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APPLICATION OF THE SYSTEM DYNAMICS TO THE WRECK OF THE TORREY CANYON

Shinji SHIMA 1, Kenji ISHIDA 2, Masao FURUSHO 3, Masaki FUCHI 4

1A senior student

Faculty of Maritime Sciences, Kobe University, JAPAN

Tel: +81-90-9857-2858

shimashin2@hotmail.com

2 Prof. Ph.D.

Graduate School of Maritime Sciences, Kobe University, JAPAN

k-ishida@maritime.kobe-u.ac.jp 3 Prof., Ph.D., Capt.

Graduate School of Maritime Sciences, Kobe University, JAPAN

Tel: +81-78-431-6246 Mobile +81-90-5362-2858

furusho@maritime.kobe-u.ac.jp 4 Lecturer Capt.

Graduate School of Maritime Sciences, Kobe University, JAPAN

mfuchi@maritime.kobe-u.ac.jp

ABSTRACT

The wreck of the tanker TORREY CANYON occurred in 1967. This resulted in the biggest oil pollution

accident ever recorded up to those times. At the official report of the Liberian Board of investigation, only the

Master of the TORREY CANYON was owned the responsibility of this marine casualty. But they did not

indicate the specific quantified data why this marine casualty had happened. This is because there is no

synthesized method to major human factors.

In this study this marine casualty was analyzed by the method of the m-SHELL model to extract the factors.

Then the important factors are chosen and quantified. Finally, these quantified factors are applied to the

System Dynamics so as to know the transition process of the wreck and safety voyage for future work.

The System Dynamics is a simulation tool to understand the complex system over time which allows us to

simulate over time without model time into the system. And the models are created graphically, so the

relationships of the factors are easily understood. Furthermore, we can model feedback structures, that is,

structures where cause and effect feed back on each other. For those reasons, this simulation tool is applied to

various fields such as economics and social studies and could even be applied to almost unlimited fields.

Through this study we intended to clarify how human factors affected the wreck of tanker TORREY

CANYON just immediately before it and we also intended to identify whether the application of System

Dynamics to the marine casualty is totally effective.

Keywords : System Dynamics, TORREY CANYON, Human Factors

1. INTRODUCTION

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It is said that industrial accidents will never disappear from the world. This opinion could be applied

to the field of merchant marine transportation. In these decades navigational equipment and the structure

of ship herself have advanced much. On the other hand, the number of marine casualty has not decreased.

These are due to two main reasons. Firstly, the number and the size of ship have emerged. The quantity of

cargo is also increased along with it. The other reason is that the problem of human factors is not solved. In

the statistics of Japan, 80 percent of marine casualties are caused by the human factors and almost all of

marine disaster relates to human actions(1). It could be said that to lose or to weaken the damage of marine

casualties, we have to understand human factors more.

1.1. Objective of This Study

Though the most of investigation about the marine casualties refers to human factors as reasons of accident,

almost all of them do not show the quantitative data of them. This is because there is no synthesized

method to major human factors. But the quantitative data is needed to know the details of casualties and to

prevent future accidents.

This study had tried to show the effect of human factors quantitatively by using the System Dynamics and

applied this to the wreck of TORREY CANYON. The merits of using the System Dynamics are not only

that we can gain the quantitative data, but also that we can visually understand the transition process.

Furthermore we can output many kinds of data as a graph or chart. From these reasons, this study also

intended to identify whether the application of the System Dynamics to the marine casualty is totally

effective. 2. LITERATURE SURVEY

2.1. The wreck of the tanker TORREY CANYON

On 18th March, 1967 the tanker TORREY CANYON struck Pollard’s Rock in the Seven Stones reef, just

west of Land’s End, England. She left Mina al-Ahmadi on 19th February with full cargo of crude oil then

planed to go Milford Haven, England. She was the first of the big supertanker, carrying a cargo of 120,000

tons of oil. In this accident the 80,000 tons of oil leaked from the ship and spread along the sea between

England and France, killing most of the marine life it touched along the whole of the south coast of Britain

and the Normandy shores of France(2).

The Liberian Board of the Investigation had investigated the wreck of the tanker TORREY CANYON to

appear why this marine disaster had happened. They said that there was no failure of machines and ship

herself. They judged that this marine casualty had happened because the Master couldn’t practice Good

Seamanship. Especially, he had judged to change the course to the east of the Schilly Isles by himself.

Furthermore, they stated that he had not taken proper actions such as reducing the speed and steering the

ship in hand mode. The track of the TORREY CANYON to the wreck is shown in Fig 1.

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Figure 1: The track of the TORREY CANYON

2.2. m-SHELL model

The m-SHELL model is a theoretical framework designed to aid in the analysis of accident’s

interactions between people and all other aspects composed of Software, Hardware, Environment,

Management and other people. In this model people is referred to as Liveware. Edwards had firstly

proposed SHEL model in 1988. SHEL is an abbreviation of Software, Hardware, Environment and

Liveware. Hawkins who was a pilot of KLM Royal Dutch Airlines had developed this SHEL model to

SHELL model in 1993. He added Liveware to SHEL model and change the shape as is shown in Fig.1.

The m-SHELL model is a concept which the management of NTBS’s 4M is added to SHELL model(3). At

first SHELLl model was developed in the Airlines field as a model of human factors. As is shown in the

Fig.2, Liveware is put on the center and the others surround it. This concept means that human errors are

ought to happen when there are problems at the borders between Liveware and the others(4). In m-SHELL

model the problem between Liveware and the others are picked up and classified. The factors of Liveware

and management are also included.

0842 013°to 000°

0818 018°to 013°

0850 Wreck

0848 Hard a Port Planed Course 325°

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Figure 2: Figure of SHEL, SHELL and m-SHELL model(5)

2.1.1 Application of the m-SHELL model

In table 1, Examples of m-SHELL model are shown. The factors could be picked up and classified to

L-L, L-S, L-H, L-E, m and Liveware itself. Application of the m-shell model to the wreck of TORREY

CANYON is shown in Table 2.

Table 1: Examples of m-SHELL model Factors Examples

Management ・organaization

・atomosphere of workplace M

・safety culture

Software ・manual

・check list S

・text for training or education

Hardware ・interface of man and machine

・automation

・arrangement of machine

H

・design of machine

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Environment ・working environment

E ・working characteristics

Liveware ・phsycological state

・Somatic condition L

・abilities

Liveware(others) ・communication

・leadership L

・teamwork

Table 2: Application of the m-SHELL model L-L

Master, First Officer

First Officer noticed that the ship is off the course enormously. But the Master decided to pass through the west of Schilly isles without discussion with First Officer.

Master,

Third Officer At the wreck, Third Officer was on duty. Ship's position was not sure.

Master,

Quarter Master

Before the wreck, the Master ordered Quarter Master 'Hard a Port'. Quarter Master did not change the steering mode from 'Auto' to 'Manual'

Master, Fishing boats

Master couldn't communicate with Fishing boats.

L-S Software There was no principle of changing steering mode.

L-H

Hardware1 Maneuvering characteristics of the ship.

Hardware2 No Decca was on the ship.

Hardware3 No communication tool between the ship and light-ship.

L-E Environment1 Fishing boats in the area.

Environment2 Strong sea current.

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Environment3 To enter the port by 23:00 because of tide.

Environment4 To shift the cargo oil.

M Management1 The problem of working time.

Management2 Limited voyage information to the crew.

Management3 Laws about how to voyage.

L Master Master didn't make Stand-By Engine. Master had no experience to pass through this area

Master didn’t set the emergency positioning of the crew

2.3. The System Dynamics

In 1956, Jay W Forrester from MIT Sloan School of Management initiated the System Dynamics. At the

beginning it was applied to study industrial management field and then was rapidly implemented for other

field of study such as economics, social studies, transportation engineering and could even be applied to an

almost unlimited field. The field is now matured through more advanced research and applications.

System Dynamics (SD) is based on the theory of non-linear dynamics and feedback control. It provides a

framework to model complex systems and embedded feedback structures between various elements. SD

concerns a system’s dynamic behavior over time under various conditions. SD is designed to investigate

cause-effect relationships among equipment as well as the characteristic and functions of a complex

system. Uncertainty is another reason why SD is used. Using SD, we can simulate the uncertainty of

system easily to investigate the system response and interaction. Through this better understanding, a

conscious learning on interaction among components in a system can help decision makers in doing a

better operation and/or maintenance of the component and system in order to reduce possible risk. Using

SD, the cause-effect interactions and relationship linking components in a system could be obtained and a

better understanding of system behavior expected(6).

2.3.1 Application of the System Dynamics

As a software of the System Dynamics, Powersim Studio 2007 was used. In the model, geographical data

like depth of the water, ship maneuverability, the planned course and speed of the TORREY CANYON are

structured. Fig 2 shows basic modeling for the movement of her. In this study, three cases of simulation

had implemented. Each case is implemented 500 times and the rates of the wreck are gained.

Case 1. The instability of the positioning by Third Officer and the delay of action by Quarter

Master are structured with no fishing boats in the area.

Case 2. The instability of the positioning by Third Officer, the delay of action by Quarter Master

and existence of fishing boats in the area are structured.

Case 3. Existence of the fishing boats in the area is structured without the instability of the

positioning by Third Officer and the delay of action by Quarter Master.

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Position of ship

Movement of ship

sin speed cos speed

Speed

longth of cube

Depth of the positionPosition of ship N- S

Position of ship E- W

Droughtwreck

Depth of the position2

EastWest

South

North

EWNS

NEWS1

NEWS2

Course

Pass through N- SPass through E- W

maneuverability2maneuverability

New course

Third Officer

Quarter Master

Figure 2: System Dynamics model 3. RESULTS AND CONSIDERATION

3.1. Results

The rates of wreck are gained from three types of simulation. These are shown in the Table 3.

Table 3: Rates of wreck

The wreck rate Structured factors

Case 1 0% Third Officer, Quarter Master

Case 2 60% Third Officer, Quarter Master, Fishing

boats

Case 3 32% Fishing boats

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3.2. Consideration These results show that the rates of wreck are 0%, 60%, 32% in each simulation. The result of case 1

shows that if there were no fishing boat in the area, the wreck could not be caused. In this situation the

human factors of Third Officer and Quarter Master had not affected the wreck rate. But the actual situation

was that fishing boats were there and they had disturbed the safety movement of the TORREY CANYON.

In case 2, the rate of wreck is 62% and this is the highest rate. This result appears that the fishing boats

affect a lot to the wreck. The comparison for the case 2 and case 3 shows that human factors of Third

Officer and Quarter Master also affect the risk of the wreck. The comparison for the case 1 and case 2

shows that there is influential level of human factors by Third Officer and Quarter Master. It depends on

the area space. If the area is like narrow channel, these human factors affect a lot. On the other hand if

there is enormous space, these factors do not affect.

4. ANALYSES AND DISCUSSION The factors of these simulations were picked up by the m-SHELL model. So, all of the factors could be

considered in the system to which the Master who has all of the responsibility in the ship relates.

From these results it could be quantitatively said that the judgment of the Master to pass through this area

was the biggest fault. With no effect of factors by Third Officer and Quarter Master there was a profound

danger in this area. The Master who has all the responsibility must judge whether there is a space to safety

voyage. Also, he had to consider the relations between the space and influential level of the human

factors.

In this model the speed of her has not changed as the actual simulation. If the Master had decided to reduce

the speed, the space to pass through the area could make. These things could be also embedded in the

simulation model. From all of the factors like ship maneuverability, geographical restrictions, other ship’s

restrictions and human factors, the tool to know the risk of voyage beforehand could be made in the

System Dynamics model. This simulation tool could help people to understand marine casualties from

various quantitative angles. At the same time, this simulation tool could be used as a risk prediction model

for the determiner in the ship and as an educational tool.

5. CONCLUSION In this study the m-SHELL model and the System Dynamics are applied to the wreck of TORREY

CANYON and the main factors of the wreck are compared quantitatively. And it appeared that this model

could use in many situation. It could be said that the model structured by the System Dynamics have the

possibility to be used as analyses, prediction and educational tool.

6. REFERENCES (1) Yusuke, Y. (2002), “Outline of Ship Safety” in Japanese

(2) Crispin, G. , Booker, F., and Soper, T. (1967). “The Wreck of the TORREY CANYON”

(3)(4) Yusuke, Y. (2002), “Outline of Ship Safety” in Japanese

(5) http://www.andrewcram.com/SHELLmodel.pdf, Access Date : 26.07.2008 (6) Powersim Software(2007),”Powersim Studio 2007 user’s guide”