JAPAN P& I CLUBVol.43 July 2018

P&I Loss Prevention Bulletin
The Japan Ship Owners’
Mutual Protection & Indemnity Association Loss Prevention and Ship Inspection Department

Dragging Anchor- Case Studies and Preventive Measures -Dragging Anchor- Case Studies and Preventive Measures ＩＮＤＥＸ§1Introduction.................................................................................................................................................1§2

Typhoons

２－１ Definition of a typhoon (from the Japan Meteorological Agency website [available only in Japanese])......2
２－２

Number of typhoon landings (from the Japan Meteorological Agency website).................................4

２－３

The paths and the wind speeds of the typhoons that landed in 2004.....................................................5

２－４

Typhoon marine accidents in 2004...............................................................................................................7§3

Dragging Anchor Cases
(From the Maritime Casualty Analysis Report [Vol.6]):
Typhoons and marine accidents issued by the Marine Accident Inquiry Agency [MAIA] in 2006)

３－１

The Aomori - Hakodate ferry “Touya Maru” accident ..............................................................................12３― ２Cargo Vessel B Dragging anchor and grounding accident...................................................................21

３― ３

Cargo Vessel C Dragging anchor and grounding accident...................................................................26

３－４

Questionnaire conducted by the Marine Accident Inquiry Agency (MAIA)
for Masters of the coastal vessels that experienced sheltering from the typhoon.................................36§4

Mechanism of dragging anchor

４－１

Accidents involving ships at anchor............................................................................................................38

４－２

The reasons as to why an anchor drags......................................................................................................39

４－３

Detection of dragging anchor.....................................................................................................................42４－４

Wind pressure force........................................................................................................................................45

４－５

Holding power created by anchor and anchor cable.............................................................................47

４－６

Countermeasures to prevent an anchor from dragging in stormy weather..........................................51

４－７

Difficulty in maintaining manoeuvrability after dragging anchor has started........................................58

４－８ Safe distance from other ships, shallows and other facilities....................................................................59§5

Conclusion...................................................................................................................................................62

JAPAN P& I CLUB

01

§1

Introduction

In the event of anchoring, it is common tocarry out single anchor mooring, using one of
the anchors outfitted on either side of the ship.
However, due to strong winds from typhoons orviolent storms, as a dragging anchor preventative
measure, one must be ready to drop the snubber
anchor on the opposite side (to the sea bottom),or carry out two-anchor mooring or ride at two
anchors.
In order to learn from the Aomori - Hakodate“Touya Maru” ferry accident that occurred on
26th September, 1954, the anchor dragging
mechanism, which will be introduced in §3 wasstudied and it was ascertained that once the JIS
type anchor started dragging, the holding powerof the anchor system was lost.
In addition, the Master decided on an anchoring
method and length of anchor chain needed toveer, taking the following into account: space
for anchorage, depth of the water, nature of thesea bottom, other ships’ anchoring situations,
expected maximum wind speed and tidal currents
etc. However, this has not led to a significant
decline in dragging anchor cases.
In 2012, we provided a lecture mainly focusing
on the technical aspects of preventing an anchor
from dragging and also issued the Loss Prevention
Bulletin No. 25.
This time, we are going to introduce typhoon anddragging anchor cases, referring to “Typhoons
and marine accidents” in the Maritime Casualty
Analysis Report (Vol. 6), that was issued by the
Marine Accident Inquiry Agency (MAIA) at thattime in 2006.

Snubber anchor

Riding at two anchorsTwo-anchor mooring

Fig. 1 Anchoring method

Photograph 2
AC14 type anchor－1－

Photograph 3
JIS type anchor

JAPAN P& I CLUBP&I Loss Prevention Bulletin02§2

Typhoons

Accidents due to a dragging anchor are not only caused by Typhoons, but also occur during gales. However, according
to statistics they predominantly occur when a typhoon has just passed. First, it is necessary to understand how
typhoons move.

２－１

Definition of a typhoon (from the Japan Meteorological
Agency website [available only in Japanese])

Typhoons are defined as follows.

Definition:“Atmospheric depression that comes forth in the tropical ocean is called ‘tropicaldepression’. Among them, those which are found in the north-western part of the
Pacific Ocean (sea area to the north of the equator and west from 180 degrees
east longitude) or in the South China Sea, moreover, with a maximum wind speed
within the region of atmospheric depression (10 minutes average) of more thanapproximately 17m/s (34 knots and wind force 8) are called ‘typhoons’”.

A typhoon also has characteristics whereby it is moved by
the wind in the sky and heads north due to the rotation of theearth. Therefore, the typhoon gradually moves northward
while being blown to the west at a low latitude, where
regular easterly winds blow. Then, once it reaches middle
and high latitudes, where strong westerly winds (heights of 8
- 13km and speeds of approximately 100km/h) are in the air,
the typhoon proceeds north east at a high speed.
Also, regarding the force and the size of the typhoon which
we frequently hear of in weather forecasts and so on, theJapan Meteorological Agency expresses the “size” and“strength” of a typhoon based on the wind speed (at an
average within ten minutes). This can be seen in Tables 5 and6. In addition, the range where there is a wind speed of morethan 25m/s blowing or when it has the possibility of beingthat speed, it is referred to as the storm area. For example, it
is expressed as a “very large and violent typhoon” when it isa typhoon with a maximum wind speed of more than 54m/s
with more than an 800km radius of strong wind at 15m/s.
－2－

Fig.4 Surface weather chart at 9:00 on July 13th, 2007
（The centre of typhoon No.4, which is large andseverely strong, found in the sea around Okinawa's
main island)

JAPAN P& I CLUBTyphoon categorised by strength
Category

Maximum wind speed

N/A

Less than 33m/s (64 knots)

StrongMore than 33m/s (64 knots) but less than 44m/s (85 knots)

Severely strong

More than 44m/s (85 knots) but less than 54m/s (105 knots)

Violent

More than 54m/s (105 knots)
Table ５Typhoon categorised by size
Category

Radius of more than 15m/s wind speed

N/A

Less than 500 km

Large

More than 500 km, but less than 800 km

Super large

More than 800 km
Table 6

Fig.7 shows a comparison of a typhoon’s size with thatof the Japanese islands. In the event of such a supertyphoon appearing, a strong wind area with a windspeed of 15m/s will cover most of Honshu. Because adragging anchor is often caused in the event of the windspeed exceeding 15m/s (approximately 30 knots), it isnecessary to pay attention to the size of the typhoon.
In addition, the wind of a typhoon has the following
characteristics.
Although there is a region called the “eye of thetyphoon” where the wind is relatively mild close to
the centre, the region surrounding the eyewall has
the strongest wind. A typhoon is a swirling mass ofair, which blows anticlockwise to the centre of thetyphoon close to the ground. Moreover, it is common toobserve the typhoon’s right side blowing stronger whencompared to the left side. This is because the typhoon’s
wind itself and the flow direction which moves thetyphoon are identical in terms of the right side of thetyphoon. To the contrary, it will be less strong on the left
side of the typhoon, because it is reversed.
Furthermore, at the front right side of the typhoon, it isreferred to as a “dangerous semicircle” due to the factthat vessels drift into the centre. On the other hand, it is
known as a “navigable semicircle” on the left side of theRadius of more than 15m/s wind speed
Large（500～800 km）

Super large（800 km more or more than 800km）

Fig. 7path
wind
direction
Typhoondangerous
semicircle

navigable
semicircle

typhoon because it is blown away from the centre.
Fig. 8－3－

JAPAN P& I CLUBP&I Loss Prevention Bulletin

２－２

Number of typhoon landings (from the Japan Meteorological Agency website)

According to the Japan Meteorological Agency, “in the event that the centre of a typhoon approaches the coastline of
Hokkaido, Honshu, Shikoku and Kyushu, it is defined as being ‘a typhoon that visited Japan”. However, if it goes backto the sea again only crossing small islands and peninsulas, it is said to be a “pass”. Tables 9 and 10 show the typhoons
that have landed between 2001 and 2017. There are 10 typhoons that landed in 2004, which makes it a remarkable
year. The average number of typhoons that landed within this specific 16 year period, except 2004, is 2.7 per year.
Also, the typhoons that landed between July and October came to 92% of the total. Within those, the typhoons thatlanded among the months of August and September came to 60% of the total. On the contrary, there were no typhoons
that landed between the months of November and April in sixteen years.

Jan. Feb. Mar. Apr. May June

2017

July

Aug.

Sept.

Oct.

1

1

1

1

4

2

6

1

4

2016
2015

2

1

2014

1

1

Nov.

Dec. Yearly total
4

2

2013

4

2

2012

1

2011

1

2010

1

2

1

2

2

3

1

2

2009

1

1

2008

0

2007

1

1
1

1

2

1

1

1

3

3

2

2006
2005
2004

2

2003

1

1

3

2

10

1

3

1

2002

2

2

2001

1

1

3

10

16

16

7

0

0

53

0% 0% 0% 0% 2% 6%

19%

30%

30%

13%

0%

0%

100%

Sum total
%

1

0

0

0

0

1

2

34444244441
92%

144444444444424444444444443

Number of typhoon landings in Japan (2001-2017）
Year

Annual average number oftyphoon landings over 16
years excluding 2004:

2.7

Table 9

(Number of Typhoon Landings)
10

10

Number of typhoon landings (2001-2017）

Prominent only in 20148

Annual average
number of typhoon landings over
16 years excluding 2004:

2.7

6

6

4

3

3
2

2

2

4

4

14

15

4

3

3
2

2

2

2

12

13

1
0

01

02

03

04

05

06

07

0

08

09
Table 10

－4－

10

11

16

17
(Year）JAPAN P& I CLUB

２－３

The paths and the wind speeds of the typhoons that landed in 2004

The paths and wind speeds of ten typhoons that landed in 2004 are shown in Fig. 11 and Table 12. It was observedthat the maximum instantaneous wind speed was more than 60m/s for typhoons No. 10, 18 and 22. Also, it wasobserved that the maximum instantaneous wind speed was more than 50m/s for eight typhoons except No. 11 and 15.
The solid line indicates the typhoon path and the dotted line is the path in the event of a tropical dipression.

No. 18Hiroshima 60.2m/s

No. 22Iro Zaki 67.6m/s
No.10
Muroto-Misaki 60.9m/s

Typhoon No.15
Typhoon No.18

Typhoon No.11

Typhoon No.10

Typhoon No.21
Typhoon No.4

Typhoon No.22

Typhoon No.23
Typhoon No.6

Typhoon No.16

Fig. 11

TyphoonMaximum wind Maximum instantaneous
speed
wind speed (m/s)

Period■ No. 4

June 11th■ No. 6stJune 21 to 22■ No. 10

July 31st to Aug. 2nd■ No. 11

th

29.2
nd

th

Aug. 4 to 5

Meteorological Office

51.5

Miyako Island

43.7

57.1

Muroto-Misaki

47.7

60.9

Muroto-Misaki

20.3

29.8

Shiono-Misaki■ No. 15

Aug. 20

th

27.1

48.7

Izuhara■ No. 16

Aug. 30th to 31th

46.8

58.3

Muroto-Misaki■ No. 18

th

33.3

60.2

Hiroshimath

Sept. 7 to 8

■ No. 21

Sept. 29 to 30

31.5

52.7

Kagoshima■ No. 22

Oct. 9th to 10th

39.4

67.8

Iro Zaki■ No. 23

Oct. 20th to 21st

44.9

59.0

Muroto-Misakithth

Table 12－5－

JAPAN P& I CLUBP&I Loss Prevention Bulletin

Coastal vessels that experienced anchoring problems, following the passing of ten typhoons, are shown in Fig. 13
and Table 14. Approximately half of the number of ships anchored at Seto Inland Sea. In addition, 30% of the ships
anchored at main sea areas such as: Tokyo Bay, Ise Bay, Mikawa Bay, Osaka Bay etc.

Sum total

700
Off Hokkaido 9

Hakodate Bay 9

Mutsu Bay and Aomori Bay 16

Coast of Japan sea(Oga Peninsula-Oki)
16
Hiroshima Bay
and Port of Kure 55

East coast of Honshu(off Shiriyazaki-off Choshi) 25

Osaka Bay 63

Tokyo Bay 82

Tokuyamakudamatsu area 48
South coast of Honshu (Iro Zaki -Cape Shiono -misaki) 6

Northwest coast of Kyushu 33

Ise Bay and Mikawa Bay 68

Yatsushiro Sea 24

Eastern Seto Inland Sea(Kii Suido〔Strait〕, Awaji-shima Island and westward-Bingonada) 163

South coast of Kyushu 4

Western Seto Inland Sea(Akinada and Bungo Suido〔Channel〕) 76
Okinawa and Amami Oshima 3

Fig. 13

Others 145

Osaka Bay 63
Ise Bay and Mikawa Bay 68

21%
9%Area ofanchorage
by ratio

10%
11%

Tokyo Bay 82

Table 14

－6－

Seto Inland Sea

49%(except Osaka Bay)

342

JAPAN P& I CLUB

Prefecture (Authority
name name)

0

10

20

30

40

50
（m/s）

× 3.2

Aichi (Owase)
Aichi (Irago)

× 1.9

Aichi （Nagoya）

× 2.1
× 1.7

Shizuoka (Iro Zaki)

× 2.0

Shizuoka (Omaezaki)
× 2.5

Shizuoka (Shizuoka)

× 2.1

Kanagawa (Yokohama)
Chiba (Chiba)

× 1.7

Chiba (Tateyama)

× 2.3

Chiba (Choshi)

× 1.5

Maximum wind speed
Maximum instantaneous wind speed

× 1.8

Tokyo (Oshima)
Tokyo (Tokyo）

× 2.4
× 1.7

Ishikawa (Wajima)

× 1.8

Ishikawa (Kanazawa)× 2.1

Toyama (Fushiki)

× 1.8

Toyama (Toyama)
Niigata （Niigata）

× 2.8
0

10

20

30

40

（m/s）
50

Table 15

Following a comparison of the maximum wind speed (the maximum value of the 10 minute average wind speed) andthe maximum instantaneous wind speed (the maximum value of the instantaneous wind speed) which were detected
at each meteorological office, at the time when typhoon No.23 landed on October 20th and 21st, is shown in Table 15.
Maximum instantaneous wind speed becomes 1.5 - 3.2 times greater the average wind speed.
At sea, where there are few structures that stand against the wind, it is particularly necessary to estimate the maximum
instantaneous wind speed to be at least 1.5 - 2 times that of the average wind speed.

２－４

Typhoon marine accidents in 2004

Typhoons have caused large-scale disasters, not only for ships, but also on shore. Figs. 16, 17, 18, 19, 20, 21, 22 and23 indicate damage statuses.

－7－

JAPAN P& I CLUBP&I Loss Prevention Bulletin

No.4 and 6

6

4

No.10 and 111011

ㅦ June 10th to 22nd
ㅦ No. of deceased and missing: 5
ㅦ No. of totally or partially destroyed houses: 6

ㅦ July 29th to Aug. 6th
ㅦ No. of deceased and missing: 3
ㅦ No. of totally or partially destroyed houses: 32

It brought damage to the Chubu,
Kinki and Shikoku regions. Alongwith major disruptions caused toeach form of transportation, part of
the national highway in Tokushima
prefecture was closed.

It brought heavy rain mainly in the
Shikoku regions, and continuously,
it caused landslides and mudslides
in Tokushima and Kochi prefectures.

http://agora.ex.nii.ac.jp/digital-typhoon/wnp/by-name/200404/0/512x512/GOE904061106.200404.jpg
http://agora.ex.nii.ac.jp/digital-typhoon/wnp/by-name/200406/0/512x512/GOE904062003.200406.jpg

http://agora.ex.nii.ac.jp/digital-typhoon/wnp/by-name/200410/0/512x512/GOE904080103.200410.jpg
http://agora.ex.nii.ac.jp/digital-typhoon/wnp/by-name/200411/0/512x512/GOE904080403.200411.jpg

15

No.15

１６

No.16

ㅦ Aug. 17th to 20th
ㅦ No. of deceased and missing: 10
ㅦ No. of totally or partially destroyed houses: 105

ㅦ Aug. 27th to 31st
ㅦ No. of deceased and missing: 17
ㅦ No. of totally or partially destroyed houses: 256

It brought extremely heav y rain,
not only to the Kyushu and Shikoku
regions, but a storm that swept eacharea on the Sea of Japan side from
Kyushu to Hokkado.

It brought heavy rain and flooding,due to high tide, to the Pacific coastof western Japan. A wide area of
the Seto Inland Sea coast, suchas Kagawa Prefecture, Okayama
Prefecture and Hiroshima Prefecture
were affected.

http://agora.ex.nii.ac.jp/digital-typhoon/wnp/by-name/200415/0/512x512/GOE904081903.200415.jpg

http://agora.ex.nii.ac.jp/digital-typhoon/wnp/by-name/200416/0/512x512/GOE904083003.200416.jpg

18

No.18

21

No.21

ㅦ Sept. 4th to 8th
ㅦ No. of deceased and missing: 46
ㅦ No. of totally or partially destroyed houses: 1,650

ㅦ Sept. 25th to 30th
ㅦ No. of deceased and missing: 27
ㅦ No. of totally or partially destroyed houses: 893

In the regions of Okinawa, Kyushu,
Chugoku and Hokkaido, there wereareas that recorded the highest
instantaneous wind speeds.
Buildings were damaged and trees
were fallen in each area while a large
number of people were injured.

S h e c r o s s e d t h e Ky u s h u a n d
Shikoku regions, kept proceeding to
the Kinki and Hokuriku regions andfinished up in the Tohoku region.

http://agora.ex.nii.ac.jp/digital-typhoon/wnp/by-name/200418/0/512x512/GOE904090704.200418.jpg

http://agora.ex.nii.ac.jp/digital-typhoon/wnp/by-name/200421/0/512x512/GOE904092803.200421.jpg

22

No.22

23

No.23

ㅦ Oct. 7th to 9th
ㅦ No. of deceased and missing: 9
ㅦ No. of totally or partially destroyed houses: 435

ㅦ Oct. 18th to 21st
ㅦ No. of deceased and missing: 98
ㅦ No. of totally or partially destroyed houses: 8,836

The typhoon was not so big, however,the vicinity of the centre wasaccompanied by raging rain and wind.
It caused sediment damage suchas landslides, flooding and damage
caused by gusts, from the Tokai
region to the southern part of Kanto.

Because she crossed Honshu with alarge force, she brought overflow torivers, flooding and sediment damage
to a wide area. There were a large
number of the deceased and missing
on a wide scale, mainly in Hyogo,
Kyoto and Kagawa prefectures.

http://agora.ex.nii.ac.jp/digital-typhoon/wnp/by-name/200422/0/512x512/GOE904100803.200422.jpg

Fig. 16 ～ 23
Source: “Digital Typhoon Project” courtesy of the National Institute of Informatics－8－

http://agora.ex.nii.ac.jp/digital-typhoon/wnp/by-name/200423/0/512x512/GOE904101803.200423.jpg

JAPAN P& I CLUBTable 24 indicates each typhoon marine accident situation that occurred in 2004 (as published in the Marine Accident
Inquiry Agency [MAIA]).. The total number of marine accidents was 233, however, the number of marine accidents (72
accidents) and the number of vessels (88 vessels) affected by Typhoon No. 18 are remarkably prominent.

2004

Typhoon marine accident situation

100
90

No. of accidents caused by
Typhoon No.18

88

No. of accidents

80

No. of ships

70

No. of deceased and missing

72 cases/88 ships

72

60
50

48

45
39

40
30

27

20
6

No. 4

6

2

No. 6

No. 10

31
26

14 14

12 13

10
0

52

2

14
2

No. 11

No. 15

4

No. 16171

No. 18

No. 21

1

No. 22

No. 23

Table 24

Typhoon marine accidents in 2004 (regions that had more than 5 accidents)
Port of Tokuyamakudamatsu 6

Port of Mizushima 5Port of Hiroshima 37

Aioi‐Ieshima 7

Amagasaki Nishinomiya
Ashiya port 5

Seto Inland Sea

Mishima-Kawanoe port 5

Nansei Shoto

Akashima Island
15

Kanmon port 6
Tokyo Bay 8
Kagoshima Bay 7
Port of Kochi 6

Fig. 25－9－

JAPAN P& I CLUBP&I Loss Prevention Bulletin＝ Summary of Typhoon No. 18 (From the Japan Meteorological Agency website) ＝
On the 28th of August 2004, approximately 09:00 Japan Standard Time (here in after referred to as JST),
Typhoon No.18 which was formed in the sea around the Marshall Islands moved northwestward over thesouthern Sea of Japan and passed through the northern part of the main Okinawan island with great size andforce on the 5th of September. Afterwards, she proceeded north, to the East China Sea and changed path to thenortheast. At approximately 9:30 on the 7th of September, she landed in the vicinity of Nagasaki-city and passed
through the northern part of Kyushu. In the afternoon of the 7th she reached the Sanin offing. Then, while
accelerating northeastward up the Japan Sea, on the morning of the 8th she headed north on the western offingof Hokkaido with a storm area accompanying after. Then, after changing into an extratropical cyclone at 09:00
on the 8th, she reached the Soya Strait, while still growing.
Gale force winds with a recorded maximum instantaneous wind speed of 50m/s were observed in regions of
Okinawa, Kyushu, Chugoku and Hokkaido, for example, 60.2 m/s in Hiroshima and 50.2 m/s in Sapporo. In
addition, there was an area of the Kyushu region where heavy rain which exceeded 900mm was observed.
Moreover, damage caused by high water levels on the coast of the Seto Inland Sea and on the coast of theJapan Sea from western Japan to northern Japan was also observed.
This typhoon caused damage to buildings and trees to fall in each area it passed. A large number of people were
injured because of falling debris. Also, grounding accident of ships occurred one after another in western Japan.

Fig. 26
The route of Typhoon No.18 in 2004

Photograph 27

Fig. 28 shows the routes of Typhoons No. 18 and 23. Moreover, the severe dragging anchor accident of the
cargo ship "MV TRI ARDHIANT" (6,315 tons) and grounding accident of the training ship “Kaiwo Maru” (2,556
tons) may be familiar.

－ 10 －JAPAN P& I CLUBDragging anchor
Grounding accidentΔ

Typhoon No.18
Cargo Vessel
MV TRI ARDHIANT (6,315tons)
Grounded
September 7th Kasadojima,
Kudamatsu-shi, Yamaguchi Prefecture
Total loss, 19 deceased and 1 missing.

Typhoon No.23
Training Ship
Kaiwo Maru (2,556tons）
Grounded

Sept. 8th
October 20th Fushiki Toyama Port
30 severely injured

×Oct. 21st×
Sept.7th

Typhoon No.18

Oct. 20st

Typhoon No.23
Fig. 28

Looking closely at 233 accidents due to the typhoons in 2004 “by type of case”, the main aspects of typhoon maritime
accidents will follow. The ratio of those accidents will be shown in Fig 29.

Detailed Breakdown ofMarine Accidents
Collision (single)
54

Others 4
2%

23%
Shipwreck
102
44%＊ Collision (single)▶ Whle moored at a pier, the hull collided with the quay due to strong winds.
▶ W hile berthing was in progress using the anchor, it collided with the quay
because the strong winds did not allow for anchorage.
＊ Aground▶ While anchored, grounded on a rocky stretch due to a dragging anchor andsinking.
▶ W hile turning round in the harbour, pressed by strong winds and therefore
grounded in a swash.
＊ Equipment damage

Total

233
cases

14%

▶ Due to the strong wind, the antenna at the top of the mast was lost.
▶ Because there was a danger of collision with another vessel due to dragging
anchor, the anchor chain was cut off.
＊ Collision2%

Capsize67%8%Aground32

Equipment damage
19
Collision
16
Fig. 29▶ Pressed by dragging anchor, ships collide with other ships while anchored.
＊ Capsize▶ Very stormy weather (at sea) was brought by typhoons approaching and fishingboats that were sailing out were discovered capsized.
＊ Shipwreck▶ Propellers which made contact and were damaged by floating matter such as
driftwood due to heavy rain.
▶ Towed objects drifting and being grounded in shallows due to a severed tow rope
was cutted.
▶ A loss of a lamp door due to a direct hit from a high wave.

－ 11 －JAPAN P& I CLUBP&I Loss Prevention Bulletin

§3

03
３－１

Dragging Anchor Cases(From the Maritime Casualty Analysis Report [Vol. 6]: Typhoons and marine
accidents issued by the Marine Accident Inquiry Agency [MAIA] in 2006)

The Aomori - Hakodate ferry“Touya Maru”accident

Touya Maru：
The Aomori - Hakodate ferry, 4,337 tons

Date, time and the point/location of occurrence:
22:45 JST on the 26th of September in 1954 in Hakodate Bay (during harbourage from thetyphoon)Weather at the time of sinking：Rain, southwest wind, wind speed at 20m/s, wave height at 3m and 1 hour had passed since low
tide had begun.

Accident summary
26th September, 1954

Off Nanaehama

Circumstances of Hakodate Bay

Touya Maru sinking
Touya Marudragging anchor

Arikawa
Pier

Hidaka Maru sinking
No.11 Seikan Maru sinking
Hokkaido

Tokachi Maru sinking

Hidaka Marudragging anchor

No.11 Seikan Marudragging anchor

Hakodate Bay

Kitami Marudragging anchor
Hakodate
Pier
Hakodate
Train Station

Tokachi Marudragging anchor
Hakodateyama

Kattoshimisaki Lighthouse

Kitami Maru
sinking
NauticalMileskm

Fig. 30

Regarding the Aomori - Hakodate ferry, Touya Maru, the total number of persons on board was 1,314, (crew members:
111, passengers and so on: 1,203) with 12 freight cars loaded. While Typhoon No. 15 was approaching, Touya Maru
－ 12 －JAPAN P& I CLUBdeparted Hakodate Pier from within the Port of Hakodate bound for the Port of Aomori. She was to take refuge at the
Hakodate Bay because outside the Port of Hakodate had already been seeing very stormy weather (at sea), however,she dragged anchor due to a gale and high waves. Touya Maru therefore grounded in the shallows of Nanaehama
in Hakodate Bay. She then capsized and sank which caused a total number of 1,155 deceased or missing persons
including passengers etc.
Also, four other vessels from the Aomori - Hakodate ferry, namely, No. 11 Seikan Maru, Kitami Maru, TokachiMaru and Hidaka Maru capsized and sank in Hakodate Bay in succession. The total number of deceased and missing
passengers etc. came to be 275.
The state of affairs at Hakodate Bay on the 26th of September in 1954 is shown in Fig. 30. Hakodate Bay has a land
shape that makes it less influenced by wind and waves because it is shielded by high mountains, when there is anorthwest wind.
“However, the bay mouth is open widely towards the direction of the ‘south-southwest’. Thus, because of the longfetch, in the event that a southerly wind blows continuously, high waves are thrusted into the bay as time goes by”.

Typhoon No.15 (International name: Marie)
Typhoon No.15, Marie, formed at the north of the Yap Islands on the 21st of September and hit the Northern Osumi
Peninsula from Kagoshima Bay on the 26th at around 14:00 JST at a very fast speed. Afterwards, she cut across theeastern part of Kyushu and passed through the region of Chugoku, at a speed of 100km/h.
On the 26th at approximately 08:00 she moved off of Sanin to the Japan Sea and grew as she headed north to
Hokkaido. At 21:00 on the same day, she reached her peak then she passed off Suttsu in Hokkaido. She reached nearby
Wakkanai City at around 0:00 on the 27th. Regarding the precipitation of this typhoon, there are some areas which
exceeded 200mm like the regionsof Kyushu and Chugoku, however,there were lesser amounts in otherareas. Because the typhoon continued
developing even after entering the Sea
of Japan, a violent storm of more than
9/26 21:00 JST
30m/s was blowing in each area of
9/26 15:00 JST
western Japan, Tohoku and Hokkaido.
Normally we rarely think that typhoons 9/26 09:00 JST
develop in the Sea of Japan at theend of September when the seawater
9/26 02:00 JST
temperature is lower. Therefore, it canbe considered that the typhoon had
9/25
in fact changed into an extratropical
cyclone (a so-called “bomb low
pressure” cyclone) from approximately
3:00 on the 26th of September when she
landed in Kyushu.
9/18
Fig. 31－ 13 －JAPAN P& I CLUBP&I Loss Prevention Bulletin

HakodateTD

warm front

Aomorioccluded
front

cold front

Sept. 26th 16:00 JST
Fig. 33

Sept. 26th 09:00 JST
Fig. 32

Path of Typhoon No. 15

958mb 27 th 03：00
956mb 21:00

Esashi port
960mb 15:00

Hakodate Bay

The following are characteristics of Typhoon
No.15 (International name: Marie):

964mb 09:00① After crossing the regions of Kyushu andChugoku, she went up north to the Sea ofJapan while maintaining her force.
② She approached Hokkaido at approximately
100km/h, then her speed decreased to

26 03:00
965mb
thapproximately 50km/h as she reached thesea in the southwest of Oshima Peninsula.
Fig. 34－ 14 －JAPAN P& I CLUB

Photograph 35

Photograph 36"Capsized Touya Maru""Bygone days of Touya Maru"

Movement of Touya Maru
The movement of Touya Maru on the 26th of September is as follows.

11：05

She moored Hakodate Pier (Aomori → Hakodate Port).
“Typhoon No. 15 proceeded northeast 100km northwest of Noto Peninsula.
According to the weather information, it was highly possible that it would pass to the south of
Hakodate in the evening”.

14：40

Station for leaving port. (Leaving the Hakodate Pier bound for the Port of Aomori)

15：00

Because it was not possible to remove a movable bridge between the railway track and the ship due
to a blackout, the Master decided to delay departure for the time being. Touya Maru was awaiting withpassengers on board, while mooring.
“Weather information: the typhoon passed the northern part of the Ou region or the southern part of
Hokkaido in the evening and proceeded to the Kuril Islands at night”.

17：00

The wind suddenly weakened, sunny spells were observed in the sky and it would have seemed as if
they had been swallowed up and had reached the centre of the typhoon.
“At Hakodate Pier, there were no changes in wind direction for over one hour from 17:30. Then, thewinds became stronger, but there were no changes in atmospheric pressure”.

17：40

It was decided that the ship depart at “18:30”.

17：59“Weather information: the typhoon proceeded 100km northeast or north-northeast off Esashi Port
offing”.

18：39
Departed Hakodate Pier from the port of Hakodate. While being blown by a south-southeast gale fromher astern port side, she manoeuvred the normal route in the breakwater at full speed.

18：53

Passed the breakwater entrance nearby. It was confirmed that the port side bow took gale force winds
and that the waves were also high.

－ 15 －JAPAN P& I CLUBP&I Loss Prevention Bulletin

18：55
19：01

19：30

She passed the breakwater lighthouse which was on her port side.
Anchored due to a violent storm and waves (two-anchor mooring with 8 shackles on her starboard sideand 7 shackles on her port side).
“There was a south-southwest wind at 25 - 30m/s, a gust at 40m/s and there were no changes inatmospheric pressure”.
Along with pitching of the hull, car deck flooded from the opening of the stern.

Low freeboard
Photograph 37

19：50

Fig. 38

The 7 shackles at port side were extended by 1 shackle to become 8 shackles on both sides. Flooding
started in the engine room (machinery room).

20：00
Anchor dragging started. Flooding started in the boiler room.

20：10

Initial accident report was made to JCG via radio communications.

20：30

Operated the ballast pump, but shortly it became in vain. Flooding started in the steerage.

20：40“The anemometer on the ship was recording gusts of 57m/s anda wave height of 6m”.

Photograph 39

21：00

Ship heeled to the port side.

Photograph 40－ 16 －JAPAN P& I CLUB

21：40

Further heeled to the port side.

21：50

Main engine on the port side became inoperable, and the bilge could not be discharged. Ship’s heel
started shifting from port side to starboard side.

22：05

Main engine on the starboard side became inoperable and the vessel became trim by the stern due toflooding.

22：15

Passengers were instructed to wear life vests.

22：26

Grounded in the shallow off Nanaehama, with a
45 degree inclination to the starboard side.

Fig. 41

22：42

Blackout on board with a deluge of water flowing in.

22：45

Sinking after rolling over to the starboard side.
Ofﬁng

NanaehamaSea surface
a ﬁrst/secondclass cabin

Engine room
the steerageDeck(B)(Passage deck)

FunnelCrew cabin

Steering gear room
Photograph 43

Fig. 42

Sinking circumstances: location at a depth of 8.3m
The hull was parallel with the coast with a 135 degree inclination on her starboard side. The starboard
side was buried in the seabed under mud with the port side bilge keel visible on the sea surface.
Later the Japan Meteorological Agency concluded that “the reason why the wind had weakened
for a moment near the Hakodate Bay was because a cold air current, accompanying the cold front,
offset the wind of field, and therefore, the cold front rapidly disappeared when it interacted withthe wind field”. Regarding the “wind becoming weak along with a mysterious westering sun”, they
announced that this was not caused by the typhoon as the centre of the typhoon passed the vicinityof the port of Hakodate.
Also, the four Aomori - Hakodate ferries, including Touya Maru, experienced groundings andcapsized as a result of a dragging anchor.

－ 17 －JAPAN P& I CLUBP&I Loss Prevention Bulletin

Registered nameof ship

No.11 Seikan Maru

Kitami Maru

Touya Maru

Tokachi Maru

Hidaka Maru

G/T

3,142 tons

2,928 tons

4,337 tons

2,911 tons

2,923 tons

Length113.8 meters113.7 meters113.7 meters113.6 meters113.7 meters

No. of Crew

90

76

111

76

77

No. of Passengers

None

None

1,203

None

None

Loaded freight cars

45

46

12

35

43

Route

Hakodate → (Anchoredin heavy weather)

Hakodate → (Anchoredin heavy weather)

Hakodate → Aomori

Aomori → Hakodate

Aomori → Hakodate

Between 13:00
and 14:00:
East-southeast
8-12m/s
999.2mb

13:20 Left port of
Hakodate boundfor port of Aomori
Departed (Hakodate
Pier)

Between 14:00
and 15:00:
East
15-17m/s
989.2mb

Between 17:00
and 18:00:
South
12-15m/s
982.6mb
Between 18:00
and 19:00:
South
15-20m/s
982.6mb

Between 19:00
and 20:00:
South
15-20m/s
982.6mb

Departed port of
Aomori)

14:48 Because thewaves rose could
no longer sail andreturned to port

14:40 Bound for port of
Aomori

14:20 Departed portof AomoriS/B Station for departure

15:17 Left wharf toshelter from stormy
weather(Arikawa
Pier)

Between 15:00
and 16:00:
East
15-17m/s
986.6mb

Between 16:00
and 17:00:
East
10-15m/s
985.2mb

11:20

15:30 Anchored(starboard anchor
with 8 shackles)

15:00 Due to blackout, adjustable shore
ramp could not be
removed. This caused adelay,and departure wassuspended.

16:02 Left wharf toshelter from stormy
weather (Hakodate
Pier)

16:33 Anchoredin the break water（starboard anchor
with 5 shackles andport anchor with 5
shackles)

16:25 Anchored
17:40 Departed andbound for port of
Aomori

Details are
unknown because
all crew deceased

17:30 Commenced
anchoring watch

18:40 Commenced
anchoring watch
Engine ready

18:38 Departed Port of
Hakodate (Hakodate
Pier)

18:50 Anchored(starboard anchor
with 8 shackles andport anchor with 4
shackles)

19:00 Used engine

19:01 Anchored(starboard anchor with
8 shackles and port
anchor with 7 shackles)

19:30 Used engine
Flooded in car deck

19:30 Flood inengine room andboiler room

19:30 Flooded in cardeck
19:50 Laid down bothanchors with 8 shackles
Flood in boiler room

－ 18 －

19:30 Used engine
Laid down bothanchors with 8
shacklesJAPAN P& I CLUBRegistered nameof ship

Between 20:00
and 21:00:
South
20-30m/s
979.9mb

No.11 Seikan Maru

Kitami Maru

20:00 Sinking fromastern

20:20 Dragging
anchorTouya Maru

Tokachi Maru

20:00 Dragging anchor
Flood in boiler room

20:00 Dragging
anchor Flood in boilerroom

20:45 Weighing
anchor commencesin order to heave-to

Between 21:00
and 22:00:
South
15-20m/s
979.9mb

20:40 Drifted 1 nauticalmile northeasterly bywind pressure andoscillates violently

21:15 Heaved cable
to 3 shackles and fullspeed ahead Heeled
10 degrees to portside

21:40 Heel increased on
port side

22:00 Heeled at 15
degrees starboardside

22:05 Main engine on
starboard side inoperable

22:30 Engine
inoperable, rolled
over to starboard
side, sinking

Between 22:00
and 23:00:
Southwest
15-20m/s
979.9mb

Hidaka Maru

21:50 Heel increasedon starboard side

21:50 Main engine on
port side inoperable

21:15 Weighing
anchor commencesin order to shift
outside of breakwater
21:45 Weighingof the anchor
completed and fullspeed ahead

22:15 Instructed passengers to wear life vests

22:20 Engine
inoperable

22:00 Flooded to cardeck

22:30 Generator
stopped (Blackout)

22:10 Flooded inengine room andboiler room
22:25 After lowering
anchor (starboard
anchor with 4
shackles), entire
anchor cable (10shackles) was laiddown

22:26 Grounding in shallows and heeled at 45
degrees starboard side
22:42 Blackout, large
amount of seawater encroached
22:45 Rolled over tostarboard side, sinking
23:41 Loaded cars
were rolled over

Between 23:00
and 24:00:
Southwest
20-250m/s
981.2mb

23:42 Capsized on
starboard side

23:00 Heeled at 10
degrees starboardside
23:35 Discarded
anchor, but engine
inoperable. Engine
stopped23:43 CapsizedTime of marine
accident
occurrence
Point of marine
accident
occurrence
No. of deceased
and missing

20:00
257 degrees
and 1,785m
from Hakodate
Port breakwater
lighthouse

90

22:30
89 degrees and2,900m from
Kattoshimisaki
lighthouse

22:45
257 degrees and 1,785m
from Hakodate Port
breakwater lighthouse

70

1,155

23:42
257 degrees
and 1,785m
from Hakodate
Port breakwater
lighthouse

59

23:43
257 degrees
and 1,785m
from Hakodate
Port breakwater
lighthouse56

Note: The wind direction, wind speed and pressure are figures that are read at Hakodate Pier every hour on the hour.
Table 44

It is presumed that it was difficult to grasp the actual changes of the typhoon’s state, because there wasno means of observation via weather satellite, bar that of weather forecasts based on the information
available from weather stations located in each region.

－ 19 －JAPAN P& I CLUBP&I Loss Prevention Bulletin＝ Quoted from the Marine Accident Inquiry Agency (MAIA) determination ＝Provisional translation Courtesy of the Marine Accident Inquiry Agency (MAIA) homepage
The Marine Accident Inquiry Commissioner’s Office completed their survey in a short period of only 62 days
following the occurrence of the accident. Appointing the 2nd navigation officer and the 2nd engineer of
Touya Maru as examinees, appointing also the president of the Japanese National Railways (JNR), the chiefof Aomori ‐ Hakodate Railway Bureau, the chief of the Central Meteorological Observatory and chief of the
Marine Meteorological Observatory in Hakodate as designated persons regarding the marine accident, filed
an application for a trial to commence on the 27th November, 1954 at the Marine Accident Inquiry Agency in
Hakodate.The first trial was concluded on the 15th of July, 1955. The decision regarding the second trial wasconcluded on the 9th of February, 1959.

Main text of judgement:

Although this accident occurred because the Master of Touya Maru neglected to carry out his duty, other factors
include inappropriate operation management of the Aomori ‐ Hakodate ferry company along with a generallack of understanding regarding the vessel’s hull construction.

①

Master’s negligence of duty regarding shipping operation▶

Even though the vessels are structured and equipped to the standards stipulated in the convention and law,
it is necessary for the Master to pay extra attention to the safety of the vessel and lives of those on board,
because it should be anticipated that navigating will be dangerous, in the event of encountering a typhoon.

▶

The Master should have departed as usual once the danger of the typhoon had passed.

▶

In the vicinity of the port of Hakodate, the wind veered and gradually increased from the southwest west
between 22 - 25m/s, and turned into a squall at 32m/s. Thus, it could not be accepted that the typhoon
had passed, as the barometric height decreased and stagnated. This accident was caused by the Master’s
negligence, who proceeded to set sail from the port of Hakodate bound for the port of Aomori while
carrying a large number of passengers and cargo, under rough sea conditions.

②

Hull construction▶

Because there was a vessel that encountered such weather and sea conditions whereby sea waves flowed
deep into the car deck of the vessel, whose hull structure was similar to this one, in the past, this hull
structure was not appropriate, taking into consideration the actual operation to be carried out on this sea
route.

▶

Regarding the accident, having not being able to have prevented flooding from the various openings on the
cargo deck would have caused the subsequent sinking after rolling over. Thus, the inappropriateness of thehull construction is one of the factors concerning this accident.

③

Inappropriate operation management▶

Despite such rough seas that could be expected to bring about great danger when navigating, the vessel
continued operating on a fixed schedule and the operation continued as long as possible, without
evacuating at an early phase, as would have normally been the case.

▶

The management department were of the opinion that it was enough to leave the safe operation of ferries
to the Masters and that they should not intervene.

▶

There was no arrangement of personnel or personnel charged with authority in order take necessary care

－ 20 －JAPAN P& I CLUBand measures for the safe operation of the ship in the organization. In addition, there was no provision regarding
emergency personnel arrangement and authority of management, in time of an emergency such as this.
▶

The management mechanism and policy for ferries had been properly carried out over the years, from when thegovernment started managing this sea route until this accident occurred. It is not however appropriate for it to be
managed by a shipping management company, when considering how dangerous this route is.

３―２ Cargo Vessel B Dragging anchor and grounding accident
Cargo Vessel B:
General cargo vessel with 2 cargo holds of 5,552 G/T
Date, time and location of occurrence:
30th of August 2004, 12:25 Japan time (JST), Yura-misaki offing of Ehime Prefecture
Weather at time of sinking:rain, southeast wind: wind force 12, wave height 8m, end of ebb tide

Accident summary
Twenty Vietnamese crew were on board Vessel B, which departed the Port of Pohang of the Republic of Korea andarrived at the Port of Ohita via the Kanmon Straits on the 26th of August. Anchored in order to await berthing. The
Master (Vietnamese) was at the age of 42 with 18 years of sea experience and 4 years as Master.
In the morning of the 28th, the Master knew that Typhoon No.16 was approaching Oita, between the 29th and the30th, via weather information provided by NAVTEX and telex from the local agent. He decided to shelter from thetyphoon by moving to another sea area. The vessel heaved up anchor in the afternoon, and the Master made a plan tostart operating southward toward the Bungo Suido (Channel), while searching for an appropriate place to anchor.
The vessel heaved up anchor on the 29th of August at 09:55 JST, the Master started sailing southward along the
Bungo Suido (Channel) as planned. However, due to the deep depth of the water that was also present in Uwakai etc.
she continued southward and conducted single anchor mooring at a location of 92 meters depth of water in the bay ofthe southeast part of Yura-misaki offing of Ehime Prefecture at 14:40 on the same day. Afterwards, the wind directionchanged to the southeast and sea waves encroached from the bay mouth that was exposed to the south. However, theMaster continued to anchor without shifting from an early stage.
At 17:40 on the 29th, noticing that the anchor was dragging, the Master attempted to heave up the anchor in order toevacuate offshore. However, the vessel had no choice but shift off while dragging the anchor, and anchored again at
20:40, because it was not possible to weigh the anchor due to the extremely deep depth of water. At 11:30 on the 30thof August, the anchor was dragging again and Vessel B was grounded on the shore of Yurajima at 12:25 on the same
day.
Four crew members who panicked and climbed down the stern deck and were carried away by the waves (one was－ 21 －JAPAN P& I CLUBP&I Loss Prevention Bulletin

deceased and three missing). The remaining 16 crew members including the Master were rescued by the helicopters of
the Japan Coast Guard and the Self-Defense Force. Photograph 45, Figs. 46 and 47 show the path of Vessel B and its
anchor being dragged.

Aug. 29th 09:55

Departed anchorage

Source: website courtesy of the Geospatial Information Authority of Japan (GSI)

Photograph 45

Fig. 46

suge
Ehime Prefecture

20m

Aug. 30th 12:25
Grounded×Yuranohana
Yuranohana
light house

<11

3>

2.6

0>

<07

2.6

nau

tica

n

lm

Aug. 30 11:30

iles

th

+

iles

lm

ica
aut

+

Aug. 29th 14:40
Single anchor mooring
Aug. 29th 17:40
Dragging anchor started

Aug. 29th 20:40
Single anchor mooring again

Dragging anchor started again
Regarding the wind direction from thesoutheast to southwest, the topography001of the land was considered as such thatsea waves could easily encroach fromthe south. There are also few shields
such as land or islands.

3km
1

2 nautical miles

Source: courtesy of the Geospatial Information Authority of Japan (GSI) website

Fig. 47－ 22 －JAPAN P& I CLUBTyphoon No.16 in 2004 (Asian name: Chaba)〔Chaba: Naming country: Thailand, Meaning: Hibiscus〕

Aug. 30th 18:00JST
965hPa 35m/sec
Aug. 30th 15:00JST
965hPa 35m/sec

200km

Aug. 30th 12:00JST
955hPa 40m/sec

Point grounded
Aug. 30th 06:00JST
950hPa 40m/sec
Source: courtesy of the Geospatial Information Authority of Japan (GSI) website

Fig. 48

Fig. 49

Photograph 50
Typhoon No.16 at her peak (August 23rd)
910hp Maximum wind speed 155kts (80m/s)－ 23 －JAPAN P& I CLUBP&I Loss Prevention Bulletin

Figs. 48 and 49 show the route of Typhoon No. 16 in 2004, which caused a case of dragging anchor.
On the 19th of August 2004, approximately 21:00 JST, the tropical cyclone in the sea around the Marshall Islands
formed Typhoon No.16. Afterwards, the typhoon proceeded to the west while developing gradually. Then on August
23rd, she became 910hPa and 110knots (55m/s) at her peak and the strong wind area broadened. In Saipan, amaximum wind speed of 65m/s and a maximum instantaneous wind speed of 75m/s was observed.
At approximately 10:00 on the 30th of August, she landed as a “large and strong force” in the vicinity of Kushikinocity of Kagoshima Prefecture (Currently Ichikikushikino-city). Central pressure upon landing was 950hPa. Afterwards,
she crossed Kyushu. The central location of the typhoon was in the vicinity of Amakusa of Kumamoto Prefecture at
12:00 on the 30th when Vessel B experienced a dragging anchor and grounding accident. Where it was located wasapproximately 200km from Yurajima, within the storm area and the wind speed was greater than 25m/s.
After that, typhoon No.16 landed again in the vicinity of Hofu-city of Yamaguchi Prefecture at approximately 17:30 on
the 30th. It then increased in speed but later decayed and landed again near Hakodate-city of Hokkaido at around 12:00
on the 31st. Then, at 15:00 on the 31st, she changed into an extratropical cyclone in the eastern part of Hokkaido. She
was the largest typhoon both in terms of force and size among the typhoons that landed in 2004.

Movement of Vessel B
August 26th
12：40

Entered into the outside port of Ohita from the Port of Pohang of the Republic of Korea. Lowered
anchor at the point of anchorage in order to wait for berthing.

August 28th

In the morning of the 28th, the Master knew that Typhoon No.16 was approaching Ohita, between
the 29th and the 30th, via weather information provided by NAVTEX and telex from the local agent.
He decided to shelter from the typhoon by moving to another sea area. In the afternoon or on thefollowing morning they heaved up the anchor and the Master decided to sail southward to the Bungo
Suido (Channel), while searching for appropriate anchorage.

22：00

The first warning was issued by the harbour master of Ohita.
“Regarding the ships at harbour, they must take measures that allow the ship’s personnel to beable to operate immediately if necessary. On top of that they must wait while paying attention to
the movement of the typhoon while keeping in close contact with organizations on shore such as
shipping agencies. They must also prepare for countermeasure of rough sea.

August 29 th
9：55

Departed anchorage in the Port of Ohita and sailed southward to the Bungo Suido (Channel).

14：40
Started anchoring at 6.5 shackles on the port side at a point of 92 meters of water depth at <070>, 2.6
nautical miles from Yuranohama-Misaki Lighthouse.

16：00

17：00 (Approx.)

The second warning was issued by the harbour master of Ohita.“Regarding the large vessels in the
harbour, immediately evacuate to a safe area outside port in principle”.
The wind direction changed from north east to south east and reached a wind force of 8. In addition,
the waves from the south increased in height to 7 meters. Anchor cable was extended by one
shackle.

－ 24 －JAPAN P& I CLUB

17：40

20：40

Dragging anchor started. Tried weighing the anchor, but it was not possible to heave up it. Gaveup weighing the anchor and started shifting to the south while using the engine under dragging theanchor.

Started anchoring at 8 shackles of the anchor cable at the point <113>, 2.6 nautical miles from Yuramisaki Lighthouse. Using the engine, countermeasures were taken to prevent anchor dragging
against the wind.

August 30th
11：30

Wind force reached 12 due to the increase of southeast wind, and dragging anchor started in a
leeward direction.

11：57
Distress alarm was activated via Emergency Position Indicating Radio Beacon (EPIRB) and Digital
Selective Calling (DSC). Instructed the crew to wear life vests and muster at the bridge.

12：25

Grounded at the point of <066> 1,750m from Yuranohana Cape Lighthouse. At approximately 13:00,
four panicked crew members left the bridge. When they climbed down the stern deck they werecarried away with the waves and fell into the sea.

The 16 crew members were rescued by thehelicopters of the Japan Coast Guard and the
Self-Defense Force. Among the four who fell
into the sea, one was confirmed as deceased
and three as missing.

Photograph 51－ 25 －JAPAN P& I CLUBP&I Loss Prevention Bulletin＝ Quoted from the Marine Accident Inquiry Agency (MAIA) determination ＝Provisional translation
Cause

①

The selection of the anchorage was not conducted appropriately.

▶

If appropriate anchorage; where the depth of water is shallow and she was shielded from gale force
winds and waves, was chosen, it was thought that the accident could have been avoided.

② Obtaining information on the typhoon and taking shelter by anchoring was insufficient.
▶

There were facts related to the process leading to the accident such as not obtaining the information aboutanchoring from the agency and only obtaining weather information by means of NAVEX. Also, not being
able to use the anchor on the starboard side due to windlass failure was one of the causes of the accident.

The anchor and anchor cable outfitted on the ship were as follows:
Anchor:

JIS type Weight 3,300kgs

Anchor cable:

1 shackle was at 27.5m × 9 shackles
per side 248m

When tentatively calculating the minimum required length for an anchor chain, in
92m of water, an anchor chain with 513m (19 shackles) of length is required (at timesof rough seas: 4 × d + 145m). Sheltering from stormy weather in a location which
exceeds 50m in water depth is thought of as unsuitable.

３―３

Cargo Vessel C

Photograph 52
JIS type anchor

Dragging anchor and grounding accident

Cargo Vessel C :Panamax bulker with cargo holds 36,080 tons
Loa : 224.0m
Date, time and point of occurrence :On the 25th of July 2002, at 21:11 JST Shibushi Bay of Kagoshima Prefecture
Weather at the time of grounding :Rain, east-northeasterly wind, wind force of 10, wave height at 5m and end of ebb tide

－ 26 －JAPAN P& I CLUB

Accident summary
Regarding dry bulk, Vessel C, the total number of crew
members on board was 23 (four Indian nationals and
19 Filipino nationals) and 57, 474 tons of corn was
loaded at the Port of New Orleans in North America.
She entered into the Port of Shibushi, Kagoshima
Prefecture, on the 23rd of July, 2002 in order to unload.
At the Port, among the people disembarking were: 9crew members (a chief officer [Indian national] and8 others [Filipino nationals]) that disembarked and a
total number of 5 crew members (the successor, a chief
officer [(Indian national)] and 4 other crew members)
relieved them and boarded. The crew arrangement at the
Photograph 53
time when the accident occurred was 4 Indian nationals
made up of the Master, the chief officer, the chief engineer and the 1st engineer and 15 other Filipino nationals. (Thenumber of crew members decreased by 4)
The Master boarded Vessel C as the Master at the Port of New Orleans on June 4th, after serving as a Master of several
large cargo ships. The Master had a boarding history of 7 years as a Master in his 27 years of sea-service. During thisperiod of time, the Master had experience calling at many different ports in Japan, however, it was the first time forhim to enter the Port of Shibushi.
At Shibushi Port, the Shibushi Port Typhoon Response Committee was established with the purpose of preventing any
accidents due to a typhoon at the port and the sea area in the vicinity.
This Typhoon Response Committee consisted of the Chairman of the Kagoshima Coast Guard Director who was the
harbour master of Shibushi Port, governmental organizations such as Kagoshima Local Meteorological Observatory
and Kyushu Regional Development Bureau Shibushi Port and Harbour Construction Office, regional organizations
such as Shibushi Town, Police Station, Fire Station, Shibushi Port and Harbour Office etc, Kagoshima Licensed Pilot’s
Association and 43 other organizations and groups such as harbour related companies engaged in various businesses
in the port. The committee used to hold a regular annual committee meeting in early July before the typhoon season
came and attempted to inform all members on the typhoon countermeasure guidelines thoroughly regarding thewarning issue and the communication system to ensure that the procedure for sending information to the ships in the
harbour when a typhoon approaches was well known.
Regarding the warning system and recommendations to be issued by the Typhoon Response Committee, in the eventthat a possible accident is predicted to occur due to an approach of a typhoon to Shibushi Port, they are to hold apolicy committee meeting, if necessary, in order to discuss how to spread typhoon information, prediction of thetyphoon’s path and its impact, grasp of the ships in the port, preparation for rough seas regarding ships, timing of
evacuation recommendations and how to relay the information thoroughly and so on. Then, based on the outcomeof the discussion and typhoon countermeasure guidelines, before it would become difficult to navigate the ships, thechairman would issue the warning and contact the ships in the port via each member.
Because the strong wind area of typhoon No. 9 was predicted to reach Shibushi Port within 48 hours, on the 23rd

－ 27 －JAPAN P& I CLUBP&I Loss Prevention Bulletinof July, at 15:00 JST, the Typhoon Response Committee recommended preparing for evacuation by issuing the firstwarning. Moreover, because the strong wind area was predicted to reach the port within 24 hours, on the 24th, at
13:00, they issued the second warning. They recommended that ships in the port take strict precautionary measures bytaking shelter outside of the port and so on.
On the afternoon of July 23rd when the first warning was issued, the Master had a meeting with the person in charge at
the local agent and decided to take shelter at Kagoshima Bay.
On the following day, July 24th, when the cargo was unloaded 17,194 tons, cargo handling was interrupted and the
Vessel C left the wharf at 10:40.
The Master was thinking that he had not experience with entering Kagoshima Bay, it would take 11 hours as a roundtrip and there was a risk of being close to the centre of the typhoon according to the forecast of the typhoon’s path,then. He also judged that the force would decay judging by the information from NAVTEX. Because there was ample
spare time until the typhoon approached, the Master decided to choose the anchorage according to the movement of
the typhoon from the following three choices as his original plan: ① head for Kagoshima Bay, ② stay anchored at
Shibushi Bay without navigating a direct course to Kagoshima Bay or ③ seek shelter offshore. As a result, at 11.30, thevessel dropped her starboard anchor at 6 shackles <056> 2.0 nautical miles off of Birou Island and 2.1 nautical miles off
Shibushi south breakwater, light house <193>, where the sea bottom was sand with a water depth of around 25 metres.

July 24th 10:40
Left the wharf

Kagoshima

Souof th b
Sh re
ib ak
us
hi watPo errt

Wakahana
Whorf

Zen-noh Silo
Dolphin

5

10

July 25th 2１:11
Grounded

it
rl
ou
rb

Quarantine
anchorageha

Shibushi Bay

im×

Shibushi Bay

Birou Island

20

<193>
2.1nautical miles

July 25th 20:30
Dragging anchor started

July 24th 11:30
Started anchoring

Shibushi Bay

Fig. 54

Afterwards, partly because a similar size of ship, Vessel M started anchoring at Shibushi Bay, Vessel C also continued
single anchor mooring with 6 shackles of anchor cable. However, contrary to expectation, the force of the typhoon
did not decrease and Shibushi Bay gradually entered the storm area and the right semicircle of the typhoon. Due to－ 28 －JAPAN P& I CLUBthe violent storm and swell encroaching on the Bay, at 20:30
on July 25th, dragging anchor occurred and they grounded at
21:11.
Regarding the damage, cargo holds, between No. 5 and No. 6,
near the centre of the hull there was breakage and No. 2 Fuel
Oil Tank under No. 5 cargo hold was damaged. Immediately,at the same time as he activated the distress signal by operating
the EPIRB, the Master reported the distress to the Japan Coast
Guard via international VHF radio communications.
The Master judged that there would be a danger of thedamaged part of the hull ending up sideways. At 21:30, theMaster commanded all of the crew to wear helmets and life
vests in order to abandon the ship. Then they lowered thelifeboats outfitted on both sides of the deck respectively, allof the crew boarded the lifeboat on the starboard side (leewayside) and then they started to lower the lifeboat.

Photograph 55 EPIRB

However, the lifeboat was violently beaten against the shell
plating of Vessel C due to the gale force winds and highwaves while lowering. Also, some crew were injured when
their bodies were beaten in the lifeboat. Due to the constantbuffeting, all of the crew evacuated from the lifeboat andPhotograph 56 Breakage
jumped into the sea. As a result, although 15 out of 19 crew
members managed to swim to the nearby coast, 4 (one second engineer, two ABs and one C/Cook) were deceased.

Path of Typhoon No. 9 in 2002: Asian name is FENGSHEN
On the 14th of July 2002, a
tropical depression formed in thesea around the Marshall Islands
and changed into Typhoon
No. 9 accelerating in force
and heading north. She took awesterly path in the vicinity of
15 degrees north in latitude and,by the 20th, reached the vicinityof 200 nautical miles southwestof Minami-Tori-Shima islandand changed to a northwesterly
path nearing the Ogasawara
Bonin Islands while gradually
increasing in speed.
Fig. 57－ 29 －Path of Typhoon No.9

JAPAN P& I CLUBP&I Loss Prevention Bulletin（1）July 24th
Regarding Typhoon No.9, according to an observation at 00:00 JST, weather information provided by NAVTEX
announced that at 03:00, she was located in the vicinity of the northeast at 100 nautical miles away from Chichijima
Island of Ogasawara Bonin Islands. She developed into a “strong typhoon” with a central pressure of 945hPa and amaximum wind speed of 41m/s close to the centre. The storm area was 120 nautical miles moving northerly at 25m/s with a strong wind area of 250 nautical miles and a wind speed of more than 15m/s as she advanced into southern
Kyushu taking a westerly path at 15 knots.

（2）July 25th
Source: courtesy of the Geospatial Information Authority of Japan (GSI) website
Shiono-misaki

Muroto-misaki
Ashizuri-misaki

0

60

120

180

240

nautical miles
300

Kagoshima Bay
Shibushi Bay
Approx.60 kms

967hPa 33m/s

970hPa 30m/s

21:00 JST

18:00 JST

15:00 JST

970hPa30m/s

965hPa 35m/s

12:00 JST
09:00 JST

06:00 JST

970hPa30m/s
Fig. 58

03:00 JST

25th
00:00 JST

18:00 JST

15:00 JSTPath of Tyhoon No.9

On the following day of the 25th, by 00:00, Typhoon No.9 was already in the vicinity of the east-southeast 350
nautical miles from Shibushi Bay, with a central pressure of 965hPa, a maximum wind speed of 35m/s, a storm area of
80 nautical miles and a strong wind area 250 nautical miles. She approached southern Kyushu taking a westerly pathand maintained a speed of 11 knots. At 06:00, she reached the vicinity of 240 nautical miles east-southeast of Shibushi
Bay and the bay was now in the strong wind area.
Later, by 09:00, Typhoon No.9 was located in the vicinity of <124> 191 nautical miles from the point where Vessel C
had anchored in Shibushi Bay and the force had more or less decayed with a central pressure of 970hPa, a maximum
wind speed of 30m/s, a storm area of 80 nautical miles and a strong wind area of 270 nautical miles. However, she
moved west-northwesterly at a speed of 17 knots and was predicted to pass 50 to 60 nautical miles south of Shibushi
Bay between 19:00 and 20:00, if she proceeded on the same path and at the same speed. There was even the possibility
Shibushi Bay would be exposed the storm area, in particular the “right semicircle of the typhoon”: “a Dangerous
semicircle”.
－ 30 －JAPAN P& I CLUBOn the other hand, although the maximum wind speed was at 33m/s according to an observation at 06:00 by
NAVTEX, by 09:00, it had decayed to 30m/s, according to further observation. Due to this, the international notationof Typhoon No. 9 was changed from a “T” to an “STS” (one category down). The maximum wind speed was also
forecast to have decreased to 28m/s within the next 24 hours. (Note: please refer to the notes below)
Yet, the storm area of 80 nautical miles did not change, and, at 12:00, Typhoon No.9 was still located in the vicinity of<128> 135 nautical miles from the point where Vessel C had anchored. She proceeded west-northwest at 18 knots withincreasing speed, maintaining a central pressure of 970hPa and a maximum wind speed of 30m/s. Then, it was highly
likely that shortly Shibushi Bay would come in range of the 80 nautical mile storm area.
By 15:00, with the force of the typhoon still unabated and with a central pressure of 970hPa with a maximum windspeed of 30m/s, she approached the vicinity of <141> 93 nautical miles from the anchored point of the vessel. At
approximately 16:30, she reached the vicinity of <150> 80 nautical miles (estimated position) from the anchoredpoint, and the outer edge of the storm area encroached on Shibushi Bay.
At 18:00, Typhoon No.9 reached the vicinity of 30 nautical miles southeast of Tanegashima Island of Kagoshima
Prefecture which was in the vicinity of <162> 73 nautical miles from the anchored point. And then, she moved west.
At approximately 19:30, she passed the vicinity of <180> 67 nautical miles from the anchored point, the closest she
had been to Shibushi Bay. Furthermore, at 21:00, she reached Yakushima Island in the same prefecture.
Note: In Japan, as explained in page. 2 - 3, it is categorized as a “Typhoon” when its maximum wind speed isgreater than 17m/s (wind force 8) and as a “Tropical cyclone” when it is less than 17m/s. On the other hand,according to the international scale, typhoons and storms are classified into the following three categories.

①

The maximum wind speed is more than 33m/s (wind force 12):TYPHOON (T)②

The maximum wind speed is more than 25m/s (wind force 10) but less than 33m/s:

SEVERE TROPICAL STORM (STS)③

The maximum wind speed is more than 17m/s, but less than 25m/s:

TROPICAL STORM (TS)In addition, a tropical cyclone that has a maximum wind speed of less than 17m/s is categorized as a TROPICAL
DEPRESSION (TD).

－ 31 －JAPAN P& I CLUBP&I Loss Prevention Bulletin

Movement of Vessel C
July 21st
01：06
July 22nd
06：34

Vessel C arrived at Shibushi Bay. Anchored in the bay in order to adjust the time for berthing.

A pilot registered with the Kagoshima Licensed Pilot’s Association embarked.

07：36

Berthed at the quay of Zen-Noh Silo Corporation and started cargo discharging work.
Total of 9 crew members (the chief officer [Indian national] and 8 other members (Filipino
nationals) disembarked.
Total of 5 crew members (the successor chief officer [Indian national] and 4 other members [Filipino
nationals]) embarked.
Note: Decrease of four crew members

July 23rd

Because the strong wind area of Typhoon No.9 was predicted to reach Shibushi Bay within
48 hours, the Typhoon Response Committee issued the first warning and announced therecommendation of preparing for evacuation.
Later, the Master and the person in charge at the local agent discussed the following items in their
meeting.

15：00

Should the typhoon pass thesouth of Shibushi Bay,
where is one to evacuate?

Shibushi Bay would not besuitable for sheltering anchorage.
Until now, large vessels
took refuge anchorageat Kagoshima Bay.

MasterAgent

As a result, the Master decided to leave the wharf on the following morning and shelter from thetyphoon in Kagoshima Bay. At the same time, in order to carry out draft adjustment, the Masterchanged the discharging plan in order to complete the cargo discharge of No.2 and No.6. He also
arranged for the ballast tanks to be filled so as to adjust departure condition fore draft 8.00m andaft 11.60m.
July 24th
10：40

After completing discharge of No.6 cargo, filling ballast was also completed. At the time when
17,194 tons had been unloaded, the cargo handling was interrupted in order for the ship to leave
the wharf (with a remaining 40,280 tons still loaded).

－ 32 －JAPAN P& I CLUB

11：30

13：00

After the pilot disembarked, the Master decided to anchor at Shibushi Bay without taking a direct
course to Kagoshima Bay that was originally planned as a sea area of sheltering. The Master
decided to observe the movement of the typhoon and anchor using the starboard anchor at 6
shackles at 2.1 nautical miles from south of the breakwater. The water was at a depth of 25m andthe sand type was sea bottom sedimentary.
The reason for the change of plan, as mentioned above, was because the following threeanchoring methods were planned. Paying attention to the movement of the typhoon, the Master
decided to observe the situation while anchoring at Shibushi Bay.
● To anchor at Shibushi Bay●

Avoided sailing into the open sea to keep a distance between the ship and the typhoon●

To shelter at Kagoshima Bay

Because the strong wind area was predicted to reach Shibushi Bay within 24 hours, the Typhoon
Response Committee issued a second warning.
In the evening, the Master got to know that a ship of similar size, Vessel M (38,567 tons), left thewharf in a similar way and started anchoring at Shibushi Bay.

July 25rd
06:00(observed)

09：00(observed)

The strong wind area encroached on Shibushi Bay.
Typhoon No.9 was in the vicinity of <117> 243 nautical miles from the anchored point and she wasproceeding west-northwesterly at 16 knots. Because Shibushi Bay had entered the storm areaat 250 nautical miles, if she continued to proceed on course, it was estimated she would pass at
approximately 50 nautical miles south of Shibushi Bay between 19:00 to 20:00.
There was a possibility that Shibushi Bay would enter the storm area of the right semicircle of thetyphoon.
Typhoon No. 9 was proceeding west-northwesterly at 17 knots close to the vicinity of <124> 191
nautical miles from the anchored point and it was estimated that there was a possibility of Shibusi
Bay entering the storm area of the right semicircle of the typhoon.
The Master only used the typhoon information provided by NAVTEX. Although the Master wrote
down the position, path and speed of the typhoon on the nautical chart, he did not write down thefact that the ship was in a strong wind area or a storm area.
In addition, the Master obtained the following information from NAVTEX.

● Category of the typhoon was downgraded by one category from T to STS.
● It was forecast that the wind speed would decrease to 28m/s within the coming 24 hours.
Furthermore, because it was still observed that the wind speed was less than 10m/s and the wave
height was at 2m, the Master decided to stay sheltered at Shibushi Bay.

It would take at least 11 hours to navigate to Kagoshima Bay...
I have never experienced this before...
It is a ship of similar size, Vessel M which is also anchoring at
Shibushi Bay...
I should be able to manage this using the engine and rudder.

－ 33 －JAPAN P& I CLUBP&I Loss Prevention Bulletin

12：00(observed)

16：00

The Master obtained the information from NAVTEX that Typhoon No.9 was proceeding westnorthwesterly maintaining a force of 970hp and a storm area of more than 30m/s.

North wind suddenly became strong and the wind speed exceeded 15m/s. Also, the height of theswells which encroached the bay mouth increased. Anchoring watch was enforced, however, theMaster stayed sheltering at Shibushi Bay without evacuating to the open sea.

16：24

Started use of engine keeping 6 shackles of anchor cable.

16：30

Shibushi Bay entered the storm area at the right semicircle of the typhoon.

17：00

Wind direction changed to northeast. Wave height at 3 meters.

19：30

The typhoon moved the closest at this point, with a wind direction now changed to east-northeast.
Wind speed was 17m/s, maximum instantaneous wind speed was 28m/s and wave height was 5m.

Started dragging anchor. Wind speed was 25m/s, the maximum instantaneous wind speed was
35 to 41m/s and the highest wave height was 8m.
20：30

20：40

21：11

21：30

Confirmed anchor dragging via radar. Started weighing the anchor, but this became constrained
when heaving the cable to 2 shackles of 6 shackles. It was because the cable was extremely
tense, even with the engine at full speeded ahead.
Tried to prevent drift by using the engine. Even if it was temporarily effective, it was not possible tostop it completely.
Aft part was grounded at the point of south <238> 1.9 nautical miles from the breakwater in
Shibushi Bay, water depth at 10m.
Immediately after this, cargo holds between No.5 and No.6 near the centre of the hull were broken
and the No.2 Fuel Oil Tank under the No.5 cargo hold was damaged.
The Master judged that there was a possibility that the damaged aft part might rollover. Then,
as was described above, at the same time of activating the distress signal via EPIRB, the Master
reported the distress to the Japan Coast Guard by VHF.
The Master commanded all crew to wear life vests and started abandoning ship with the lifeboat
outfitted on the starboard side (leeway side). However, the lifeboat was violently beaten anddamaged due to the gale and high waves. Because some were injured, all crew jumped into thesea, however, 4 crew members out of all 19 members were confirmed as deceased.

－ 34 －JAPAN P& I CLUB＝ Quoted from the Marine Accident Inquiry Agency (MAIA) determination ＝Provisional translation
The following were analyzed as main accident causes.

① Insufficient realization regarding the typhoon▶

Wishful observation that the typhoon’s force would decay because of the typhoon information provided by
NAVTEX.

▶

Lack of crisis consciousness regarding the entering of a storm area, changes of wind direction andencroachment of gale and high waves.

▶

Lack of awareness towards typhoons by the Master and each navigation officer② Insufficient information of sea area for sheltering etc.
The Master decided to take refuge at Kagoshima Bay, because when the Master and the local agent had ameeting, the Master of Vessel C asked the person in charge of the local agent where he should sheltering and he
was advised by that person that “Shibushi Bay was not suitable for sheltering anchorage. Until now, large vessels
took refuge anchorage at Kagoshima Bay”. In fact, as described above, the Master did not navigate to Kagoshima
Bay and stayed anchored at Shibushi Bay.
▶

The Master made his judgement based on only what the local agent told him and typhoon information
supplied by NAVTEX.

▶

Thus, there was insufficient typhoon information (such as the range of strong wind or storm areas, winddirection, wind speed etc.)▶

One of the reasons to keep anchoring at Shibushi Bay was that it would take an extra 11 hours to sail in thestorm to Kagoshima Bay and, once again, the vessel was to return the Shibushi Bay, if the typhoon was to
pass.

▶

The Maser was hesitant to enter Kagoshima Bay, as he was not familiar with the area.

▶

According to typhoon information provided by NAVTEX, the category of the typhoon was downgraded by
one rank to category “STS”. With this information, the Master judged that the typhoon would decay naturally,
however, the wind speed did not decrease and a large swell encroached into the bay again.

③ The Master had a false sense of security because a vessel whose size wassimilar was also anchoring.
▶

The Master felt a false sense of security, because a foreign registered Vessel M (38,567 tons) was anchoringat the Port of Fukushima off in the northeast part of Shibushi Bay.

▶

Vessel M was advised: “If there is a wind from the East, Fukushima port off in the northeastern area of
Shibushi Bay should be suitable” by their pilot, and conducted single anchor mooring with 9 to 10 shackles atthat port. Although she dragged anchor due to a violent storm and swell, she managed not to get grounded.

－ 35 －JAPAN P& I CLUBP&I Loss Prevention Bulletin

３－４Questionnaire conducted by the Marine Accident Inquiry
Agency (MAIA) for Masters of the coastal vessels thatexperienced sheltering from the typhoon

When the Marine Accident Inquiry Agency (MAIA) at that time issued their Maritime Casualty Analysis Report (Vol.
6): “Typhoons and Marine Accidents”, they conducted a questionnaire for Masters of the coastal vessels that actuallyexperienced sheltering from typhoon. Some of them are introduced here, as there were many practical comments.

There were many comments, such as“Matters to note when sheltering from a typhoon”
 aying attention to the distance between one’s own vessel and the one anchored nearby, the MasterㅦP
was cautious regarding both the anchoring of his own ship and other ships.
ㅦ While the typhoon was nearby, the Master was careful to observe changes in wind direction following
her passing and the strong wind that would be blowing back.
ㅦ Because a foreign registered ship tends to conduct single anchor mooring and can easily drag anchor,
the Master tried not to anchor in the vicinity of those ships. He especially avoided being leeward in
relation to the position of those ships.
ㅦ Using the engine, steering and thruster, the Master tried to stand bow against the wind.
ㅦ Commenced anchoring watch and stand-by of the engine at an early stage.
a strong wind was predicted and there were many anchoring ships in a narrow anchorage,
ㅦ Becausein an attempt to not cause horsing (yawing and swaying), the Master conducted two-anchor mooringin order to increase the holding power.
ㅦ The Master wrote down the vessel names of the anchoring ships nearby, in case there was an incidentof dragging anchor, it would have been possible to contact the other ships via VHF or telephone.
ㅦ Estimated the wind direction at the time of maximum wind speed, and applied two-anchor mooringin that wind direction.

In addition, other specific comments will be introduced.
In the event of wind speed exceeding 35m/s, it is dangerous to carryout an anchoring work at foreward station. Thus, the Master judged it
would be difficult to heave up anchor because it was in excess of 40m/s.
Therefore, the Master weighed the anchor before the wind became strong
and heaved-to while keeping course so as to receive the wind at the rightahead with a headway speed to some extent. （Large ferry）

The Master dared to conduct single anchor mooring, because Hakodate Bay waspredicted to have high waves sooner or later. Because she dragged anchor at a wave
height of 3m, the Master managed to keep not getting pressed by using the engine.
Single anchor mooring is desirable, if we are to prevent collision accidents due toanother vessel’s dragging anchor. It is impossible to prevent accidents using twoanchor mooring. (4,000 G/T Coastal Tanker）－ 36 －JAPAN P& I CLUB

Because the wind speed exceeded 20 m/s, the chief engineer was stationed inorder to prepare for S/B engine. While the hull was yawing in a “figure-of-eight”
movement, the angular velocity of blowing back was faster than that of thelarge cargo ship, thus it was originally a mistake to judge that the holding power
would be strong enough, which resulted in the subsequent response. At thatmoment, the Master should have judged that a strong wind force was to press
instantaneously on the side of the vessel and prepared the engine and thruster.
（Large ferry）

If the fore station operation was deemed to be dangerous at the time ofweighing the anchor, pressure could have been prevented by using theengine. When contacting the Japan Coast Guard regarding anchorage
location and to ascertain information about anchorage, they kindly
responded and even gave information about where the typhoon washeading.（3,552 G/T Coastal Tanker）

Judging from the path of the typhoon, the Master carefully judged as to whether
it was a suitable place to anchor by considering which direction the wind would
blow and condition of gales and waves that may affect where the ship wasplanning to anchor. After having anchored, the Master made sure to write down
the names, positions etc. of other ships nearby so that he may contact them
immediately in case of an emergency. Regarding how harsh nature can be, it isa must to always consider countermeasures because one can never be wellprepared enough.

Because the vessel was too concerned with cargo handling, the commencement ofsheltering was delayed. Cargo handling should have been suspended, and the crew
should have taken refuge earlier evacuating to Mutsu Bay if it was possible. Off thecoast of Kitaura (off the Oshika Peninsula) was not a suitable choice for anchorage
because the kind of sea bottom was too rocky for anchorage, and fishing equipment
was set up in the vicinity. Anchor as early as possible. It would be difficult to lower
anchor as planned after the typhoon had come into close proximity and the windforce had increased. Also, it would be constraining to find a suitable position in
relation to other ships. It is important to plan for anchoring not only for during thenight but also during the daytime.

－ 37 －JAPAN P& I CLUBP&I Loss Prevention Bulletin

04§4

Mechanism ofdragging anchor

JAPAN P& I CLUBThe following are important
extracts from our Loss Prevention
Bulletin Vol.25 titled“Preventing
an Anchor from Dragging”which
was published on the 13th July,
2013. For details, please refer tothis guide.

４－１

第 25 号 2013 年 7 月 Vol.25

July 2013

P&I ロス・プリベンション・ガイド
P&I Loss Prevention Bulletin
編集：日本船主責任相互保険組合 ロス・プリベンション推進部

The Japan Ship Owners’
Mutual Protection & Indemnity Association
Loss Prevention and Ship Inspection Department

走錨防止Preventing an Anchor
from Dragging
目

次

INDEX

はじめに／ Preface ………………………………………………………………………………………………………………… P 2
1章

錨泊中の事故／ Accidents Involving Ships at Anchor …………………………………………………… P 2 ～ 3

2章

走錨はなぜ発生するのか／ The Reason Why an Anchor Drags ………………………………………… P 4 ～ 7

3章

風圧力計算／ Wind Pressure Force Calculation ………………………………………………………………… P 8

4章
5章
6章

錨と錨鎖による把駐力／ Holding Power Created by Anchor and Anchor Chain ………………………… P 9
錨鎖の懸垂部（カテナリー部）の長さの計算方法／ Calculating the Catenary Length of an Anchor Chain ……………………………………………… P 10
錨・錨鎖の搭載例／ Examples of Anchor and Anchor Chain Stowed on Board ……………………… P 10

7章

Excel による風圧力計算（参考値）／ Excel Spreadsheet Calculation of Wind Pressure Force …… P 11

8章

振れ回り運動と衝撃力／ Horsing(Yawing and Swaying) Motion and Impact Force ………………… P 12

9章

Excel による錨・錨鎖による把駐力計算（参考値）／ Excel Spreadsheet Example of Anchor Holding Power Calculation …………………………… P 13

10 章

操船運用上の錨泊安全対策とその効果／ Ship’s Operational Safety Measures for Anchorage and Their Effects………………… P 14 ～ 20

11 章

走錨限界風速／ The Critical Wind Speed ……………………………………………………………… P 20 ～ 21

12 章

走錨後の措置とその効果／ Emergency Measures Taken and Their Effectiveness After Dragging Anchor ……… P 21 ～ 2213 章

船体姿勢制御の難しさ／ Difficulty in Maintaining Manoeuverability ……………………………… P 22 ～ 23

14 章

安全な錨泊への備え／ Preparation for Safe Anchorage …………………………………………… P 24 ～ 25

15 章

他船との安全な船間距離・浅瀬や海上構造物との離隔距離／ Safe Distance from Other Ships, Shallows and Other Facilities ………………………… P 26 ～ 29

16 章

投錨作業／ Dropping Anchor Operation ………………………………………………………………… P 29 ～ 30

17 章

錨鎖の繰出速度・繰出量・揚錨機のブレーキ力／ The Anchor Cable Veering Rate・Scope of Cable To Be Paid Out・Brake Force of Windlass …… P 30 ～ 31

参考文献／ Reference Books ………………………………………………………………………………………………… P 32

Accidents involving ships at anchor

Accidents involving ships at anchor usually occur when the anchor drags and the vessel drifts without holding power,
leading to collisions and/or groundings or strandings. The following considerations should be taken into account:①

It can take some time to realize the anchor is dragging, despite the fact that the ship isdrifting.

②

It takes some time to weigh the anchor and restore the ship to full manoeuvrable
condition, even though the ship may be drifting for that period.

③

During the period beginning with the detection of dragging to the time full control isachieved over the ship’s manoeuvrability, the vessel may run dangerously close aboard,
or into another ship or structure, or into shoal water.

Unless heavy weather causes the vessel to capsize, no serious accident should occur just because a ship is dragging
its anchor, provided there is enough space around it for manoeuvrability and enough time available. The above threeconsiderations may also be applied to the cases introduced in the previous chapter (excluding vessel capsize due toheavy weather).

－ 38 －JAPAN P& I CLUB

４－２

The reasons as to why an anchor drags

A ship’s anchor drags due to the impact of external forces on it which exceed the holding power of the anchor andcable. That is, dragging anchor occurs as a result of a relatively simple reason: “When an external force exceeds thatof the anchor’s holding power, it will drag”.

Holding power ＜ External force ▶▶ Dragging anchor

Empirical or Rule of Thumb Methods for Assessing the Minimum Required Length of Anchor Cable
The following is a well-known method for assessing the Minimum Required Length of Anchor Cable, however,factors related to ship type, actual wind speed etc. are not found in this method. It can be considered that those factors
were consolidated in the process of formulating this method for the minimum required length of an anchor cable.
Japanese Publication Theory of Ship Operation● Fine weather： Ｌ＝ 3d ＋ 90m● Rough weather ： Ｌ＝ 4d ＋ 145m

United Kingdom Publication Theory of Ship Operation

L ＝ 39 ×d

Ｌ：Minimum required length of anchor cable(m)ｄ：Water depth(m): up to a wind speed of around 30 m/s.
According to the Marine Accident Inquiry Agency (MAIA), at that time the wind speed and wave height whichcorresponds to the Japanese theory are introduced as simulation results and actual statistical data regarding theanchoring situation of 700 coastal vessels, when the landed typhoons (10 typhoons) passed in 2004, are documented
in their publication titled Maritime Casualty Analysis Report (Vol. 6): Typhoons and marine accidents (in 2006). The
findings are as follows. Naturally, because this theory or guideline will vary depending on the type of sea bottom andanchorage conditions regarding one’s ship and the other ships, actual minimum required length of anchor cable is tobe determined, with safety being the priority.

－ 39 －JAPAN P& I CLUBP&I Loss Prevention Bulletin

Fine weather

When, Ｌ ＝ 3ｄ ＋ 90m

Wind speed 20m/s and wave height up to 1ｍ

Rough weather

Ferries etc. Wind speed 25m/s and wave height up to 2.5m

When, Ｌ ＝ 4ｄ ＋ 145m

OthersWind speed 30m/s and wave height up to 2.0m

The above guidelines will vary depending on the type of sea bottom and the condition ofsourrounding ships in anchorage.

In addition, in the publication of the Maritime Casualty Analysis Report, the simulation results are introduced andattempt to answer question regarding the difference in the anchoring limit between “being exposed to wind only” and“being exposed to wind and swell” concerning cases in (3-3) in reference to Vessel C.
10

12

（Ton）

100

shackles9

shacklesshackles8

shackles6

shacklesWhen exposed toonly wind from the ahead
50

Holding power
External force(only wind)

0

5

10

15

20

25

wind speed（m/s）

Fig. 59

As can be seen from the anchor holding power of the anchor and anchor chain, which will be referred to later, because
the bottom part of the anchor chain decreases when wind pressure increases, it was found that the anchor does not
drag until the wind speed is 25m/s and when the minimum required length of anchor chain in the water is more than 6
shackles, although anchor holding power does decrease.

When exposed to windand swell (wave height
5m and wave length200m) from the ahead

12100（Ton）

10

shacklesshackles9

shackles8

shackles6

shacklesHolding power

50
Dragging Anchor

External force（external force exceeds
holding power）(wind and swell)

05
Fig. 60－ 40 －

10

15

20

25

wind speed（m/s）

JAPAN P& I CLUBIn the event that a swell is added, due to Wind pressure force + Wave drift force (the force at which a wave moves
a floating object), the anchor chain tension reaches approximately 50 tons at a wind speed of 10m/s and exceeds its
holding power at 6 shackles at this point in time. Also, it was revealed that the anchor drags at 8 shackles at a windspeed of 15 m/s and at 12 shackles at a wind speed of 25m/s.

Don’ t underestimate “swell” and “wave height” which may cause ship motion during anchoring.

Watch out for wind and for waves ! !
◆ Be careful regarding changes in wind direction, when a typhoon or windy atmospheric depression approaches.
◆ At sea, where there are few structures against wind, it is estimated that the maximum wind speed will be
be1.5-2 times stronger than the average wind speed.
◆ The higher the swell becomes, the greater the danger of dragging anchor will be, remarkably. Anchor at a
position where the encroachment of a swell is expected is to be avoided. Occasionally, the maximum wave
height may be 1.5-2 times of that of the signiﬁcant wave height (*1).

*1）Significant wave height (from the Japan Meteorological Agency website)
Wave length λDisplacement

Choose 1/3 of the wave observations (within a timeframeof 20 mins.) in descendingorder from the top. Of those,
the average wave height andperiod becomes the significant
wave. According to this definition, this is also referred to as
the “1/3 maximum wave”.

Wave length λA

PeakAmplitude A

Wave
heightｙh[m]ーATroughTroughDistance travelled per second m

Graph expressing waves: in the event that two waves are generated per second

(m)
3.0

(m)
3.0

2.5

2.5

2.0

2.0

1.5

1.5

1.0

1.0

0.5

0.5

0.0

1

2

3

4

5

6

7

8

Peak

0.0

9 10 11 12 13 14 15

Wave hight detected at a point(Irregularly changing)

Average value of 1/3 fromthe biggest wave hightSigniﬁcantwave height
14

6

5

11

8

1

3

15 10 134

72

Sort in descending order of wave height－ 41 －

12

9

JAPAN P& I CLUBP&I Loss Prevention Bulletin
４－３

Detection of dragging anchor

There are conventional methods to check for anchor dragging:①

Check the ship’s position, to confirm whether it is locatedoutside of a turning circle (see Fig. 61).

Fig. 61

Turning Circle②

The bow cannot stand against the wind.

③

The ship's side against the wind has not changed.

④

Check to see that there is no slacking of chains, just before a ship’s side is about to turnagainst the wind.

⑤

Check as to whether there are extraordinarily large vibrations coming from the anchor
chains.

In the event that the course recorder does not show a sine curve movement.

⑥

Photograph 62 shows the course record
when being anchored while being exposed
to wind at a wind speed of 8 m/s, when theauthor was on board a Pure Car Carrier(PCC). It is difficult to tell if it is a sine curve
movement or not.

Photograph 62

The above methods remain well-tried but, of course, only confirm thatthe anchor is dragging. They do not predict when dragging is likely tocommence.

－ 42 －JAPAN P& I CLUB＝ Actual ship movement at the time of anchor dragging ＝With GPS now being commonplace, a recent study analysis shows that anchor dragging is a phenomenon thatconsists of two different stages. This study points out that anchor dragging started before it was detectable, prior toconventional methods of dragging anchor detection today (the first stage: dragging anchor with yaw and sway). (Note:
this is not applicable when the anchored point is precisely written down, whereby even a slight change in the ship’s
position can be grasped.)

The first stage: dragging anchor with yaw and swayWind

The yaw and sway motion of a ship during anchoring is often
compared to a “figure-of-eight” pattern. (Part “A” in the diagram to
the right shows that the anchor is not dragging.) It has been foundthat as wind pressure force begins to exceed the anchor’s holding

Anchor chain

power, the ship yaws and is pressed transversely, as shown inAarea “B” in the diagram. Also, it should be relatively easy to control
the manoeuvrability of a ship and weigh the anchor).

The second stage: Anchor dragging caused by

B
Path of Anchor

wind pressure
Where wind pressure force gradually becomes stronger, oneside of the ship turns against the wind and is then pressed andCmoves transversely at a certain speed, as shown in area “C” in the
diagram. The conventional method of detecting anchor dragging
takes place at this stage. At this stage, it is getting difficult(more time is needed) to weigh the anchor and if weighing theanchor cannot be accomplished, it is almost impossible to start
manoeuvring.

Hull
Fig. 63

Using tracking devices that display location information such as GPS, ECDIS and RADAR, it is now easy to detectanchor dragging during the first stage. When an anchor does drag now, in addition to the usual methods of detection
concerning dragging anchor, it is desirable that “early prediction” and “early detection” of a dragging anchor be thenorm and that “safety countermeasures are taken as early as possible”.

－ 43 －JAPAN P& I CLUBP&I Loss Prevention Bulletin

Photographs 64, 65 and 66 are actual displays of the ECDIS and RADAR when the author was on board the Pure Car
Carrier (PCC). It was possible to grasp the actual ship’s movement using the ship’s position record and the electronic
displays.

Display of ECDIS and RADAR
Using the ECDIS display, it is possible to viewthe full size of the hull by narrowing in on thedisplay range. Also, GPS tracks are shown for
approximately 60 minutes.
This helps us understand the first stage inmore detail: Dragging Anchor with Yaw and
Sway.

Photograph 64

Similarly, the RADAR range was set to 0.75
nautical miles and the track of the GPS was
set for 60 minutes.
This helps to solidify understanding of thefirst stage: Dragging Anchor with Yaw and
Sway.

Photograph 65

Because there were no other vessels atanchorage, an anchor dragging wind pressure
experiment was conducted. The hull faced
sideways to the wind direction instantly andwas pressed at a speed of 3 to 4 knots, thus
more time was required for weighing theanchor.

Photograph 66－ 44 －JAPAN P& I CLUB

４－４

Wind pressure force

In order to have a grasp of the external forces that cause anchor dragging, we must have an understanding of the windpressure force. Wind pressure force can be calculated with the following “Hughes Formula”.

Hughes Formula
Ra =

1
2

×ρ× CRa × Va2 ×（A cos2 θ＋Ｂ sin2 θ）/1000（ton）
θ

Relative winddirection from bow（θ）

θ
Length frombow to wind аpressure centreαWind speed

Va（m/sec）
Wind pressure
force angle：Wind direction from bow ［degree］（Relative Wind Direction）

Va ：Headwind speed ［m/sec］
ρ
A
B
a
Ra

：Air density ［0.125 kg ・ sec /ｍ４］
：Ship’s projected area from bow above waterline ［㎡］：Ship’s projected area from side above waterline ［㎡］：Length from bow to wind pressure center［m］（Point of Action）：Resultant wind pressure force［kg］→ divided by 1,000 to be "ton"（Total Wind Force）

Ra

α ：Wind pressure force angle［degree］（Angle of Action）
CRa ：Wind pressure force coefficient（this can be calculated

Resultant windpressure force

by the following formula）

CRa：This varies for different ship types, as follows.
Passenger, PCC, Ctnr ：1.142－0.142cos2θ－0.367cos4θ－0.133cos6θ
General cargo ：1.325－0.050cos2θ－0.350cos4θ－0.175cos6θ
Tanker & bulk carrier ：1.200－0.083cos2θ－0.250cos4θ－0.117cos6θ

Resultant wind pressure force is proportional to the square of wind speed.

It is difficult to calculate for wind pressure force at a specific time instantly when manually calculating. However, it
is easy to calculate the wind pressure force once the formula has been input into a PC. Examples for reference using
Excel are shown in Table 67.

－ 45 －JAPAN P& I CLUBP&I Loss Prevention BulletinWind Pressure Force Cal.：Just Reference
12
3

Relative winddirection from bow（θ）

This formula calculates the wind force of your vessel at the wind speed.
The wind force coefficient in each kind of ship is calculated automatically.
Input the following data
200

Loa（m）

800（Projected area（Side）
）
（m2）
（B）

5,800

（Wind Speed ）（m/s）

19.5 （Ave.Wind Speed × 1.25 or 1.50）（Passenger, PCC, Ctnr:1 General Cargo：2 Tanker, Bulker: 3）

Input Wind Speed by below ref. data
Less than 8 m/s
Strong Wind : 8 ～ 13m/sec
Storm Wind : More than 13m/sec

αLength frombow to wind аpressure centre（Projected area（Front）
）
（m2）
（A）

（Kind of ship）＊

θWind speed

Va（m/sec）
Wind pressure
force angle

1

Ra

Resultant windpressure force：Ave. Wind Speed：Ave. Wind Speed × 1.25
：Ave. Wind Speed × 1.50

RESULTS（θ）
Wind direction
from bow (deg)（Ra ）Total wind force (t)（RL）
Longitudinal(t)（RT ）Transverse(t)

0

14.26

14.26

0.00

58.20

0.00

0.75

10

20.84

18.50

9.60

62.80

27.43

0.92

1

2

3

20

43.23

30.23

30.90

67.40

45.62

1.31

30

80.39

40.60

69.38

72.00

59.67

1.65

0.500000

0.750000

0.75000040

118.0140.06

111.01

76.60

70.15

1.73

0.660925

0.922400

0.87199450

139.7829.83

136.56

81.20

77.68

1.58

1.035993

1.313421

1.15150660

145.9818.21

144.84

85.80

82.83

1.35

1.387500

1.650000

1.40050070

150.599.95

150.26

90.40

86.21

1.22

1.528709

1.732710

1.47901080

159.95

4.46

159.89

95.00

88.40

1.19

1.445025

1.575075

1.390836

90（Impact）

165.4185.56

0.00
165.41
99.60
90.00
Wind Force on Front（θ＝０）×６, Tanker/Bulker × 4））

1.20

1.263500

1.350000

1.249500

1.120549

1.215025

1.161670

1.060798

1.191369

1.144983

1.050000

1.200000

1.150000（a ）（α ）Point of action(m) Angle of action(deg)（CRa）
FactorImpact Force :Wind Force on Front × 5 ～ 6 for PCC/CTNR/Passenger ship, × 3 ～ 4 for Tanker/Bulker（Ｃ R ａ）

Table 67

Regarding the calculating formula in the table, the following were used.

Calculation Formula in Above table
Total Wind Force

Ra = 1 × ρ × CRa x Va2 ×（A cos2 θ＋ B sin2 θ）/ 1000（ton）
2

Longitudinal Force

RL ＝ Ra × Cos α
Transverse Force

RT ＝ Ra × Sin αaPoint of Action

α Angle of Actiona ＝（0.291 ＋ 0.0023 ×θ）× Loa
α ＝｛ 1 － 0.15 ×（1 －θ /90）－ 0.8 ×（1 －θ / 90）3 ｝× 90

Wind Pressure Co-efficiency（CRa）
1

1.142－0.142cos2θ－0.367cos4θ－0.133cos6θ（Passenger Ship / PCC / Container）

2

1.325－0.050cos2θ－0.350cos4θ－0.175cos6θ（General Cargo）

3

1.200－0.083cos2θ－0.250cos4θ－0.117cos6θ（Tanker / Bulker）

Impact Force
PCC/CTNR/Passenger Ship

Wind Pressure on Front × 6

BulkerWind Pressure on Front × 4－ 46 －JAPAN P& I CLUB

４－５

Holding power created by anchor and anchor cable
Holding power created by anchor and anchor cable

H (Holding power created by anchor and anchor cable) = Ha + Hc = λ a x Wa’ + λ c x Wc’ x ℓ
H：Holding Power Created by Anchor and Anchor cable （kgs）

Ha ：Holding Power Created by Anchor（kgs）
Hc ：Holding Power Created by Anchor cable（kgs）
Wa ：Anchor Weight in Air（kgs）
Wc ：Anchor Chain Weight per m in Air（kgs）
Wa' ：Anchor Weight in Water（kgs）＝ 0.87×Wa（kgs）
Wc' ：Anchor Chain Weight per m in Water（kgs） ＝ 0.87×Wc（kgs）
l：Minimum Required Length of Anchor cable（ｍ）

λa ：Anchor Holding Factor
λc ：Anchor Holding Factor

Anchor holding power during anchoring is the sum of “holding power by anchor” and “frictional force of anchor cablelying on the sea bottom”.
The holding factor of an anchor or anchor cable (λ a and λ c ) is different depending on the type of anchor or typeof sea bottom. The anchor holding factor (λ a ) and anchor cable holding factor (λc ) of a JIS type or AC14 type areshown in Tables 68 and 69 respectively.
λ a：Anchor Holding Factor
Type of Anchor

Sand

Mud

Dragging
Anchor

JIS

3.5

3.2

1.5

AC14

7.0

10.6

2.0

Table 68

λ c：Anchor Chain Holding Factor
Holding

λc

Dragging

0.75 ～ 1.0

Sand

Mud

0.75

0.60

Table 69

－ 47 －JIS

AC14

JAPAN P& I CLUBP&I Loss Prevention Bulletin

In addition, a representation of the anchor and anchor chain in the sea when external force was applied can be seenin Fig. 80. The catenary forms the suspension part of the anchor chain, from the anchor chain outlet (outside of
hawsepipe) of the bow to the sea bottom.

B: Bell Mouth

Tx：External Force

Tx：External ForceSea Surface

L = S +l

y

S

l
Cable
Contact

Sea Bottom

Catenary

S ：Catenary length against the external force（m）
y ：Water depth + hawsepipe height from sea surface（m）l：Minimum required contacted length of the cable（m）

L ：M
 inimum required length ofanchor cable（S ＋ l ））Tx ：External force（kgf）

Fig. 70

The catenary length of an anchor cable can be calculated with the following calculating formula.

Calculating the Catenary Length of an Anchor ChainS=y2 + 2

Tx
y
Wc’

S

：Catenary length against the external force（m）y：Water depth + Hawsepipe height from sea surface（m）

Wc' ：Anchor cable weight per m in water（kgs）= 0.87 × Wc（kgs）

Tx ：External force（kgf）

With the above mentioned formula, the more external force ( Tx ）increases, the longer the catenary is.
Therefore, under the condition that Minimum Required Length of Anchor cable is fixed at a certain level, as thereis the following relationship, if External Force increases while the Anchor cable is fixed, the anchor holding power
decreases, which leads to a vicious circle.

－ 48 －JAPAN P& I CLUB

Minimum required length of anchor
cable (L) is ﬁxed at a certain level (L)External force increases

Catenary length (S) also increases
Contacting length of cable (l) becomesshorter accordingly
Anchor holding power decreases because
contacting length of cable is shorter.

Also, it is not easy to manually calculate the catenary length and decrease of anchor holding power along with anincrease in external force. Similar to the calculation used for external force (wind pressure force), the calculation result
will be instantly displayed once the formula is input in the Excel File.
When entering data on holding factor coefficient, observed wind speed, and type of sea bottom coefficient, etc. be on
the safe side when entering the data and do not over rely on it as it is intended to be a guide. Tables 71 and 72 show
catenary length and calculation examples of anchor holding power.

Anchor Holding Power Calculation：Just Reference
1 The formula in this page are to calculate the holding power of your vessel's anchor and anchor cable.
2I n case of External Force<Anchor Holding Power（Wa' × λa），required length of cable is to calculate by following formula.
Required Length of cable = 3 × d + 90 m（Only External Force < Wa’ × λa）

3 Expected total external force should be input by Maximum Impact force. For PCC/CTNR Ship : Wind Pressure on front × 5 ～ 6,
Other type of ship : Wind Pressure on front × 3 ～ 4 times＊ IE）As per Wind force Cal., Relative Wind Direction θ=0 : 15ton : Max Impact Force 15 × 5 ～ 6 for PCC/CTNR= 75 ～ 90 tons

Input Data
Expected total external Max. force（MT）：（Ｔｘ
Anchor weight （MT）in Air：
（Ｗａ）
Anchor chain weight in Air （MT/m）：（Ｗｃ）
Kind of anchor（1: JIS, 2: AC14）

Result of Calculation
Impact Force）

85.56

Total height (Bottom to Hawsepipe):

10.5

Catenary length against the external force：
（Ｓ）

174 m

Minimum Required Contacted length of the chain：l

150 m

Minimum Required Length of Anchor Chain：Ｌ＝Ｓ＋ l

324m 12ss

0.166 ton
2

Total Length（Shackles）of using Chain on board

12 ss

Water depth（m）：ｄ20.0 mHawsepipe height from the sea surface（m）：ｈ5.0 m

Anchor Holding Factor:（λ a）
Anchor Chain Holding Factor：（λ c）

AC14 7.0
1.0

25 m

(y)

NoticeKeep Anchor Watch Strictly
Anchor Holding Factor（λ a）：Use Calculation Formula or Input by
mannual.
Anchor Chain Holding Factor（λc ）： 0.75 ～ 1.0

Table 71

－ 49 －JAPAN P& I CLUBP&I Loss Prevention Bulletin
Calculation Formula in above table◉ Anchor Holding Factor（Subj. to Kind of Sea Bottom）
λ a： 3.0（JIS）：7.0（AC14）λa：Anchor Holding Factor

λcType ofAnchorSand

Mud

Dragging
Anchor

JIS

3.5

3.2

1.5

AC14

7.0

10.6

2.0

：Anchor Cable Holding Factor
Holding
λc

Dragging

0.75 ～ 1.0

Sand

Mud

0.75

0.60

◉ Anchor Chain Holding Factor
λ c：0.75 ～ 1.0◉ Total height（Sea Bottom to Hawsepipe）
y ：d ＋ h
Water Depth（d）+ Hawspipe Height from Sea Surface（h）◉ Catenary Length Against the External ForceS ：S =

y² ＋ 2( Wc' ) yTx

◉ Anchor Weight in Air（Wa）, Anchor Weight in Water（Wa'）（Wa’）＝ Wa × 0.87
◉ Anchor Cable Weight per m in Air（Wc）, Anchor Cable Weight per m in Water（Wc'）（Wc’）＝ Wc × 0.87
◉ Minimum Required Contacted Length of the Cable
l：Tx = Wa' ×λ a ＋ Wc' ×λ c × l：l =Tx - Wa' ×λ a
Wc' ×λ c◉ Minimum Required Length of Anchor Cable
L：L = S ＋ l◉ In case of Tx ＜ Wa' ×λ a
：L = 3 × d + 90（m）
Table 72

－ 50 －JAPAN P& I CLUB

４－６

Countermeasures to prevent an anchor from dragging instormy weather

Conventionally, there are guidelines, such as those listed below that serve as countermeasures against an anchor
dragging in stormy weather. Consider the following reasons and remarks.

①
Reason②
Reason③
Reason④
Reason⑤
Reason⑥
ReasonMake the deep draft
The ship’s weight will increase, and the chanceof the vessel horsing will decrease. Also, adecrease in wind pressure area can decrease
the impact of external forces.

Remarks

Consider increasing ballast quantity and hullstrength.

Even keel, or by the head (trim by bow) if possible, is to be applied.
Horsing（yaw and sway) motion can be limited
when wind pressure centre is moved to thestern.

Remarks

Consider increasing ballast quantity and hullstrength. Maintain propeller immersion.

Remarks

It takes 3 minutes heave-in one shackle (longer
time taken during rough seas). The longer theveered anchor cable, the more time it will take.

Veer anchor cable
Because holding factor between the anchor
cable and sea bottom increases and catenary
length increases, it is effective for improvementof anchor holding power and mitigation of
impact force added to cable.

To drop the other anchor as a snubber anchor
It is effective to drop the snubber anchor
because it can halve the amount of horsing(yaw and sway) motion which will decrease
the amount of impact force on the anchor byapproximately 30 to 40%.

Remarks

Consider length needed for a second cable.
One and a half times the depth of water will beneeded. Consider the possibility of cable fouling,
particularly when pitching heavily.

From the outset of anchoring, deploy both anchors
Anchor holding power increases when riding
at two anchors. Two-anchor mooring restricts
horsing (yaw and sway).

Remarks

There is a danger that the anchor cables may
tangle. Two-anchor mooring is not flexible when
the wind direction changes.

Main Engine, steering in combination with bow thruster
It is an effective way to suppress horsing (yawand sway) when an attempt is made to standbow against the wind, using a combination ofdead slow ahead speed and steering.

Remarks

It is necessary to have in-depth meetings withthe engine department. Ensure that the bow
thrusters are kept submerged when the ship is
pitching and rolling. Loosen the anchor chain
temporarily by manoeuvring forward, and notethat any sudden increase in tension may breakout the anchor when the hull falls leeward, which
may lead to anchor dragging.

Of the above guidelines, we simulated ③ Veer anchor cable and ⑥ Main Engine, steering in combination with bow
thruster (as per the situation of Vessel C, Case 3-3).
－ 51 －JAPAN P& I CLUBP&I Loss Prevention Bulletin＝ “Increase of anchor holding power in the event of a veered length of the anchor cable” for single anchor mooring ＝
An increase in critical wind speed when the anchor chain was veered due to strong wind, during anchoring with awindlass at 6 shackles (distance of 151 meters from hawsepipe, with Hawsepipe being 25m from sea bottom) of a Pure
Car Carrier laden with 6,000 units was calculated as a simulation under the following conditions:＝ Calculation conditions ＝Anchor weight in air（Wa）：10.5ton➡

Anchor chain weight per m in air（Wc）

Holding factor（λ a）7.0

Anchor weight in water

9.135 tons（Wa'）：0.166 ton/m Holding factor ／（λ c）1.0➡

Anchor weight in water

0.144 ton/m（Wc'）

Water depth + Hawsepipe height from sea surface（y）：25.0mLength of one shackle of anchor cable①：27.5mProjected area (front）（A）：800 sqm

The wind force coefficient（CRa）：0.75

Air density（ρ）：0.125kg/sec2/m4

When the anchor cable is constantly fixed

The external force is increased when keeping the anchor cable at 6 shackles and the catenary length of the anchor
cable is enlarged. However, once the external force reaches 63.9 tons (wind speed at 16.9m/s), the anchor cableconsists entirely of catenary which means that the only anchor holding power is by the anchor itself. When calculating
backwards the wind speed to be given a critical wind speed, and dividing the critical wind speed by 1.25 to 1.50 andthen replacing it with the average wind speed, 11.3 to 13.5 m/s will be the anchoring limit.

Tx :External Force

B: Bell Mouth

63.9t

Tx :External ForceSea Surface

S′=150.9m

y =25mCatenary

Fig. 73－ 52 －

Sea Bottom

JAPAN P& I CLUB（Calculation basis）
Before veering the anchor cable, the ship is moored exclusively with the anchor. This can be compared to theanchoring limit, as the anchor holding power is equal to the external force (impact force). The anchor cable is assumed
to have formed a catenary with no cable lying on the sea bottom. Before determining the critical wind speed, the windforce from ahead must be calculated. It can be demonstrated that the impact force (which, in this case, is the same as
the anchor holding power) should be divided by 6.
Anchor holding power ＝ external force（impact force）：63.9 tonf➡

Wind force from ahead

10.65 tonf

：150.9 m（5.5ss）

Catenary length（S'）

Calculate critical wind speed against wind force on front (110.65 tonf) from the Hugh’s formula to find the criticalwind speed and average wind speed as follows.

Critical wind speed：16.9 m/sec
Average wind speed: 11.3 m/sec ～ 13.5 m/sec＊

 he critical wind speed can be converted into the average wind speed which can be solved by dividing theTcritical wind speed by1.5 or 1.25.

These average wind speeds are the maximum limits under which the vessel in this example can lay safely atanchor without any more force being exerted on the anchor and cable system than it can withstand.

②

Situation after one additional shackle of cable is veered

The critical wind speed was simulated assuming that seven shackles of anchor cable were veered.

B：Bell Mouth

Tx :External Force 67.3t

Sea Surface

L = S + l =178.4m

S=154.8m

y =25ml =23.6m

Cable
Contact

Catenary

Fig. 74－ 53 －

Sea Bottom

JAPAN P& I CLUBP&I Loss Prevention Bulletin

When calculating the critical wind speed assuming that one additional shackle of anchor cable is veered, the ship canwithstand an external force of up to 67.3 tons (wind speed at 17.3 m/s). (This external force is balanced assuming that
23.6m of veered anchor cable is contacting the sea bottom. If the external force is greater than this, part of the anchor
cable will be contacting the sea bottom. However, the total anchor holding power will be smaller than the external
force, and the ship will drag anchor.)
Similarly, replacing it with average wind speed, it becomes 11.5m/s to 13.8m/s. Even when compared with 6 shackles
being veered, only an average wind speed of 0.2 to 0.3m/s was applicable.

（Calculation basis）
After a further shackle of cable was veered, the critical wind speed increased. Only part of the longer cable system
will lay along the sea bottom with the remainder forming part of a new catenary, which will now be longer as it will
be extended by the increased external force caused, in turn, by the increased critical wind speed. Veered length of thecable (laid over the sea bottom) ( ｌ ) was calculated by the quadratic equation from the calculation formula as below.

S’+（27.5m – l ）=Wc' ×λ c × l［ Wa' ×λ a ＋Wc'
]× yy2 + 2 ×

S'：Catenary length before one shackle is veered ：150.9ml ：Veered length of the cable（laid over the sea bottom）（this is to be calculated）③

Veered anchor cable contact ：23.6m

Catenary ：3.9m

Total ：

27.5m

When the anchor cable is completely veered to 12 shackles

Similar to the above, when calculating the critical wind speed assuming that all additional shackles (12 shackles)of anchor cable have been veered, the ship can withstand up to an external force of 86.3 tons (wind speed at 19.6m/s). However, replacing it with the average wind speed, it becomes 13.1m/s to 15.7m/s. Even compared with theassumption that 6 shackles are veered, only an average wind speed of 1.8 to 2.2 m/s was applicable.

（Calculation basis）（S）Catenary length（l）Contacted length of the cable（laid over the sea bottom）（L）Total length of anchor cable
The holding power created by the anchor and cable system Total：175.0m：155.0m（+22.4 tonf）：330.0m（12ss）：86.3tonf（Impact force）➡ Wind force from front 14.38tonf

Critical wind ：19.6 m/sec
The average wind speed can then be calculated as13.1 m/sec ～ 15.7 m/sec(This is an increase of 1.8 ～ 2.2 m/sec）－ 54 －JAPAN P& I CLUBIn summing up; from the viewpoint of the ship commander, even veering anchor cable as a countermeasure ofdragging anchor cannot be considered highly effective for increasing anchor holding power. This is because wind
gusts and does not blow in a constant direction or speed, thus it is also worth considering the necessity of weighing the
dragging anchor in time of an emergency, just in case.

Importantly for those on the bridge, the critical wind speed does not increase
as much as might be expected even if the anchor cable is veered considerably.

＝ Combination use of main engine, steering and bow thruster ＝Countermeasures to be taken under rough sea conditions, using a combination of the main engine, steering and bow
thruster, will be examined.
①

Use of the bow thruster

In order to avoid horsing (yaw and sway), it may be necessary to use a bow thruster, if one was outfitted on the ship. In
this situation, it is necessary to consider the influence on the generator as a result of outputting from the bow thruster
or when changing load frequently.
Regarding a pure car carrier laden with 6,000 units, the wind force on front at a force of 16m/s (it will be time at 1.50
= 24m/sec, if under the gusting at storm) is 22 tons. Because 80% of the horsepower (one ton ≒ 100PS) is necessary,
the following amount of power from the bow thruster will be required.

22 tons × 0.8 × 100 ＝ 1,760PS②

Combination use with main engine

In theory, it is assumed that ship operating using both the main engine and the steering in order to stand the hull
against the wind can limit horsing (yaw and sway) and reduce tension on the anchor cable. However, from a practicalperspective, a situation that requires the use of an engine will mean that it is getting closer to critical wind speed foranchoring. In addition, according to the usage of the engine, the anchor chain may repeatedly slacken and then becometaut, which may rather increase the impact force and lead to dragging achor.
The result simulated using the case of Vessel C above in 3-3 is introduced in the Maritime Casualty Analysis Report(Vol. 6): “Typhoons and Marine Accidents”. The conditions for simulation are shown in Tables 75.

－ 55 －JAPAN P& I CLUBP&I Loss Prevention Bulletin（Simulation method）
Ship's particulars

Loa

224.0 ｍDraft (fore)

8.00m

Length between perpendiculars

215.0 ｍDraft (aft)11.60mTotal width32.2 ｍMean draft

9.80m

Block coefficient of fitness (Cb)

0.821

B

Classification of speed force
Speed(full load / ballast)Engine rpm(revolution per minute)

Navigation full speed (Nav. Full)

14.0 knots

75 ～ 77 ｒｐｍ

Harbour full speed (S/B Full)

10.3/11.0

56 ｒｐｍHalf ahead eng. speed

8.9/9.6

48 ｒｐｍSlow ahead eng. speed

7.4/8.040 ｒｐｍDead slow ahead eng. speed

5.5/6.030 ｒｐｍClassification

Conditor of external force
Wind speed

25m/sWind direction

East-northeast (direction of 67.5 degrees)

Wave height of swell/wavelength

5m/200m

Wave height of swell and wavelength incident angle

Direction of 118 degrees

Table 75

DSP Simulator
Photograph 76 This was not the actual simulator used.

－ 56 －JAPAN P& I CLUB（Simulation method）
By rotating the propeller during horsing (yaw and sway) motion, in order to supply the need for holding power
against the force, propeller thrust power applicable to the ship speed in flat water of 6 to 14 knots was given. Then, anevaluation was conducted using the following calculation, in the event of giving the propeller thrust power.
◉ Maximum of cable tension（ Tmax ） ◉ Maximum of holding power（ FAmax ） ◉ Minimum of holding power（ FAmin ）The method of evaluation will be described below. A summary of it is shown in Table 77.
When Tmax does not exceed FAmin ：（ Tmax ＜ FAmin ） ⇒When Tmax exceeded FAmin：（ Tmax ＞ FAmin ） ⇒“Non-dragging of anchor”“Dragging anchor”

Anchorage in heavy weather using engine Simulation results
Anchor cable
VeeredEquiv. to 6kt(D.Slow)
Dead slow aheadeng. speed

Equiv. to 8kt(Slow)
Slow aheadeng. speed

Equiv. to 10kt
(Half)
Half aheadeng. speed

Equiv. to 11kt
(S/B Full)
Harbour full
speed

Equiv. to 14kt
(Nav. Full)
Navigation fullspeed

(tons）

51.1

48.8

50.0

0.0

0.0

FAmin (tons）

16.2

48.8

48.8

64.2

64.2

FAmax (tons）

52.6

56.5

64.2

64.2

64.2

Judgement

Dragging
anchorNon-dragging
of anchor

Excess thrust

Excess thrust

Excess thrust(tons）

51.9

48.8

58.8

0.0

0.0

FAmin (tons）

22.1

48.8

21.4

70.2

70.2

Propulsion /judgement

Tmax

6 shackles

Tmax

8 shackles

FAmax (tons）

58.6

62.5

70.2

70.2

70.2

Judgement

Dragging
anchorNon-dragging
of anchor

Excess thrust

Excess thrust

Excess thrust(tons）

48.8

48.8

61.2

0.0

0.0

FAmin (tons）

13.6

48.8

48.8

82.2

82.2

FAmax (tons）

70.6

74.6

82.2

82.2

82.2

Judgement

Dragging
anchorNon-dragging
of anchor

Excess thrust

Excess thrust

Excess thrust

Tmax

12 shackles

Table 77

－ 57 －JAPAN P& I CLUBP&I Loss Prevention Bulletin

Regarding Vessel C case, the Master started to use the engine before anchor dragging started. Under the 25m/s windspeed condition, it was possible to prevent anchor dragging with engine thrust power at the slow ahead engine speed(Slow Ahead), but there was a shortage of thrust power when it was set to Dead slow ahead engine speed (D. Slow
Ahead). However, the thrust power was too large at more than Half Ahead engine speed (Half Ahead) which caused
the anchor to drag as a result.
Vessel C attempted to control the ship’s posture by setting the engine to full speed, however, she was exposed to thewind from the Unmanouvrable area during dragging anchor caused by wind pressure, which will be referred to below,
and as a result, she was presumably grounded without the Master being able to control the ship’s posture.
In addition, because the wind does not blow in the same direction and speed, it is necessary to fully understand thatwrong usage of an engine may rather lead to greater impact force.
In the event that large vessels can evacuate to the open sea, it would be ideal to refuge at a point away from thetyphoon by heaving up anchor rather than staying anchored while using the engine.

４－７

Difficulty in maintaining manoeuvrability after dragging
anchor has started

If the ship swings broad on to the wind and begins to move to leeward, considerable time and space may be required
before effective control can be restored by using the main engine, rudder and bow thruster. In addition, when thepropeller is working the effect of the bow thruster will be decreased by about 20% per 1 knot of ahead speed. (Ahead
speed at about 5 knots, turning round yields no affect even when setting to full power.) It is important to understandthe Unmanouvrable area of the ship.
12
Wind velocity/ ship speed ratio

10

Unmanouvrable area

Unmanouvrable area

8
6
4

Maneuvering Area

2
0

60

120

180

240

300

360

Relative wind direction from bow (degrees）
A pure car carrier laden with 4,500 units: h（water depth）/d（draft）= 1.3
Graph 78

Graph 78 indicates the Unmanouvrable area of a pure car carrier laden with 4,500 units. This illustrates the limitations
on manoeuvrability imposed by various wind strengths compared to the vessel’s speed. Numbers entered in the－ 58 －JAPAN P& I CLUBvertical axis are wind speed per ship’s speed and the wind force angle is entered along the horizontal axis. Except forwhen being exposed to tailwind from the stern direction, it is an Unmanouvrable area area if the wind speed is morethan four times that of the ship’s speed.
For example, in the event of turning round to the starboard side (windward) by being exposed to wind from the
starboard side, it is impossible to change course at more than an 8 of wind velocity/ship speed ratio. On the other hand,in the event of turning round to the port side (leeward) by being exposed to wind from the port side, it is impossible tochange course at a 4 of wind velocity/ship speed ratio. The cause is the transient change due to the mutual influencesof wind pressure moment, water resistance moment and steering moment.
With a wind speed of 20m/s, the ship’s speed would have to be more than 5 knots (2.5m/s), in order to stand a chanceof stemming the wind. If it is more than 5 knots, the bow thruster will cease to be effective.

Note:

A difference in a ship’s speed will permit as to whether the vessel can maintain a given course.
This should not be confused with limit for course keeping. The limit for course keeping is an area
whereby it is not possible to keep on course if the wind velocity/ship speed ratio is large during
the voyage. It is different from limitation of manoeuvring by rudder.

PCC loaded with 6000 vehicles
Curve of limit of ability to maintain course (rudder angle of 30°)

The graph on the right shows
the limit for course keeping,
the area whereby it is or is notpossible to keep on course atOnce the wind velocity/ship
speed ratio exceeds 3.7, it will
be in an area whereby it will not
be possible to keep on course
because of the relative winddirection from bow. This should
not be confused with limitationof manoeuvring by rudder.

Region in whichcourse cannot be
maintainedWind speed (Va)/Vessel Speed(Vs)the rudder angle at 30 degrees.

Region in whichcourse can be
maintained
°

°

°

°

°

°

°

Relative wind direction
Graph 79

４－８

Safe distance from other ships, shallows and other facilities

There is no definite criteria regarding a safe distance to keep from other ships, shallows and other facilities. The
reasons are as follows.
The following items are to be considered, when focusing on the area of sea one is to use for restoring the ship’s postureusing a combination of the main engine, steering and bow thruster promptly after discovering a dragging anchor.

－ 59 －JAPAN P& I CLUBP&I Loss Prevention Bulletin①

A radius of swinging circle

A circle with a radius of minimum required length of anchor cable + theship’s Loa②

S p e e d of d r a g g i n g a n c h o r
under wind pressure force:

approximately 3 - 4 knots③

Required time to weigh anchor:

In general, an anchor cable will be retrieved at a rate of about 9 m/min andto retrieve 1 shackle takes about 3 minutes.
It may not be possible to heave in a taut cable continuously, thus prolonging
the operation of weighing anchor.

④

Time needed for preparing themain engine:

Early S/B Eng.

⑤

Time required to obtain speed ahead needed to restore the ship to full manoeuvrable condition after being
exposed to wind from the leeward

Compared with the situation of weighing the anchor during dragging anchor with yaw and sway (the first stage) andthen regaining control of the hull, with weighing the anchor after the anchor has dragged caused by wind pressure, thesimulation result indicates that approximately 3.5 times the amount of water area on the leeward side will be required.

Simulation of the time full control is achieved over the ship’s manoeuvrability
following dragging anchor: Case study
Turning Circle

Case 2

Steering takes eﬀect

0.23 nautical miles

1.0 nautical miles
5kts
Weigh the anchor

Case 1

2.4 nautical miles

Weigh the anchor

1.0 nautical miles

5kts
0.3 nautical miles（3L）

0.625 nautical miles
Fig. 80－ 60 －JAPAN P& I CLUBCase1 Weighing anchor after dragging anchor is detected
In the case of

Fig. 80

The ship’s LOA is 200m.
ㅦ She is lying at anchor with 8 shackles.
ㅦ Time to weigh anchor is 1.5 times longer than is usually required.
ㅦ During that period, the ship is being brought to leeward at 4 knots.
ㅦ After weighing anchor, it takes 15 minutes until the ship’s speed reaches 5 knots.
ㅦ In the interval, the ship’s side has been pressed by the wind.
ㅦ The main engine and bow thruster are ready prior to dragging anchor.
ㅦ Whilst weighing anchor, both are available. The wind speed was at 20m/sec.
It has been clarified that accidents may be caused, if there is no navigable water area with 3.63 nautical miles to the leeward
direction and 0.925 nautical miles in the horizontal direction. It would be difficult in many cases to secure this size of waterarea when needing to shelter from a typhoon.
1 Turning Radius of the Circle is:
8 shackles (220 m) ＋ 200 m ＝ 420 m ＝ 0.227 nautical miles
2 Time needed for weighing the anchor:
After dragging anchor caused by wind pressure starts, it is no longer possible to manoeuvre the ship. The anchor cable
recovery rate in moderate weather is known to be 9m per minute. Therefore, it would take about 24 minutes to weigh anchor
in moderate weather. However, in this situation, it would take 1.5 times as long or about 36 minutes.
In this interval, the distance which the ship is pressed to leeward = 4 knots x 0.6 hours = 2.400 nautical miles (distance coveredin 36 minutes at 4 knots).
3 After the anchor is aweigh, a further 15 minutes elapse before the vessel’s speed reaches 5 knots. During this period,
the vessel will drift about 1 mile to leeward (distance covered in 15 minutes at 4 knots).
0.25 hours × 4 knots ＝ 1.000 nautical mile
Leeward direction:

3.627 nautical miles (6,717m) is necessary.

4 The distance sliding transverse
Advance at 5 knots is (3L)＝

0.300 nautical miles（0 knot ＋ 5knots）÷2 × 0.25 hours＝

0.625 nautical miles

Horizontal direction: 0.925 nautical miles (1,713m) are required

Case2 Started to weigh the anchor during dragging anchor with yaw and sway
In the case of

Fig. 80

If weighing the anchor at the early stage of dragging anchor with yaw and sway, it may be possible to weigh the anchor
almost right away using the engine for operation to weigh the anchor accordingly. Even if the vessel has entered into an
unmanouvrable area and, even worse, exposed to wind from the side, as long as the following water area both for leeward
direction and sliding transverse are secured, it is possible to achieve full control over the ship’s manoeuvrability.

Leeward direction:

1.230 nautical miles (2,278m)

Horizontal direction: 0.925 nautical miles (1,713m)
Most accidents such as collisions and groundings involving ships occur when an anchor drags because an insufficient amount of sea
area was not secured.

－ 61 －JAPAN P& I CLUBP&I Loss Prevention Bulletin

05§5Conclusion

Three different cases and mechanisms of dragging anchor were introduced. We are sometimes forced to anchor to
shelter from stormy weather such as from large swells and wave heights exceeding 5 meters.
However, as can be seen from the introduced cases, even though there were opportunities to evacuate from the sea
area away from the typhoon, a large number of accidents were caused due to a lack of weather information.
In the case of large vessels that had a method of riding at two anchors and two-anchor mooring, it is concluded thatmainly single anchor mooring was decided on because of the difficulty of ship handling.
Therefore, it is a requirement that as much weather information be available as possible in order better ensure safety.
Also, the Master should not be alone in making a judgement, it is also necessary for operators and ship managementcompanies to support the Master. Even if dragging anchor is already under way, the ship’s posture may be adequately
controlled if it is detected at an early stage.

－ 62 －JAPAN P& I CLUB

References
・

Maritime Casualty Analysis Report (Vol. 6):
Typhoons and marine accidents issued by Marine Accident Inquiry Agency (MAIA) in 2006

・

Marine Accident Inquiry and Safety Investigation Association, “Determination record by Marine Accidents
Inquiry Agency”

・Theory and Practice of Ship Handling, by Dr. Kinzo Inoue・Japan Captains’ Association, DVD “Safety Maneuvering in Restricted Water Area”

・

Ship Handling, by Dr. Keinosuke Honda

・

Ship Handling, by Dr. Satoshi Iwai・

Study of Ship Anchoring Supporting system (Kobe University)

Reference documents were provided by:・Japan Captains’ Association

・

Nippon Yusen Kabushiki Kaisha・Japan Marine Science Inc.

－ 63 －JAPAN P& I CLUBP&I Loss Prevention Bulletin

The author

Capt. Takuzo Okada
Master Mariner
General Manager
Loss Prevention and Ship Inspection Dept.
The Japan Ship Owners’ Mutual Protection & Indemnity Association

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Translated by : YUZEN Translation LLC－ 64 －