International Journal

on Marine Navigation

and Safety of Sea Transportation

Volume 6

Number 2

June 2012

187

1 SUMMARY OF THE ACCIDENT

On the 23rd September 2008, the M/V OCEAN

ASIA with engine-trouble is towed through the Ha

Nam canal into the port of Haiphong at the speed of

3 knots. At buoy No. 21, the pilot of M/V OCEAN

ASIA saw three vessels intended to overtake him so

he required the other three vessels stop these actions

because of narrow area. But they are continued over-

taking M/V Ocean Asia. First one, a tanker overtak-

en M/V Ocean Asia at buoy No. 21; then M/V Far

East Cheer had overtaken M/V Ocean Asia on the

portside. The last one, M/V SITC Qingdao proceed-

ed to overtake M/V Ocean Asia.

Figure 1. The scene of the accident

At this moment, M/V Ocean Asia was in the cen-

ter line of the canal. The M/V SITC Qingdao sailed

at the speed of 12.7knots. When the distance be-

tween two vessels is 0.5 NM, M/V SITC Qingdao

reduced her speed and her speed is 9 knots when she

was passing M/V Ocean Asia. The distance between

side to side of the vessels is 10 – 15m when they

were passing.

At the moment, when the stern of the M/V SITC

Qingdao had passed the bow of M/V Ocean Asia,

the M/V Ocean Asia quickly crashed into the shore,

stranded on the right bank of the canal.

The particulars of these vessels are as follow:

- M/V Ocean Asia:

o Call sign: 3EMN4

o Flag: Panama

o IMO number: 7712353

o L.O.A: 158.85 m

o Breadth: 23 m

o Air draft: 41.8 m

o Draft F/M/A: 6.3 m /6.4 m /6.6 m

o GT 10835

o DWT: 13992 MT

o Cargo: 345 containers equal 5738 MT

- M/V SITC Qingdao:

o Call sign: V2BO3

An Analysis the Accident Between M/V Ocean

Asia and M/V SITC Qingdao in Hanam Canal

(Haiphong Port)

V. NGUYEN CONG

Vietnam Maritime University

ABSTRACT: The paper presents a special case of the ships accident. The accident was happened without any

contact between ships. The cause of the accident is the hydrodynamic interaction between ship in a shallow

canal and the analysis is consulted to determine the percent of fault of the accident.

188

o Flag: Antigua & Barbuda

o IMO number: 9207560

o L.O.A: 144.83 m

o Breadth: 22.4 m

o Air draft: 41.5 m

o Draft F/A: 7.0 m /7.2 m

o GT 9413

o DWT: 12649 MT

o Cargo: 5900 MT

The canal’s depth and breadth are 8 m and 80 m

respectively. It is one way canal and taking over is

prohibited here. The M/V Ocean Asia was towed by

three tugboats: M/V Da Tuong towed at the bow by

towing line 150 m in length; M/V Transvina and

M/V Marina 18 supported at the stern (Fig. 1). At

the moment of the accident, there was not current in

the canal; water is still.

In this accident, there was no contacting between

vessels so there was no evidence on the hulls. To

blame on M/V SITC Qingdao, it is necessary to im-

prove that the M/V Ocean Asia came aground due to

the influence by overtaking of M/V SITC Qingdao.

2 RESEARCH BY SCALED MODELS

To research by scaled models, it is necessary to have

condition of the experiment as same as real situation.

The formula of the relation between a real vessel

speeds and a scaled model vessel is as follows:

kVV

vesselrealelmod

×=

(1)

where, k is the dimensional ratio of real vessel and

model.

In 2003, a research about “Hydrodynamic Interac-

tion between Moving and Stationary Ship in a Shal-

low Canal” were carried out by Stefan Kyulevche-

liev, Svetlozar Georgiev, Ship and Industrial

Hydrodynamics Department, Bulgarian Ship Hydro-

dynamics Centre, Varna, Bulgaria and Ivan Ivanov

Shipbuilding Department, Technical University of

Varna, Bulgaria. They use two scaled models with

the parameters are show in the Table 1.

Table 1. Parameter of the models

__________________________________________________

Moving hull Stationary hull

__________________________________________________

Length between perpendiculars [m] 4.000 4.400

Length at waterline [m] 3.881 4.400

Beam [m] 0.456 0.456

Draft [m] 0.080 0.080

Block coefficient 0.928 0.870

Displacement [m

] 0.131 0.139

__________________________________________________

The experimental set-up with the accepted coor-

dinate system for the forces and moments are shown

schematically in Figure 3 below. The relative posi-

tion of the two models has been determined by de-

tecting a marker at the bow of the moving model

with a laser fitted at the stationary model.

a) Moving hull

b) Stationary hull

Figure 2. The models were used in the experiments

Both the models have been free to sink and trim,

but fixed in all other degrees of freedom. The mov-

ing model has run along the centerline of the tank

with a width of 2.6 m.

Figure 3. Experimental set-up

The measuring unit, mounted on the stationary

hull, has comprised two strain gauges for the longi-

tudinal force, allowing in this way deduction of the

yawing moment, and one strain gauge for the lateral

force. Two lasers detecting the distance to fixed hor-

izontal plane attached to the canal wall have meas-

ured the sinkage of the hull.

Experiment was carried out with the sets of canal

depth, model speed, and distance between two ves-

sels when overtaking others (Stefan 2001). In this

189

paper, the results of experiments which have condi-

tions similar to conditions of the accident of the M/V

Qingdao and M/V Ocean Asia will be presented.

The Figure 4 and Figure 5 show the experimental

results when the moving model was overtaking sta-

tionary model at the speed of 0.875 m/s and ratio of

canal depth and draft (H/T), respectively, 1.5, 2 and

2.5.

The length between perpendiculars of SITC

Qingdao LBP is 134m. The length of the moving

model in experiment is 4m. So the speed of 9 knots

of the M/V SITC Qingdao equivalent to the model

speed as follows (Cohen 1983):

)s/m(800.0)knots(56.1

134

elmod

==×=

(2)

The speed of moving model in the experiment

was 0.875m/s, so it can be considered as same as the

speed of SITC Qingdao when she was overtaking

M/V Ocean Asia.

About the depth of the canal, the rate of draft and

depth of both vessels draft SITC Qingdao and Ocean

Asia were only about H/T = 1.1 ÷ 1.14. From Figure

3 to Figure 5, forces and torque acts on the station-

ery are depended in inversely proportional to the

value of H/T. This leads to the amplitude of forces,

moment acts on the M/V Ocean Asia will be greater

than the value represented on a graph of the case

H/T = 1.5.

Figure 4. Hydrodynamic load CX at equal speed and different

water depths

On the Figure 4, when the distance from SITC

Qingdao to the Ocean Asia was about two lengths of

a vessel (x/l=-1.5) the M/V Ocean Asia was pushed

a bit forward. Since bow SITC Qingdao access to

the stern of M/V Ocean Asia (x/l = -1), the M/V

Ocean Asia was pulled back until the stern of M/V

SITC Quingdao is passed the bow of M/V Ocean

Asia (x/l = 1). During this period, the force got the

maximum value as the bow of M/V SITC Qingdao

passing the bow of M/V Ocean Asia.

The transverse force acting on the hull M/V

Ocean Asia was variable as follows: When the dis-

tance of two vessels is half of vessel’s length (x/l = -

0.5, Fig. 5), the M/V Ocean Asia was pushed toward

the shore. Then, from x/l=0 to x/l=1, M/V Ocean

Asia was pulled to M/V SITC Quingdao. This pull-

ing force was maximum value at the position A on

the Figure 5.

Figure 5. Hydrodynamic load CY at equal speed and different

water depths

At the moment, when the stern of M/V Quingdao

passing the bow of M/V Ocean Asia (x/l=1), the

transverse force was change the direction quickly

and the M/V Ocean Asia was pushed strongly to the

shore.

The Figure 6 shows the moment effects on the

hull of M/V Ocean Asia. Before x/l=0, the moment

changed the direction frequently. It courses the

swaying to the M/V Ocean Asia. When the bow of

SITC Qingdao was passing the bow of Ocean Asia,

the moment rises quickly (point B in Fig. 6). It turns

the bow of Ocean Asia strongly toward to the right

canal.

Figure 6. Hydrodynamic load CN at equal speed and different

water depths

The transverse force and moment acting on the

M/V Ocean Asia peaked almost at the same time as

the bow of SITC Qingdao passing the bow of Ocean

Asia (points A and B in Figure 5 and Figure 6). Un-

der the influence of pulling force and moment, the

M/V Ocean Asia changed her course toward the

right bank of the canal.

190

Figure 7 The distance from Ocean Asia to the shore

According to accident document, at the position

M/V Ocean Asia run on ground, its heading was

about from 40

to 45° compared to axial canal. As-

sume that when SITC Qingdao passed M/V Ocean

Asia, the heading of Ocean Asia was deflected away

from the direction of canal 20

(Fig. 7). The distance

to shore from the bow of Ocean Asia is:

OCODCD −=

(3)

where:

(117

20sin

2/B

===

(4)

)m(79158

LOA

AsiaOcean

=×=×=

(5)

The distance from Ocean Asia to the shore is:

)m(3879117CD =−=

(6)

The M/V Ocean Asia is towed at speed of 3

knots. It takes 24.6 seconds to pass over the distance

CD = 38 meters. This is a very short period of time,

it not allows the M/V Ocean Asia and tugs to have

any actions to against this effect.

Moreover, the tugboat M/V Da Tuong towed by

the towing line 150 m in length, so it is not available

to adjust the course of M/V Ocean Asia. Two other

tugboats at the stern of the M/V Ocean Asia also

could not reduce the changing course suddenly of

M/V Ocean Asia because the M/V SITC Qingdao

was passing too close to M/V Ocean Asia, there was

no room for tugboat maneuvering. In additional, the-

se two tugboats were at the stern of M/V Ocean Asia

while the hydrodynamic force acted on the vessel’s

bow. That’s why in this situation, the three tugboats

could not against the changing course of M/V Ocean

Asia which caused the accident.

3 EFFECT OF NARROW CANAL

In the above experiments, the overtaken vessel was

near the shore. In the case of the accident, the M/V

Ocean Asia was towed at the center line of the canal

and the M/V SITC Qingdao ran very near the shore

so the forces and moment effect on M/V Ocean Asia

are not only as the analysis above, there are addi-

tional impacts.

Figure 8 Cross section of the canal when the M/V SITC Qing-

dao was over taking M/V Ocean Asia

At the cross section describing on the Figure 8,

the maximum allowed speed of the SITC Quindao is

just 1.7 knots while it ran at the speed of 9 knots. At

this speed, it creates much of chaos water flow and

has lost control.

Figure 9 Effect due to narrow canal

When M/V SITC Qingdao passing M/V Ocean

Asia, the flow of water between vessels was strong

chaotic. A big volume of water at the bow of SITC

Qingdao could not transfer to the stern because of

narrow canal. It creates a low pressure area behind

the M/V SITC Qingdao. To fill up the water to this

low pressure area, large volume water on the star-

board stern of M/V Ocean Asia had moved and it

causes the heading of M/V Ocean Asia changes sud-

denly toward to the shore (Fig. 8).

4 CONCLUSIONS

Thus, when the M/V SITC Qingdao overtook M/V

Ocean Asia, they simultaneously affected by:

− Forces and moment as analysis in the section 2,

and

− Low pressure area behind M/V SITC Qingdao

due to narrow canal as analysis in the section 3.

Both of effects have peak at the same time so

they create powerful effect, making the M/V Ocean

Asia sudden shift to the right bank of the canal.

According the above analysis, the cause of the

accident between M/V SITC Qingdao and M/V

Ocean Asia are as follows:

− M/V SITC Qingdao had violated regulations on

safety, running at large speed and overtaking at

the narrow area, where it is prohibited by the Port

Authority.

Qingdao

Ocean Asia

= 80 m

Qingdao

Ocean Asia

Low pressure

191

− The pilots on the vessels did not have the neces-

sary coordination of their work. The pilot on the

M/V SITC Qingdao was not obeyed the rule and

regulation of the canal which prohibits overtaking

and limits the speed at this section of the canal. If

M/V SITC Qingdao sailed at lower speed and

M/V Ocean Asia kept out of the way of the M/V

SITC Qingdao, they accident could not happen.

− M/V Ocean Asia did not be applied any safety

measures. The anchor of the vessel did not use as

it should be. M/V Ocean Asia is towed vessel but

it not means that M/V Ocean Asia has no respon-

sibilities in this case.

− M/V Ocean Asia was towed so the ability to ma-

neuver is limited, especially the ability to use a

rudder to keep track. This makes the risk of inci-

dents such as when she is overtaken by others.

M/V Ocean Asia ran aground due to these above

reasons. According to the analysis, it can be said that

the accident of M/V Ocean Asia was caused by the

overtaking of M/V SITC Qingdao.

NOMENCLATURE

B Beam of ship(s)

BCH Canal width

CN = 1000 Mz / (0.5 ρ VM

CX = 1000 Fx / (0.5 ρ VM

CY = 1000 Fy / (0.5 ρ VM

LS T)

FH Froude number (based on water depth)

Fx Longitudinal force

Fy Lateral force

H Water depth

hw Wave elevation

LM Length of moving ship

LS Length of stationary ship

l = 0.5 (LM + LS)

Mz Yawing moment

T Draft of ship(s)

VM Speed of moving model

x/l Non-dimensional stagger between the mid-

dle sections of the ships

YW Spacing between stationary ship side and

canal wall

YY Spacing between ship sides

ρ Mass density of water

REFERENCES

Brix J. Manoeuvring Technical Manual, Seehafen Verlag

GmbH, Hamburg, 1993.

Cohen S., Beck R., Experimental and theoretical hydrodynamic

forces on a mathematical model in confined waters, Journal

of Ship Research, Vol. 27, No 2, 1983

Kyulevcheliev S., Georgiev S., Experimental observations of

ship wavemaking at trans- and supecritical speeds, Euro-

Conference HADMAR 2001, Varna, Bulgaria, 2001.

Stefan K., Svetlozar G. Hydrodynamic interaction between

moving and stationary ship in a shallow canal. Bulgarian

Ship Hydrodynamics Centre, Varna Department.

Vantorre M., Laforce E., Verzhbitskaya E., Model tests based

formulations of ship-ship interaction forces for simulation

purposes, IMSF 28th Annual General Meeting, Genova,

2001.

Varyani K., McGregor R., Wold P., Empirical formulae to pre-

dict peak of forces and moments during interactions, Hy-

dronav’99, Gdansk-Ostrada, 1999.