143

1 INTRODUCTION

Rapidly developing industry and technology since

the 19th century lead to increased oil  production

whichbecamethemanagingpoweroftheeconomic

structureandinturntoday’slargescalecommercial

oilcirculationisemerged(Soylu,2000).Asoneofthe

mostsignificantelementsofdevelopment,theenergy

and efficient use of such energy necessi

tated

connecting the countries supplying the energy to

demandingcentersviavarious transportationways,

aboveall,viapipelines inourworldgoingthrougha

rapid globalization process. Pipe line transportation

is fast, economic and safe. Furthermore, the large

scaleinvestmentissatisfiedinashortti

me.Startedat

the end of 19th century with small scale and short

distance lines, today, the oil and natural gas

transportation turned towards for longer distances

andathighpressuresviapipewithwiderdiameters

inparallelwiththeincreasedconsumption,demand

andtechnologicaladvancements(ÇubukandCansız,

2005).

While the pipe line tra

nsportation is a high cost

investment compared to land and maritime

transport,thepipelinetransportationhasadvantages

such as being faster, safer and more ecological

compared to other transportation modes and not

being affected by atmosphericconditions as well as

having a shorter return on invest

ment period.

Therefore, transporting oil  and natural gas to the

consumption areas via pipe lines in the most

economicalwaystandsout(TUBİTAK,2003).

Generally,pipelinesareexaminedintwogroups

ascrudeoilpipelinesandnaturalgaspipelines.The

oil is tra nsported to ports or markets from regions

with rich fields via crude oil pipelines (Çubuk and

nsız,2005).Constitutingthebasisofthemaritime

system, ports are the locations where ships and

marinevesselsberth,andperformoperationssuchas

Simulation Model on Determining of

Port Capacity

and Queue Size: A Case Study for BOTAS Ceyhan

Marine Terminal

Ö.Uğurlu&E.Yüksekyıldız

aritimeTransportationandManagementEngineeringDepartment,KaradenizTechnicalUniversity,Trabzon,Turkey

E.Köse

NavalArchitectureandMarineEngineeringDepartment,KaradenizTechnicalUniversity,Trabzon,Turkey

ABSTRACT: Simulation programs are a useful and effective tool for analysis of projects requiring high

investmentcosts,studiestoimprovethefunctioningofanexistingsystem,andtheanalysisoftheeffectiveness

andefficiency.Theymakeitpossibletocontrolofsystemorsubstructurebylessinvest

mentcost.Simulation

modelsareoftenusedinportmodeling,capacityanalysis,queuesizeandportefficiency.

Inthisstudy,simulationmodelofloadingterminalsoftheBOTAŞCeyhanpipelineweredone.Forthisreason,

AWESIMsimulationprogramwasused.Thismodelingevaluatedfor365daysandeachshiphasa

pproached

theportwithintervalsof12‐24,12‐36,24‐36and24‐48hours.Stormydaysinayearhavebeenassumedas30.

Each ship demands  trailer and pilotage service when approaching and leaving the port. In this simulation

model;shiptypes,capacities,comingfrequencies,loadingti

mes,maneuveringtimeandtransportationcapacity

ofBOTAŞCeyhanMarineTerminalwereinvestigated.

http://www.transnav.eu

the International Journal

on Marine Navigation

and Safety of Sea Transportation

Volume 8

Number 1

March 2014

DOI:10.12716/1001.08.01.16

144

loading, unloading, maintenance and supply. It is

difficult to solve the problems of ports analytically.

The complexity of port functions has a complex

structure dynamically, as in production systems.

Utilizing simulation system in analysis of complex

structureisinevitable(Demircietal.,2000;Demirci,

2003).Simulation isa scientificmethodology

 that is

performed to understand the behavior of a real

system without disrupting its environment.

Simulation has been used in different systems such

asurban, economic, production, transportation, and

the maritime field (Hassan, 1993). In the maritime

field, for example, simulation methods were

constructedtoanalyzetheimpactofterminal

layouts

and to determine the optimum level  of equipment

investment(Hayuth,1994).

2 LITERATUREREVIEW

Simulationapplicationsareoneofthemostadvanced

and powerful in system analysis. The simulation

approach would enable the designer and analyst to

foresee the behavior of such system (Azadeh and

Farahani, 1998). Simulation applications are

 often

usedonportmodeling.

In the study conducted by Alan, B. Pritsker the

frequency of vessels arriving at a tanker port in

Africa, their duration at the port, days with stormy

weatherareassessedandtheoperabilityoftheport

and the tugboat activity are evaluated (Pritsker,

1986).Teo

(1993)builtananimatedsimulationmodel

ofacontainerport and investigatedthe movements

of containers with automatic guided vehicles (Teo,

1993). Ramani (1996) has developed an interactive

computer simulation model in order to support the

logistic planning of container operations (Ramani,

1996). In the study conducted by Köse, Başar,



Demirci, Güneroğlu and Erkebay, the traffic stream

of the Bosphorus is modeled in AWESIM and

investigated the effects of the new pipe line to be

built on the strait traffic (Köse et al., 2003). In the

study conducted by Yeo, Roe and Soak (2007), the

maritimetrafficcongestionpotential

ofBusanportis

evaluated using an AWE‐SIM simulation model.

They concluded that one of the existing mooring

berthswithintheharborreachneedstoberemoved

andtwoquaysshallbeexpandedinordertoprevent

thetrafficcongestion(Yeoetal.,2007).

3 METHOD

Investigatingthesystembehaviors

usingsimulation

techniqueaimstopredictthefuturebehaviorsofthe

existing or future system to be built. In studies

conductedusingsimulations,itispossibletoseethe

results by applying strategies merely on the

simulationmodelwithoutmakinganychangestothe

actualsystem(Ali,2008;Demirciet

al.,2000).Onthe

other hand designing simulation models is difficult

andtimeconsumingandallowsmaking predictions

regarding the actual system. Simulation studies

generally consist of various stages. These well‐

arranged stages are monitored separately and the

relations in each stage are investigated (Demirci et

al., 2000). Simulation project adapting

 the general

model to the specific problem situation plays

essentialrole(Neumann,2011).

Thisstudy ispreparedinordertodetermine the

handling capacity and usability of BOTAŞ Ceyhan

MarineTerminal.Furthermorethefollowingaspects

of the BOTAŞ Ceyhan Marine Terminal are

investigated: number of incoming vessels, queue

valuesfor

berthingintheport,vesselwaitingtimes

for berthing, usability values of the ports, queue

valuesfortugboatservice,thetime the vessels wait

forgettingtugboatservice,totaltugboatactivity.Stay

inport durations, frequency of arriving to the port,

stormydaysandthetugboatservicerenderedarethe

most

 critical criteria of this study. Accordingly

AWESIMsimulationmodelingapplicationisusedin

thepresentstudy.

3.1 AWESIM

AWESIM refers to the simulation language for

problem solving. It may be used in courses,

professional life, industrial engineering, managerial

works, operational  works and computer sciences.

AWESIM is a simulation language for

alternative

modeling. High level understanding and compiling

of AWESIM lead to an increase in worldwide

simulationandmodelingutilization(Pritsker,1996).

An AWESIM project consists of one or more

scenarios, each of which represents a particular

system alternative. A scenario contains component

parts. AWESIM incorporates the Visual SLAM

modeling methodology. The

 basic component of a

VisualSLAMmodelisa network, or flow diagram,

which graphically portrays the flow of entities

(people, parts or information, for example) through

thesystem. A VisualSLAM network ismade up of

ʺnodesʺatwhichprocessingisperformed,connected

byʺactivitiesʺ which define the routing

 of entities

and the time required to perform operations 

(O’Reilly and Lilegdon, 1999). Symbols frequently

used in AWESIM are shown in Table1 along with

theirdescriptions.

Thecreatenodecreatesanewentitywithinthe

networkatintervalsdefinedbyTBC(TimeBetween

Creations)andcansavethearrival

timeasanentity

attribute. TF; time the first entityenters the system,

MA; variable used to maintain mark time, MC;

maximum number of entities to create. Activity

determinesthetimeoftheactivities.Thedurationof

an activity is the time delay experienced by the

activity. DUR; specifies the duration

 of the activity

using either explicit time or a distribution,

CONDITION/PROBABILITY; specifies under what

circumstance/probabilityaparticularbranchwillbe

traversed by an entity,N;represents the number

ofparallel identicalserversiftheactivityrepresents

servers,A;istheactivitynumberwithinthemodel.

A Queue node

is location in the network where

entitieswaitforservice.Whenanentityarrivesata

Queuenode,itsdispositiondependsonthestatusof

the service activity that follows the Queue node. If

theserverisidle,theentitypassesthroughtheQueue

nodeandgoesimmediatelyintotheservice

activity.

Ifallserversarebusy,theentitywaitsinafileatthe

Queue node until a server becomes available. The

145

sequenceofoccurrencesinqueueisevaluatedinthe

prioritynodeoutsidethenetwork.FIFO(FirstInFirst

Out)isthedefaultpriorityforfiles.IQ;initialnumber

in queue, QC; capacity of queue, IFL; file number.

The Terminate node is used to delete entities from

thenetwork.Itmaybeusedtospecifythenumberof

enti

ties to be processed on a simulation run. This

number of entities is referred to as a termination

count or TC value. When multiple terminate nodes

are employed, the first termination count reached

ends the simulation run. Assign node used as a

method to assign va

lues to entity attributes as they

passthroughthenode.Alsoitcanbeusedtoassign

valuestosystemvariablesateacharrivalofanentity

to the node. VAR defines global or entity variable. 

Thetype of Value(expression) must agreewith the

variable being assigned.  A ma

ximum of M

emanatingactivitiesareinitiated.Theresourceblock

identifiesaresourcenameorlabel,RNUM;resource

number, RLBL; the initial resource capacity, CAP;

number of units of the resource initially available,

IFL; file to poll for entities waiting for a resource.

Await node used to store entities waiting for UR 

unitsofresourcetobeav

ailableorgatetoopen(use

resource or gate  label names). Arriving entities are

placedinfileIFL.QCspecifiesthequeuingcapacity

of the node.Rule specifies the resource allocation

rule. M specifies the maximum branches leaving

entitiescantake.Freenodeusedtoreleaseresources

previously allocat

ed at an AWAIT node when an

entityarrivesatthenode.Everyentityarrivingata

FREE node releases UF units of RES resource. A

maximumofMemanatingactivitiescanbeinitiated

from the node. The alter node is used to change to

capacityofresourcetypeRESbyCCunits.CCcanbe

constant or an expression. If CC is positive, the

number of av

ailable units is increased. If CC is

negative, the capacity is decreased (Pritsker and

OʹReilly,1999;Pritskeretal.,1989).

3.2 TechnicalSpecificationsofBOTAŞTerminal

BOTAŞCeyhanMarineTerminal,thet

erminationof

Iraq–TurkeyCrudeOilPipeline,locatedwithinthe

district borders of Ceyhan at 36°51,9’N 35°56,7’E is

discussed in the present study. BOTAŞ Terminal is

ownedandoperated by BOTAŞ. It is in the BOTAŞ

Ceyhan Port Authority management area. The first

loadingoperationofthistermi

nalwasperformedin

1977. It consists of 4 quays. The loading arms in

loading‐unloading facilities are hydraulic system

operated via the crane tower located on the quay.

Quay1andquay2aresuitableforberthingvessels

with 100.000‐300.000 deadweight tons and quay 3

and quay are suit

able for berthing vessels with

30.000‐150.000deadweighttons(Figure1).

Figure1. BOTAŞ Ceyhan Marine Terminal quay

dimensions

Table1.SymbolsfrequentlyusedinAWESIM

__________________________________________________________________________________________________

SymbolNodeNames  Description

__________________________________________________________________________________________________

Create Createsentities

Activity Specifiesdelay(operation)timeandentityrouting

Queue Holdsentitiesuntilaserverbecomesavailable

Terminate Terminatestheroutingofentities

Assign Assignsvaluestoattributesorglobalsystemvariables

ResourceResourcedefinitionandinitialcapacity

Await Holdsentitiesuntilaresourceisavailableoragateisopen

Free Makesresourcesavailableforreallocation

AlterChangesthecapacityofaresource

__________________________________________________________________________________________________

146

Table2.CapacitiesofBOTAŞCeyhanMarineTerminalloadingarms(BOTAŞ,2005)

__________________________________________________________________________________________________

Port  Numbers Diameterofthe Loadingrate Maximum  Maximum  Minimum  Maximum

number ofarm  manifoldm3/hours  Draft(meter) LOA(meter) LOA(meter) Dwt.Tons

__________________________________________________________________________________________________

14 20ʺ‐18ʺ‐16ʺ4x500023 355 200 300000

24 20ʺ‐18ʺ‐16ʺ4x500023 355 200 300000

34 16ʺ‐14ʺ‐12ʺ4x250018 300 168 150000

 4416ʺ‐14ʺ‐12ʺ4x250017300168150000

__________________________________________________________________________________________________

4 AWESIMSIMULATIONAPPLICATIONS

AWESIM simulation network model is used in the

presentstudyforCeyha

nMarineTerminal.Thereare

4quaysinthismodel.Vesselsarriveattheportwith

4differentscenarioswithintervalsof12‐24hour,12‐

36 hour, 24‐36 hour and 24‐48 hour. It is assumed

tha

t same amount of vessels arrive at these four

quays. Waiting times of the vessels at the terminal

are calculated as 24 hours minimum 64 hours

maximumforquays1and2takingintoaccountthe

vessel dimensions, ballast capacities, coast loading

rateanddocumentprocessingpriortoandfollowing

the operation. On the other hand, tankers with

smaller dimensions compared to quays 1 and 2

berthsatquay3andquay4.Therefore,wait

ingtimes

of the vessels at the terminal are calculated as 16

hoursminimum64hoursmaximumforquays3and

4. Tugboat and pilotage service are required for

berthing and unberthing. Tugboat and pilot

age

servicecannot be rendered for other vessel  beforea

vesselberthingorunberthing.Tugboatandpilotage

serviceareconsideredasonehoureachforberthing

and unberthing operations. This port is unable to

offer tugboat and pilotage service on days with

stormyweather(Uğurlu,2006).Itisknowntha

tthere

are 30 days with stormy weather in one year for

CeyhanMarineTerminal(BOTAŞ,2005).

This simulation program is assessed for each

scenario over 8760 hours in total, i.e. 365 days.

Accordingly the number of vessels arriving at the

port,port queue volume,wait

ingtime for berthing,

waiting time for tugboat and pilotage services,

operability of tugboat and pilotage services and

operabilityofberthsareevaluated.

4.1 Scenario1

Scenario1issimulatedas vessel arrivingatBOTAŞ

CeyhanMarineTerminalin12to24hours(Figure2).

According to simulation outputs, it is observed

tha

t486vesselsarrivedintotalbeing118atquay1,

114atquay2,140atquay3and114atquay4.Any

vessel arriving at the berthing is able to commence

berthingafteranaveragewaitingtimeof12minutes.

Itisseentha

t1queueisformedforfourquays.The

quaysoperate at2,449 efficiency on the In terms of

tugboat service, any vessel arriving at the terminal

receives the tugboat service after an scale of 4; in

otherwordswith61%efficiency.

Averagewaitingtimeof13minutesandthereisa

queue of 2 vessels for such tugboa

t service. The

activityofthetugboatsis11%intotal(Table3).

Figure2. BOTA Ş Ceyhan Marine Terminal Scenario 1

simulationflowchart(12‐24hours)

4.2 Scenario2

Scenario2issimulatedas vessel arrivingatBOTAŞ

CeyhanMarineTerminalin12to36hours(Figure3).

According to simulation outputs, it is observed

that372vesselsarrivedintotalbeing94atquay1,90

atquay2,97atquay3and91atquay4.Anyvessel

arriving at the berth is ab

le to commence berthing

afteranaveragewaitingtimeof11minutes.Itisseen

that 1 queue is formed for four quays. The quays

operateat1,885efficiencyonthescaleof4;inother

words with 47% efficiency. In terms of tugboa

t

service, any vessel arriving at the terminal receives

thetugboatserviceafteran averagewaitingtimeof

10minutesandthereisaqueueof2vesselsforsuch

tugboatservice.Theactivityofthetugboatsis8,5%

intotal(Table4).