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8/16/2019 [Doi 10.1057_jos.2014.38] T. Van Vianen; J. Ottjes; G. Lodewijks -- Belt Conveyor Network Design Using Simulation
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Belt conveyor network design using simulationT van Vianen*, J Ottjes and G Lodewijks
Delft University of Technology, Delft, The Netherlands
In this paper simulation is applied to design belt conveyor networks at dry bulk terminals. Stochastic variations in ship interarrival
times, shiploads and equipment availabilities enforce the use of simulation. Parameters that affect belt conveyor network designs
like the network connectivity, storage policy and stochastic distributions are evaluated in this paper. One of the main ndings is that
installing the maximum number of connections does not necessarily lead to better performances. Another nding is that redundancy
of piles (a pile is in reach of two stockyard machines) is more ef cient than increasing the number of connections. In a case study,
designs for belt conveyor networks were formulated and assessed using the simulation model developed.
Journal of Simulation advance online publication, 13 February 2015; doi:10.1057/jos.2014.38
Keywords: transport; queuing; simulation; stochastic processes; allocation and scheduling
1. Introduction
Dry bulk terminals are essential nodes in the supply chains for
coal and iron ore. These bulk materials are used for the world-
wide production of energy and steel. To facilitate the expected
growing cargo ows, new dry bulk terminals will be built or
existing ones will be expanded. In the supply chains for these
materials, bulk ships and cargo trains are generally used for
transport. The terminal operation is complex when both ships and
trains have to be served at the same time to meet predened
agreements (Robinson, 2007). This research focuses on the
transport network at the terminals. Such networks have to
facilitate all required transportation needs linking several sourcesand destinations and consist of belt conveyors and transfer points.
In a transfer point, the material ow is transferred between
different belt conveyors.
In this paper simulation is applied to determine the parameters
that affect the design of belt conveyor networks and to assess
such designs. In section 2, a literature review is presented about
dry bulk terminal design and in particular the network design.
The simulation model developed is introduced in Section 3.
In Section 4, the impact of terminal parameters on the network
design (like the network connectivity, the storage policy and the
redundancy of stockyard machines) is investigated. Section 5
demonstrates the integration of simulation for a belt conveyor
network design. Finally, conclusions are presented in Section 6.
2. Literature review
In Section 2.1, a literature review is presented for the design of
dry bulk terminals and in particular for belt conveyor networks.
Due to the lack of a comprehensive design method, references
published about pipeline networks were investigated to verify if
models presented can be applied for belt conveyor networks.
In Section 2.2, these papers are reviewed. Section 2.3 presents an
evaluation of this review and the selection for the modelling
approach.
2.1. Dry bulk terminal design
Papers that discuss belt conveyor network designs were hardly
found; possibly due to the protection of its substantial commercial
value by industrial practitioners or consultation companies. Even in
the most comprehensive design method for terminals, already
introduced by the United Nations Conference on Trade and
Development in 1985 (UNCTAD, 1985), there was no information
found how belt conveyor networks should be designed.
Many authors used simulation for the design of (parts of ) dry
bulk terminals. In Table 1, an overview is listed. Most of these
references applied simulation for a specic case; these models
cannot easily be applied for the design of belt conveyor networks.
Two references discussed the network design in particular.
Lodewijks et al (2009) proposed several belt conveyor congura-
tions for an export terminal. In this paper the following parameters
were investigated that affect network design; direct transshipment
of materials, type of belt conveyor and using multiple shared or dedicated transport routes. Boschert and Hellmuth (2010) applied
the ‘Simulation Tool for Conveying Systems’, developed by
Siemens AG, to design conveying systems. Although the case
studies presented look promising, the commercial programme is
required to perform comparable studies.
2.2. Pipeline network design
On the design of pipeline networks for the transport of water,
natural gas or hydrogen, a signicant amount of research has
*Correspondence: T van Vianen, Delft University o f Technology, Department
of Marine and Transport Technology, Mekelweg 2, 2628 CD, Delft,The Netherlands.
E-mail: [email protected]
Journal of Simu lation (2015), 1 – 9 © 2015 Operational Research Society Ltd. All rights reserved. 1747-7778/15
www.palgrave-journals.com/jos/
http://dx.doi.org/10.1057/jos.2014.38mailto:[email protected]://www.palgrave-journals.com/joshttp://www.palgrave-journals.com/josmailto:[email protected]://dx.doi.org/10.1057/jos.2014.38
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been performed; see for an extensive review André et al (2013).
Similar to the dry bulk industry products are transported in a
continuous mode. A belt conveyor can be compared with a pipe
and stockpiles with tanks. Some of the rst authors that discusspipeline networks were Mah and Shacham (1978). These authors
formulated the optimal network design as a constrained mini-
mization problem based on the number of pipe sections, the
length and diameter of the pipe sections, and cost coef cients that
are directly related to investment costs. This problem corresponds
with the determination of the required transport capacity of belt
conveyors but gave no suggestions for network layouts. Further-
more, a difference between dry bulk and tank terminals is that
generally at tank terminals, product dedicated or customer
dedicated pipelines are used between specic sources and
destinations.
André et al (2013) presented a methodology for the simulta-
neous determination of the topology and the diameters of
hydrogen transport networks. These authors stated that with the
choice made for a quadratic cost function and with head losses,
losses of energy due to the internal wall friction of pipes, optimal
networks are trees. This suggestion is a relevant one and can be
translated to belt conveyor networks where the yard conveyors
(that feed the stockyard machines) form the trunk and conveyors
that connect the loading and unloading machines to these yard
conveyors are branches. A difference between pipeline networks
and a belt conveyor network is that the rst networks are
generally equipped with multi-sources (ie many hydrogen pro-
duction plants) and the network ’s objective is to realize an
optimal facility location/allocation problem. At dry bulk term-inals there are multiple transports required at the same time from
specic sources and to specic destinations using a limited
number of belt conveyors.
2.3. Evaluation and selection of modelling approach
Design methods for belt conveyor networks were not found in
literature, although several authors used simulation to assist
during the design process of dry bulk terminals. Several batches
of materials must be transported simultaneously and on time
while taking the stochastic arrival processes, equipment break-
down behaviour and material ows into account. Furthermore,
dedicated transports have to be performed at the same time using
a limited number of belt conveyors. A simulation model will bedeveloped to consider the stochastic processes mentioned.
By varying characteristics in belt conveyor networks and by
registering the corresponding performances, relevant insight will
be acquired to design such networks.
3. Simulation model
This section introduces the simulation model that was developed
for the design of belt conveyor networks. The advantage of this
model is that not only the stochastic processes are considered but
also specic terminal operational procedures like the storage
policy and particular network characteristics are taken intoaccount. The approach followed is mentioned in Section 3.1.
Specic details of the simulation model are presented in Sections
3.2 and 3.3; the verication of this model is discussed.
3.1. The simulation-based approach
For the development of the simulation model the process-
interaction method introduced by Zeigler et al (2000) and
Fishmann (2001) was followed. The terminal was virtually
broken down into relevant element classes each with their typical
attributes resulting in an object-oriented data structure of the
system. For all active element classes process descriptions, whichdescribe the functioning of each element as a function of time,
were dened. In the simulation model all active elements act
parallel in time, synchronized by the sequencing mechanism of
the simulation software, in this case Delphi®, using the simula-
tion application TOMAS (Veeke and Ottjes, 1999).
3.2. Simulation model
The simulation model is applicable for both import and export
terminals but in this section the model will be explained for
Table 1 Review of references that applied simulation-integrated design of dry bulk terminals
Author(s) Year Design Application
Baunach et al 1985 Compare alternative berth and equipment congurations Coal terminal in Indonesia El Sheikh et al 1987 Planning of future berth requirements Third-world port Park and Noh 1987 Simulate future port capacity required Port of Mobile (US)Kondratowicz 1990 Simulation methodology for intermodal freight transportation terminals General
King et al 1993 Planning and de-bottlenecking studies Power plant in China Weiss et al 1999 Optimize receiving, storage, blending and shiploading facilities GeneralDahal et al 2003 Design and operation, including equipment replacement and operational scheduling Iron ore terminal in UK Sanchez et al 2005 Determination number of berths Power plant MexicoOttjes et al 2007 Improving operational control GeneralLodewijks et al 2009 Network design layouts and belt conveyor types (bi-way or single-way) Iron ore terminal India Boschert and Hellmuth 2010 Design and optimization of belt conveyor systems Stockyard at a steel factoryCassettari et al 2011 Determination grab unloader and storage capacities Coal power plant
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import terminals. Ships deliver bulk materials and trains pick upmaterial in small portions. Figure 1 shows an arbitrary terminal
layout with the main element classes; ships and trains with their
generators, piles of bulk materials at stockyard lanes (L1–L4),
belt conveyors and stockyard machines, in this case stacker-
reclaimers. Stacker-reclaimers combine the two functions of
stacking and reclaiming into a single unit. Consequently, only
one of the two functions can be fullled at a time.
Bulk handling activities are called jobs. A job can be a
trainload or a (part of the) shipload. The job material is stored
temporarily in a pile at the stockyard. Piles stored at the middle
lanes (L2 and L3) are in reach of two stacker-reclaimers. These
piles can be stacked and/or reclaimed together or separately at thesame time. In Figure 1 two generators are shown; one for ships
and one for trains. In the ship generator, the ship arrivals and
shiploads are determined using historical data or are sampled out
of analytical distributions. In the train generator the pile’s storage
time is determined using the storage time distribution and trains
are generated to pick up the pile’s material within its storage time.
To express the network connectivity, the indicator (τ ) [ − ] was
introduced. This indicator expresses the ratio between the number
of installed and the maximum number of connections. A connec-
tion is formed by a transfer point. For example, the routing
exibility (τ ) is 7 / 12 for the network shown in Figure 1 because
this network is equipped with seven transfer points while the
maximum number is 12.
3.3. Veri cation
Verication of the simulation model is required to check the
correct translation of the conceptual model into computer code
and to determine if the simulation model performs as intended.
Simulation results for a simplied network (as shown in
Figure 2a ) were compared with analytical results using queuing
theory. For the incoming (Qin) as well as the outgoing material
ow (Qout ) it was assumed that the interarrival times werenegative exponential distributed. Furthermore, it was assumed
that there was no variation in job size (called in queuing theory:
deterministic (D)) and both incoming and outgoing job sizes were
assumed as 100 kilotons [kt]. To each stacker-reclaimer three
grades were assigned. For example, at the lanes within the reach
of stacker-reclaimer 1 only material with grades A, B or C is
stored. When these conditions are considered, the terminal layout
of Figure 2a can be represented by two individual M/D/1-queuing
systems, as shown in Figure 2b.
The relation for the job waiting time as function of the service
time and the stockyard machines utilization was derived from an
M/G/1-queuing system. This relation was formulated by Tijms andKalvelagen (1994) and is expressed algebraically in Equation (1).
Wt ¼1
21 + c2 B
ρSR1 - ρSR
1
μ(1)
where Wt is the average job waiting time, expressed in the
inverse of the service rate [ μ], cB [ − ] is the variation coef cient
for the service times (for the M/D/1-queuing system this
coef cient is 0) and ρsr
[− ] is the average utilization for the
stacker-reclaimers.
For the simulation results the average ship and train port times
were determined at the end of each simulation run (displayed as a
single dot in the graphs that show the results) as function of the
machine utilization. To achieve an accuracy of ± 5% at least 8000ships have to be generated per simulation run.
Figure 3 shows the results for the verication study. From this
gure it can be concluded that the simulation results of the
simplied network correspond with the analytical results for the
M/D/1-queuing system. For more complicated networks and
more realistic input data (that takes the real-world ship interarrival
times and shiploads into account) the tracing function of TOMAS
was used to follow the unloading process of several ships. Results
of this analysis have shown suf cient reasons to consider that the
simulation model performs as intended.
Ship
generator
Interarrival time
distribution
Shipload
distribution
Bulk ship Cargo trainStacker-
reclaimer
Pile SR1
SR2
SR3
Train
generator
Storage time
distribution
Belt conveyor Transfer station Pile
Stockyard
lane
(un)loader Control signals
L1
L2
L3
L4
Figure 1 Schematic representation of the simulation model (description follows in text).
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4. Assessment of design parameters
In this section the following parameters that affect the network
design will be investigated; the network connectivity, the storage
policy and the stochastic processes. The network connectivity (τ )
was already introduced in the previous section and expressed the
number of transfer points installed versus the maximum number.
The storage policy and stochastic processes will be further
explained in Section 4.1. Simulation experiments are shown in
Section 4.2
4.1. Storage strategy and stochastic processes
For the storage policy, two different strategies were introduced by
Leech (2010); the cargo assembly mode (CAM) and Identity
Preserved (ID). For CAM, materials are stored in piles based on
their grade and for the ID-storage policy segregated piles are
formed for individual clients. The CAM storage policy is
generally applied at export terminals, where materials from a
limited number of mines are stored, or at single-user import
terminals. When the ID-storage policy is applied several piles can
contain the same grade but the pile owners are different. The
ID-storage policy is generally applied at stevedoring import
terminals where customers’ materials have to be stored individu-
ally to prevent mixing and to realize tracking and tracing of material. The potential downside of the latter storage policy is
that it demands a greater level of network exibility and
operational planning.
For the stochastic processes, several distribution types were
proposed. For the ship interarrival time distribution UNCTAD
(1985) and Bugaric and Petrovic (2007) stated that the arrivals of
bulk ships are best approximated by a Poisson arrival process.
The ship interarrival times can then be represented by a negative
exponential distribution (NED). Altiok claimed that at specialized
dry bulk terminals (eg, single user terminals) the interarrival
times show less variation. An Erlang-2 distribution can better be
applied for these terminals (Altiok, 2000).
For the ship service time distribution two references proposed
an Erlang-2 distribution, UNCTAD (1985) and Jagerman and
Altiok (2003). However, these distribution types do not corre-
spond with measured data from three dry bulk terminals. This
analysis has shown that the shipload varies signicantly and a t
with analytical distributions cannot be made. Empirical shipload
data can better be used as input to comply with real-world
operation.
There was no reference found that discussed the stochastic
variations of material stored at stockyards. To get an impression,
real-world data that contain storage times of 8500 piles during
19 years of operation for a specic terminal was analysed. The
average pile’s storage time was 0.2 year. A χ2
method was usedto t the storage time distribution with analytical distributions.
Results of this t show a match with the NED. This distribution
was implemented in the simulation model but using empirical
data is also possible.
For the belt conveyor network, the conveyor breakdown
behaviour must be considered as well. A transportation route
consists of multiple belt conveyors in series, if one belt conveyor
fails the entire route fails. According to van Beek (2009), the
system reliability can be approximated by multiplying the
availability of the individual components. Historical operational
Qin+ Qout
SR1
M/D/1
SR2
M/D/1
A B C
D E FQout
(M/D) 100 [kt]
B
C
Qin
(M/D) 100 [kt]
A
E
F
D
a b
SR1
SR2Qin+ Qout
Figure 2 Verication of the simulation model for a simplied network layout (a), which can be represented by two individualM/D/1-queuing systems (b).
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
0.3 0.4 0.5 0.6 0.7 0.8 0.9
W t [ 1 / µ ]
sr [-]
M/D/1
Simulation Results
Figure 3 Verication of the simulation model; comparison
between analytical results (M/D/1) and simulation results for thesimplied network layout as shown in Figure 2a .
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data of the utilization of belt conveyors at an export terminal
during 1 year of operation has shown a variation of the tech-
nical availability between 0.9 and 0.97. In this research, a
technical availability of 0.97 will be used for each belt conveyor.
In accordance to Tewari et al (1991) and van Beek (2009) the
(negative) exponential distribution is implemented in the simula-
tion model to describe the probability density function of a
failure. This distribution type corresponds with real-world opera-
tion; usually the failure time is relatively small (eg, fuse out due
to overloading) and a single time exceptional long (eg, the belt is
demolished).
In the simulation model, the active job’s handling time will be
extended with the repair time of the broken conveyor. This
corresponds with reality, changing a route is not regularly
performed due to the short downtime and relatively long start-up
times of another route.
4.2. Simulation experiments
A network layout as shown in Figure 1 is used to investigate thestorage policy on the network design. The simulation model was
applied to determine for several scenario’s the sum of the average
ship and train port times. The input parameters used are listed in
Table 2.
Two network congurations are shown in Figure 4 for the
CAM-storage policy. The allocation of grades to the stacker-
reclaimers is different for both scenarios. In Figure 4a each grade
is assigned to a single machine and in Figure 4b each grade is
assigned to two machines. This distribution of grades across
multiple machines corresponds to the stockpile duplication
proposed by Leech (2012) and introduces a stacker-reclaimer
redundancy.
Figure 5 shows the sum of the average ship and train port times
versus the annual throughput (Q) for both layouts as shown in
Figure 4. Another layout with a fully equipped network (τ =1)
was assessed. This layout is not displayed separately in this paper
but can easily be derived by combining the network conguration
from Figure 6b with the stockyard layout of Figure 4a . From
Figure 5 it can be concluded that stacker-reclaimer redundancy
realizes a larger reduction of the sum of the average ship and train
port times than a fully equipped network.
For the assessment of the ID-storage policy, the network
congurations as shown in Figure 1 and 6 are used. The network
connectivity varies from τ =7/12 (Figure 1) until τ =1 (Figure 6b).
0
30
60
90
120
150
10 12 14 16 18 20
W s h i p + W t r a i n
[ h ]
Q [Mt/y]
Fig. 4A, CAM, τ=7/12
CAM, τ=1
Fig. 4B, CAM, τ=7/12, SR-redundancy
Figure 5 The sum of the average ship and train port times versusthe annual throughput for the CAM-storage policy.
(CAM, τ=7/12)
SR1
SR2
SR3
A
BC
DE
F
(CAM, τ=7/12, stacker-reclaimer redundancy)
SR1
SR2
SR3
BA
C D
E F
A B
a b
Figure 4 CAM-storage policy with different grade allocation procedures; (a) each grade is assigned to a single stacker-reclaimer and
(b) each grade is assigned to two stacker-reclaimers.
Table 2 Input parameters for the simulation model
Parameter Value Parameter Value
Ship interarrival time distribution NED SR-capacities [kt/h] 2.5Shipload distribution Historical data* Average pile’s storage time [h] 500Storage time distribution NED Average shipload [kt] 101Belt conveyor technical availability [− ] 0.97 Trainload 4
*Based on data of 898 visited ships at a dry bulk terminal.
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Figure 7 shows the results determined. As expected, the average
port times decrease when the network connectivity increases.
However, the reduction of the port times is limited when the
network connectivity was increased from ¾ until the maximum
value of 1. For this case, a fully equipped network does not
bring that much improvement anymore compared to a less
extended belt conveyor network.
The impact of the stochastic distributions on the network
design was investigated by evaluating the layout of Figure 1 with
different stochastic distributions. The rst series (Figure 1, ID,
τ = 7/12, M/G (Hist. data)) was already shown in Figure 7. For
the same layout, the Erlang-2 distribution was used to represent the ship interarrival times and shiploads were sampled uniformly
between 50 and 150 [kt]. The results are shown in Figure 8.
A reduced variability of the ship arrival processes enables
installing a less extended belt conveyor network still guarantee-
ing the predened performance.
5. Network design: a case study
To demonstrate the application of simulation during the design
process of belt conveyor networks a case study was formulated.
A terminal operator planned to redesign a part of its belt conveyor
network. Within this part, shown with the hatch lled rectangle in
Figure 9, many connections between different belt conveyors can
be made. The rst step was to implement Layout 2011, which is a
combination of Figures 9 and 10a , into the simulation model to
determine the initial performance. Besides, the possible connec-
tions for Layout 2011 were investigated. Two alternative designs
will be formulated and assessed in this case study. These designs
must comply with the requirement that at least the same
connections must be possible as it was in the original layout.
More details from the formulation of both alternative designs are
listed below.For the rst design (as shown in Figure 10b) an extra
requirement was formulated that even a comparable simultaneity
of the transport activities should be realized as in the current
layout. This means that the number of routes that can be used at
the same time may not be reduced. To reduce the number of
transfer points, dedicated belt conveyors are proposed between
the stacker-reclaimers (SR1: 210, SR2: 220 and SR3:230) and
loading machines. The consequence was that all quay conveyors
(numbers 10, 20 and 30 in Figure 10b) need to be connected
to the three stacker-reclaimers via the four cross-conveyors
SR1
SR2
SR3
(ID, τ=¾) ba (ID, τ=1)
SR1
SR2
SR3
Figure 6 ID-storage policy applied at two layouts each with different values for the network connectivity (τ ).
0
30
60
90
120
150
10 12 14 16 18 20
W s h i p + W t r a i n
[ h ]
Q [Mt/y]
Fig.1, ID, τ=7/12
Fig.6A, ID, τ=¾
Fig.6B, ID, τ=1
Figure 7 The sum of the average ship and train port time versusthe annual throughput for different network layouts.
0
30
60
90
120
150
10 12 14 16 18 20
W s h i p + W t r a i n
[ h ]
Q [Mt/y]
Fig.1, ID, τ=7/12, M/G (Hist.data)
Fig.1, ID, τ=7/12, E2/G (50-150 [kt])
Figure 8 ID-storage policy applied for network layout as shownin Figure 1 with different stochastic distributions.
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(100, 110, 120 and 130) while one or two of them are active with
reclaiming. Using dedicated belt conveyors reduced the total
number of belt conveyors in the terminal from 51 to 45. Two
extra transfer points are needed to realize all connections resulting
in an increase of the network connectivity (τ ) from 0.9 to 0.94.
Advantages of this design are the expected decrease of the
disturbance time, thanks to the reduction of belt conveyors, and
the decrease of the transportation power because the material
does not need to be fed up as frequent as in the existing layout.
For the formulation of the second design (as shown in
Figure 10c) it was allowed that some routes, which are hardly
used simultaneously based on historical operational data, cannot
be performed at the same time anymore. The transport of
materials to the second barge loader (belt conveyor 520 in
Figure 10c) cannot be performed at the same time anymore when
material is transported to the iron ore railcar loader (135) or to the
blending silo’s (114). This concession was justied by the fact that at the terminal three barge loaders are installed and loading of
three barges at the same time did hardly happen. Moreover, a
relatively small amount of material (11% of coal) is fed to the
blending silos so the probability is limited that this conicting
situation will occur. Design 2 applies further the fundamentals of
the rst design; all quay conveyors need to be connected to the
cross-conveyors and dedicated belt conveyors are proposed for
the transport to the loading machines. In Design 2 less transfer
points are then needed resulting in a decrease of the network
connectivity (τ ) to 0.83.
For the terminal layout of Figure 9 combined with one of the
network layouts as shown in Figure 10, the average port times for
ships and landside jobs (trains, barges, coastal ships and exports
to the coal-red power plant) were determined using the simula-
tion model as function of the annual throughput. The input
parameters as listed in Table 2 were used and the results are
shown in Figure 11. From this gure, it can be concluded that the
average port times will be reduced when both designs will be
applied in comparison to the existing layout, which is
Layout 2011.
The minor difference in port times between design 1 and
design 2 is remarkable. Although the belt conveyor network of
design 2 is less redundant, the higher network connectivity does
not bring a signicant reduction of the average port times for
design 1. Apparently, the conicting situations when material
must be transported to the second barge loader, the iron ore rail
car loader and the blending silos at the same time are rare.In conclusion, for the redesign of the belt conveyor network
design 2 is proposed because a comparable reduction of the
average port times will be realized as for design 1 but the network
can be carried out simpler and cheaper.
6. Conclusions
Belt conveyor networks have to facilitate transport activities
to meet the contractual agreements for the terminal’s seaside
SR5
SR6
SR3
SR4
Figure 10
SR1
SR2
QCV1 QCV2 QCV3
L1
L7
L2
L3
L4
L5
L6
Figure 9 The investigated terminal layout with the redesign object (shown with the hatch lled rectangle).
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and landside. Due to the lack of comprehensive models that
can support the belt conveyor network design and to take the
stochastic processes into account, a simulation model was
developed. To be in line with the terminal operation, empirical
data can be used as input. Nevertheless, analytical distri-
butions can also be selected to represent the stochastic
variations. The simulation model was applied to determine the
consequence of parameters like the network connectivity,
storage policies and stochastic processes on the design of belt
conveyor networks. The stacker-reclaimer redundancy, a pilestored at the stockyard is in reach of two stockyard machines,
results in a larger reduction of the average ship port time
(which is the objective for terminal operators) than an
increase of the number of connections. Another nding was that
installing the maximum number of connections does not
lead directly to better performances. The stochastic variations
should be considered as well during belt conveyor network
design. An increase of the variation requires more active
transport routes at the same time and more connections are
needed to realize the performance predened. In a case study,
Layout 2011 (τ: 0.9) Design 1 (τ: 0.94) Design 2 (τ: 0.83)
135
240 240
20
30
10
210
220
230
5 1 0
5 2 0
410
1 1 4
1 4 4
1 5 4
240
420
712
135
1 3 0
1 2 0
1 1 0
1 0 0
1 1 1
1001
1 3 1
1341000
340
330
210
220
230
135
20
30
10
1 3 0
1 2 0
1 1 0
1 0 0
210
220
230
1 1 1
5 1 0
5 2 0
410
1 1 4
1 1 1
1 2 1
1 3 1
1 4 4
1 5 4
134
340
420
712
330
Belt conveyor
1 1 4
10
20
connection
1 3 0
1 2 0
1 1 1
712
5 1 0
5 2 0
410
420
1 1 3
1 2 2
1 3 2
1 3 6
1 4 4
1 5 4
330
134
1 3 3
1 2 3
340
131121
Transfer point
30
a b c
Figure 10 Different network congurations for the redesign object; existing layout in 2011 (a) and two designs (b–c).
60
75
90
105
120
25 30 35 40
W s h i p +
W l a n d s i d e j o b [ h ]
Q [Mt/y]
Layout 2011 (τ=0.9)
Design 1 (τ=0.94)
Design 2 (τ=0.83)
Figure 11 The sum of the average port times for ships andlandside jobs (trains, barges, etc) for the existing layout and newdesigns.
8 Journal of Simulation
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the simulation model was applied to formulate and to assess belt
conveyor networks for the replacement of a part of an existing
network.
Acknowledgements—The authors acknowledge the terminal operator whoprovided operational data of the ship arrival and storage processes and for giving valuable feedback during this research.
References
Altiok T (2000). Tandem queues in bulk port operations. Operations
Research 93(2000): 1–14.
André J et al (2013). Design and dimensioning of hydrogen transmission
pipeline networks. European Journal of Operational Research
229(1): 239–251.
Baunach GR, Wibberley ES and Wood BR (1985). Simulation of a coal
transshipment terminal: Batam Island, Indonesia. Mathematics and
Computers in Simulation 27(1985): 115–120.
van Beek A (2009). Advanced Engineering Design. Lifetime Perfor-
mance and Reliability. VSSD: Delft.
Boschert S and Hellmuth T (2010). Simulation in bulk material handling.Proceedings of the BulkSolids Europe Conference, Scotland.
Bugaric US and Petrovic DB (2007). Increasing the capacity of terminal
for bulk cargo unloading. Simulation and Modelling Practice and
Theory 15(2007): 1366–1381.
Cassettari L, Mosca R, Revetria R and Rolando F (2011). Sizing of a
3,000,000t bulk cargo port through discrete and stochastic simulation
integrated with response surface methodology techniques. Proceed-
ings of the 11th WSEAS International Conference on Signal Proces-
sing, Computational Geometry and Articial Vision, Italy.
Dahal KP, Galloway SJ, Burt GM, McDonald JR and Hopkins I (2003).
A port system simulation facility with an optimization capability.
International Journal of Computational Intelligence and Applica-
tions 3(4): 395–410.
El Sheikh AAR, Paul RJ, Harding AS and Balmer DW (1987).
A microcomputer-based simulation study of a port. Journal of theOperational Research Society 38: 673–681.
Fishmann GS (2001). Discrete Event Simulation — Modeling, Program-
ming and Analysis. Springer-Verlag: New York.
Jagerman D and Altiok T (2003). Vessel arrival process and queuing in
marine ports handling bulk materials. Queuing Systems 45(3): 223–243.
King DH, Radomske BA and Manocha GS (1993). Recent advances
in simulation models for bulk terminal design. Bulk Solids Handling
13(1): 23–27.
Kondratowicz LJ (1990). Simulation methodology for intermodal freight
transportation terminals. Simulation 55(1): 49–57.
Leech J (2010). Design of an ef cient coal export terminal. Proceedings
of the Queensland Mining & Engineering Exhibition, Australia.
Leech J (2012). Optimizing a bulk minerals export chain. Mining
Magazine 11: 42–48.
Lodewijks G, Schott DL and Ottjes JA (2009). Modern dry bulk
terminal design. Proceedings of Beltcon 14 Conference, South Africa.
Mah RS and Shacham M (1978). Pipeline network design and synthesis.In: Drew TB (ed). Advances in Chemical Engineering. Academic
Press: London, pp 142–226.
Ottjes JA, Lodewijks G and Schott DL (2007). Bulk terminal modelling
and simulation. Proceedings of the Industrial Simulation Conference
(ISC 2007), The Netherlands.
Park CS and Noh YD (1987). A port simulation model for bulk cargo
operations. Simulation 48(6): 236–246.
Robinson R (2007). Regulating ef ciency into port-oriented chain
systems: Export coal through the Dalrymple Bay Terminal, Australia.
Maritime Policy & Management 34(2): 89–106.
Sanchez C, Uribe R and Espinal JC (2005). Port simulation model
for the discharge and delivery of imported coal for a thermal power
plant located in Lazaro Cardenas Port, Mexican Pacic Coast.
Proceedings of 2nd International Conference on Maritime Heritage,
Spain.Tewari PC, Singh IP and Khare MK (1991). Reliability analysis of a
conveyor belt system, with only one server, subject to failures and
idleness after repair. Microelectronic Reliability 31(5): 823–826.
Tijms HC and Kalvelagen EM (1994). Modelbouw in de Operations
Research. Academic Service: Schoonhoven.
United Nations Conference on Trade and Developments (UNCTAD)
(1985). Port Development, A Handbook for Planners in Developing
Countries. United Nations Conference on Trade and Developments
(UNCTAD): New York.
Veeke HPM and Ottjes JA (1999). Tomas: Tool for object-oriented
modeling and simulation. Proceedings of the Business and Industry
Simulation Symposium ASTC 1999, United States.
Weiss M, Thomet M and Mostou F (1999). Interactive simulation
model for bulk shipping terminals. Bulk Solids Handling
19(1): 95–98.Zeigler BP, Praehofer H and Kim TG (2000). Theory of Modeling and
Simulation. Academic Press: San Diego.
Received 25 February 2014;
accepted 29 October 2014 after one revision
Teus van Vianen et al —Belt conveyor network design using simulation 9