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    BONTANG FUTURE 3RDLNG/LPG DOCK:A DESIGN WHICH ACHIEVES VERY HIGH LEVELS OF

    FLEXIBILITY, SAFETY AND RELIABILITY

    LA FUTURE 3MEJETEE DE CHARGEMENT GNL/GPL DEBONTANG: UNE CONCEPTION QUI ASSURE DES

    NIVEAUX TRES ELEVES DE FLEXIBILITE,SECURITE ET FIABILITE

    Yosua SitepuTrain G and 3rd Dock/LPG Storage Project Manager

    Pertamina Projects PKPGedung Patra Jasa, 13th Floor

    Jl. Gatot Subroto Kav. 32-34 - Jakarta 12950, Indonesia

    Bertrand LanquetinGas Shipping Department Technical Manager

    Total S.A., Tour Total24 Cours Michelet

    92069 Paris La Dfense Cedex, France

    ABSTRACT

    The Bontang LNG/LPG expansion project includes a 8th liquefaction train, a 6th LNG

    tank, a 5th LPG tank and a 3rd LNG/LPG loading dock, making this plant the biggest in

    the world with a forecast of 390 to 410 LNG cargoes and 30 to 40 LPG cargoes to be

    lifted every year by year 2000.

    Given the docking requirements, the design of the new loading dock has been an

    extremely challenging task for PERTAMINA and considerable emphasis has been put on

    flexibility, safety and reliability aspects :

    - flexibility : the new dock has been designed for 65 LNG ships of all types with sizes

    ranging from 18,000 m3 to 145,000 m3and for 128 LPG ships with sizes ranging from

    15,000 m3to 100,000 m3, which is the biggest fleet ever used for a loading dock design.

    - safety : particular attention has been paid to all safety matters including : siting and

    orientation of the dock, fire fighting, emergency escape routes, prevention, alarms,

    emergency shut down and release systems, monitoring and control of loading

    operations.

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    - reliability : equipment overlap and appropriate methods of structures calculations allow

    a reduction in the risk of prolonged unavailability in case of damages to the dock.

    The present paper discusses the above in detail and various other aspects of the new

    dock design.

    RESUMELe projet d'expansion en cours de l'usine GNL/GPL de Bontang inclut un 8me train

    de liqufaction, un 6me bac de stockage GNL, un 5me bac de stockage GPL et une

    3me jete de chargement GNL/GPL, faisant de cette usine la plus grande du monde avec

    390 410 cargaisons de GNL et 30 40 cargaisons de GPL prvues annuellement

    l'horizon 2000.

    Dans ce contexte, la conception de la nouvelle jete de chargement a constitu un

    norme challenge pour PERTAMINA et une attention toute particulire a t porte sur

    les aspects de flexibilit, scurit et fiabilit :

    - flexibilit : la jete a t conue pour 65 navires GNL de tous types et de taillescomprises entre 18 000 m3 et 145 000 m3 et pour 128 navires GPL de tailles comprises

    entre 15 000 m3 et 100 000 m3, ce qui constitue la plus importante flotte jamais utilise

    dans la conception d'un tel ouvrage.

    - scurit : l'accent a t mis sur toutes les questions de scurit, incluant la recherche du

    site optimum, l'orientation de la jete, la lutte incendie, les routes d'vacuation

    d'urgence, la prvention, les alarmes, les dispositifs d'arrt d'urgence des oprations et

    de dconnexion du navire, la surveillance et le contrle des oprations.

    - fiabilit : la redondance des quipements ainsi que des calculs de structure adapts

    permettent de rduire le risque d'une indisponibilit prolonge en cas de dommages sur

    le jete.

    Le prsent papier dtaille les sujets ci-dessus et aborde encore divers autres aspects de

    la conception de la jete.

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    BONTANG FUTURE 3RD LNG/LPG DOCK:A DESIGN WHICH ACHIEVES VERY HIGH LEVELS OF

    FLEXIBILITY, SAFETY AND RELIABILITY

    BONTANG EXPANSION PROJECT 3rd

    DOCK / 5th

    LPG TANK

    INTRODUCTION

    Due to the increasing capacity of the Bontang liquefaction plant operated by PT.

    Badak with a 7th liquefaction train operational in year 1997 and a 8th train to be

    operational in year 2000, PERTAMINA and its Production Sharing Contractors : TOTAL

    Indonesie, VICO and UNOCAL, decided, based on the results of port simulation studies

    commissioned by TOTAL Indonesie, to build a 3rd loading dock for LNG and LPG ships

    together with one additional LNG Storage Tank and one additional LPG Storage Tank in

    order to cope with the increasing traffic of ships.

    After the completion of the 8th liquefaction train it is estimated that 21.6 million tons

    per year of LNG will be lifted by 390 to 410 LNG cargoes under various sales contracts

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    mainly to Japan, Korea and Taiwan as well as around 1.35 million tons per year of LPG

    lifted by 30 to 40 LPG cargoes.

    The dock no. 3 siting study and the preparation of the Statement of Requirements

    (SOR) covering as a milestone project the dock no. 3, the additional LPG tank and the

    associated process (pipe racks, tie-ins, flares) were completed in 1995.

    A fairly detailed and comprehensive Front-End Engineering Design (FEED) wasperformed by PT.INCONED Indonesia in 1995 and completed at the beginning of 1996.

    Finally, the Detailed Engineering, Procurement and Construction Contract (EPC) was

    awarded in January 1997 to a joint operation between IKPT (PT. Inti Karya Persada

    Tehnik Engineering and Construction) of Indonesia and CHIYODA CORPORATION of

    Japan for a mechanical completion scheduled for January 1999 and an operational

    acceptance three months later.

    The LNG dock no. 1 was commissioned on 9 August, 1977 and the LNG/LPG dock

    no.2 was commissioned on 19 December, 1988, i.e. already twenty-one and ten years ago

    and with a much smaller fleet of ships. Consequently the design of dock no. 3 could notre-use previous studies : it had not only to accommodate the latest state of the art for dock

    designs and the latest technologies, but also the biggest fleet of LNG and LPG ships ever

    used for a dock design.

    1. BASIS OF THE DESIGN

    1.1 Process

    The LNG/LPG dock no. 3 has two independent LNG transfer lines from the LNG

    storage tanks farm. It means that when enough storage inventory is available, up to three

    LNG ships can load simultaneously in Bontang (one on each dock). A new LNG marine

    flare has been added, which can handle the simultaneous maximum vapor return rates from

    both dock no. 2 and dock no. 3. However during normal operation the vapor return from

    dock no. 3 will use a new vapor return line connected to the vapor recovery system and

    used for both dock no. 2 and dock no. 3.

    It was deemed necessary to have LPG loading facilities on two docks for flexibility

    and back-up but simultaneous loading of LPG ships on two docks has not been considered

    as a probable scenario with regard to LPG current and future production levels.

    Consequently the LPG transfer lines of dock no. 3 (one line for C3 and one line for C4)

    are tied-in to the existing LPG transfer lines of dock no. 2 as well as the vapor return lines

    (one for C3 and one C4), which are tied-in to the existing BOG reliquefaction facilities at

    the LPG storage tank farm. The excess vapor is flared on the existing LPG flare.

    The LNG loading system for dock no. 3 is designed for loading at a minimum rate of

    10,000 m3/hr using three 16" liquid arms and one 20" vapor arm with a minimum battery

    limit pressure at ships rail of 3.50 kg/cm2abs (in order to take into account a mesh 60

    loading strainer). However, ships can be loaded at 12,500 m3/hr using the four liquid arms

    in place (fast loading scenario).

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    The LPG loading system for dock no. 3 is designed for loading at a minimum rate of

    5,000 m3/hr (single product C3 or C4) using the two 12" liquid arms and the two 8" vapor

    arms with a minimum battery limit pressure at ships rail of 2.10 kg/cm2 abs. However,

    most of the ships will load simultaneously C3 and C4 at 2,500 m3/hr each. Small ships

    with smaller freeboard and smaller size of manifold can also load a single product (or two

    products sequentially) using the two 8" LPG arms, which are slightly longer than the 12"

    arms to achieve a greater outreach.

    1.2 Ships Used for The Dock No. 3 Design

    Usually LNG ships calling at Bontang are dedicated to specific LNG sales contracts

    and LNG trades while LPG ships are nominated. For dock no. 3 being an extension of

    existing facilities, it was not possible to be satisfied with a design using a limited number

    of generic ships as is often done for grassroot projects. Accordingly, an exhaustive list

    of ship type and size has been established for dock no. 3 design and 65 LNG ships have

    been selected, with sizes ranging from 18,000 m3 (SURYA AKI for Medium City Gas

    Companies in Japan) to the future 145,000 m3 ships still on the design boards. These 65

    ships represent more than half of the worldwide LNG fleet, existing or under construction.

    These ships have been selected according to following principles:

    - ships calling at Bontang.

    - ships usually calling at Blang Lacang ( Indonesias second LNG/LPG Plant in Sumatra

    Island), because they also come from time to time to Bontang.

    - ships in lay-up condition worldwide because past experience has shown that short term

    charters of this category of ships was not to be excluded.

    - new ships under construction, deemed to be representative of the LNG carriers of the

    latest generation, even if they were not built for Indonesian trades.

    - future 145,000 m3LNG ships: there is a very high probability that these ships will be

    built in the near future, therefore these ships had to be incorporated in the design. Ships

    bigger than 145,000 m3would require special consideration with regard to the coralline

    hard bottom in Bontang, the dredged depth limited to 14 m and the operational limits in

    use.

    This selection also allowed, as a matrix approach, to cover all categories of ships:

    membrane, prismatic or spheres with 3,4,5 or 6 tanks, resulting in almost all possible flat

    bodies, decks arrangements, manifolds configurations, etc.

    128 existing LPG ships (refrigerated) have been selected, ranging from 15,000 m3 to

    100,000 m3, representing all the LPG fleet worldwide within these size limits.

    In addition to data already held by PERTAMINA, inquiries have been sent to about

    55 companies worldwide for ships data collection in order to have enough information to

    perform the design. PERTAMINA would like to take this opportunity to thank warmly all

    ships Owners/Managers, who contributed generously to the dock no. 3 design in

    providing data on ships. Their contribution to all of the efforts made to design a safe port

    has been invaluable and is a good example of how the LNG/LPG family stands close

    together in sharing the goal of safety.

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    1.3 Others

    The dock no. 3 design allows round-the-clock operations.

    For safety reasons it has been decided that the dock no. 3 control room will not be on

    the dock (unlike docks no. 1 and 2) and that the gangway platform will be separated from

    the loading platform in order to provide a remote emergency escape. This is further

    developed in Chapters 6 and 7.

    The International Safety Guide for Oil Tankers & Terminals better known as ISGOTT

    (ICS, OCIMF, IAPH) and the Safety Guide for Terminals Handling Ships Carrying

    Liquefied Gases in Bulk (OCIMF) have been used extensively for the design as well as all

    relevant SIGTTO publications. On the particular subject of regulations, the interested

    reader could refer to the information paper no. 14 Site Selection and Design for LNG

    Ports and Jetties and to the information paper no. 15 A Listing of Design Standards for

    Liquefied Gas Terminals (referencing Ports and Jetties), both produced by SIGTTO.

    They contain a fairly good background for dock siting and design aspects. (The

    explanation of various acronyms for the societies and international bodies mentioned is

    given at the end of the paper).

    A Hazard and Operability Study (HAZOP) was conducted in May of 1997 and its

    results incorporated in the design of dock no. 3.

    2. DOCK NO. 3 SITING AND ORIENTATION

    2.1 Siting Study

    A siting study was performed in order to select the best possible location of dock no. 3

    using a weighted multi-criteria analysis technique. Ten possible locations have been

    considered with evaluation criteria covering overall nautical, operational, safety,

    structural/construction and cost viewpoints.

    In particular, safe distances and hazard zones have been evaluated using various

    LNG/LPG spills scenarios and vapor cloud computations with the DEGADIS model

    developed by the US Coast Guards.

    The recommended location for dock no. 3 was further subject to confirmation by a

    nautical risk assessment study using a real time navigation simulation model.

    2.2 Nautical Risk Assessment Study

    This study was commissioned to DELFT HYDRAULICS using the Maritime

    Simulation Center in the Netherlands (MSCN) simulator located at Wagenignen. Bontang

    pilots attended and performed the simulations using their Bontang port knowledge, thus

    bringing more credibility to the design of this new installation.

    The aim of this study was to confirm the location of the dock no. 3 from a nautical

    point of view and to optimize the dock orientation through berthing/unberthing simulation

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    maneuvers in routine and emergency conditions for different weather patterns and with the

    assistance or not of tugs. An example of berthing maneuver is given on Figure 1.

    Of the two lay outs 110oand 115o, derived from previous screening studies (also by

    DELFT HYDRAULICS but using the fast-time ship simulator SHIPMA-5), the 115o

    orientation has been selected and a mooring configuration of the ships bow out has been

    recommended for safe departure.

    Accordingly dredging plans to the 14 m isobath have been established and results of

    the soil survey shown that enough good coral sand was available for reclaiming the

    necessary space for the additional LPG tank.

    FIGURE 1: EXAMPLE OF BERTHING MANEUVER

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    3. DOCK NO. 3 LAY OUT OPTIMIZATION AND DESIGN OFBREASTING DOLPHINS AND MOORING DOLPHINS

    Although ships will generally moor bow out on dock no. 3, i.e. on the starboard side,

    the port side mooring has been systematically studied as well, not only for the optimization

    of the lay out of the dolphins, but also for other design areas, like the arms flanging areas,

    with the understanding that in case of conflict between port side and starboard sidemoorings, starboard side mooring will prevail and ships with restrictions for port side

    mooring will be clearly identified.

    3.1 Breasting Dolphins Lay Out

    The optimum location of the breasting dolphins has been determined by graphical

    analysis as shown on Figure 2, taking into account the flat part of the hull of the vessels,

    the hull curvature and flare angles and the OCIMF criteria with regard to the spacing of

    breasting dolphins to be between 25 % and 40 % of ships Length Overall (LOA). Ships

    with possible restrictions were systematically studied in further details, assessing low

    tide/high tide conditions, loaded/ ballasted conditions and longitudinal drifts due to

    weather. An example of such study is given on Figure 3.

    As a conclusion :

    - the lay out of the main breasting dolphins and their number (four) has been optimized. It

    has to be further noted that the top of the inner breasting dolphins has been set at + 5.00

    m while the top of the outer breasting dolphins has been set at + 6.50 m, while keeping

    the vertical angles of mooring lines within recommended OCIMF values, i.e. less than

    25o - 30o (25o for spring lines) with no negative values. This arrangement significantly

    reduces the number of ships having a partial contact with the fender panels.

    - for smaller ships it has been necessary to provide, in addition to the four main breasting

    dolphins, a sub-breasting dolphin in the form of a berthing beam located in front of but

    not connected to the loading platform. Accordingly, the kinetic energy absorption of this

    beam is based exclusively on piles deflection and special high tensile steel grade has been

    used for that purpose.

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    FIGURE 2: EXAMPLE OF GRAPHICAL ANALYSIS FOR

    BREASTING DOLPHINS LOCATION

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    FIGURE 3: DETAILED STUDY ON THE RELATION

    FLAT BODY / FENDER PANELS

    3.2 Mooring Dolphins Lay Out

    The optimum location of the mooring dolphins has been obtained by the use of the

    graphical analysis method as shown on Figure 4 : the mooring lines and their orientations

    are plotted against the dock lay out in order to define the most suitable and best mooring

    configuration of each vessel.

    The basic principles used for the design are based on the good mooring practice

    recommended by OCIMF, i.e., head and stern lines are omitted as much as possible

    because they are not very effective in restraining vessels due to their long length and poor

    orientation. In other words, ships are moored within their own lengths. Furthermore it

    has been verified that the horizontal angles of the breast lines do not exceed in general

    +/- 15o.

    Finally mooring calculations were done for each ship, using a software incorporating

    mooring line elasticity in order to determine the maximum tensions in the lines (to remain

    under 55 % of the Minimum Breaking Limit - MBL) and the ships displacements.

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    FIGURE 4: EXAMPLE OF GRAPHICAL ANALYSIS

    FOR MOORING DOLPHINS LOCATION

    As a conclusion:

    - the lay out of main mooring dolphins and their number (six) has been optimized

    according to good mooring practice and results in a dock length of 367.5 m (distance

    between outer mooring dolphins).

    - for a limited number of smaller and/or atypical ships, a seventh dolphin has been added

    (MD4) with a two hooks assembly in order to achieve a satisfactory spring lines

    arrangement in most cases. An example of use of this dolphin is given on Figure 5.

    Catwalks connecting to this dolphin are elevated to avoid mooring boats becoming

    trapped between the ship and this dolphin.

    - finally and for some ships using a mixed wire/synthetic mooring pattern or showing

    possible overstress in their breast lines, a shore augmentation consisting of a pulley has

    been added on three mooring dolphins. The use of this additional facility will be left to

    the masters discretion.

    FIGURE 5: EXAMPLE OF USE OF DOLPHIN MD4

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    3.3 Design of the Dolphins

    - Breasting Dolphins: although the acceptable hull pressure of LNG carriers should be in

    the range of 15 t/m2 for ship berthing at angles different from 0o, a value of 11.6 t/m2

    has been chosen for dock no. 3 as the most conservative value resulting from ship data

    collection. The berthing speed chosen for the breasting dolphin design is 1 knot at an

    approaching angle of 10

    o

    , which gives a normal component (berthing at 0

    o

    ) of 18.2cm/s, while 15 cm/s is recommended by PIANC for an area such as Bontang. Breasting

    dolphins are of rigid structure type supporting low recoiling buckling rubber fenders.

    The breasting dolphins are calculated in accordance with the weak line defence

    mechanism, i.e. in a catastrophic scenario, the dolphins shall be capable of being re-

    used in case of an overload resulting in plastic deformation of the subsoil without

    damaging the ships hull (deformation of the subsoil has been preferred to plastic

    deformation of the piles because a more or less inclined fender is preferred compared to

    a system where some piles cannot be relied upon any more). See reference [1]

    Further, safety factors are introduced namely :

    - The design absorption capacity of the fender units at 50 % fender compression and 0o

    berthing angle is two times the berthing energy at controlled berthing speed of 18.2

    cm/s. As a result the berthing energy is absorbed at approximately 30 % fender

    deflection based on the fender characteristic curve.

    This builds into the system a reserve energy allowing a berthing speed at 0o of

    18.2 2 =25.7cm/s

    preventing the risk of the rubber fender becoming rigid due to full compression.

    It has to be noted that the reaction force remains approximately the same between 30 %

    and 50 % compression for this type of fender and is in the range of 285 t.

    - Since the reaction force on the dolphin increases very sharply when the fender is fully

    compressed, the piles are designed with a load factor of 2, i.e. for an ultimate reaction

    force of 570 t, which is two times the reaction force corresponding to the design

    absorption capacity of the fender. Consequently, if the berthing speed at 0ois above 25.7

    cm/s, the ultimate soil bearing will be met at some point of energy absorption and the

    concrete cap will travel due to subsoil deformation while the dolphin structure will

    remain undamaged.

    Taking into account that the concrete cap of the dolphin can travel up to 1.70 m

    (remaining horizontal distance between the compressed fender and the edge of the

    loading platform), an emergency reserve of 485 t.m (= ultimate reaction force x

    displacement) is built into the system which, when added to the design absorption

    capacity of 215 t.m of the fender, gives a total energy absorption of the dolphin of

    700 t.m leading to a berthing velocity of

    18.2 700 107 5 . =46 cm/s

    i.e., 2.5 times the design berthing velocity. In this catastrophic scenario, the ships hull

    will not be damaged and the damaged dolphin could still be used with some precautions.

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    - Mooring Dolphins: the mooring dolphins are both analysed for the sum of the MBL of

    each line to be hooked to the dolphin perpendicular to the dolphin, including the

    extreme vertical angle and for the maximum horizontal angle due to the most extreme

    mooring line position, including the extreme vertical angle. This is in order to assess the

    maximum compression and extension forces on the piles. Extreme line positions are

    given by the graphical method showing the apex of the most extreme orientation of any

    mooring line.

    Because the strongest lines are used for the design (44 mm diameter with 127 t MBL),

    no further safety coefficient is taken.

    4. LOADING PLATFORM AND TRESTLE

    The loading platform is 36.25 m in length and has three levels : main deck, 2nd deck

    and 3rd deck. The main deck has a maneuvering platform and is connected to the shore by

    the main trestle -300 m in length, supporting a road 5 m width allowing the passage of a

    wheel crane for loading arms maintenance (barges are not readily available in Bontang).

    This road is also used for emergency access from the dock control room. The loading

    arms are mounted on the 3rd deck while the 2nd deck supports various valves and

    manifolds arrangements. The figure 6 shows the front view and various sections of the

    dock. After study of various solutions, the pipeway has been separated from the main road

    trestle. In addition, a completely separated catwalk connects the gangway platform to the

    shore.

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    FIGURE 6: FRONT VIEW OF THE DOCK AND VARIOUS SECTIONS

    5. LOADING ARMS

    5.1 Description

    For LNG loading, four 16" liquid loading arms are provided (one being able to be used

    as vapor arm) in order to allow a loading rate up to 12,500 m 3/hr. After a thorough vapor

    return calculation study, it was decided that the vapor arm will be 20" terminated by a 16"

    triple swivel assembly for better interchangeability of components with dock no. 2 and

    weight reduction consideration. A 20" x 16" vapor arm equipped with a 12" reduced bore

    Powered Emergency Release Coupling (PERC) has also a lower pressure drop than a 16"

    vapor arm with full bore PERC.

    These five arms are equipped with an Emergency Release System (ERS) consisting of

    12" reduced bore PERC using for the first time the no spill technology, which reducesthe leakage of LNG to about 2 liters at the time of PERC opening compared to 10 liters

    for a conventional reduced bore type PERC and 16 liters for a full bore type PERC. This

    will significantly enhance the safety of the personnel in the vicinity of the manifold. The

    principle illustrated on Figure 7 is that one of the ball valves has a concave shape which

    allows for the reduction of the space between the two ball valves when closed (due to

    mechanical interlock, the upper valve closes first when ESD is initiated, and the lower

    valves closes after when the ERS is initiated).

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    FIGURE 7: PERC WITH NO SPILL TECHNOLOGY

    For LPG loading, two 12" arms are used for liquid and two 8" arms are used for

    excess vapor. Both propane and butane can be loaded separately or simultaneously. One

    of the 8" arms is able to be used as a liquid arm so that smaller ships can be loaded using

    the two 8" arms only. For this reason the 8" arms are also slightly longer than the 12"arms. After hydraulic calculation, the decision was taken to use full bore PERC for the

    LPG arms, for which the no spill technology was unfortunately not available at the time

    arms were ordered.

    Dock no. 3 is also the first gas installation with the whole triple swivel assemblies for

    LNG and LPG arms being fire resistant (OCIMF requests this for PERC and QCDC only).

    All arms normal connecting and disconnecting operations, are controlled by a portable

    radio device (1.285 kg, battery life time 3 years), which is much easier to handle compared

    to the traditional pendant with umbilical cable and also allows more functions.

    Accumulators, Arms Position Monitoring System (PMS) and Uninterruptible Power

    Supply (UPS) are designed in such a way that all arms will automatically retract clear from

    a drifting ship after PERC opening even in case of electricity black-out. This facility will

    also allow a better protection of the loading arms in case of a fire on the ships manifold.

    Finally, it was decided that a Hydraulic Quick Connect/Disconnect Coupling (QCDC)

    will not be installed due to flanging problems yet to be solved due to the great variety of

    ships calling at Bontang. However, arms and supporting structures are designed in such a

    way that this equipment can be easily retrofitted in the future.

    5.2 Arms Envelopes and Alarms

    The arms design and their mechanical limit envelopes have followed OCIMF loading

    arms specification Edition 1987 (the new Edition being not available at the time of dock

    no.3 design) except that the drifting area has been taken as a rectangular shape rather than

    a circular shape for conservative purposes.

    However, it was decided not to follow the drifting speeds of 15 cm/s and 5 cm/s often

    used for setting up, respectively, the alarm 2nd step (ERS) and alarm 1st step (ESD). A

    study was provided by DELFT HYDRAULICS using the MSCN real time navigation

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    simulation programme in order to obtain an accurate estimation of longitudinal and lateral

    components of the drifting speeds and drifting distances in the first seconds after a ship

    break out. Also, and in order to build more safety into the system in case of high drifting

    speeds, it was decided that the closure time of the PERC valve will be 5 sec. (surge

    analysis calculation and surge protection are based on this figure) and that the closing

    time of the ESD valve (arm MOV = Motorized Operated Valve) will be reduced to 20

    sec., this figure still being compatible with the design of the loading lines compared to themore traditional value of 30 sec. It was finally decided that the alarm 1st step, if triggered

    by the PMS, will be in spherical coordinates rather than more commonly used rectangular

    coordinates, because the spherical coordinates are also used for alarm detection by

    proximity switches and both systems back-up each other in our design philosophy.

    The lateral drifting distances and speeds used are given on Figure 8 for lateral wind

    and current pushing the ship off the berth.

    With these values, the distance from mechanical limit of the arm to the alarm 2nd step is:

    (20 cm/s + 2 cm/s).5s = 110 cm rounded up to 1,200 mm ;

    and the distance alarm 2nd step to alarm 1st step is:170 cm + margin for PMS accuracy = 2,000 mm ;

    where : 20 cm/s = drifting speed after 25s

    170 cm = drifting distance after 20s.

    2 cm/s = PMS accuracy.

    A similar calculation is done for longitudinal drift for which the dimensioning case is a

    quarterly wind and current (and not a longitudinal wind and current which generates

    smaller effort on the ship).

    It has to be noted that the scenario of the ship break-out due to starting of the engine

    full ahead harbor has not been kept as the worst scenario particularly for the lateral

    drifting speeds and distances.

    Based on the hereabove, the loading arms envelopes are given on Figure 9 for LNG

    arms.

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    0

    5

    1 0

    1 5

    2 0

    2 5

    3 0

    0 5 1 0 1 5 2 0 2 5 3 0 3 5

    T I M E F R O M B R E A K - O U T ( s e c . )

    DRIFTING

    SPEED(cm/sec.)

    0

    50

    10 0

    15 0

    20 0

    25 0

    30 0

    35 0

    40 0

    45 0

    50 0

    0 5 1 0 1 5 2 0 2 5 3 0 3 5

    TIME FROM BREAK-OUT (sec . )

    DRIFTING

    DISTANCE(cm)

    FIGURE 8: LATERAL DRIFTING

    SPEEDS AND DISTANCES

    FIGURE 9: LOADING ARMS

    ENVELOPES (LNG)

    6. ACCESSES, EMERGENCY ESCAPE ROUTES, GANGWAY

    6.1 General Philosophy

    Present arrangement of dock no. 3 trestle is given on Figure 10 and was found to be

    the best possible having regard to :

    - an unmanned dock concept, i.e., the loading operations do not require any operator to

    be present on dock 3 from the moment the gas is introduced into the arms for arms

    cooldown prior to loading startup until the purging of the arms after the loading is

    completed. Obviously this does not exclude patrols by safety/operations/marine staff on

    the dock, but no permanent attendance is needed.

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    - segregation of authorized safety/operations/marine people involved with operations

    from unauthorized people on the loading platform not directly involved with

    operations (like immigration, customs, shipping agent, crew change, visits on board,

    etc...).

    The authorized people have a dedicated access from the dock 3 control building to the

    loading platform using the road trestle, while unauthorized people must use the

    separate catwalk trestle giving direct access to the gangway tower and pass a securitycheck at catwalk entrance.

    - emergency escapes : the gangway tower is voluntarily separated from the loading

    platform and is located on a dedicated dolphin at a distance of 31.6 m from the closest

    loading arm. Accordingly the gangway bulwark ladder on board the ship is at some

    distance from the manifold, where a fire is most likely to occur, and closer to the ship

    accommodation space. The catwalk connecting the gangway to the shore is therefore

    used as an emergency escape between ship and shore while the road trestle is used as an

    emergency escape between the loading platform and the shore. Secondary escapes are

    also provided for personnel trapped on dolphins to reach a safe area without passing

    over the loading platform. Two ladders are also provided on each dolphin for access tothe water. Finally a connection is provided at the middle of the trestle between the

    catwalk and the main road trestle. This arrangement is in line with OCIMF

    recommendations which require that two remotely separate evacuation routes from all

    work or occupied areas are provided for emergency egress.

    FIGURE 10: ACCESSES, EMERGENCY ESCAPE ROUTES AND GANGWAY

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    6.2 Gangway

    Due to the great diversity of ships sizes and deck obstructions the choice of the

    gangway design is a tower type gangway with four intermediate platforms, provided with

    stairways and equipped with a steel turntable going up and down by means of a cable lift.

    The turntable platform supports an aluminum telescopic gangway ladder equipped at the

    end of the telescopic part with a bulwark ladder for easy access to the ships deck.

    The gangway is of the gravity type, i.e., it lands directly on ships decks and follow the

    ships movements by gravity (free-wheel mode).

    In case of emergency the gangway is equipped with an emergency raise and retract system

    in order to be clear of a drifting ship.

    The finalization of the gangway envelopes has required a considerable effort for the

    identification of ships deck obstructions which are particularly numerous when going away

    from the manifold platform, like : LN2 tank, dry chemical units, ships accommodation

    and pilot ladders, cargo machinery room , etc. An example of such study is given on

    Figure 11.

    The number of intermediate platforms has been fixed to four to restrict the maximum

    vertical angle to 22oor less for safety reasons. The gangway is equipped with a safety net

    and generally follows SIGTTO Guidelines for Ship to Shore Access for Gas Carriers.

    FIGURE 11: GANGWAY LANDING AREA STUDY

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    7. SHIP TO SHORE COMMUNICATION AND DOCK NO. 3MONITORING AND CONTROL OPERATIONS FROM THECONTROL BUILDING

    7.1 Ship to Shore Communication

    For LNG ships the following means of communications are provided :- one communication cable with connector for the hot line, interphone and public

    telephone (similar to docks no. 1 and 2).

    - one pneumatic ESD link with connector for the ESD signals from shore or ship (similar

    to docks no. 1 and 2).

    - one telemetry link for the integrated Marine Monitoring System (MMS) in order to

    display the MMS information (wind and current on dock no. 3, approaching/departing

    speeds and distances of the ship and mooring lines tensions) on a portable computer

    placed on board the ship cargo control room at the time of the pre-loading meeting.

    For those LNG ships equipped with an optical fiber link (mainly ships trading with

    Japan), an optical fiber cable with connector is also provided for convenience with thefollowing functions:

    - communications (3 lines).

    - ESD link (signal from shore and signal from ship).

    - MMS information interfaced with ship computer facilities.

    - two spare cores are available for possible future use.

    For LPG ships, which are not as well equipped as LNG ships, the following is

    provided:

    - one communication cable with telephone handset to be put on board, used as a hot line.

    - one electric ESD link with a pendant to be put on board the ship (SIGTTO ESD link).

    - one telemetry link for the MMS information to be displayed on a portable computer put

    on board the ship upon arrival.

    All radio transmissions generally follow the SIGTTO guidelines for Ignition Hazards

    due to Marine Radios and Radio Transmission.

    7.2 Dock no. 3 Monitoring and Control

    The dock no. 3 monitoring and control of operations are done from a remote blast

    proof control building located onshore at approximately 330 m from the loading platform.

    The dock design is based on the unmanned concept, which means that a lot of emphasishas been put on monitoring and control of operations.

    The overall control of the installation is through a Distributed Control System (DCS).

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    Additional monitoring and control devices are as follows :

    - for the loading arms: a Position Monitoring System (PMS) is provided. The PMS will

    not only display the position of the arm flange closest to the alarm 1st step but will also

    trigger the pre-alarm, the alarm 1st step (ESD) and the alarm 2nd step (ERS) in parallel

    to proximity switches for alarms detection. The PMS is equipped with a failure auto

    check mode.

    - for marine operations : the integrated Marine Monitoring System (MMS) will provide

    long term weather data collection in the vicinity of dock no. 3 (i.e. wind and current,

    Bontang port not being subject to waves). It will monitor, when a ship is approaching or

    departing, the distances and speeds fore and aft together with wind and current

    conditions (with a handy display for the pilot) and, when the ship is alongside, the

    tensions in the mooring lines and ship drift off together with wind and current conditions.

    This later information will be also displayed by telemetry on a portable computer placed

    on board the ship during the pre-loading meeting with alarms provided on the handy

    display as well. Trouble shooting assistance is provided by the vendor of the MMS

    through a dedicated (or part-time dedicated) telephone line to be made available at the

    Bontang plant. The schematic drawing of the MMS is given on Figure 12.

    FIGURE 12: MMS CONFIGURATION

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    - CCTV system : three remote controlled cameras with pictures displayed on three large

    color monitors are provided : one on each side of the loading arms to permanently

    watch the ship manifold, and one on an elevated tower to permanently watch the

    gangway. Five other remote controlled cameras (dock entrance, main deck, 2nd deck (x

    2) and 3rd deck) are provided with scanned pictures displayed on two other color

    monitors (i.e. a total of 5 monitors is provided in the control room).

    - a complete Hazard and Monitoring Systems (HMS) is also provided in the dock no. 3

    control room.

    Finally, quick disconnection of the ship is possible using the loading arms Emergency

    Release System (ERS) through PERC activation by push button or excessive ship drift, by

    the Quick Release Hooks (QRH) system for the disconnection of the mooring lines and by

    the emergency raise/retract system of the gangway.

    7.3 Dock no. 3 Control Building

    As explained before it has been judged that a control building located at some distance

    from the loading platform was considered safer for personnel and control equipment than

    a control room located on the loading platform or in its immediate vicinity.

    Easy access to the loading platform is possible by vehicles or bicycles parked on the

    emergency park lot or by feet for authorized personnel.

    The control room is at 330 m from the loading platform, however safety studies have

    shown that it can be engulfed in an LPG gas cloud in the most serious spillage scenario on

    dock no 3. Although this scenario is very unlikely, it was decided, after a detailed review

    of various regulations for buildings design in such case, that the recommendation

    Process Plant Hazard and Control Building Design from Chemical Industries

    Association would apply for the dock no. 3 control building, i.e., the building will

    withstand a static blast pressure of 3 psi and an incident dynamic blast pressure of 2.9/14.5

    psi for respectively 100/30 milliseconds duration times.

    Apart from the control room, the stand by mooring team room and the safety room

    (equipped with fire protection suits, respiratory masks, etc...), the dock no. 3 control

    building has also an instrument room, an electrical room, an air condition room and other

    common rooms. A transformers yard is provided near this building. The control building

    lay out is given on Figure 13.

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    FIGURE 13: CONTROL BUILDING LAY OUT

    8. FIRE PROTECTIONA detailed review of regulations and guidelines has been done at the beginning of the

    project including international conventions, advice from kindred societies: OCIMF,

    SIGTTO, ICS, IAPH, national regulatory bodies, with the conclusion that there appears to

    be no international regulations but rather broad, general and often inconsistent guidelines

    on fire protection for jetties. Risk analysis studies did not seem to be available as well.

    For the dock no. 3 it was therefore decided to cover as many fire scenarios as was

    possible. The following design is still under finalization at the time of preparation of this

    paper, in particular in relation with the protection of the top of the loading arms :

    - one fixed water curtain is provided on the sea-side front on 3rd deck for loading armsprotection.

    - under deck fixed water curtains are provided on the sea-side front for curbed areas on

    main deck platform and 2nd deck.

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    - two tower elevated oscillating fire water monitors remotely controlled from a fire station

    located at a 60 m distance on the trestle are provided for the cooldown of the surfaces

    of the main deck platform and 3rd deck (one of these monitors can reach the gangway

    tower and the pipeway close to the loading platform as well).

    - the gangway tower and telescopic part are protected by water curtains from heat

    radiations. The part of the catwalk close to the gangway tower is protected by a waterspray.

    - two pre-aimed tower elevated dry chemical monitors are provided on the 3rd deck in

    order to help extinguish a possible fire on a ship manifold or on loading arms.

    - curbed deck areas on main deck and 2nd deck are also protected by fixed dry chemical

    fire fighting system with hose reels and flooding system.

    - hydrants with hoses together with portable and wheeled fire extinguishers are provided

    at different places.

    - an international fire connection with hose reel is provided on the 3rd deck.

    - besides the CCTV already described, the dock no. 3 is provided with automatic flame,

    smoke, gas, and spill detection with alarms system. Controls for fire fighting are made

    not only from the dock no. 3 control room, but also from the plant main control room in

    order to have two fire control safe remote places.

    9. MISCELLANEOUS

    The following other items are provided:

    - cathodic protection by impressed current.

    - ship grounding cable.

    - lighting.

    - protection against lightning for both external (direct strike) and internal (induced

    voltage) phenomena.

    - telephone, paging, speaker system and public address.

    - navigational aids following IALA recommendations.

    Finally the millennium problem has been carefully assessed with the vendors of all

    computer based systems that are provided for the dock no. 3 in order to insure a trouble

    free passage to year 2000.

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    10. CONCLUSION

    Past operating experience with loading docks no. 1 and no. 2 has been used widely for

    the design of the new dock no. 3 in Bontang.

    Besides, a lot of effort has been deployed in order to emphasize the flexibility, safety

    and reliability aspects of this new facility. In this regard, the design of dock no. 3 goes

    into many aspects which are beyond more conventional and perhaps less costly designs. Ithighlights PERTAMINAs desire to consistently promote safe and efficient operations in

    the Bontang port to maintain its reputation as a reliable LNG and LPG supplier.

    GLOSSARY OF TERMS USED (in the order they appear in the paper)

    ICS = International Chamber of Shipping

    OCIMF = Oil Companies International Marine Forum

    IAPH = International Association of Ports and Harbors

    SIGTTO = Society of International Gas Tanker and Terminal OperatorsPIANC = Permanent International Association of Navigation Congresses

    IALA = International Association of Lighthouse Authorities

    REFERENCE CITED

    [1] Second Loading Dock for LEG Purposes in Bontang, East Kalimantan, Indonesia -

    International Harbor Congress Antwerp, June 1988, R.F. Janssen.