed, 270 effect on ta nk a t mos phe re, 279 pote nt ia l hazard s, 2 70 prep ara tion for hot work , 282-4 NFPA S ee a/so Enclosed apace e nt ry

infcrm etion , 274 Manu al 111 306 , 2 84

marine chemis t, 284 marin e che mist certificate. 285 Nit rogen syste ms . Sff Inert gss Nonretum verve (l G) . 3 14--6. SF(' oho Inert g~

Manager. 212 Manifold. SN oho Piping eargo, 70, 165 l.TOUingo,~r I t. 77 llangN, 72-4

gmetl,72 Jumper, 78

OC I~fF.

tnWll&lIter, 77-8, 165

quick·a mnfd. couplings, 72, 74

nduern, 74, 76 1'WWtIund. 77 ~ng o(

Not ice ofreadiness (N OR). See 01.0 Cha~r party commencement oflaytime, 2 16, 2 18 laytime.215-6 sample. 217

70,201-2

Ip:lOl preee. H . 96 V8por, 10741 ¥annr chrml.t, 284 Set alsa Enclosed spe~rnlry

L 7ana, :llI8-303. Sn ah a Poilu-

See also Vetting oombination arrier. 15 fla mm a ble range diagram. 28 oil tan ke r manifol ds. 72 S IRE,230-1 vetting, 230-1 Offsh ore moori ngs . See 01.'0 Lightering multi point moori nga , 203 platforms, 204 single-poin t m oorings. 203-5 Oil expl oration . 52-5 Oil Pollution Act of 1990 (OP A 90). 6. 7, 16, 297-8. See also Pollution 0iJ Record Book, 298-300. S~e also Pollut ion Oil tanker, 3-10. See also Con structi on Onboard quantity (O BQ I, 129, 141 Operational dischargell at sea crude carriers, 262 Load on top {LOT), 245-7 "pefllislent- oil, 262 quantity, 264 reduction of, 246 s.$gregatcd·ballaat eysteme, 239 iftfI'tea, 295-6 r I;jslls,~ 262 u e See Gaujing erfl.lI a .;See 0/110 AJarrIu!I 08 199 207 ntrol 110

f109

t" Htinll. 115 Oxygen conten t . Sf'C Inert gas OXyJo(cn dt"fici('ncy h nt ar d from ine rt gas , 40. 48 impa ir mt"n t due to , 47-8 normal level in air , 47 POrn' 1 lanke r oonstruction req uirement8, 13 de scribed , 10 · d rupto re " vessel , 10 e xte rn al fra ming. 10-1 la yout, 14 tank types, 12-3 types I, II, III a m tainme nt, 10-3 P'>nni Mible expo sure limit. SN 0 1&0 Threshold limit value tTLVl de lined,36 measurement. 282 . 292-3 Permit to Ente r, 286-7. See also EnclOMd s pace e ntry Pe rao n·in-eh a rge (P IC) cargo calculat ion, 33 ca rgo cha racteristics, 24 com mence me nt of cargo tlllllSfer , 197 commercial impact, 211 dirty ball asting, 243 fini shing cargo loading. 201-2 loading s ta t ic accumulators, 43 personal supervision, 197 s hutdown ofcargo transfer, 199-200 top ping olToperation, 200- 1 tracing pip ing, 64 Pi peli ne, 2 11 Pip in g bottom , 64 br anch , 6 6 classifi cation , 64

cons truc tion, 68 d eck piping. 70, 165 direct piping system, ~ Dre sser coupling, 68, 70-1 drops !loading), 85,165-7,207 Ilanged connection, 68-70 hydrostatic testing, 58 loop (ring mainI67-8, 163 main linea, 64 . 70 piping conned~one'8~ 197-8,206 pumproom pIpIng, ' lies la ne, 87, 172, :l(;!243-li vapor contrtll, J05-7, .. 9~104 vent plpln(, / ~-:'d)i e. PlimAlll\;mllrl/:, S#ii 4.'!'!

369

POllution Annex 110m , 298-300 Annn II (N1.8),3Q0.-.4 s Wlren(>IlS, 295 C11"K0 !le(ord Book, 303 UIoaualtiea,296 te rt ificalel, 299, 303 dispoill of cargo rt!lIidue•• 301-2 linN lind penalt iel (U.S.), 296-7 llltel'1l.ltionallegitllltion.298-303 IOPP,299 ~IARPOL 73178, 298 nsti onal legiailltion. 296-8 NLS catl'goriea, 301 Oil Record Book. 298-9 plleard,297 f>rrxtduru ond AI'ru'lgemm u ,\Iollual IP&-'l, 30Z-3 rNIuction of, 245, 248. 270, J(H I'fgUiltio",,299 llOUrttt of, '2%-6 Ilpeaallll"l'lI,299 l W"\'e).. ,302 v_ I ~ponae plan . 297-8

Peouve duplacement pl,lfllpll . S« oUo Pum ..

esparity,177 doublfIlCting .l77 dropping lines , 175, 180.209 duplex . 176 operation, 176-9 I"I'cipl'(l('ating, 176-7 rotary, 177-9 lel t·p riming, 177. 179 It ripping 162. 175, 179,208-9,268 tank clean ing, 258, 266 Pour point delin ed, 35 cargo meeeurement, 136 ht"lIting roil openl tion. 198-9 Prelllure-vacuum relief device•. Sn llhtJ Valvps capacity, III CI'O.5ll s eetion. 93 inert Il'nB syelem, 316-9 inapection and maintenance, 93, 95, III liquid PV bn'aker, 311-8 locntion, 93-4, 317 operation. 92-3, 318 pUrpoIIl!.92 atrudural damage, 110-1. &16 3ll typical aettinge 95, 111-2 Pricing, 224-6, aUu Cha~p!rty

s-c

-

INDEX

370

INm:x S toll Innovation, 10-1

s lane. Ste P iping

ProI..~t8. Sn a/MJ CharU r party d"finPd, 219

I'l'lUIOll8 tor, 219 8&D1 pJes, 220-1

vioJal.iolll of charte r party. 219 PumplOOm. Sn a/MJ Piping bilgt alarm . 196 , 199 cargotraJUJer, 191-8

t;TOSJOvtr.85, 170-2 de«ri ption,85 forward. 169-60. J 79 iJUpeoction of, 206 location. 85. 159-61 loop (ring main ) 'Y.urn, 68 rf$('\ll',87,172

eealane, 87, 112 li m ple drawing. 66 ventilation, 196, 206

"""'po

automatie pri ming lyBu rn. , 171-3 cavitatio n, 168-70

comtrifugal , 161-7 cont ro b . 175 c:nIU1lli over , 170- 2, 201 deep well, 162-6

dift'uHr, 162 dri ve Wlita, 162 nuahioll' .251

pu.g • • 175 h..d condition , 167-8 Impeller, 162-3 klndu:, 161-7 lift oolldition, 167_9,177 location, 159-62 mam cargu pUIllIM.161 mam~lIli a prime, 110

Operllt,on, 167-75

overhull:ng, 170-1 Jlfrfonn.JACe under (hartt'r 218-9 Yea, placemeot, 181 '176-9 me 162 170 '

..e'

. e tink ~. 169

r

hn

"

ube,162

Qual ity assura nce . S f't' S a mp li ng Quick-conn ed co upli ng• . 5 1'1' Couplinll"B

Reactivity. ~N! aUo Chemica l ca rgoo. compattbl llty ,49 de fined,49 In formatien , 37-40 stability, 49 Recei ver, 122-3 gedueer . SeeM a ni fold Rt'fini ng proce ss alkylation, 62 blendi ng , 63 cracking, 26 , 61 de&eribed , 5~ di6 tilla tion, 26 , 60 fra ction a ti on , 60 fractiorlll, 26 , 60 h)'drogt-na tion , 6 2 polymeriza tio n , 62 p rocessi ng , 55 l"t'fonning. 6 2 Rem a ining on boa rd IRO B ), 129 , 141 - 2 165-7. 264 '

Saah ~ radar. See Closed. gauging sya terJ\ll Sampling all level sample . 140 close d ope rations, 124 eqwpme n t, 139-40 grahIJin e sam ple, 140 , 198 procedure, 138-40 purpose , 121 , 138, 198 quali ty ees ure nce, 138 , 2 22 retain sa m ple, 139 ROB ,142 nmning sam ple, 140 s pot sa mp le , 140 Scrubber coatinill,310 CYcl~ne separator, 309-10 demlster, 309-10 deterioration of 310 efficiency of, 310 ~lI/Jhing, 310 !Dert ga.s generator, 325-6 Pl"OCeqlng of gas, 309 PU~,309

;,utine inspedion, 310 0n.ell eeperetor, 309-10 wet" tt1lm, 309-10 _die 7,172,243,253.8"eoho m

se ud ion va lvNI, 87 , 172 , 24 3 sea ' alt>d bal la s t . See als o B all a s t se~~lI'l desi~s, 2 40-2

balhu t educto r , 179-80 balla • t wa U'r ('J.ch ange , 24S-9 debllllasting, 2 45 defined , 24 3 MARPOLrequirements , 2 39 procedure. 243 pro tectiv e location , 23 9-40 rtd,udion of s e a po ll u ti on, 2 39 , tri ppin g tanks , 179 Shear forn'&· S ee Bendin g st res ses Ship In &pec t ion Reporting Exehenge {S IRE) . See Vetting Shu tdo wn . See Loadin g Operation Simulta neou&car go di &Charge and ballasting, 2 44 Single hull. See ol¥J Construction con &truction,3-5 "dry tank.: 266 tan k. cle anin g , 260, 263 Slop tank arrangementa, 268-70, 246 crude oil washing, 268-70 di &pCI&a1 of alc pa, 269-70, 3()4 du al slop tank s, 26 9 loa d on to p (LOTl, 245-7, 269-70 precautions d uring discharge, 208-9 protesting of sl ops, 268 reduct ion of alope, 264 use of, 179 , 247.258, 269-70 , Sounding . See Gauging Spills causes, 64 , 7 1, 80-2, 109 di sch a rge contain me nt, 186 preventi on , 182 respon se equip ment, 196 Spoo l piece . See M anifold Stability baUnsting, 238 ca lcu lntion of, 142 cargo plan, 144-6 during bnll llst operatiolls, 207-8 during caT1l"0 discha!1t"c, 207-8 fro" surfncll, 3-6, 207-8 0180 Electrosteue nceumulRtor cargo. $ff etotic hllw rda cargoi"e. 4 :l recaulione, 43, 113-4, 199 c