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Human Factor of Ship-handlingand Safe Navigation

Akiko UchinoTokyo University of Marine Science and Technology

School of Internet (SOI)

Advanced Topics for Marine Technology and Logistics

14th February, 2013

Roadmap of Lecture

2

1. Man machine System

2. Human Factor in Maritime accident3. Concept of the Necessary conditions to accomplish safe

navigation4. Factors of Navigational environment5. Mariner’s characteristics toward environment6. Elemental techniques for safe navigation7. Workload for mariners8. Quantification of Workload

Ship-handling System

Machine

Vessel

Human

Mariner

EnvironmentNavigationalenvironment

Man Machine System＝ f ( Vessel as Machine, Human, Environment)

4

A Newspaper article showing :a major accident during the past half-century in Japan

Movements leading up to accident

5

Ship maneuvering simulator of our laboratory

Examining the cause of accidentby Ship maneuvering simulator

6

Bridge

Operation room Assessment room

Cylindrical screen& outside of bridge

Standard behaviour

7

All the 4 captainscarried out the same speed reductionat the similar timing to Y-Maru

A.T.

However,All the 4 captains resultedin collision / extremely close

For safety, important to clarify Characteristics of Conditions

of Environment Human Characteristics

toward environment Relationship between them

From experimental results

Distance to the collision point [m]

8

Relationship betweenEnvironment & Human behaviour leading to Accident

HumanCharacteristics

(A)

Environmental Conditions

(A)

Action(A)

Accident


in common witha lot of

standard mariners


whereY-Maru faced

Action

Y-Marucaptain

did

Collision

In case of the previously mentioned accident :

9

Countermeasure 1


(A)

Action(A)

AccidentEnvironmental

Conditions(A)


(B)

Action(B)

No AccidentEnvironmental

Conditions(A)

(B) Characteristicsof

Bride team + Pilot

(A) Characteristicsof

Bride teamExample:

10

Countermeasure 2


(A)

Action(A)

AccidentEnvironmental

Conditions(A)


(A)

No AccidentAction

(B)


(B)

YUYO

-MARU 1

3K’T

SNAKANO

SE F

’rw’y

PACIFIC ARES KISARAZU Hr(No.7)

(No.5)

(No.6)

<021

>

(No.8) <290>

Ｎｅｗ Buoy

0 500 1000（ｍ）

YUYO

-MARU 1

3K’T

SNAKANO

SE F

’rw’y

PACIFIC ARES KISARAZU Hr(No.7)

(No.5)

(No.6)

<021

>

(No.8) <290>

Ｎｅｗ Buoy

0 500 1000（ｍ）

Set up the New Buoy

Countermeasure:Change the Environmental conditions

12

Key factors for safety


ActionSafe

/Unsafe


Especially, in Ship-handling system:

Mariner is required to have expertise as mariner.Standard mariner having the expertise shows

similar behaviour toward the same navigational environment.Mariner’s characteristics

Mariner’sCharacteristics

ActionSafe

/Unsafe

Navigational Conditions

Navigational

condition Acondition B

μ'E

a b

μE difficulty

Prob

abili

ty o

f the

deg

ree

ofna

viga

tiona

l diff

icul

ty

P EN

V

13

Factors of Navigational environment

Maneuvering characteristics of own vessel

Water area for navigationWeather and sea state Traffic condition

(kinds of traffic vessels andthe density of vessels)

Rule of road Navigation instruments

Major conditions determine the Navigational environment

Condition A Condition B

14

Factors of Mariner’s competency

Mariner’s license rank (Experiences)

Mariner’s characteristics of information processingand reactionas a standard mariner

Fatigues ( relating to the elapsed time of standing watch )

Tension ( relating to the time of watch keeping)

Major conditions determine the Mariner’s competency

Mariner'sμ'H

a b

μH

Prob

abili

ty o

f the

deg

ree

ofm

arin

er's

com

pete

ncy

P HU

M

competency

Hμ

μ'E

'μH

Required Competency by Navigational Environment

Mar

iner

’s

Com

pete

ncy

μE

45°

Necessary conditions to accomplish Safe navigationbased on the Relation between Environment & Human Competency

Key factor 1 : Navigational environment

Key

fact

or 2

: M

arin

er’s

Cha

ract

eris

tics

Required > AchieveDangerous

Required ＜ AchieveSafe

16

1 Lookout The technique to identify and recognize the moving targets and the fixed targets and to gather information of the direction, the distance and the speed and to estimate the future situation of the targets

2 Position fixing The technique to find the position of ship by selecting and recognizing proper objects by visual observation, radar etc

3 Maneuvering The technique to control her course, speed and ships position by steering rudder and controlling main engine etc to realize the plan

4 Instrumental manipulation

The technique to properly utilize instruments for achieving techniques such as lookout, positioning, maneuvering, etc

5 Communication The technique to exchange information among member in bridge and inside and/or outside of the ship

6 Rule of road The technique to navigate according to the Regulations for Preventing Collision at Sea etc

7 Planning The technique to gather information concerning the navigational environment conditions and to make an operational plan and a navigational plan

8 Emergency treatment

The technique to cope with malfunction of a main engine and a steering system etc. and a rescue activity properly

9 Management The technique to use the elemental techniques mentioned above and to make good use of members ability and raise the bridge team’s performance

9 Elemental techniques to accomplish safe navigation

Hμ

μ'ERequired Competency by Navigational Environment

Mar

iner

’s

Com

pete

ncy

μE

45°




83

81

75

70

40

37

2

2

1

0 10 20 30 40 50 60 70 80 90 100

did not carry out Fog signal

did not keep a watch satisfactory

did not observe navigational law

did not keep safe speed

Captain did not do necessary order

Duty officer did not necessary report

did not put on legal light

did not keep guideline

did not set suitable course

Number of causes in 157 collisions

18

Major causes of Collision - did not carry out Necessary tasks

Japan Maritime Accident Inquiry Agency (2007)Did not achieveNecessary tasks

Other several accident investigations & researches

19

Omission error

Necessary tasks,Omission error, Workload

the Situation where Mariners don’t carry out

, causes dangerous situations.

It is often said:

“the Amount of Necessary tasks for safe navigation”

Workload

20

Standard behaviorfor Estimating the Workload

Achieving the Necessary tasks can be:

The previous research clarified:When the Standard mariners can achieve the safe navigation,

they carry out the specified tasks in common.

3) indicated by theto accomplish the Necessary tasks

2) defined by thefrom 9ETs for Safe Navigation

1) regarded as for mariners

Time required

Necessary Elemental techniques

the Workload

Calculateby the to carry out the

21

Estimating the Workload

139.2 139.3 139.4 139.5 139.6 139.7 139.834.4

34.5

34.6

34.7

34.8

34.9

35

No.20 CargoCo.<000>,Spd. 16.0kt

No.9

No.15 ContainerCo.<197>,Spd 16.0kt


No.13 TankerCo.<180>,Spd.12.0kt

fishing boats

No.30 PassengerCo.<330>, Spd.16.0kt

ShiojimaruCo.<015>

No.16 Passenger

No.21 TankerCo.<212>,Spd. 15.0kt

Fishing boats

Own Ship

Own ship

No.8 CargoCo.<046>,Spd.18.0kt

Co.<078>,Spd.23.5kt

No.22,23

Co.<011>,Spd.18.0kt

N

E

Spd.20.0kt

CarFerryCo.<064>No.1

Spd.22.0kt

No.2

No.4

No.3

No.5

No.6

No.7

Stopped

Situation for estimating the Workload

Typical situation One altering the course several avoiding actionsthese events are simultaneously occurs.

Mariners is typically required to carry out the following elemental techniques: Position fixing Maneuvering Lookout

repeatedly.

Crossing angle ( θ )

180 deg

45 deg

90 deg

135 degthe other vessel

Own vessel

0 deg

0

20

40

60

80

100

120

0 30 60 90 120 150 180

Inte

rval

tim

e of

Loo

kout

[sec

] _

Crossing angle of the other ship [deg]

Fig. Relationship between crossing angle & interval time of Lookout

Depending on crossing angle,interval time of Lookout is different: 1 time / about 25 – 100[sec]

Limit for mariner : 1time / about 25 [sec]

Necessary Lookoutdepending on crossing angle of encountering vessel

Necessary Lookout depending on Visibility

Generally, under good visibility,STD mariner carry out Lookout

every 40 [sec]

Visibility 3mile－6[sec] ⇒every 34[sec]

Visibility 1mile－10[sec] ⇒ every 30[sec]

Depending on worse visibility,become Frequent Lookout

24

Formulato estimate the Workload

Lookout

where:N : the number of target ships within the area for LookoutRunning time[sec] : the range of time in which workload is estimated τcrs[sec] : the necessary interval time, mariners carry out Lookout,

affected by a degree of crossing angle of target shipτv[sec] : the necessary interval time, mariners carry out Lookout,

affected by a degree of visibilityTinteraction [sec] : the length of time per a Lookout a mariner takes,

which is affected by dangerous degree of collision with each target

Necessary task of Lookout [sec] =

∑ Tinteraction × { running time / (τcrs + τv)}N

1

25

139.2 139.3 139.4 139.5 139.6 139.7 139.834.4

34.5

34.6

34.7

34.8

34.9

35

No.20 CargoCo.<000>,Spd. 16.0kt

No.9



No.13 TankerCo.<180>,Spd.12.0kt

fishing boats

No.30 PassengerCo.<330>, Spd.16.0kt

ShiojimaruCo.<015>

No.16 Passenger

No.21 TankerCo.<212>,Spd. 15.0kt

Fishing boats

Own Ship

Own ship

No.8 CargoCo.<046>,Spd.18.0kt

Co.<078>,Spd.23.5kt

No.22,23

Co.<011>,Spd.18.0kt

N

E

Spd.20.0kt

CarFerryCo.<064>No.1

Spd.22.0kt

No.2

No.4

No.3

No.5

No.6

No.7

Stopped

Estimated result - Total Workload

we can estimate the workload numerically,according to given navigational conditions.

0

60

120

180

240

300

0‐5 5‐10 10‐15 15‐20 20‐25 25‐30 30‐35 35‐40 40‐45

Total W

orkload every 5 minutes [sec]

time [min]

Position fixing Maneuvering Lookout

26

Experiments to compare Workload with Mariner’s behavior

In order to investigate the relation between

the estimated Workload and achieved Result by Mariners

utilizing the ship handling simulator at Tokyo University of Marine Science and Technology

mariners navigate a ship in the explained situation

Standard marinersThey have more than 6 years experience on board.They can regularly achieve safe navigation.

27

Mariner’s Achieved results toward Workload

0

60

120

180

240

300

0

60

120

180

240

300

0‐5 5‐10 10‐15 15‐20 20‐25 25‐30 30‐35 35‐40 40‐45

Total A

chieved results

by Mariners [sec]

Total W

orkload[sec]

time [min]

Position fixing Maneuvering

Lookout Total Achieved results

Mariner’s achieved resultsare kept about 240 seconds (4minutes) level.

the amount of tasks over 240 seconds-levelare not carried out

and left as:

Omission error

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

0 60 120 180 240 300

Achieved de

gree

of Total Necessary tasks

Total Workload 0 0.2 0.4 0.6 0.8 1.0

28

Correlation between ‘Total Workload’ and‘Achieved degree of Necessary tasks’

It means: 1.0:100% satisfy, 0.5: 50% satisfy

[Achieved result]

[Workload]

Achieved degreeof

Necessary tasks=

When the Workload-level exceeds 0.8, the Achieved degree of necessary tasks begins to break 1.0

Therefore, based on the Total amount of Workload,the Total achieved degree of necessary tasks is determined.

Hμ

1.0Required Competency by Navigational Environment

Mar

iner

’s

Com

pete

ncy

0.8

45°




Omission error

30

Summary of Quantification 1/2

The Quantification of Workload based on the Necessary tasks to deal with each navigational condition was shown.

Utilizing the quantified workload by the above method, the mariner’s Achieved degree of necessary tasks toward changes of navigational condition was investigated.

31

Summary of Quantification 2/2

Then, it was clarified that :when Workload exceeds about 80 %, mariners become not to achieve the Necessary tasks.

Simply put, the level of Workload is strongly related to occurring Omission error.

32

Summary of Lecture1. Human Factor in System involving Human

were shown.2. Concept of the Necessary conditions to

accomplish safety was shown.3. Conditions of Navigational environment 4. Mariner’s characteristics toward environment5. Elemental techniques for safe navigation were

shown.6. Quantification of Workload based on the

Necessary tasks / the Required competency was shown.

33

I hopeyou obtain some useful insights in this lecture..

34

Position fixing

where:Nw[times/mile] : the necessary number of times mariners carry out

Position fixing to the mile affected by a width of channelNv[times/mile] : the necessary number of times mariners carry out

Position fixing to the mile affected by a degree of visibilityDistance[mile]: total distance a mariner run

Nalt[times] : the necessary number of times mariners carry out Position fixing to the mile affected by a degree of angle for changing courses

Necessary task of Position fixing [sec] =40[sec]×{( Nw + Nv ) × Distance + Nalt }

35

Maneuvering

where:Running time[sec] : the length of time a mariner run Tw[sec] : the necessary length of time mariners take for

Maneuvering during 10 minutes, affected by a width of fairwayTv[sec] : the necessary length of time mariners take for

Maneuvering during 10 minutes, affected by a degree of visibility

Talt[sec] : the necessary length of time mariners take for Maneuvering, affected by a degree of angle for changing courses

Necessary task of Maneuvering [sec] =Tw /(600) × (running time)

+ Tv /(600) × (running time) + Talt

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