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1 INTRODUCTION

Maritime accidents have emerged in different ways

and their effects were different. The most common

types of maritime accidents were collision, allision,

contact, capsizing, flooding, foundering, breaking up,

grounding, stranding, breakdown of the ship

underway, and fire or explosion [1],[8]. Some of these

terms are quite simple, for example, grounding and

stranding are probably the most common maritime

incidents. However, most terms are often used

incorrectly. In fact, a ship is aground when she strikes

to the sea floor, while a ship is stranded when the ship

has been staying for a while. Similarly, flooding

means taking on excessive water in one or more of the

spaces of a ship such as the engine room, while

foundering is fundamental taking on water to the

point where the ship becomes unstable and begins to

sink or capsize. Another example that causes

confusion is collision vs allision and these accident

types constitute the two basic variables of this study.

These terms are generally used interchangeably, but

technically, the collision is the crashing of two ships,

while allision is used when a ship crashes to a fixed

object, such as a bridge or dock [19]. In other words,

the allision is defines an accident in which only one of

the objects moves, while the collision defines two

moving objects that collide with each other [4]. All

these accident types have different dynamics by their

nature and they have the potential to be prevented

with different intervention options. Literature review

has shown that maritime accidents occur most

frequently at chokepoints [6]. Maritime chokepoints

classified as primary routes that act as bridges

Evaluation of Tugboat Response Time as an Accident

revention Measure in the Strait of Istanbul

. Kodak

Istanbul Technical University,

Istanbul, Turkey

ABSTRACT: The Strait of Istanbul, 17 nautical miles long, is one of the main routes of international maritime

trade. Connecting the Black Sea countries with other countries of the world, the Strait is the second busiest

waterway in the world in terms of international ship traffic. In addition to busy sea traffic, limited geographical

conditions also make it difficult to navigational safety. The Strait of Istanbul is the only chokepoint that stands

out with the risk of maritime accidents on the primary routes of world maritime trade. This situation poses a

risk for both the transiting ships and the city of Istanbul, which has a dense population around it. Some of the

accidents that took place in the recent history have caused worldwide concern due to the environmental

pollution they cause. Considering the advantages p

rovided by the developing shipbuilding technology and

today load capacity of the ships, a disaster that will occur in a possible accident today will cause much greater

destruction than in the past. In this direction, it has become a necessity to examine the accident profile in the

strait in order to develop effective accident prevention measures and to strengthen the level of navigational

safety in the region. In this study, maritime accidents that occurred in the Strait of Istanbul over a 16-year period

were discussed in terms of their types and the response time of tugboats to a possible accident was examined.

http://www.transnav.eu

the

International Journal

on Marine Navigation

and Safety of Sea Transportation

Volume 16

Number 2

June 2022

DOI: 10.1271

6/1001.16.02.11

282

between major economies and secondary routes that

connect smaller markets. According to this

classification, Strait of Malacca, Strait of Istanbul,

Hormuz, Bab El-Mandeb, Gibraltar, Panama and Suez

channels are the primary chokepoints. Compared to

other primary chokepoints, the Strait of Istanbul is the

only waterway that stands out with its maritime

accident risk. In addition, the Strait of Istanbul is the

world's busiest waterway after the Strait of Malacca,

with an average of 50,000 ships passing annually [23].

The Strait of Istanbul was chosen as the study area,

both because it is the only waterway between the

Black Sea countries and other countries of the world,

and because it constitutes the riskiest area in terms of

navigation on the global maritime transport routes.

The length of the Strait of Istanbul is 17 nautical

miles. The curved geomorphology and the resulting

geometric constraints force passing ships into wide-

angle turns. A ship non stopover passage through the

Strait must change course at least 8 times during this

route [7]. These turns and route changes to be made

during these turns are shown in Figure 1.

Primary Turns

Fil Burnu 13°

Macar Burnu 73°

Koybaşı Burnu 82°

Kanlıca 46°

Aşiyan Burnu 39°

Kandilli Burnu 21°

Deftardar Burnu 36°

Kız Kulesi 51°

Figure 1. Large angular turns in the Strait of Istanbul

The Strait of Istanbul has been the subject of many

scientific studies until today due to the difficult

navigational conditions and the risk of marine

accidents. Effect of ship length as a factor in safe

navigation in the Strait of Istanbul has examined using

by AHP method. Obtained results have shown that

ships over lengths of 151 - 200 m has a risk on

navigational safety [11]. An artificial neural network

model was created to estimate maritime accidents in

the Strait of Istanbul. Study results have indicated that

vessels larger than 58.000 GRT caused accidents when

they did not receive piloting service [16]. In order to

mitigation of risks of the maritime traffic in the Strait

of Istanbul comprehensive scenario analysis has been

made [20].

It has been pointed out that the factors affecting the

safety of navigation in the Strait of Istanbul differ

according to the types of accidents [7]. Collision-type

accidents were investigated and a maritime traffic

modelling based on Automatic Identification System

[3]. It has been highlighted that collision and

grounding type accidents in the Strait of Istanbul are

generally made by general cargo ships and these

accidents tend to increase especially at night [26].

Maritime accidents in the Strait of Istanbul have

spatially analyzed the using the GIS method.

Obtained results have shown that the accidents were

concentrated in the waiting areas [21]. It has been

investigated the reducing the probability for the

collision of ships by changing the passage schedule in

Strait of Istanbul [15]. The Strait of Istanbul has been

evaluated in terms of ship passages, ship

hydrodynamics and blockage effect [5],[25]. Effect of

maritime traffic in the Strait on the number of

accidents was investigated using regression analysis.

The results obtained showed that the number of

passing ships had an explanatory power of 51% on the

accidents. Within the scope of the study, the accident

rate per ship was calculated and the results showed

that 76 out of every 10.000 ships passing through were

involved in the accident. The results of the study also

showed that the measures taken as a result of the

accidents and especially the VTS, which became

operational in 2003, have a reducing effect on the

accidents [12]. Due to one-way planning of traffic with

the Marmaray project that started in 2005, it has been

observed a noticeable reducing effect on maritime

accidents [13]. However, the Vita Spirit accident in

2017 brought forward a well-known vulnerability: in

the case of an engine breakdown and rudder failure

on the ship while passing through these narrow areas,

all the measures taken may remain useless. VTS with

all it’s services remains ineffective. In Vita Spirit case,

there was only 7 minutes between the engine

breakdown and ship crashed into house. Options that

can be initiated in order to prevent such an accident in

these 7 minutes are very limited. At this point, it has

been suggested that if there was a patrol tug near the

ship and pushed ship directing her back in the

channel could be a solution [14]. This solution

highlighted to all related parties to place patrol tugs in

certain areas in the Strait of İstanbul and monitor the

ships passing through very risky areas and take action

in the case of any wrong going. For this reason, the

need to investigate tugboat response time as an

accident prevention measure in narrow channels has

arisen and this has been the motivation of this study.

Reducing the risk of accidents for large commercial

vessels, both in port berthing and take-off maneuvers

and when navigating in restricted waters, requires the

help of specialized vessels that are well aware of the

region-specific features [17], [10], [22], [9]. These

vessels, called escort tugs, are specially designed to

produce the rudder and braking force necessary to

control the escorted vessel [17], [2]. In the literature,

there are various studies on tugboat intervention in

terms of navigational safety. When the factors

affecting collision type accidents are examined, the

importance of the arrival time of the tugboat for

emergency response draws attention [29]. Examining

the tugboat response time in the range of 15/30/45

minutes for emergency response on the Yangtze River

showed that the arrival time of the tugboat was

283

critical due to the limited response time [28]. There is

a size limit in terms of navigational safety for ships

that can maneuver even in the absence of wind,

current and wave in the Strait of Istanbul. Because

under unfavorable navigational conditions, it is not

possible for ships above certain limits to maintain

their position within the traffic lanes [24]. MSRCC

records have shown that 32 near-miss events occurred

between 2001-2016, which were caused by rudder and

engine failures and were prevented by tugboat

intervention before the accident occurred. This

number also means that about 2 accidents per year can

be prevented by tugboats. In this study, the temporal

and spatial profile of accident types in the Strait of

Istanbul was investigated, and the response time of

tugboats to a possible accident was examined. It is

thought that the results obtained will form an

infrastructure for policy makers to develop accident-

specific measures.

2 MATERIALS AND METHOD

The data used in this paper, is gathered by Republic of

Turkey Ministry of Transportation and Infrastructure

and it contains maritime casualty records between

2001 and 2016. In order to avoid confusion, maritime

accidents were categorized according to their own

characteristics. In this context, accident types that are

the categories of data set has determined as collision,

allision, contact, grounding, capsizing, drifting, fire,

engine breakdown, listing, person overboard and

other. The incidents outside of the main accident

types such as flooding, foundering, breaking up,

stranding, breakdown of the ship underway, water

ingress are mentioned under the heading "Other".

Maritime traffic in the Strait of Istanbul operates

on 3 VTS sector areas. These are Kadıköy, Kandilli

and Türkeli sector areas, from south to north,

respectively, as shown in Figure 2. The study area has

been filtered within the VTS sectors in the Strait of

Istanbul in order to observe the spatial profile of the

accidents in higher resolution and to identify the

high-risk points.

Figure 2. The area and sectors of Istanbul Vessel Traffic

Services [27]

In the scope of this study, a data set was created by

separating 590 accidents within the VTS sector areas

from all the accidents that occurred between 2001 and

2016, and these accidents were classified according to

both their types and the sector area in which they

occurred. Thus, it has become possible to see the

spatial profile of the accidents and it has been

revealed which accident type is concentrated in which

region. After the creation of the data set, the

classification of the accident types and the spatial

profile of the accidents, the time-dependent variation

of the accident types was investigated. The last part of

the study was devoted to the examination of tugboat

efficiency as accident preventive measure in the Strait

of Istanbul and the tugboat response time was

calculated in line with the geometric constraints of the

region. The process followed within the scope of the

study is shown in the flow chart in Figure 3.

Figure 3. Workflow of the study

3 RESULT AND DISCUSSIONS

The distribution of the accidents that occurred in the

Strait of Istanbul for 16 years according to their types

is given in Figure 4. As can be clearly seen from the

pie chart, the major accident type in the strait is

collision. The second type of accident that occurs

commonly is grounding. Other accidents that except

for the 10 defined accident types, take the 3rd place

among the most common accident types that have

occurred during the 16 years.

Figure 4. Distribution of accidents by types in the Strait of

Istanbul (2001-2016)

284

This was followed by drifting, fire, contact,

allision, capsizing, engine breakdown, person

overboard and listing, respectively. When the

maritime accidents in the Strait are analyzed

according to their types, it is seen that the accidents

that can be prevented by tugboat intervention have an

important place in the total accidents.

Table 1. Annual percentages by types of marine accidents in

the Strait of Istanbul

When the percentage of accidents occurring within

a year is examined separately for each year, the

percentage increase in the annual total of collision and

contact type accidents draws attention. Collision type

accidents accounted for only 30% of total accidents in

2001, while this rate increased to 83% in 2016.

Similarly, while the share of contact type accidents in

total accidents was 0.06% in 2001, this rate reached

16% in 2016. A common feature of these two accident

types, the frequency of which has increased

dramatically, is that both types of accidents are

accident types that can be prevented by tugboat

intervention. At this point, the individual profile of

accident types gains importance. In order to observe

the time-dependent change, time series plots were

created following the 16-year movement of each

accident type. Obtained results are given in Figure 5.

Figure 5. Time-dependent variation of maritime accident

types in the Strait of Istanbul

Figure 5 show the time-dependent change of each

accident type over 16 years. The vertical axis of the

graphs shows the number of accidents in the relevant

accident type, and the horizontal axis shows the years.

The blue line shows the 16-year average for the

relevant accident type. Accordingly, the findings from

Figure 5 mainly pointed out the following results for

each accident type.

− The average of collision type accidents is 11. The

number of collision type accidents, which reached

its peak in 2010, followed a steady downward

trend until 2015. The annual number of accidents

over the 16-year period is generally below the

average. Collision type accidents are the types of

accidents that can be prevented by tugboat

intervention when the time factor is used

effectively.

− Allision type accidents have shown a zig-zag

behavior over the 16-year period. Accidents

reached their maximum value in 2005. The annual

number of accidents is generally below the 16-year

average. Allision type accidents are among the

types of accidents that can be prevented by tugboat

intervention within the reaction time.

− Contact type accidents peaked in 2006 and 2007

and then showed a steady decline until 2010.

Annual accident frequency is generally below the

average. Contact type accidents are among the

types of accidents that can be prevented by tugboat

intervention within the response time.

− Grounding type accidents have not shown a steady

increase or decrease over the years. The annual

number of accidents is generally above the

average. Grounding type accidents are among the

types of accidents that can be prevented by tugboat

intervention within the response time.

− Drifting and engine breakdown accidents are the

types of accidents that reached their maximum

value in 2010. The annual number of accidents in

both types of accidents is generally below the

average. Both two types of accidents can be

prevented by tugboat intervention within the

response time.

− Fire, listing, personal overboard and other types of

accidents have followed a fluctuating profile over a

16-year period. All four types of accidents are not

accident types that can be prevented by tugboat

intervention in terms of navigational safety.

The Strait of Istanbul has its own dynamics in

terms of environmental factors affecting maritime

traffic. Features such as its curving geomorphology

and current system make different areas of the strait

defenseless for different types of accidents. At this

point, the spatial distribution of accident types is

important. Figure 6 shows the distribution of

accidents in the strait by VTS sector areas.

285

Figure 6. Spatial profile of maritime accident types in the

Strait of Istanbul

As can be clearly seen from the pie chart, the

accidents occur overwhelmingly within the

boundaries of Sector Kadıköy. So much so that the

accidents occurring in the Sector Kadıköy region

constitute 65% of the total number of accidents in 16

years. It is followed by Sector Kandilli with 19.6% and

Sector Türkeli with 15.4%, respectively. Another

result given by Figure 6 is that the accidents in the

Strait of Istanbul increase from south to north. In

other words, when the spatial profile of the accidents

in the strait is examined, it is observed that the

accidents increase from south to north.

Table 2. Distribution of accident types by regions in the

Strait of Istanbul

Table 2 shows that collision type accidents in the

Strait of Istanbul are overwhelmingly concentrated in

the Sector Kadıköy region. At this point, it has become

a requirement to develop special measures for

collision type accidents within the boundaries of

Kadıköy sectoral area in order to prevent collision

type accidents. To prevent this situation, tugboats

patrolling the Strait of Istanbul have been suggested

as a solution in the literature [14].

Wide of the Strait of İstanbul in most areas changes

between 0.5 and 1 nautical mile. This geometric

constraint creates a major difficulty in terms of

navigation. Typical ship speed on the ground varies

between 8 to 12 knots, it roughly means that the

response window for the tug intervention could be as

little as 1 minute (half the strait width) and 30 minutes

the most. On the other hand, maximum speed of a

typical tug at low sea conditions is about 14 knots. In

other words, if the tugboat is at a distance of 0.25

nautical miles from the ship, it will take

approximately 2 minutes to reach the ship [7]. In this

direction, considering the geometrical constraints of

the Strait, the response time of the tugboat for a

possible accident was calculated as follows.

Figure 7. Route alternatives for tugboat.

In Figure 7, L represents the straight area channel

length and B represents the channel width.

B1 = B

min = 0.5 nm.

L1 = L

min = 3 nm.

V1 = 8 knots.

B2 = B

max = 1,0 nm.

L2 = L

max = 4 nm.

V2 = 12 knots.

The route alternatives that the ship with a rudder

or engine failure can make from the 0 point (origin) at

the entrance of the straight channel and on the middle

axis are

and

OB OC OA= +

(Pythagorean theorem)

1 1852

1 0,5144 / .

1 3600

Distance

Time

Speed

nautical mile m

knot m s

hour s

= ≌≌

Table 3. Tugboat response time

_______________________________________________

Alternatives B L V Route t

(nm) (nm) (kn) OA OB OC (minute)

(nm) (nm) (nm)

_______________________________________________

1 0,5 - 8,0 0,25 - - 1,875

2 0,5 - 12,0 0,25 - - 1,250

3 1,0 - 8,0 0,50 - - 3,750

4 1,0 - 12,0 0,50 - - 2,500

5 0,5 3,0 8,0 0,25 3,010 3,0 22,600

6 0,5 4,0 8,0 0,25 4,008 4,0 30,600

7 1,0 3,0 8,0 0,50 3,041 3,0 22,800

8 1,0 4,0 8,0 0,50 4,031 4,0 30,230

9 0,5 3,0 12,0 0,25 3,010 3,0 15,050

10 0,5 4,0 12,0 0,25 4,008 4,0 20,040

11 1,0 3,0 12,0 0,50 3,041 3,0 15,210

12 1,0 4,0 12,0 0,50 4,031 4,0 20,160

13 - 3,0 8,0 - - 3,0 22,500

14 - 3,0 12,0 - - 3,0 15,000

15 - 4,0 8,0 - - 4,0 30,000

16 - 4,0 12,0 - - 4,0 20,000

_______________________________________________

a) Time to hit the channel edges: (Alternative 1-4)

minimum = 1,25 minutes, maximum = 3,75 minutes

(Route (

))

b) Hitting the channel edge for the diagonal route

((

) ): (Alternative 5 -12)

minimum = 15,05 minute, maximum 30,23 minutes

286

c) End of straight channel for straight course ((

) )

in midline:

minimum = 15 minutes, maximum = 30 minutes

(Alternatives 13 - 16)

Within the framework of the above calculations,

the response time for tugboat intervention can be

change between a minimum of 1.25 minutes and a

maximum of 30 minutes. This rate can be expressed as

approximately 1 to 30 minutes.

4 CONCLUSION

As a result of the study, the following conclusions

have been reached.

− It has been observed that the main accident types

in the Strait of Istanbul are collision and

grounding, respectively. These accidents were

followed by drifting, fire, contact, allision,

capsizing, engine breakdown, person overboard

and listing respectively.

− Main accident groups except by "other" are the

types of accidents that can be prevented by tugboat

intervention within the response time.

− When the spatial profile of the accidents is

investigated, it is observed that the accidents are

concentrated in the Sector Kadıköy area.

− Maritime accidents in the Strait of Istanbul increase

from north to south.

− The temporal profile of the accidents did not show

a stable trend on the basis of accident type, but it

revealed that the measures introduced recently had

an effect on increasing the safety of navigation.

− The establishing of VTS and the one-way planning

of the traffic in line with the Marmaray Project led

to a sharp decline, especially in Collision and

contact type accidents, after 2010.

− In line with the accident profile obtained, it has

been concluded that tugboats will contribute to the

safety of navigation as an accident preventive

measure. In other words, it has emerged that

tugboats can intervene in accidents before they

occur with the effective use of the time factor. In

this direction, the response time of a tugboat was

calculated considering the geometrical constraints

of the Strait of Istanbul. Obtained results showed

that tugboat response time varied between 1.25

and 30 minutes. In this direction, it is critical for

policy makers to develop measures that will

highlight tugboat intervention.

− The results of the study supported the judgment

that especially patrolling tugboats would play an

active role in preventing accidents within the

response time.

− In this concept, tugboats using Kort – nozzle

propeller, Voith – Schneider propeller and

Schoettel propeller are recommended.

ACKNOWLEDGEMENT

This work was supported by the Research Fund of Istanbul

Technical University. Project Number: 41217.

REFERENCES

[1] Akten, N. (2006). Shipping accidents: a serious threat for

marine environment, J. Black Sea/Mediterranean

Environment, Vol 12:269-304.

[2] Allan, R., Molyneux, D. (2004). Escort tug design

alternatives and a comparison of their hydrodynamic

performance. Trans. SNAME (112), 191–205.

[3] Altan, Y.C. (2017). Analysis and modeling of maritime

traffic and ship collision in the Strait of Istanbul based

on Automatic Vessel Tracking System. PhD Thesis,

Graduate Program in Civil Engineering Boğaziçi

University, Istanbul.

[4] Arnold & Itkin (2018): What Is an Allision?

https://www.offshoreinjuryfirm.com/maritime-

law/maritime-law-glossary/what-is-an-allision-/, last

accessed 2022/01/25.

[5] Aşkın, F., Oğuzülgen, S., Tenker, S. (2020). İstanbul

Boğazı ve Kanal İstanbul’un gemi geçişleri açısından

değerlendirilmesi, Kanal İstanbul - Çok Disiplinli

Bilimsel Değerlendirme, İstanbul Buyukşehir Belediyesi

Kultur A.Ş., (Eds: Orhon D., Sözen S., Görur N.,

İstanbul, 2020)

[6] Butt N., Johnson D., Pike K., Pryce-Roberts N., Vigar N.

(2012). 15 Years of shipping accidents: a review for

WWF, Southampton Solent University.

http://awsassets.panda.org/downloads/15_years_of_ship

ping_accidents_a_review_for_wwf_.pdf, last accessed

2022/05/27.

[7] DNV (2013). Det Norske Veritas Report, Escort tug

effectiveness in the Bosporus Strait, Chevron Products

UK LTD, REPORT NO./DNV REG NO.: 2013-9178 / 1-

6YRAF0, REV 1, 2013-04-25

[8] EMSA (2014). European Maritime Safety Agency,

Annual overview of marine casualties and incidents

2014, http://emsa.europa.eu/news-a-press-

centre/external- news/item/2303-annual-overview-of-

marine-casualties-and-incidents-2014.html

[9] ETA (2015). Guidelines for harbour towage operations.

Tech. Rep, European Tugowners Association.

[10] Iglesias-Baniela, S., Vinagre-Rios, J., Perez-Canosa, J.

M., (2021). Ship handling in unprotected waters: a

review of new technologies in escort tugs to improve

safety. Appl. Mech. 2, 46–62.

[11] Keçeci, T. (2010). Analysis of the effects of ship length

factor to safe navigation in the Strait of Istanbul by using

the AHP Method. MSc Thesis, Istanbul Technical

University, Graduate School of Science Engineering and

Technology, Istanbul,

[12] Kodak, G., Acarer, T. (2021). İstanbul Boğazı’nda deniz

trafik düzenlemelerinin kaza oranına etkisinin

değerlendirilmesi. Aquatic Research, 4(2), 181-207,

DOI:10.3153/AR21015

[13] Kodak, G., Kara, G., Yıldız, M., Salcı, A. (2022).

Investigation of maritime accidents in the strait of

Istanbul in the perspective of navigational safety:

İSTANBULMAX ship type recommendation. Aquatic

Research, 5 (1), 63-88. DOI: 10.3153/AR22007

[14] Kodak, G., Istikbal, C. (2021). A Suggestion to improve

navigational safety in the Strait of Istanbul (Bosphorus):

Patrol tugs, J. Black Sea/Mediterranean Environment,

Vol. 27, No. 3: 342-366 (2021)

[15] Korçak, M., Balas, C. E. (2020) Reducing the probability

for the collision of ships by changing the passage

schedule in Istanbul Strait. International Journal of

Disaster Risk Reduction. doi: 10.1016/j.ijdrr.2020.101593

[16] Kuçukosmanoğlu, A. (2012) Maritime accidents forecast

model for Bosphorus, Ph.D Thesis, Middle East

Technical University, Faculty of Civil Engineering.

[17] Mauro, F. (2022). A flexible method for the initial

prediction of tugs escort capability, Ocean Engineering,

246 (2022) 110585, DOI:10.1016/j.oceaneng.2022.110585

[18] MSRCC (2018). Main Search and Rescue Coordination

Center, Ministry of Transport Maritime Affairs and

287

Communications, GMK Boulevard, No 128, Maltepe

ANKARA/TURKEY

[19] NOAA (2018). Office of Response and Restoration,

“You Say Collision, I Say Allision; Let's Sort the Whole

Thing Out”,

https://response.restoration.noaa.gov/about/media/you-

say-collision-i-say-allision- lets-sort-whole-thing-

out.html

[20] Özbaş, B., Or, İ., Altıok, T. (2013). Comprehensive

scenario analysis for mitigation of risks of the maritime

traffic in the Strait of Istanbul. Journal of Risk Research

16(5): 541-561.

[21] Özdemir, M. (2019). Spatial analysis and evaluation of

ship accidents occurred in Turkish Straits. MSc Thesis,

Karadeniz Technical University, Graduate School of

Natural and Applied Sciences, Maritime Transportation

and Management Engineering Graduate Program,

Trabzon.

[22] Paulauskas, V., Simutis, M., Placiene, B., Barzdziukas,

R., Jonkus, M., Paulauskas, D. (2021). The influence of

port tugs on improving the navigational safety of the

port. J. Mar. Sci. Eng. 9 (342), 1–20.

[23] Rodrigue, J. P. (2017). Maritime Transport, Major

maritime shipping routes and strategic passages, The

International Encyclopedia of Geography, Richardson

wbieg0155.tex V1 - 01/25/2016, Page 2.

https://doi.org/10.1002/9781118786352.wbieg0155

[24] Sarıöz, K., Narlı, E. (2003). Assessment of manoeuvring

performance of large tankers in restricted waterways: a

real-time simulation approach, Ocean Engineering,

Volume 30, Issue 12, August 2003, Pages 1535-1551.

[25] Şalcı, A. (2020). Evaluation of Canal Istanbul Project in

terms of ship movements, Kanal İstanbul - Çok Disiplinli

Bilimsel Değerlendirme, İstanbul Buyukşehir Belediyesi

Kultur A.Ş., (Eds: Orhon D., Sözen S., Görur N.,

İstanbul, 2020.)

[26] Şirin, Ö. (2018). Risk Analysis and Modeling of the

Maritime Traffic in the Strait of Istanbul, Ph.D. Thesis,

Graduate Program in Industrial Engineering, Boğaziçi

University.

[27] User’s Guide of Turkish Straits Vessel Traffic Services

(2018). Directorate General of Coastal Safety,

https://kiyiemniyeti.gov.tr/Data/1/Files/Document/Docu

ments/9S/6R/yY/wu/TSVTS_User_Guide_21.05.20.pdf

[28] Wu, B., Yan, X., Yip, T. L., Wang, Y. (2017). A flexible

decision-support solution for intervention measures of

grounded ships in the Yangtze River, Ocean

Engineering, Volume 141, 1 September 2017, Pages 237-

248, https://doi.org/10.1016/j.oceaneng.2017.06.021

[29] Wu, B., Zhaoa, C., Yip, T. L., Jiang, D. (2021). A novel

emergency decision-making model for collision

accidents in the Yangtze River, Ocean Engineering,

Volume 223, 1 March 2021, 108622,

https://doi.org/10.1016/j.oceaneng.2021.108622