International Journal

on Marine Navigation

and Safety of Sea Transportation

Volume 5

Number 3

September 2011

279

1 INTRODUCTION

In the last two decades, the boom in international

trade and the function expanding of port, have led to

more vessels to get in and out port water. There has

been a strong focus on the relationship between port

water unexpected incidents and port authorities, ves-

sels, berth operators, onboard and port workers, ter-

minal operators, owner and operators of different

transport modes interacting with the port water area

(rail, road, inland navigation). Port water incident is

a kind of serious disaster with high consequence. A

disaster at port water is an accident which affects the

vessel, the berth, the persons on board or berth, the

cargo or the environment.

Marine traffic risk has been a core subject in mar-

itime studies, because it is coupled with transport

safety, shipping efficiency, distribution reliability

and loss prevention (Tsz Leung Yip, 2006). Some

coastal countries have undertaken the task of equip-

ping their coastline with the appropriate sea rescue

means, following the guidelines of the International

Maritime Organization and in accordance with the

International Convention of Search and Rescue

(IMO, 1974, 1999). Meanwhile, some decision-

making methods have also been used in the sea

shipping areas. Port water area is much different

from sea water in navigation density, width of fair-

way, type and number of vessels, and other naviga-

tion environment. Meanwhile, vessels’ berth and an-

chorage operations, port operations, port and

waterway engineering operations, can lead port wa-

ter accidents.

The port water incidents to which this work refers

are those which occur in port water region. The port

water region is the water area within the port bound

lines. It includes berths’ connecting water areas, port

fairways, vessel turn around areas and port anchor-

ages.

Although the port authorities do their best to im-

prove the port water’s navigational environment,

port city safety is still faced with port operation ac-

cidents, maritime accidents, and result in personnel

injury or death, property loss, as well as severe envi-

ronmental damages. If effective rescue operation

cannot be taken immediately, a great ecological or

economic tragedy is unavoidable. Therefore, the port

water incident rescue is an emergency operation that

requires quick response.

From the technical viewpoint, port water rescue

can be defined as an external action aimed at rescu-

ing persons, vessels, public property, and protecting

Improving Emergency Supply System to Ensure

Port City Safety

Zesheng. Wang, Zhonghua. Zhu & Wencai. Cheng

Zhenjiang Watercraft College, Jiangsu, Zhengjiang,China

ABSTRACT: To efficiently implement emergency response program to port unexpected incidents, a perfect

emergency supply system which including communications supplying, transportation supplying and rescue

equipments supplying must be ready-to-used. Considering physical geography, harbor area, possible incident

type and incident scale and other factors, using multi-objective fuzzy decision theory to set up emergency

supply centers, improving sharing resource mechanism, administrative legislation and other measures are be

used to improve port emergency supply system. Shanghai port’s practice prove the improve port emergency

supply system is effective.

280

water area environment from an incident which is

immediate and irreversible unless action is taken.

The main activity of the port water emergency

rescue services is to attend to incidents that occur in

the port water environment. These are services relat-

ed with the activation of extinguishing a fire, the

withdrawal of floating and sinking objects which are

dangerous for navigation, separating the un-

safe vessel, controlling and clearing up the leakage

matters, medical rescue.

When an incident occurs, the authorities in charge

the port water area send all of the corresponding re-

ports to the government centre of the port city and to

the superior port management department. With this

data, official statistics are drawn up, using various

parameters related to the characteristics of the vessel

and the berth, type of accident and damage incurred.

The distribution of the port water rescue resources is

planned by using this incident data and the charac-

teristics of the possible locations.

The response time is critical in rescue operations

and the rescue charge is very high. The port water

rescue activity must be carry out immediately at the

time that the emergent rescue centre accepts the of-

ficial reports. The emergent rescue plan made under

time limiting pressure may be not a good one and

delay the rescue. The process of planning sea rescue

resources and their distribution in the various loca-

tions should be carried out according to scientific

criteria, both of a technical nature and in terms of

cost-effectiveness.

The paper first provides an analysis of the inci-

dents type in the port water area and the rele-

vant rescue resources. Then outline the multi-

objective fuzzy decision method based on timeliness

and economical efficiency target. At last, describes a

practical example of the distribution of a rescue re-

source and draw some conclusions on the method

proposed.

2 INCIDENT TYPE AND THE NECESSARY

RESCUE RESOURCES OF PORT WATER

AREA

2.1 Critical characteristics of the port water area

Vessels passing in and out the water area, vessels’

berthing operations, vessels’ anchoring operations,

port and waterway engineering operations, make the

port water area is the busiest navigation area, and

bring the port water area’s safety faced with more

menaces. Port water area’s navigation environment

is associated with a number of critical characteris-

tics:

− High traffic volumes;

− Wide variation in vessel size and types;

− High portions of speed craft and ferries;

− Close proximity of marine facilities within a

small geographic area;

− A high proportion of coastal and inland water

craft;

− Active mid-steam operations for cargo move-

ments;

− Lots of port and waterway engineering opera-

tions;

− Multiple water approaches to the port and

− Lots of anchoring areas.

Above characteristics are disadvantageous in port

water area. The following are several advantageous

key characteristics:

− Good navigation traffic control of vessel activity;

− Perfect navigation system and

− A high level of reporting of port water area inci-

dents.

2.2 Incident types in the port water area

The causes of port water area incident can be vari-

ous, such as design defects of vessel, navigation traf-

fic events, port operation accident, port and water-

way engineering operation failure, badly weather

and other disadvantageous factors. The direct im-

pacts of the disaster may include oil/chemical spills,

raw sewage discharges, cargo losing, fairway blocks,

port paralysis, crews and workers casualties, with

indirect impacts such as ecology disaster.

Table 1 illustrates the accident types and the pos-

sible consequences of each kind of accident.

Table 1 Incident types and the possible consequences

___________________________________________________

Type of incidents Possible consequences

___________________________________________________

Vessel accidents Fire/explosion

Danger cargo falling

Gas/liquid leakage

Collision/contract

Stranding/grounding

Foundering/sinking

Capsized/list

Man overboard

Structural failure

Others(e.g., machinery failure)

___________________________________________________

Port operating Fire/explosion

accidents Danger cargo operation failure

Gas/liquid leakage

Damage to equipment

Capsized/list

Damage to wharf

___________________________________________________

Heavy nature Fire/explosion

damage Danger cargo falling

Gas/liquid leakage

Damage to equipment

Capsized/list

Damage to vessel

Damage to wharf

___________________________________________________

281

Each kind of incident needs the suitable rescue re-

sources to effectively carry out emergency response.

2.3 The point of determining how to response the

incident

Port water incident rescue gains great attention from

decision-makers and researchers. On reporting an

incident, it always covers the precise location, the

latest condition, and the physical parameters (type,

construction, and size) of the disaster vessel, the

berth, the fairway, the nature and quantity of the

cargo, as well as the nature of the damage, in partic-

ular any harmful and poisonous substances. There-

fore, port water area incident rescue is a necessary

and complicated subject.

At the point of determining how to response the

port water incident, some factors must be taken into

account which is decisive in the process of distrib-

uting port water rescue resources. These factors con-

sist of:

1 Characteristics of the incident, the wharf, the

fairway, the vessel and the damage produced.

2 Types of the incidents and establishment of a

scale of severity.

3 Risk source and sensitive area analysis.

4 Distribution of resources such as tug-boats, fire-

fighting boat, oil-absorbing ship, rescue boats,

cleaner vessel, helicopters, with a definition of

their radius of action.

5 Placement of rescue resources assigning indica-

tors of suitability to every possible incident loca-

tion.

6 With shorter response time.

7 Cost-effectiveness.

3 METHOD FOR ASSIGNING PORT WATER

RESCUE RESOURCES

In the port environment, rescue resources distribu-

tion is one of the most important parts of the port

emergency response plan. In China, work on the

emergency support system is managed by port au-

thorities and the Ministry of Maritime Safety Ad-

ministration. When the authorities draw up the

emergency response plan, they firstly carry out haz-

ards identification and evaluation, and study on sen-

sitive areas according to port function zone.

The efficient assignment of port rescue resource

requires, on the one hand, various port operation ar-

eas to be interrelated with areas in which accidents

are concentrated and on the other hand, a planning

process to be developed in which information on the

past and present, as well as predictions on the future,

are handled. The information is about vessels’ in-

formation (type, size, performance, loading condi-

tion and, manning), port water’s navigation envi-

ronment (traffic flow, hydrological condition, mete-

orological conditions and, channel condition), and

service at port (pilotage service, vessel traffic ser-

vice, berth condition, and port operations).

Thus, the method to be applied in assigning res-

cue resources combines aspects of models for the lo-

cation of port activities with elements of planning,

such as port areas planning and port functions plan-

ning. A general methodology based on gravitational

models to optimize distribute sea rescue resources

has been applied to assign ‘sea rescue boats’

(Azofra, 2007). To overcome limited time pressure,

while retaining minimum rescue project duration, a

rescue plan for the maritime disaster rescue is ob-

tained with the application of heuristic resource-

constrained project scheduling approach (Liang Yan,

2009).

3.1 Problem statement

In the port emergency response plan, according to

the characteristic of unexpected incident, the degree

and the development, the scale of severity is classi-

fied into four grades: particularly serious (Grade I),

grave (Grade II), severely (Grade III) and general

(Grade IV). The particularly serious incident needs

the nation to start the emergency response plan and

dispatch domestic each kind of rescue resources, or

even receive overseas support resources. The general

incident can be deal with the port enterprise by self-

prepared resources. The Grade III incident only

needs the port authority to use resources of one res-

cue center. The grave incident needs more resources

than one rescue center, so that several rescue centers

need to take part in the rescue activity.

Here only the rescue resources distribution of the

grave incident is discussed, that is to solve how to

use more than two rescue centers to deal with unex-

pected incident. To the port city, the emergency re-

sources candidate storages are those areas where

many berths are concentrated. Port operation areas,

port fairway and anchorages are those areas where

need resources. To improve port city’s safety and

competitiveness, the port areas are planed scientifi-

cally according to the types of unload cargoes and

berthing vessels. Berths with the same function are

centralized in one area, so that vessels entering and

outgoing the port area are the same. So that the pos-

sible incidents in the area are the same and the need-

ed resources are regular. The locations of all of the

rescue resources do not necessarily have to coincide

and an incident at port water area may or may not

require the presence of one or several means of sea

rescue.

282

3.2 Multi-object decision models

The evaluation of location should be performed tak-

ing into account several factors of the accidents:

their number, type, scale of severity and, considering

that any accident should be responded to immediate-

ly, the distance between the place where the acci-

dents takes place and the location of the resource to

be used. Moreover, for any possible location (port

zone, harbor enterprise) its suitability or capacity

should be assessed (fire fighting, sewage cleaning

and other rescue installations available).

The response time is critical in rescue operations.

This will depend on the technical characteristics of

the means of rescue used (speed and operability), on

the distance to be covered and on the weather condi-

tions at the time of the rescue. However, once the re-

source to be used is identified, the only controllable

parameter is distance. Thus, for the purposes of the

present work, it is assumed that time is proportional

to distance.

Storage and usage rescue resources have to pay

quite a large amount of money. On the one hand, to

keep the resource storage into use need a vast cost,

this is a flat-rate fee. On the other hand, sending re-

source from the storage point to demand points need

fee which is related to means of delivery and trans-

mission distances. Considering the economic target,

the number of storage point to be used should be as

small as possible.

The decision of distribution rescue resources is

one kind of multi-objective problems. The targets of

the decision are that the response time is short and

the number of storage point to be used is small.

Provided that one port city has port areas as

,,,

BB B

.The possible needed resources in the

port areas are

XXX ,,,



. Supposed that the port

has n candidate resource storages

AAA ,,,



. The

flat-rate fee of each storage and the weights of the

two criterions (timeliness and economic) are known.

The weights of the two criterions can be gotten by

using Analysis Hierarchy Progress (AHP) according

to incident type and characteristic of the port area.

The most proper decision is that the rescue resource

support scheme based on an overall consideration of

timeliness and economic factors. For one kind of in-

cident, the rescue resources’ support scheme has two

targets as follow:

− The target function of economic

11 11

ij ij i

ij ij

C C X SC

= = = =

= +

∑∑ ∑∑

(1)

where

is the costs of resources transmitted from

storage i

( 1, )in=



to the demand point j

( 1, )jp= 

;

is the flat-rate fee of each storage i

( 1, )in= 

is the criteria be used to judge

whether the resource is transmit from storage i

( 1, )in= 

to the demand point j

( 1, )jp= 

. If the

resource is transmit for storage i to the demand point

X =

, else ,

X =

. And there is a relation:

sgn( )

ij ij

XC=

− The target function of timeliness

max( )

ij ij

T XT

= =

= ×

∑∑

(2)

where T is the timeliness target.

is the time that

the resource send form storage i

( 1, )in= 

to the

demand point j

( 1, )jp=

 . If there are more than

one storage to attend the rescue activity, the timeli-

ness target is the time of the scheme with the longest

time.

− The general objective

Use the Linear Weighted Technique (LWT) to get

the general objective:

min( )S TC

λλ

= +

(3)

where

0,0,1

2121

>>=+

λλλλ

λλ

can be get by

using Uncertainty AHP (WANG Zesheng 2007)

based on incident type and incident degree.

Form the function (1) and (2), it is easy to see that

the decision variable is

4 EXAMPLE OF THE MULTI-OBJECT

DECISION MODELS: ASSIGNING A RESCUE

RESOURCE

The Port of Shanghai faces the East China Sea to the

east, and Hangzhou Bay to the south. It includes the

heads of the Yangtze River, Huangpu River (which

enters the Yangtze River), and Qiantang River. The

Port of Shanghai is a critically important transport

hub for the Yangtze River region and the most im-

portant gateway for foreign trade. The port of

Shanghai includes 5 major working zones as shown

in Fig 1.

The possible main types of accidents occurring in

each zone are shown in Table 2.

Table 2 Port zone area and possible accidents

___________________________________________________

Port zone area Possible accidents

___________________________________________________

Zone A Collision/ Man overboard

Zone B Collision/ Grounding

Zone C Collision/ Damage to wharf

Zone D Collision/ Damage to equipment

Zone E Fire/explosion/Gas/liquid leakage

___________________________________________________

283

Fig 1 Port zone area

The distances between every zone are shown in

Table 3.

Table 3 Distances between every zone (kilometer)

___________________________________________________

Zone A B C D E

___________________________________________________

A 0 10 30 150 100

B 10 0 15 140 90

C 30 15 0 120 70

D 150 140 120 0 50

E 100 90 70 50 0

___________________________________________________

The supporting provided that every zone area is

the candidate storage, the flat-rate fees of each stor-

age are as shown in Table 4.

Table 4The flat-rate fee of each storage (ten thousand Yuan

RMB)

___________________________________________________

Zone A B C D E

Fee 20 20 20 25 23

___________________________________________________

The costs of one kind of resource (for example

for liquid leakage) transmitted form zone

( 1, 5)ii= 

to zone

( 1, 5)jj= 

are shown in Ta-

ble 4.

Table 5 Transmitting costs between zones (ten thousand Yuan

RMB)

___________________________________________________

Zone A B C D E

___________________________________________________

A 0 0.3 0.5 2 1.5

B 0.3 0 0.4 1.8 1.2

C 0.5 0.4 0 1.7 1.1

D 2 1.8 1.7 0 1

E 1.5 1.2 1.1 1 0

___________________________________________________

To response liquid leakage accident in port areas,

the timeliness is very strong. Set up

2.0,8.0

λλ

, by using the above multi-

objective model, get that Zone A and Zone E are the

best point to set up storage.

5 CONCLUSION

The principle on which a port city should take deci-

sions about the supply center of port rescue re-

sources should be based on highly objective criteria.

At present, when assigning rescue resources, a wide

variety of technical factors are taken into account

(e.g. water area of the port to be covered, traffic

flows and types of traffic, danger involved in these

traffics and port operations, accident rates, port facil-

ities). By using these factors it is possible to weigh

the suitability of a candidate location. In fact, how-

ever, political factors often affect and the process of

determining the supply center of rescue resources.

Although it is the most subjective factor, it usually

has the greatest weight in taking the final decision.

When assigning port rescue resources, it is neces-

sary to use a holistic viewpoint of the problem. This

vision is essential if the problem involves manage-

ment of port water rescue resources. In practice, the

management of all port rescue resources of a port

city is interdependent, regardless of how they are

distributed.

The proposed model is for individual allocation

of port rescue resources supply center. The method

presupposes that these resources supply center will

be assigned one by one, but this does not imply that

a previous assignment will not condition a later one.

Therefore, once a given resource has been assigned,

it must be considered in an interdependent way with

the other resources located along the same zone of

the port. In this context, it should be pointed out that

the assignment of a resource to a location would lead

to a reduction of the suitability factor of the rest of

the possible locations near the selected location.

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Liang Yan, 2009. A heuristic project scheduling approach for

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Azofra M., 2007. Optimum placement of sea rescue resources.

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