Research on
Navigation Safety Measuresin the Event ofMajor Earthquake/Tsunami Strikes
Final Report (Excerpt)

February, 2015

The Japan Association of Marine Safety
Japan Maritime Center

PrefaceThis report was prepared for foreign seafarers by the Japan Association ofMarine Safety in collaboration with Japan Maritime Center as an English version
excerpted from “Research on Navigation Safety Measures in the Event of Major
Earthquake/Tsunami Strikes,” published in FY2012 to FY2013 after the joint research
project: the Marine Accident Prevention Project.
This report is consisted of three key chapters entitled “Guidance for Tsunami
Safety Measures in a port”, “Safety/Disaster Prevention Measures for Large Vessels
Carrying Dangerous Cargo”, and “Conclusion”.
Note that descriptions concerning small boats or pleasure boats, which are notnecessary for foreign seafarers, were skipped.
February, 2015

The Japan Association of Marine Safety
Japan Maritime CenterI. Guidance for Tsunami Safety Measures in a Port ··················································· 1
Chapter 1. Purpose of the Guidance for Tsunami Safety Measures in a port ··················· 1
1. Purposes of the Guidance ········································································ 1
2. Needs for Tsunami Safety Measures ··························································· 1
Chapter 2. Establishing Tsunami Safety Measures ················································· 2
1. Studies on Tsunami Safety Measures··························································· 2
1-1. Conference for Establishing Tsunami Safety Measures ································ 2
1-2. Consistency in Regional Disaster Prevention Plans (skipped) ························ 2
1-3. Preparation Procedures for Tsunami Safety Measures ································· 2
1-4. Assessment of Tsunami Impact in a Port ················································· 4(1) Identification of port-specific features ·················································· 4(2) Gathering information on port usage ···················································· 5(3) Understanding of tsunami dynamics and behaviors in a port ························ 5
1-5. Tsunami Impact Assessment on Vessels ·················································· 8
1-6. Vessel Actions in the Event of Tsunami ·················································· 9(1) Tsunami Information Delivery Flow and Vessel Actions in general ················ 9(2) Evacuation ·················································································· 9
2. Preparation of Tsunami Safety Measures for vessels ·······································14
2-1. Designation of Tsunami-Sheltering Areas···············································14
2-2. Recommended Vessel Actions ····························································15(1) Large/mid-sized vessels (including fishing vessels) ·································16(2) Small Boats (Pleasure Boats or Small Fishing Boats) (skipped) ···················21
2-3. In-Table Summarized Tsunami Response Actions by Vessel Type and Situation ·26
3. Preparation of Tsunami Safety Measures ·····················································27
3-1. Information Delivery Means ······························································27
3-2. Evacuation Methods········································································28(1) Agreement on prioritized evacuation order and assistance arrangement ··········28(2) Agreements on voluntary evacuation measures, etc. ·································29(3) Port re-entry after the cancelation of a recommendation ····························29<<Appendix>> ····························································································31
1. Characteristics of Tsunami ······································································31
2. Past Tsunami-Damages ··········································································39
3. Earthquakes Predicted in Future ·······························································42
4. Understanding of Mooring Criteria (Critical Conditions) ··································43

5. Understanding of Anchoring Criteria (Critical Conditions) ································46
6. Guide to the Estimation of Critical Maneuvering Conditions ·····························51
7. Tsunami Information·············································································54
8. Laws and Regulations on Measures against Tsunami Disaster ····························65
II. Safety/Disaster Prevention Measures for Large Vessels Carrying Dangerous Cargo ········71
III. Conclusion ·····························································································89

I. Guidance for Tsunami Safety Measures in a port
Chapter 1. Purpose of the Guidance for Tsunami Safety Measures in a port

1. Purpose of the Guidance
The purpose of the Guidance is to promote the preparation of tsunami measures
for individual ports or port areas by providing basic ideas for tsunami measuresthat vessels should take for the safety of vessel traffic in port areas, as well as bypresenting points to be considered in preparing tsunami measures.
“Research Report on the Preservation of Vessel Safety under a Tsunami Alert” (FY2003)
summarized tsunami’s characteristics and impacts on vessels and presented guidance concerning
important points to be considered in preparing tsunami measures in port areas with a view topromoting deliberation on such measures.
This guidance has been prepared by reviewing the conventional guidance, based on thelessons of the Great East Japan Earthquake that occurred on March 11, 2011, as well as the results ofthe discussions of the Committee for the Navigation Safety Measures on the Occasion of Tsunami
held in FY2012 and FY2013.

2. Needs for Tsunami Safety Measures
It is necessary for individual ports (or regions) to have specific tsunami measuresin advance, since little time is allowed from the occurrence of an earthquake to thearrival of a tsunami. In addition, tsunami behaviors and impacts on vessels vary
according to the port-specific conditions such as geographical conditions andusage.
It is generally very difficult to prevent tsunami damage unless prompt decisions are madeand swift actions are taken, since little time is allowed before tsunami arrival once atsunami-accompanied earthquake occurs. Therefore, it is necessary to fully study in advance theactions vessels should take as well as Tsunami Safety Measures in a Port (hereinafter referred to as"Tsunami Safety Measures").

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Chapter 2. Establishing Tsunami Safety Measures
1. Studies on Tsunami Safety Measures

1-1. Conference for Establishing Tsunami Safety Measures
In preparing and implementing Tsunami Safety Measures, individual relevantorganizations should be assigned with clearly-defined roles and implement suchmeasures in a concerted way. Therefore, those organizations should havemeetings, discussions and mutual consultations on a regular basis to promote
understanding on the measures and to ensure their smooth execution.
In order to establish port/region-specific tsunami measures based on an understanding ofdetailed conditions of the port or region, cooperation among different relevant organizations is
indispensable. Furthermore, in some cases, tsunami arrives in a short time from the occurrence of anearthquake, so it is important for relevant organizations to discuss and agree how to respond in thecase of tsunami in advance. Unfortunately, in the Great East Japan Earthquake disaster, there weremany cases where the relevant organizations had difficulty in taking action as they could notcommunicate with each other due to a power outage and communication failure. Those cases serve
as lessons in the importance of establishing mutual agreements on Tsunami Safety Measures.
To this end, it is necessary to ensure discussion and coordinated consideration on issues
concerning tsunami measures on a regular basis at conferences (Tsunami Safety Measures
Conference) to ensure compliance with tsunami measures and the smooth execution of those steps.
In addition, regular tsunami drills should be conducted.

1-2. Consistency in Regional Disaster Prevention Plans(Skipped)

1-3. Preparation Procedures for Tsunami Safety Measures
As for the preparation of port/region-specific tsunami measures, each specificmeasures must be established based on the understanding of region-specifictsunami characteristics and their impacts on vessels.
Below are the standard procedures for establishing Tsunami Safety Measures at the
Tsunami Safety Measures Conference, etc.

-2-Study Flow of Tsunami Safety Measures
Identification of port’s
characteristics
・Natural conditions(Geographical features)・Situation of port facilities,
etc.

Identification of port usage
status・Anchoring vessels in theport area
・Type of ship service

・Surveys on past tsunami damages
・Assumed earthquakes/tsunami
simulation

Regional Disaster Prevention Plan

Understanding tsunami’s characteristics
・Determination of target tsunami
・Understanding tsunami’s characteristics specific to individual
areas (such as height and flow speed)

Assessment of tsunami’s impacts on vessels
・Estimation of damages on vessels by area

・Establishment of measures for vessels
Determination of evacuation sea areas
Establishment of earthquake and tsunami measures forvessels

Coordination /Cooperation

Preparation of a tsunami hazard map (proposal)

・Role assignment among relevant organizations (coordination)
Regular integrated drills
・Communication, etc. (to identify behavior / location of vessels)Multiplexing of communication channels
Orientations for foreign seafarers on general knowledge oftsunami and other phenomena
・Evacuation means
Sheltered mooring / outside-port evacuation / on-terrene
evacuation
Agreement on principles of evacuation / assistanceprocedures
Agreement on voluntary evacuation
Re-entry after the cancellation of evacuation
recommendation

Figure 2-1: Flow of Tsunami Safety Measures-3-1-4. Assessment of Tsunami Impact in a Port

(1) Identification of port-specific features
Information on port-specific features is indispensable for the establishment of
Tsunami Safety Measures. Therefore, a full investigation must be conducted onnatural characteristics and situation of facilities that affect tsunami behaviors,such as terrain, water depth, and port facilities.
In addition to surveys on natural characteristics, such as seabed topography and slope,water depth, coastal topography, and hydrographic conditions, surveys must be conducted on thelocations of port facilities, including breakwaters and quays, hazardous material facilities anddocks. In particular attention must be paid to hazardous material facilities, timber basins, andaquaculture facilities as those facilities could, due to driftage, cause a secondary disaster or
disturbance of navigation route, etc.
Port facilities and areas (and their functions/features/specifications) that should be
identified are as follows:(Major port facilities, etc.)[1] The locations and functions of breakwaters and levees[2] Quays, boat-lift yards, and cargo unloading yards (water depth, crown height, andusage)[3] Anchorage areas, navigation route, ship basins, and harbor[4] Timber basins and basins for small boats including pleasure boats[5] Hazardous material facilities and passenger facilities[6] Ship yards and docks[7] Rivers and canals, etc.
[8] Other facilities
Check if the following items can be used in case of emergency: the location ofanti-seismic quays, outdoor lighting equipment, facilities with fire-fighting equipment,
facilities with disaster-prevention materials and equipment.
(Other facilities that require attention)[1] Places with a large number of visitors, such as beaches, fishing spots, and recreationalareas[2] Culturing rafts, fixed fishing nets, and other surface structures[3] Places where tsunami is likely to run-up, such as slopes and inclined ground[4] Spots of low crown height-4-(2) Gathering information on port usage
In order to prepare safety measures including evacuation of vessels in advance,
when a tsunami is expected the congestion status of vessels in the port and theirtypes of services must be identified.
Tsunami Safety Measures must be developed on realistic assumptions based on anunderstanding of the conditions such as the congestion status of vessels in the port, type of vessels’
services, status of offshore construction, etc. Though swift gathering of precise information on vessel
situations cannot be expected in emergent situation, it is useful grasp the information about theberthing situation from daily-based survey when tsunami happened.
Such regular surveys should include the following items:[1] Vessels’ arrival/departure patterns; distribution of anchoring/mooring vessels by timezone, day of week, and area; the maximum number of cargo-handling vessels; and the
maximum number of entering vessels[2] Areas of vessel traffic congestion such as navigation route; the severity of congestion[3] Usage of anchorages[4] Situation of vessels that could require special assistance in the event of emergency: e.g.
vessels carrying dangerous cargo; timber carriers; offshore cargo handling vessels;
vessels not under command (mooring/ repairing, dredging boats, etc.); pleasure boats;fishing boats; barges; etc.
[5] Situation of vessels supporting entry/departure operations: e.g. tugboats, pilot boats, or
ferry boats[6] Situation of surface construction works[7] Regular events at port area

(3) Understanding of tsunami dynamics and behaviors in a port
Assumptions of tsunami dynamics in port/port area must be made throughreferencing tsunami hazard maps for disaster prevention (based on tsunami
simulation outputs), tsunami flood risk maps, past tsunami damages, andestimated tsunami height based on tsunami damage in past earthquakes.
Moreover, tsunami dynamics in port/port area must be supposed and identified as
possible.
Determining tsunami impact in conjunction with Tsunami Safety Measures must be properly
conducted while preserving consistency with regional disaster prevention plans and taking pasttsunami damage into consideration.

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The characteristics/behaviors of tsunami in a port (specifically, height, flow speed, etc.)
must be estimated for each zones in a port and calculated based on port features and usage (asmentioned above), paying attention to the following areas.
[1] Areas where tsunami are likely to rise higher[2] Areas where tsunami flows are likely to go faster[3] Areas where eddy currents are likely to occur[4] Areas where geographical conditions could cause surge waves[5] Positions where crown height is so low that small boats could easily be carried onto theground[6] Areas of rivers, etc. where tsunami are likely to run up[7] Areas where water depth decreases to an extreme when undertow[8] Areas where tsunami impact is likely relatively low
The following items are recommended as a reference in understanding tsunami
dynamics/behavior in a port:(a) Tsunami risk maps
Japan Cost Guard has prepared such maps based on tsunami risk information obtained
through conducting tsunami simulations using the fault models for the following major
earthquakes feared to occur in future: a Tokai earthquake, a Tonankai/Nankai earthquake,and a Nankai Trough earthquake. The information includes estimated tsunami behavior in
specific sea areas.
The results of simulations by Japan Coast Guard were made available on the following
web site in the form of a “Tsunami Risk Map,” a “Tsunami Time-Variation Diagram,” and a“Tsunami Animation”: http://www1.kaiho.mlit.go.jp/KAIYO/tsunami/.
Note: In actual situations, hypocenter positions, earthquake magnitudes, and details ofgeographical conditions will affect tsunami behaviors. Therefore, actual tsunami scale orheight may differ (larger or smaller) from the simulation results.
(b) Tsunami Flood Risk Map
Tsunami flood risk maps were prepared as base materials for the preparation ofmunicipality-specific tsunami evacuation plans or tsunami hazard maps. At the same time,
tsunami flood risk maps are supposed to be used in studying physical measures for theenhancement of tsunami measures. Tsunami flood risk maps, although primarily prepared
for the establishment disaster prevention on terrene, will be helpful for the estimation ofgeneral tsunami behaviors.

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Note: Tsunami hazard maps for separate municipalities are publicly open on the hazard
map portal site (http://disapotal.gsi.go.jp) prepared by the Ministry of Land, Infrastructure,
Transport and Tourism(c) Damage caused by past tsunami
Unfortunately, almost all of the tsunami damage information found in historical
documents is tsunami damage on terrene. Therefore, for the study of tsunami damage on thesea, in addition to surveys of local historical records, it is necessary to collect informationfrom local residents.
(d) Other materials
Impact of tsunami in a specific port must be estimated by using following materials:"Survey Report on the Methods of Tsunami Estimation for Pacific Ocean Earthquakes"(prepared in FY1996 jointly by the Ministry of Construction, the Ministry of Agriculture,
Forestry and Fisheries, the Fisheries Agency, and the Ministry of Transport); "Tsunami
Inverse-Spread Diagram" (estimate time of tsunami arrival by using the tsunami diagram,
port/port area as hypocenter, then inverse); and general tsunami dynamics/behaviors.

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1-5. Tsunami Impact Assessment on Vessels
Based on the tsunami characteristics in a port estimated through surveys or thepreviously described investigations, area-by-area estimations are made on theseverity of tsunami impacts on vessels at sea where impacts are expected andstudies are made on sheltering sites/routes, evacuation orders/priorities.
As previously shown, tsunami characteristics (height, flow speed, etc.) are numericallyestimated through simulations and other methods. On the other hand at present, tsunami impact on
vessels is yet to be estimated; and numerical assessments will be difficult. However, while theestablishment of evaluation methods for tsunami impact on vessels has to be left to future research, it
is possible to estimate such impact somewhat accurately using the results of tsunami simulations or
mooring criteria simulations on specific ports/port areas. It is likely realistic to make comparisons ofrelative risk degree according to estimations on the impact on vessels using the methods describedabove.
It is recommended that studies are conducted and that sheltering sites/routes, andevacuation priorities and orders are established based on the relative estimated risk degree calculated
via the methods described above. In addition to the usefulness of such graphical presentations of port
areas’ risk degrees (for example, tsunami hazard maps for a port) for promoting studies on Tsunami
Safety Measures, such graphical representations of risk degree, when delivered to the persons
responsible for the vessels, will aid in the promotion of their awareness of disaster prevention and of
the appropriate actions, such as smooth evacuation, in the event of a tsunami strike.
The following items should be shown on such hazard maps: tsunami height estimation;
tidal stream; and risk-degree estimation for vessels. These items are expected to set up by
circumstances of each ports/port areas.
The “Guide to Tsunami/High Tide Hazard Map*” (compiled by the administration officeof “Tsunami/High Tide Hazard Map Study Group, in March 2004) is recommended as a consultation
tool for such studies.
* At present, the guide is available from the Coastal Development Institute of Technology (a general incorporated
foundation)-8-1-6. Vessel Actions in the Event of Tsunami(1) Tsunami Information Delivery Flow and Vessel Actions in general
Figure 2-2 shows the general flow of tsunami information delivery and the actions thatvessels are supposed to take on receipt of information

Meteorological Agency (Section in Charge of Tsunami Forecast)
Tsunami warning / advisory (Major Tsunami Warning, Tsunami
Warning, Tsunami Advisory)
Earthquake / Tsunami Information

News Media

Regional Coast Guard
Headquarters
Coast Guard Office / Station(Recommendations
and Others)(Extreme
Weather Report)(Vessel’s Self-Action)(Assistance / Rescue
Request)Ship Agency,
etc.
(Arrangement Request /Vessel’s Self Action)

Vessel(Broadcasting)
Vessel’s Decisions and Actions◆ Cancel Entry (Offshore Standby / Destination
Change)◆ Arrangement Request (Cancel
Cargo-Handling / Tug / Pilot)◆ Evacuation Stand-by◆ Offshore Sheltering◆ Sheltered Mooring◆ On-Terrene Evacuation◆ Request for Assistance / Rescue◆ Navigation Following Recommendations◆ Other Actions for Safety

Figure 2-2: General Flow of Tsunami Information Delivery and the Action thatvessels are supposed to take on receipt of information(2) Evacuation(A) Decisions on Evacuation
When getting informed of tsunami strikes through tsunami warnings/advisories, vessels
have to make decisions on their actions such as offshore sheltering, staying at their mooring sites-9-and taking tsunami measures, or ordering crews to evacuate on-terrene. In making such decisions,
it is necessary to take the following factors into consideration:(a) External factors (information or instructions)
・Recommendations, etc. on evacuation by the Chief of Coast Guard Office/Station (Captainof the port)
・Instructions on evacuation by the port administrator, fishing port administrator, fishing port
administrators (fisheries cooperative administration, etc.), or marina operators.
・Measures vessels are to take against tsunami strikes in consideration of the following:
Navigation Safety Measures for Large Vessels Carrying Dangerous Cargo; Administrative
Provisions on Cargo Handling; Conference on Port Construction Works; Conference ofDangerous Cargo Handling Operators; and manuals for emergency operations prepared byoperators.
(b) Port conditions/situations
・Tide level projection at the estimated time of tsunami arrival, crown height of quays, andvessel draft
・Tsunami behaviors in port areas estimated from past tsunami records or tsunami simulation
results
・Port capacity for vessels (mooring, in-port anchorage, , cradling, landing)・Situations of port and nearby vessels
・Situation of vessel traffic congestion on routes and other areas
・Situation of earthquake damage on port facilities
・Navigational warnings(c) Situation of own vessel・Time required to complete "evacuation standby"(Time required for the following: engine standby; passenger /vehicle offloading andretract gangway/lamp; cargo handling suspension and housing onboard/land cargohandling equipment; suspension of working and housing equipment; housing fishinggear, etc.; picking up workers/divers; getting landing/cradling)
・Time required for reaching safe offing from mooring point/anchorage, or operation/worksite
・Evacuation method and safety of each method (offshore evacuation, shift to andmooring/anchoring in smaller port less susceptible to tsunami impact, landing/cradling)
・Time required for each evacuation method
・Time and measures required for surviving tsunami by staying at quay, anchorage, or
working sea area

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・The number of crew members required for completing evacuation and the time required
for assembling this number
・Time required for returning to vessel from home, work site, or other place
・ Land shelter locations and required time for crew members, passengers, andworkers—placing the highest priority on safety
・Availability of self unberthing (arrangement or availability of pilot or tugboat)
・Availability of arrangement of carriage/landing and facilities and required time・Allowance of sufficient time margin (evacuation time, tsunami arrival time, tsunami
height)(B) Time required for completing offshore evacuation
Offshore evacuation cannot succeed unless sufficient time for moving to safe sea areas isafforded before estimated tsunami arrival time. Therefore, it is important for a ship master tohave confirmed the time required to accomplish offshore evacuation.
Time required for offshore evacuation consists of the following two factors: (1) time forstanding-by evacuation; and (2) time required to move the vessel to safe sea areas. However, it isdifficult to estimate such time in advance, because (1) the time depends on the situation of thevessel and the quay where the vessel stays, and (2) it depends on the port situation. Therefore, itis necessary for a ship master to confirm times (1) and (2) every time they enter port.
In addition, quay masters are required to consider the following in ensuring smooth offshore
evacuation:
・Facility improvement, such as preparing multiple power source for cargo handlingequipment and mooring equipment
・Applicability of berthing/unberthing methods (head-out) to ensure large vessels are able
to achieve this smoothly
・For the case of large vessels carrying dangerous cargo:○ Installation of equipment such as quick release hooks○ Arrangements for smoothly putting oil fences back
○ Preparation of manuals and drills for cargo handling suspensions and emergency
unberthing
With regard to time required in entering evacuation standby status, two questionnaire
surveys have been conducted as follows:(a) The Japan Association of Marine Safety conducted surveys in 1997 on targeting
general vessels that were regularly using nine ports located in the prefectures which-11-are facing the Sea of Japan between Aomori and Ishikawa. The survey results areshown in Table 2-1.
The table indicates that two thirds of the vessels replying were able to enter
evacuation standby in less than 30 minutes; one third, in less than 15 minutes; andanother third, in more than 30 minutes.
(b) Tokyo-wan Association for Marine Safety conducted similar surveys in 1984 on
vessels entering Tokyo Port. The results of the survey are shown in Table 2-2 forquay-moored vessels, and in Table 2-3 for buoy-moored vessels.
Recent large LNG tanker berths have emergency unberthing equipment such as
quick release hooks installed and the time to standby un-berth is reportedly around40 minutes. (“Symposium Proceedings on Vessel Tsunami Measures,” the 3rd
Conference on the Great East Japan Earthquake, November 20, 2013, Japan
Institute of Navigation)(C) In the case of insufficient time allowed for offshore evacuation
Many large vessels are unable to un-berth without tugboats, particularly when gales arepushing the hull onto the quay. Almost all vessels under the command of non-Japanese masters
who have less experience of Japanese ports, in particular, will not be able to un-berth without
pilotage and tugboat assistance.
Furthermore, only limited port/port area provides 24/7 tugboat services, in addition, at thetime of tsunami strikes, tugboats themselves must evacuate. Also, pilotage service will not be
available at night as pilots and tugboat crews are generally off-duty.
It is considered as a "best available procedures" for the following vessels to stay berthing
using more mooring lines: there is difficulty to unberth without assistance by tugboat, in spite ofthis might be the only way to evacuate; there is no sufficient time to evacuate from the port,
regardless of availability of evacuating from the port.
Furthermore, it is recommended for small boats such as fishing boats, work boats, orpleasure boats that enhanced berthing measures are taken before crews proceed to evacuate via
land.

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Table 2-1: Time Required to Complete Evacuation Standby (General Vessels)
Number of ships (%)
Gross Tonnage

AnytimeReadyLess than
15 min

15 to 29min

30 to 44min

45 to 59min

60 to 89min

90 to 119min

Over 120
min

Total

Less than 58(22)15(43)

6(17)

3(9)

3(9)

5 to 19

7(15)13(28)

17(37)

4(9)

5(11)

46

1(10)

7(70)

2(20)

10

2(28)

7

20 to 4935

50 to 99

3(43)

2(28)

100 to 499

5(6)35(41)

25(29)

9(11)

6(7)

3(3)

2(2)

500 to 999

7(5)38(27)

59(42)

27(19)

4(3)

3(2)

1(1)

1(1)

140

1,000 to 2,999

6(5)31(27)

45(39)

22(19)

8(7)

1(1)

1(1)

1(1)

115

3,000 to 5,999

4(4)15(16)

21(23)

24(26)

14(15)

7(8)

2(2)

4(4)

91

12(19)

3(5)

3(5)

62

9(1.5)

9(1.5)

607

6,000 to 9,999

3(25)

4(33)

5(42)

10,000 to
49,9996(10)21(34)

8(13)

9(15)
1(25)

1(25)

102(16.8)54(8.9)27(4.4)50,000 or more
Total

40(6.6)

1(25)

1(25)

160(26.4)

206(33.9)

85

12

4

Table 2-2: Time Required to Complete Evacuation Standby (Vessels Berthed at Quay)
Number of ships (%)
Less than 30min

40 to 59 min

Less than 1,000

63(85)

10(14)

1,000 to 2,999

38(72)

15(28)

3,000 to 4,999

13(43)

13(43)

5,000 to 9,999

15(39)

13(34)

10,000 to 49,999

24(19)

50,000 to 99,999
100,000 to 149,999

Gross tonnage

90 to 119min

120 to 149minOver 150
min

Total

1(1)

74
53

2(7)

2(7)

3(8)

2(5)

5(13)

38

68(54)

7(6)

24(19)

3(2)126

10(19)

30(56)

6(11)

4(7)

4(7)

54

5(20)

15(60)

1(4)

4(16)

150,000 or more
Total

60 to 89 min

2(67)
168(42)

166(42)

30

25

1(33)
17(4)

3

38(9)

14(3)

403

Table 2-3: Time Required to Complete Evacuation Standby (Vessels on Buoy-Mooring)Number of ships (%)
Gross tonnage

Less than 30
min

30 to 59 min

60 to 89 min

90 to 119min

120 to 149minOver 150
min

Total

Less than 1,00044(94)

3(6)47

1,000 to 2,99933(87)

5(13)38

3,000 to 4,999

12(55)

6(27)5,000 to 9,999

12(41)

14(48)

10,000 to 49,999

42(37)

51(45)

50,000 to 99,999

21(41)

24(47)

100,000 to 149,999

7(29)

12(50)

150,000 or more

2(67)

Total

173(53)115(35)

2(9)

2(9)

22

1(3)

2(7)

29

5(4)

12(10)

4(4)

114

1(2)

4(8)

1(2)

51

2(8)

2(8)

1(4)

24

10(3)

-13-

21(6)

1(33)

3

9(3)

185

2. Preparation of Tsunami Safety Measures for vessels

2-1. Designation of Tsunami-Sheltering Areas
As a matter of procedure, areas for tsunami sheltering and the navigation route tothose areas when a tsunami risk is expected must be designated in advance. The
features of the port region and the assessment of tsunami-impact on vessels must
be considered in preparing such procedures.
Sheltering areas must be determined taking care of the following:(a) Areas must be determined in full consideration of tsunami impact on surrounding areas.
(b) Areas must be chosen among areas relatively close to the port that are projected toreceive less tsunami impact.
(c) Area sheltering capacity must match the number of vessels under normal situations. Notethat it is necessary to designate more than one area and assign prioritized order to thoseareas.
(d) Areas should be separated for large or mid-size vessels from those for small vessels.
(e) Time for moving from each of the quays to the sheltering areas for each category ofvessel must be estimated and kept available during emergencies.
(f) Areas inside the port that are expected to have relatively lower tsunami should bedesignated as emergency-evacuation areas for vessels that have no time to make offshore
evacuations due to delays in evacuation actions.
(g) In assigning sheltering areas, it must be ascertained whether safe sea evacuation routes
exist. In doing so it is important to pay attention to the fact that tsunami impact may
increase near breakwaters etc.
(h) Additional measures should be prepared in advance, particularly for small vessels, inconsideration of bad weather or sea conditions that might interfere with vessel evacuationin tsunami risk situations.
(i) All concerned port organizations and vessels should be kept well informed of sheltering
areas and evacuation routes.
(j) With regard to vessel-traffic congested areas (for instance, Tokyo or Osaka Bay) wheresheltering areas may overlap with those of neighboring ports, adjustments and agreements
in regard to evacuation areas should be made in advance with such ports.

-14-

2-2. Recommended Vessel Actions
It is necessary to conduct studies on recommended vessel actions for each vessel
category and situation based on an assessment of earthquake/tsunami impacts forvessel.
For the preparation of a port-specific vessel-action manual for the cases where a strong
earthquake has occurred or there is a tsunami risk, it is necessary to have completed, in advance,
studies on what actions are desirable for individual vessels to take.
In this sub-section, tsunami impacts on vessels of different types and in different situations
are summarized, and then recommended standard actions are introduced.
Table 2-4 shows what impact on what types of vessels tsunami will give, and what actions
vessels are recommended to take.
Table 2-5 shows what type of vessels and in what situations the type of tsunami
information (warning or advisory) is issued.
Figure 2-3 shows the procedural flow of actions to be taken by large/mid-sized vessels.
When taking the above mentioned actions, attention should be paid to the following:(a) Those tables show the standard actions that vessels are recommended to take for vesselsof various types in different situations. However, as previously mentioned, tsunami impact
on vessels is heavily dependent on the characteristics or situations of individual ports/port
areas, it is recommended to prepare port/port area specific tsunami measures based on
considerations of specific conditions or situations.
(b) The measures shown in the tables were originally established based on surveys andresearch conducted in FY2003, and then reviewed to reflect lessons from the Great East
Japan Earthquake on March 11, 2011.
(c) In the tables, vessels are classified into the two categories—large/mid-sized vessels andsmall vessels. Note that the classification of vessels cannot be made simply by tonnage;
one reason for classifying large vessels and mid-sized vessels into the single category of“large/mid-sized vessel” is that, although large vessels and mid-sized vessels will be
impacted differently—for instance, mooring line break conditions or situations for large
vessels are different from those for mid-sized vessels—there is no significant difference interms of recommended measures for those two sizes.
However, large vessels are required to prepare additional measures to cope withsituations where they are unable to leave port by themselves as most large vessels requiretugboat assistance or pilotage services to do this. On the other hand, the category “Small
Vessels” designates vessels that, judging from port-facility conditions, can be consideredsmall enough for measures such as being carried onto land and tied down. Small boats
such as pleasure boats or small fishing boats fit this category.

-15-

(1) Large/mid-sized vessels (including fishing vessels)(A) vessel berthing in a port
Tsunami impact for vessels berthing in a port and recommended measures or actions
for those vessels is shown below:(Expected Tsunami Impacts on Vessels)[1] Earthquake movement causes hull motion (simultaneously in hull and beam
directions) that increases tension on vessels’ mooring lines, which engenders arisk of mooring line breakage/elongation.
[2] Power loss due to earthquake damage will in some cases interfere with theseparation off the vessel or housing of cargo handling equipment.
[3] Hull lifts due to a rise in water level or movement caused by flow pressures ofstrong tsunami currents will elongate mooring lines, increasing tension on
those lines.
[4] In extreme cases, hull lift or movement may cause mooring line breaks and set
vessels drifting off quay; and, in the worst case, lead to collisions or
groundings.
[5] There is a risk that a vessel will be lifted and carried onto the quay by
overflowing tsunami water.
[6] There is a risk that a vessel dragged down by back-drawing tsunami water will
touch the seabed with the bottom of its hull.
[7] There is a risk that tsunami pressure flow will press a vessel onto the quay,
preventing it from unberthing.
[8] There is a risk that a vessel will fail to house the oil-fence it has erected.

(Recommended Vessel Actions)<General Vessels (including working vessels)>[1] Vessels are required, on receipt of a major tsunami warning, a tsunami warning,or a tsunami advisory issued by the Meteorological Agency, to Suspend theircargo handling operations and other work, even if in the middle of operations
and make efforts to collect earthquake/tsunami information.
Note: In the case where an earthquake occurs in an area close to the coast,
there is a risk that vessels will be trapped in a situation where a tsunami arrives
before the Meteorological Agency is able to issue a tsunami warning or otherreport. Therefore, vessels are recommended to make efforts to collect tsunami
information immediately after sensing a strong earthquake (of intensity 4 or-16-

over) or sensing an earthquake, even if not strong, with a slow but long-lasting
movement.
[2] In a situation where a major tsunami warning or tsunami warning has been
issued, vessels are recommended to make offshore evacuation as their first
choice if they have sufficient time to reach evacuation sheltering areas before
the tsunami is expected to arrive. Note that tsunami with a height of more than 1
to 2 meters can cause damage. However, in the case where a no more severe
warning than a (general) tsunami warning has been issued, vessels can choose
moored sheltering, judging from the comparison of their hull-size to the
expected tsunami height.
[3] Vessels in a situation where, although a major tsunami warning or tsunami
warning has been issued, they cannot afford the time to execute an offshore
evacuation are recommended to choose, as a second best counter-measure,moored sheltering with enhancing mooring by way of adding or tightening
mooring lines. However, in the case where a major tsunami warning has been
issued and it is likely dangerous to stay onboard, vessels are recommended to
let their crew members leave to evacuate by terrene if sufficient time is available
to reach high ground.
[4] Vessels, in the case where a tsunami advisory has been issued, arerecommended to choose moored sheltering or offshore evacuation, judging
from the scale of the expected tsunami height and the vessel’s hull size.
[5] Vessels are recommended to take, judging from the vessel size and conditions,following maneuvering or ship-securing measures:(a) Enhanced supervision on water-level variations, water-flow situations, orobjects drifting on surface.
(b) Standby main engines and anchor.
(c) Anchor before the completion of berthing: this will make emergency
unberthing maneuvering easier.
(d) Berthing with head-out will drastically reduce the time required for emergency
unberthing and turning.
(e) In emergency self-unberthing, let-go or cutting all of the mooring lines will beeffective.
(f) Aft-swing maneuvering using forward spring-line will be effective in the casewhere tsunami pressure flow is blocking the vessel from unberthing.
(g) Having long spring/breast mooring lines will be effective in adding mooring
forces.

-17-

(h) Enhanced arrangements for securing mooring lines: take measures for theenhancement of mooring by adding/tightening mooring lines, and otherappropriate measures.

<Vessels Carrying Dangerous Cargo>[1] Vessels carrying dangerous cargo are recommended to consider offshore
evacuation as the first choice if they have sufficient time to reach the sheltering
area in order to prevent secondary disasters that might be caused by dangerous
cargo onboard.
[2] Vessels carrying dangerous cargo are recommended, in addition to the action
shown in [1], to take the same measures/actions recommended for general
vessels (including working vessels).
[3] Vessels carrying dangerous cargo are recommended to promptly take thefollowing emergency actions, as well as action [5] for general vessels (including
working vessels):(a) Promptly clear off water and house any oil fences that have been erected.
(b) Membrane-type LNG carriers must execute protection measures to avoid
sloshing that might occur after emergency unberthing.
(B) Anchoring/buoy-mooring vessels (including working vessels)
With regard to anchoring/buoy-mooring vessels, tsunami impacts and otherphenomena are shown below as well as recommended vessel actions.
(Expected tsunami impacts on vessels)[1] Bays, coves, or ports that are used for anchoring are, in general, almost fully
closed in except for a narrow entrance where a tsunami will increase flow
speed. Therefore, anchoring vessels will face a high risk of dragging anchor.
[2] Buoy-moored vessels will be put in a similar situation to that of anchoringvessels. In addition, when receiving abeam or diagonal tsunami flows they will
face a high risk of suffering drag forces exceeding the mooring force given by
the buoy if forward-aft moored.
[3] Reversing of tsunami-flow direction accompanying the pushes and pulls of
tsunami-flow will, in some cases, cause a loss of holding power by anchor
chain.
[4] Vessels will face the risk of grounding in shallow water or colliding with quay
when pushed by a tsunami’s pressing flows.
[5] Vessels will face the risk of touching ground with hull bottom in tsunami-18-

backflows.
[6] Vessel radars will be at risk of losing reflections due to tsunami water covering
quay surfaces or other structures.
[7] Vessel radars, according to the situation, may be able to detect tsunami comingfrom the offing.

(Recommended Vessel Actions)[1] Vessels are required, where the Meteorological Agency has issued a tsunami
warning/advisory, to suspend operations and make efforts to collect tsunami
information.
Note: in the case where an earthquake has occurred in a point close to coast, atsunamimight

arrivewarnings/advisories.

earlier

Therefore,

than

the

vessels,

Meteorological

Agencyissueswhen

sensedstronghavingearthquake motions (of intensity 4 or over) or slow but long-lasting earthquake
motions, even if the earthquake is not so strong, are recommended to promptly
take action in collecting information.
[2] Vessels are recommended, where major tsunami warnings/tsunami warnings
have been issued, to heave up anchor or let-go their mooring lines and go
offshore sheltering areas if there is sufficient time to evacuate.
[3] Vessels are recommended, where a major tsunami warning/tsunami warning
has been issued, to choose sheltering in a port if there is insufficient time to
execute offshore evacuation.
[4] Vessels are recommended, where tsunami advisories have been issued, tochoose sheltering in a port; however, they can choose offshore evacuationaccording to their situation.
[5] Vessels are recommended to prepare, considering vessel-size and conditions,for the following vessel maneuvering and ship-securing measures:(a) Enhance vessel’s tsunami resistance by using main engines, rudders, andthrusters, as well as enhancing holding power by extending anchor cables orapplying double anchors. Note: when applying double anchors, make sure toconstantly supervise vessel’s turning conditions to prepare for clearing
fouled anchor.
(b) Turning ship's heading by dredging in the direction of oncoming tsunami willaid in resisting the tsunami’s force.
(c) Standby slipping anchor for emergency break-away.
(d) Maintain high-level supervision on the transit of land markers to detect-19-anchor dragging.
(e) Enhance supervision on changes in tsunami water level, water flow
situations, and drifting objects on surface.
(C) Proceeding Vessel
Tsunami impacts on proceeding vessels and recommended vessel actions are shown
below.
(Expected tsunami impacts on vessels)[1] Vessels proceeding inside bay or port will face a high risk of sufferingnavigational

maneuvering

problems

suchasfluctuationofship'sposition/heading, less steerage (if ship's draft is not enough) by tsunami flow.
[2] Vessels proceeding in a port will face the risk of being pressed by strong
tsunami flows and will be unable to proceed due to strong currents, even if theyuse full-ahead.
[3] Vessels proceeding in a port at the time of tsunami strike will face a very highrisk of grounding or collision, because tsunami flows have different directionsor speeds at different points. Particularly around the port entrance tsunami will
form eddy currents.
[4] Large vessels will face the risk of being trapped in uncontrollable situations
even with tugboat assistance or using thrusters due to tsunami flow pressures.
[5] When overriding the tsunami crest, vessels will face the risk of suffering rapid
reduction of speed because the engine limiter works to prevent the main engine
from rotating too fast while propeller racing.
[6] When receiving tsunami on aft, vessels will face the risk of being trapped in asurf-riding situation on the front slope of the tsunami.
[7] Vessels proceeding in tsunami situations will face the risk that their radars lose
quay reflections due to floods on quay surfaces.
[8] Vessels proceeding in tsunami situations have the chance of identifying
tsunami coming from the offing via radar reflections.

(Recommended Vessel Actions)[1] Vessels are required, where the Meteorological Agency has issued major
tsunami warnings/tsunami warnings/tsunami advisories, to make efforts incollecting earthquake/tsunami information.
Note: in the situation where an earthquake has occurred at a point close to thecoast, tsunami may arrive earlier than the issuance of tsunami warning or other-20-

information

by

the

Meteorological

Agency.

Therefore,

vesselsarerecommended, when having sensed strong earthquake motions (of intensity 4
or over) or a slow and long-lasting movement, even if the earthquake was not sostrong, to immediately start collecting information.
[2] Proceeding vessels are recommended to immediately evacuate to offshore, ifthey have sufficient time to proceed offshore sheltering areas.
[3] Proceeding vessels are recommended to choose sheltering in a port, if they
have insufficient time to make offshore evacuation.
[4] Proceeding vessels are recommended to choose offshore evacuation in asituation where tsunami advisories have been issued.
[5] Proceeding vessels are recommended to take into account following
maneuvering actions or equivalents, according to their hull size or situations:(a) Keep steerage by setting the engine at maximum power when passing port
entrances during tsunami strikes.
(b) When proceeding nearby port entrances at the timing of tsunami
back-drawing, vessels may be able to proceed with better course stability
than when there is tsunami incoming or eddy-currents. This is because thereis less tsunami pressure flow interfering with navigation by causing speed
reduction or oblique vessel movement, etc.
(c) When trapped in tsunami, proceeding vessels are recommended to turn the
bow to the direction of the oncoming tsunami and adjust main-engine rotation
to avoid impact on the hull and rapid speed-reduction due to propeller racing.
(d) Proceeding vessels are recommended to standby anchor to avoid collision
with levees or other vessels.
(e) Proceeding vessels are recommended to enhance supervision on changes intsunami water-level, the situation of tsunami flow, and drifting objects on thesurface.

(2) Small Boats (Pleasure Boats or Small Fishing Boats)(Skipped)

-21-

-22-

Table 2-4: Tsunami Impact on Vessels and Recommended Vessel Actions
Large/Mid-sized Vessels (Including Fishing Vessels)
In a port Berthing
Tsunami Impacts

Recommended
Actions

General (Including Working Vessels)
Vessels Carrying Dangerous Cargo[1] Risk of mooring-line elongation/break due to vessel motions (hull-direction/beam-direction)
caused by earthquake motions.
[2] Risk of failures in separation/housing of cargo-handling equipment due to power-loss caused byearthquake damage.
[3] Elongation of mooring lines and rise in mooring-line tensions due to hull lift by tsunami waterlevel rises or hull movement caused by the flow pressure of strong tsunami.
[4] Risk of collision or grounding of drifting vessels off quays as a result of mooring-line breaks due
to excessive lift/movement by tsunami.
[5] Risk of vessel overriding on quay due to tsunami flowing over quays.
[6] Risk of vessels touching ground with hull bottoms by back-drawing tsunami water.
[7] Risk of failure in unberthing due to tsunami pressure-flow.
[8] Risk of failure in housing oil-fences.

[1] Required to suspend cargo-handling/operations andmake efforts in collecting information, in situations
where the Meteorological Agency has issued a major
tsunami warning, tsunami warning or tsunami
advisory. Note, vessels are highly recommended topromptly start collecting information in a situation
where they have sensed a strong (intensity of 4 orover) earthquake or slow but long-lasting earthquake
movement, even if the earthquake was not so strong,
because, in the case where an earthquake occurs at
a point close to the coast, tsunami might arrive
earlier than Meteorological Agency issues warnings.
[2] Recommended to consider offshore evacuation as
the first choice if the vessel has sufficient time, in asituation where a major tsunami warning or tsunami
warning has been issued, —tsunami of a height of 1
to 2 meters or over are said to cause damages.
Note, in the case of tsunami warning, vessels canchoose sheltered mooring, according to acomparison of their hull-size to the expected tsunami
height.
[3] Recommended to choose sheltered mooring withenhancing mooring force by adding/tightening
mooring lines. Note, in a situation where a major
tsunami warning has been issued, staying in thevessel is considered risky, and if there is sufficienttime, choose on-terrene evacuation.
[4] Recommended to choose sheltered mooring or
offshore evacuation according to the comparison of
the hull-size to the expected tsunami height, in asituation where a tsunami advisory has been issued,.
[5]
Recommended
to
take
the
following
vessel-maneuvering and vessel-securing measures,considering the vessel size:(a) Enhance the supervision of changes in tsunami
height, flow situations, and drifting objects on
surface.
(b) Standby main engines and anchor(c) Anchor before the completion of berthing: it will
likely make unberthing maneuvers easier for
emergency unberthing.
(d) Berth the vessel with head-out: it will likely
drastically reduce the time for unberthing andturning.
(e) Let-go or cutting all the mooring lines will beeffective for emergency self unberthing.
(f) Aft-swing maneuvering using forward spring lines
will likely be effective in a situation where tsunamipressure flow is blocking the vessel fromunberthing.
(g) Taking spring/breast lines long will be effective
for enhancing mooring forces.
(h) Enhance mooring forces by adding lines ortightening, and also enhance the arrangement for
securing mooring lines.

[1] Recommended to take offshore
evacuation as the first choice if thevessel has sufficient time in asituation where major tsunami
warnings or tsunami warnings havebeen issued. This is for the purposeof preventing secondary damages
due to dangerous cargo carried by
the vessel.
[2] Recommended to take the sameactions that general vessels(including working vessels) except
the action recommended in [1].
[3] Recommended to promptly prepare
for the operations shown below, in
addition to the actions shown in [5]for general vessels (including
working vessels):(a) Prompt recovery of oil-fences
the vessel has erected.
(b) Measures for preventing thesloshing that could occur after
emergency unberthing in amembrane-type
large
LNG
tanker.

Small Boats (Pleasure Boats/Small Fishing Boats)

Anchoring/Buoy Mooring (Including Working Vessels)

Proceeding[1] Risk of anchor-dragging for anchoring vessels: bays, coves, or
ports generally used for anchoring, different from open areas, arealmost fully closed in except at their narrow entrances, wheretsunami flows increase speed.
[2] Risk on buoy-mooring vessels is basically similar to that ofanchoring vessels, however high risk of having tsunami force
exceeding buoy-resistance force for forward-aft buoy-mooringvessels when receiving abeam or diagonal tsunami flow.
[3] Risk of losing holding power by anchor chain due to changes in flow
direction caused by forwarding and back-drawing of tsunami.
[4] Risk of grounding in shallow areas or colliding with quays when
carried by tsunami pressure flow.
[5] Risk of touching ground with hull bottom when dragged by tsunami
back-drawing flows.
[6] Risk of losing radar reflections from quays flooded by tsunami
water.
[7] Chance of detecting tsunami coming from offing by radarreflections.

[1] High risk of suffering navigation maneuvering problems such as
fluctuation of ship's position/heading, less steerage (if ship's draft
is not enough) by tsunami flow.
[2] Risk that vessels proceeding in a port might be unable to go
forward even if they use full-ahead, being pushed back by strong
tsunami-pressure flow.
[3] High risk of grounding or collision for vessels proceeding in a port
in tsunami situations because the direction and strength, etc. oftsunami flow in a port are so complex. Particularly near the port
entrance, tsunami flow might generate severe eddy currents.
[4] Risk of inability to control hull using tugboats or thrusters due totsunami flow, in cases of large vessels.
[5] Risk of rapid speed-reduction due to main engine limiter activatedfor suppressing engine excessive rotation as a result of engine
racing that might occur when the vessel is overriding tsunami.
[6] Risk of a vessel’s being trapped in a surf-riding situation on thefront slope of tsunami when receiving waves on aft.
[7] Risk of radar-reflection loss from quays when quays are flooded
with tsunami water.
[8] Tsunami from the offshore may be determined using radarreflections.
[1] Required to make efforts to collect earthquake/tsunami informationin the situation where the Meteorological Agency has issued amajor tsunami warning, tsunami warning, or tsunami advisory.
Note: when having sensed strong earthquake motions (intensity of
4 or over) or slow but long-lasting earthquake motions even if theearthquake is not so strong, vessels are recommended to
immediately start information collection, because in a case wherean earthquake has occurred at a position close to coast tsunami
may arrive earlier than a Meteorological Agency warning or other.
[2] Recommended to immediately evacuate offshore if the vessels
have sufficient time, in a situation where a major tsunami warning
or a tsunami warning has been issued.
[3] Recommended to take in a port sheltering if the vessel lacks
sufficient time, in a situation where a major tsunami warning or atsunami warning has been issued,.
[4] Recommended to take in a port sheltering. However, the vessel
can evacuate offshore based on the vessel’s individual situation, in
a situation where a tsunami advisory has been issued,.
[5] Recommended to consider applying the following vessel
maneuvering and vessel securing-measures according to thevessel size and situation:(a) In a situation where tsunami has arrived when passing a port
entrance, etc. set the engines at its maximum power to keep
steerage.
(b) In a situation where tsunami is back-drawing, vessels, when
passing a port entrance will have the chance to suffer lessinterference such as speed reduction or oblique shifting causedby tsunami pressure flow, and to more easily keep the heading
than in a situation where tsunami is incoming or generatingeddies.
(c) In the situation where a tsunami has arrived, face the bow into
the oncoming tsunami, and adjust engine-rotation to avoid
tsunami impact on the hull and rapid speed-reduction due topropeller racing.
(d) Standby anchors to avoid collisions with levees or othervessels.
(e) Enhance supervision on changes in tsunami-water level, flow
situations, and drifting objects on surface.

[1] Required to Suspend operations and make efforts to collectearthquake/tsunami information when the Meteorological Agency
has issued major tsunami warnings, tsunami warnings, or tsunami
advisories.
Note: in the situation where an earthquake occurred close to thecoast, there is a risk that a tsunami will arrive before theMeteorological Agency issues tsunami warnings or advisories.
Therefore, vessels are recommended, when having sensed strong
earthquake motions or slow but long-lasting earthquake motions,even if the earthquake is not so strong, to promptly collecting
information.
[2] Recommended, in a situation where a major tsunami warning or
tsunami warning has been issued, to evacuate offshore if thevessel can afford sufficient time.
[3] Recommended, in a situation where a major tsunami warning or
tsunami warning has been issued, to choose in a port sheltering if
the vessel cannot afford sufficient time to make offshore
evacuation.
[4] Recommended, in a situation where a tsunami advisory has been
issued, to takes in a port sheltering as a first choice; however,
judging from their own situations, vessels can opt for offshore
evacuation.
[5] Recommended to consider applying the following vessel
maneuvering and vessel securing-measures according to thevessel size and situations:(a) Resisting against tsunami forces by enhancing holding powerby applying double-anchors or keeping anchor cables
long-stretched, and using thrusters as well as the main engine.
Note: in a case where double-anchor is applied, it is necessary
to maintain supervision on vessel-turning situations in order toclearing fouled anchor.
(b) Dredging anchor to face the vessel’s bow head-on to theoncoming tsunami can be effective in resisting tsunami forces.
(c) Standby slipping anchor for emergency escape.
(d) Maintaining supervision on land-marker transit to detect anchor
dragging.
(e) Enhancing supervision on changes in tsunami-water level, flow
situations, and drifting objects on surface.

In a port Berthing

Proceeding/Anchoring(Skipped)(Skipped)(Skipped)(Skipped)

23～24
-23-

-24-

*1: Required Information and Its
Sources●Earthquake / Tsunami Information
Source✓ Emergency Broadcast on Marine
VHF Band✓ NAVTEX✓ Earthquake Early Warning✓ Early Warning Broadcast✓ Information / News on TV / Radio✓ Broadcast on SOLAS Equipment✓ Real-time Tide information✓ Real-time NOWPHAS●Port Radio✓ Port Information or others●Fishing Radio Station✓ Warnings and others from theMeteorological Agency●Captain of the port
Recommendation / Instruction✓ Suspend Cargo-Handling✓ Offshore Evacuation✓ Prohibit Entry●Coast Guard Vessel/Craft✓ Recommendation and others fromthe Captain of the port

Earthquake / Tsunami
Occurrence◆On-terrene personnel can provide
the following assistance:●Collection and delivery ofearthquake / tsunami information●Consultation on cargo-handlingand emergency unberthing●Suspension of work
accompanying cargo-handling✓ Removing Un-loaders✓ Removing gantry cranes✓ Removing loading arms
✓ Removing oil-fences●Cargo-handling workers
disembarkation / evacuation●Emergency unberthing
coordination✓ Pilots✓ Tugboats✓ Line men

Information Collection*1

Suspension ofCargo-Handling / Stand-by
Emergency Unberthing

Emergency
Unberthing
Feasible?

No

Sheltered MooringYes*2 Information to be Collected / Sent
/ Shared●Damage Information (Send /Share):✓ Human Damages✓ Vessel Damages✓ Port Damages✓ Troubles on Marine Aids
✓Conditions of floating debris✓ Water-Depth Information: Shallow
Water, etc.
●Situations of Vessels (Share):✓ Situations of Evacuated Vessels✓ Rescue-Assistance Ability●Vessel Traffic Safety Information(Collect):✓ Navigational Warnings✓ Captain of the port
Recommendations✓ Earthquake / Tsunami Information✓ Port-Facility Availability

Leaving Quay / Unberthing

Information
Collection *1
Vessel Adrift

Offshore Evacuation
Feasible?
In a port Sheltering

Offshore
Evacuation

Information
Collection *1

Information Collection /Sending / Sharing*2

Figure 2-3: Procedural Flow of Large/Mid-Sized Vessels’ Evacuation-25-

2-3. In-Table Summarized Tsunami Response Actions by Vessel Type and Situation
Table 2-5: Tsunami Warning/Advisory, Vessel Types, and Recommended Actions
Tsunami Warning/Advisory(PH: Predicted Height)

Major
TsunamiWarningOver 10 meters(10 m < PH)
10 meters(5m< PH≦10 m)
5 meters(3m<PH≦5m)

Time
Allowance
toTsunamiStrikeNo

Yes
No

TsunamiWarning

3 meters(1m<PH≦3m)
Yes

TsunamiAdvisory

1 meter(0.2m<PH≦1m)

Remarks

Small Vessels (Pleasure Boats,
Fishing Boats, etc.)

Large/Mid-Sized Vessels (Including Fishing Vessels)
In a port Berthing Vessels
General Vessels (Including
Vessels Carrying
Working Vessels)
Dangerous Cargo
Suspend Loading/Unloading
Suspend Loading/Unloading oror Operations
Operations
Berthing Sheltering orBerthing Sheltering or On-terrene
Evacuation on Terrene
Evacuation
Suspend Loading/Unloading
Suspend Loading/Unloading oror Operations
Operations
Offshore Evacuation
Offshore Evacuation
Suspend Loading/Unloading
Suspend Loading/Unloading oror Operations
Operations
Sheltering at Berth
Sheltering at Berth
Suspend Loading/Unloading
Suspend Loading/Unloading oror Operations
Operations
Offshore Evacuation or
Offshore Evacuation
Berthing Sheltering
Suspend Loading/Unloading
Suspend Loading/Unloading oror Operations
Operations
Berthing Sheltering orBerthing Sheltering or Offshore
Offshore Evacuation
Evacuation
Business operators are required toprepare action manuals

Anchoring
Vessels/Buoy-mooring Vessels(including Working Vessels)

Proceeding
Vessels

Suspend Operations
In a port Sheltering

In a port
Sheltering

Suspend Operations
Offshore Evacuation

Offshore
Evacuation

Suspend Operations
In a port Sheltering

In a port
Sheltering(Skipped)

Suspend Operations
Offshore Evacuation
Suspend Operations
In a port Sheltering(Offshore Sheltering, if
necessary)
Survey usual anchorage inadvance for identifying theareas where water is likely toflow fast at the time of tsunami
strikeOffshore
Evacuation
Offshore
Evacuation

Time Allowance to Tsunami Strike:
Yes: Vessels may have sufficient time to evacuate (to put the vessel in a safe state by offshore evacuation or landing and binding) following the release of a major tsunami warning/tsunami warning
No: Vessels will not have sufficient time to make evacuation (to put the vessel in a safe state by offshore evacuation or landing and binding) following the release of a major tsunami warning/tsunami warning
Large-sized Vessels: Vessels unable to make self-leaving off the port without the assistance of support boasts (tugboats, etc.) and/or pilot service
Mid-sized Vessels: Other Vessels than Large Vessels or Small Vessels
Small Vessels: pleasure/fishing boats: They are small enough to be carried onto land and sheltered (excluding docking)On-Terrene Evacuation: Crew members take refuge on terrene in high places, as high risk is predicted for in-vessel sheltering. Before leaving the vessel, complete securing-vessel-measures where possible,
such as securing dangerous cargo and ensuring protection from vessel being swept away
Offshore Evacuation: Choose a wide area where water is deep and away from the coast (if face a difficulties in evacuation, re-choose in a port sheltering.)
In a port Sheltering: Sheltering in the emergency sheltering areas inside the port and resisting tsunami water power by means of anchors or using engines/thrusters
Mooring Sheltering: Resisting tsunami power while berthing by means of enhancement of berthing force or through the use of engines. (Acceptance of land workers seeking emergency shelters onboard
should be considered)
Note: Procedures in table above should be understood as general measures. Specific measures should reflect the characteristics of the area (port) and tsunami action-manuals reflecting measures based
on-studies of the port in question should be recommended to vessels. Furthermore, it is recommended for vessels to prepare tsunami action manuals in advance, which reflect the measures mentioned above.

-26-

3. Preparation of Tsunami Safety Measures
3-1. Information Delivery Means
In general, the time from an earthquake occurrence to the arrival of a tsunami isshort. Thus, the key to the successful execution of Tsunami Safety Measures willbe the prompt and proper delivery of correct information to the parties concerned.
Therefore, the means, channels, and routes of information delivery must be
prepared based on extensive studies; and the parties concerned must be fully
informed.
In addition, the parties concerned must always have up to date information on
individual vessels’ behaviors or situations and must have prepared systems forkeeping communication channels with vessels open in order to promptly andproperly deliver accurate information.
Japan Coast Guard, in their disaster prevention action plans, outlines the following
disaster-information delivery protocol:[1] For anchoring vessels in areas close to tsunami-risk areas, send patrol boats or aircraft tovisit and give guidance, or use other means such as loud-speakers or banners to inform themof the tsunami risk.
[2] For proceeding vessels, deliver disaster information via navigational warning/safety notice.
[3] For local residents or beach visitors in coastal areas at tsunami risk, send patrol boats oraircraft and inform them of tsunami risks via loud speakers or banners.
The prompt and proper delivery of correct information is the key to disaster prevention;
therefore, the channels, routes, and effective means of delivering information must be set via the
Tsunami Measures Conference.
Information delivery channels must be duplicated to protect against situations where
communication infrastructures become unavailable. At the same time, it is important to keep
non-Japanese seafarers informed of how tsunami behaves and how to prepare for tsunami.
Business operators, such as ship agents or fisheries cooperative associations, must always
keep updated with information on their ships’ behaviors and arrange secured means ofcommunication effective under tsunami risk.

-27-

3-2. Evacuation Methods(1) Agreement on prioritized evacuation order and assistance arrangement
Prioritized evacuation order, for the purpose of ensuring that vessels around theport evacuate promptly and safely, must be established. In addition, thearrangement of evacuation assistance—particularly required for large vessels(pilots, tugboats, mooring-line release workers, or others)—must have been
established and agreed upon.
Prioritized Evacuation Order: the order of vessels’ evacuation (offshore evacuation) in theevent of expected tsunami strike must be prepared. Such orders must be determined considering thefollowing:
・Port conditions or characteristics: what impact is expected on each of the quays in the port,
which quay is expected to suffer the most severe damage, and what impacts are
estimated on vessel-navigation areas and others.
・The severity of impact in the vicinity if the vessel is damaged.
・Kinds and extent of assistance vessels will require.
・The extent of difficulty vessels will have in navigation or maneuvering.
Because the risk of secondary disasters must be considered first, except in the case where
the port-parties themselves are concerned, agreement must be made on the order in which evacuation
will be carried out. The priority of evacuation should, in general, be ordered as below (but also
considering port-specific conditions and follow the agreement if any).
[1] Vessels loaded with dangerous cargo (LNG tankers, large LPG tankers, or crude-oil
tankers)[2] Vessels carrying passengers on board[3] Large vessels such as mega-ships[4] Other vessels; they should evacuate in order of largest to smallest.
Fishing boats, working boats, or pleasure boats are allowed to un-berth for offshore
evacuation by first-ready-first-go basis (boats can un-berth whenever they are ready to move), as
they are operated with different conventions from those for general vessels; however, they are
required not to interfere with large vessels maneuvering to unberth, or other vessels that areproceeding.
With regard to fishing ports, parties responsible for port management, such as Captain of theports or fisheries cooperative associations or other organizations, are recommended to prepare plansfor evacuation procedures or mooring enhancement, and to keep the skippers, crew members, andothers that use the port well-informed of all plans.
Furthermore, with regard to evacuation assistance—e.g. by pilotage services, tugboats,mooring lines release workers—for large vessels for unberthing or other maneuvers, agreement on-28-

the emergency operations of that assistance must be agreed upon for the purpose of ensuring smoothevacuation of large vessels in accordance with evacuation prioritization.
In addition, measures applicable to situations where sufficient assistance cannot be expectedmust be prepared because through assistance—by even a single tugboat, or, if vessels are equipped,with thrusters—the likelihood of successful unberthing is increased.
Furthermore, the head of Coast Guard Office/Station (Captain of the port) must provide
guidance for securing maritime safety when necessary.

(2) Agreements on voluntary evacuation measures, etc.
Agreements must be made in advance for the purpose of ensuring that vessels
voluntarily take the Tsunami Safety Measures shown in the table even without
having received recommendation of evacuation from the head of Coast Guard
Office/Station (Captain of the port).
Although vessels, in general, will take actions following the evacuation-recommendationfrom the head of Coast Guard Office/Station (Captain of the port), there is still a risk that time will
be taken for vessels to receive the recommendation because the Captain of the port, in principle,
issues its recommendation after receiving tsunami information. There is also a risk that a vessel will
fail to receive the recommendation due to trouble of communication infrastructure.
Therefore, vessels desirably should promptly take action following the Tsunami Safety
Measures table even if they have not received recommendation of Captain of the port—not waiting
for it—when getting tsunami information from TV broadcasts or other sources. For successful
voluntary evacuation, agreement on vessels’ voluntary evacuation must be made for individual ports.
Port authorities, organizations, and other parties concerned must routinely have meetings or consult
with one another to share information on what the tsunami measures table requires in the case of
their specific port.

(3) Port re-entry after the cancelation of a recommendation
Vessels, when re-entering a port following the cancelation of an evacuation
recommendation or other some such should pay attention to what damage port
facilities may have suffered and note whether fairways have been cleared. In
addition, if the chief of Coast Guard Office/Station (Captain of the port) has issued
guidance or other statement, vessels must obey.
In general, evacuation or other recommendations are cancelled when tsunami
warnings/advisories are cancelled. Vessels must pay as much attention as possible to the information
on what if any damage the port facilities have suffered, whether the fairways have been cleared,
what changes in water depth have occurred, and follow any traffic guidance given by the chief of-29-

Coast Guard Office/Station (Captain of the port). In order to prevent traffic congestion caused byvessels heading to the entrance to re-enter, vessel should obey the traffic guidance which the Captainof the port may issue.

-30-

<<Appendix>>
These materials will be useful in exploring Tsunami Safety Measures in a port.

1. Characteristics of Tsunami
1-1. What is a tsunami?
Tsunami is induced by earthquakes that occur under the ocean bed. The ocean bed,rising/sinking/sliding, causes the upward/downward motion of the water around the location of theearthquake outbreak; and, such water motion generates tsunami waves. The amplitude ofwater-surface motion (up and down) becomes larger as the tsunami waves come closer to coast. The
Japanese word “tsunami” is composed of “tsu” (meaning “port”) and the word “nami” (meaning“wave”), combining to mean “extraordinary waves striking a port.”
Tsunami generated at a distant coast (generally belonging to foreign countries), called“Far-field Tsunami,” take a long time to arrive at the coast of Japan. On the other hand, tsunami
generated near the coast of Japan, called “Near-field Tsunami”, take a relatively shorter time toarrive.
(1) Tsunami height
Tsunami height is defined as the difference between the sea-level elevated by tsunami andthe usual tidal level. Table 1 shows the definition for terms that characterize a tsunami/tsunami
incident. Figure 1 shows an illustration representing the relations between those terms. Figure 2
shows how the sea level varies due to a tsunami; and at the same time the tsunami period andtsunami height.
Usual Tidal Level
Tsunami Height
Inundation Height
Tsunami Trace Height(Run-up Height plus
Inundation Height)
Wave Height

Table 1: Tsunami Terminology
Predicted tide level, based on an analysis of past observations of tide level(Astronomical Tide Level). This corresponds to the tide level that is
expected if a tsunami does not strike.
Elevation of the sea level raised by tsunami measured from the usual tidal
level.
Water depth in tsunami flooded area: water surface elevation measured
from the ground
Elevation of tsunami trace measured from usual tidal level: it consists of
the run-up height and the inundation height of tsunami
The difference in the elevations of the consecutive water-level rise (crest)and fall (bottom): total amplitude-31-

Tide Station
Tsunami Height

Inundation
Depth

Trace Height

Run-UpHeightUsual Tidal Level (Estimated tidal levelin the case of no-tsunami influence)

Source: Meteorological Agency Web Pages

Figure 1: Illustrated Relation of the Terms Related to Tsunami Flood

Displacement of Tide Level

Elevation from Mean Sea Level
Total Amplitude
Mean sea level
Tsunami PeriodTime

Source: Japan Weather Association Web Pages

Figure 2: Height and Period of Tsunami(2) Magnitude of Tsunami
Table 2 shows the “Imamura-Iida Tsunami Magnitude”—tsunami magnitude (“m”)
class—determined through consideration of tsunami height at coastal regions and the length of thecoast where tsunami damages have been observed.

-32-

Table 2: Tsunami Magnitude Scale (Imamura-Iida Scale)Magnitude Scale

Tsunami Height

Total Energy

Damage Severity

22(10 erg)−1

Lower than 0.5 m

0.06

No damage0

Approx. 1 m

0.25

Very limited

1

Approx. 2 m

1

Coastal areas and ships

2

Approx. 4 to 6 m

4Limited damage on inland areas;casualties

3

Approx. 10 to 20

16

m
4

Higher than 30 m

Significant damages along the coastline: total length of 400 km or more

64

Significant damages along the coastline: total length of 500 km or more

Hatori has proposed a tsunami-magnitude formula as shown below that produces atsunami magnitude consistent with Imamura-Iida scale: the formula, using both tsunami run-up
height at the coast close to tsunami-wave origin and tide level records obtained over a wide area.
m＝2.7logH＋2.7logΔ－4.3

(1.1)

where
Δ(km): ocean-surface direct distance from epicenter to observation point on the ocean
surface. Note: the formula is effective for the distance range of 20 to 2,000 km.
H(cm): the maximum total-amplitude of the variations in tide-levels and tsunami
trace height observed at the distance of Δ.
On the other hand, Abe has introduced another scale, “Mt” which is represented by theformula shown below; Mt is also referred to as “tsunami magnitude.”Mt＝logH＋logΔ＋5.55

(1.2)

where
Δ(km): ocean-surface direct distance from epicenter to observation point on the ocean
surface,
H(m): the maximum tide level observed at the point of distance Δ. It correlates withtsunami magnitude at wave origin and the magnitude of fault motions thatcaused the earthquake.
Those two magnitudes, “Mt” and “m,” can be converted to each other through thefollowing equation:
Mt＝0.37ｍ＋7.1

(1.3)

-33-

1-2. Conditions of Tsunami Generation(1) Generation mechanism
Tsunami is generated by earthquakes; an earthquake occurs when the rock ground breaks
apart to form faults. Faults are categorized as shown in Figure 3.
Note the following remarks when considering tsunami generation:
・Tsunami are likely to break-out when a dip-slip fault, reaching the ocean bed, causes
ocean-bed displacement
・There are many dip-slip faults found in the ocean around Japan; therefore, it isrecommended to consider tsunami risk when an earthquake occurs in the ocean area.
・Note that an earthquake, even if its magnitude is small, can cause a big tsunami—this isoften called a “tsunami earthquake.”
Dip-Slip Fault

Normal Fault

Reverse Fault

Strike-Slip Fault

Right-Lateral Fault

Left-Lateral Fault

Figure 3: Types of Fault
In addition, tsunami can occur due to a vast amount of sediment falling into water, avolcanic eruption, or a meteor strike.
(2) Focal depth of an earthquake
Tsunami are induced by the movements of an ocean-bed rock ground with a vast amountof energy sufficient to shake the entire block of water from the bottom to the surface; therefore, anearthquake with a deeper focal point is less likely to cause a tsunami.
As a matter of fact, the analysis of historical earthquake records led to the following
conclusions: an earthquake with a focal depth deeper than 80 km rarely causes a tsunami; anearthquake with a focal depth of 50 to 80 km causes a relatively small tsunami; and, an earthquakewith a focal depth of 50 km or shallower causes a large tsunami. A Tokai earthquake or
To-Nankai/Nankai earthquake, which is predicted to occur in near future, unfortunately, is expected
to occur at a relatively shallow point under the ocean bed.

-34-

1-3. Tsunami Dynamics
1-3-1. Propagation
Tsunami waves, because they go through water, travel much more slowly than earthquake
ground-motions; therefore, tsunami arrives later than the earthquake in the case the epicenter occurs
far away.
In addition, because of their long wavelengths tsunami travel far with almost no
dissipation, conversely earthquake attenuate by distance.
Tsunami propagation velocity (wave velocity) is represented by the equation below:
H
(1.4)
V
where
V: Wave Velocity (m /sec)
g: Gravitational Acceleration (9.8 m/sec2)
H: Water Depth (m)Tsunami waves, as they are reaching shallow areas, increase in elevation, which isrepresented by the equation below; it is called “Green’s Law.” Refer Figure 4.
(1.5)
h ∝ 1⁄ √H
where
H: Water Depth (m)h: Wave Height (m)Water Depth
Wave Height
Propagation
Velocity(Wave
Celerity)
Illustrated
Relations of
Parameters

5,000 m
1.0 m
800 km/hour

500 m
1.7 m
250 km/hour

50 m
3.2 m
80 km/hour

10 m
4.7 m
36 km/hour≒ 19knot1m
8.4 m
11 km/hour≒ 5
knot

Green’s Law
For a wave, the product of the wave height andthe forth root of the water depth is a constant: it
indicates that a tsunami wave elevates higher at aplace where the water depth is shallower.
h2 (H2)1 / 4 = h1 (H1)1 / 4 = h0 (H0)1 /4= constant

Epicenter* A wave which has experienced a rise in its elevation of 1.0 m at a place where the water depth was
5,000 m elevates to the level of 8.4 m at a place where the water depth is 1 m.
Figure 4: Relation of Water Depth to Tsunami Wave Height/Velocity-35-

1-3-2. Flow speed of Tsunami Water
Flow speed of tsunami water (water particle velocity) while the tsunami is proceeding isrepresented by the equation shown below.
U

∙

⁄H

where
U: Flow Speed of Tsunami Water (m/sec): Elevation measured from Still-Water Level (m)g : Gravitational Acceleration (9.8 m/sec2)
H: Water Depth (m)Tsunami water, for example in the instance of a 2 m high tsunami at a water depth of 10 m,
flows approximately at a speed of 2 m/sec. It flows faster in places where the water depth isshallower, if the wave height is assumed to be constant.
1-3-3. Period of Tsunami Wave
The period of a tsunami wave varies depending on the following: the geographicalconditions of the area where the tsunami was caused, such as the dimensions of the area or water
depth; conditions of tsunami wave propagation, such as the distance from tsunami origin area; and,geography of the place struck by the tsunami, such as the topology of the bay.
The wave length of a tsunami is represented by the product of the wave velocity andperiod, as shown in the equation below.
L＝T・V

(1.6)

where,
L: Wave Length (m)T: Period (sec)
V: Wave Velocity (m/sec)
Note:・Tsunami period, in general, tends to be shorter at points where it is closer to the epicenterand longer at points where it is further.
・Tsunami period, in general, is in the range of a few minutes to a few tens of minutes.
・The specific periods of the bays often seen in Japan are also in the range of a few minutes
to a few tens of minutes; therefore, there is a risk that tsunami waves, resonating withthe bay, will elevate higher than predicted.
・With regard to a Tokai earthquake, its tsunami periods are estimated to be approximately
5 to 15 minutes.

-36-

1-3-4. Deformation of Tsunami
In general, ground displacement and initial tide-level displacement caused by anearthquake, being correlated with each other, share values of similar magnitude. On the other hand,tsunami heights at coast, being uncorrelated with initial ground displacement, can have values thatdiffer in the extreme from area to area.
(1) Influence of water-channel width
The wave-elevation of a tsunami that is proceeding in a bay with a geographicalconfiguration where the width becomes progressively narrower along its length from the entrance tothe far end will get higher according to the equation shown below.
h ∝ 1⁄√W(1.7)

where,
h: Wave Elevation
W: Bay Width (assumed that the water depth is constant)(2) Seiche (resonance effect)
Tsunami-wave amplitude grows at an accelerated pace when the period of tsunami-wave isclose to the periods of the tide-level oscillations that are likely to happen in port areas or bay: this isreferred to as “seiche” (resonance effect).
Long bays—with a relatively long depth compared with its width—are prone to resonate
with far-field tsunami such as Chilean Tsunami. On the other hand, short bays are prone to resonate
with near-field tsunami.
(3) Bore (staircase wave)
Staircase waves that resemble bores which are often seen at a large-river mouth caused by
the rising tide at spring tide have been observed as being caused by tsunami. Such staircase
tsunami-waves are known for having fierce destructive power.
(4) Tsunami-wave refraction
Tsunami waves reduce their velocity in shallow waters and change their direction in such a
way as to encircle the area of shallow waters. Thus, those tsunami waves can increase in elevation
after passing such shallow waters.
(5) Tsunami-wave diffraction
A tsunami wave that is proceeding in shallow waters propagates slower than whenproceeding in deep waters. Hence, tsunami waves, after passing shallow waters, change their course-37-

in such a way as to encircle the shallow waters, in a manner similar to a light ray being diffracted bya convex lens. Thus, tsunami waves can increase in elevation after passing shallow waters.
1-3-5. Forwarding/Back-drawing of Tsunami
A tsunami is referred to as “forwarding” when the sea level is rising and as “back-drawing”
when the sea-level is falling, at the time of the tsunami’s arrival (the first tsunami strike). In general,in the event of an earthquake, the ocean-bed, rising in some places and falling in others, raises orpulls-down the ocean surface. Whether a tsunami initially hits the coast while forwarding or drawing
back depends on the distribution of ridges and troughs at the source and the relative distance to theshore.
A tsunami, after striking a coast, goes back toward offing with their offing-end portion
going first, due to the slope of the water surface.
While the tsunami goes back toward offing, because the ground elevation is lower along
the tsunami retreating direction, the surface of the out-bound water is allowed to go down further
and make the front slope of out-bound tsunami steeper. Hence, the water flow of the tsunami gains
flow speed when the tsunami is retreating.
In addition, it must be noted that tsunami back-drawing lasts a relatively long time.

-38-

2. Past Tsunami-Damages
2-1. Tsunami Incidents
Details of major tsunami and damages occurred in the past along the coast or in thevicinity of Japan are listed in Table 3.

Table 3: Major Tsunami of Japan
Magnitude
TsunamiEarthquake
Scale
8.4
3

Casualties(Number ofDeaths)Date ofOccurrence

Area of Tsunami Origin

Nov. 29, 684

Tokai/Nankaido Offing

Jul. 13, 869

Sanriku Offing

8.6

4

SanrikuAug. 26. 887

Kii Offing

8.6

3

Shikoku/Kii/Osaka

Dec. 17, 1096

Tokai Offing

8.4

3

Suruga/Ise

Feb. 22, 1099

Nankaido Offing

8

3?

Nankaido

Aug.3, 1361

Kii Offing

8.4

3

Shikoku/Osaka

Sep.20, 1498

Tokai Offing

8.6

3

Tokai/Ise/Kanto

5,000

Feb. 3, 1605

Boso/Nankaido Offing

8

3

Tokai/Nankaido/Boso

3,800

Dec. 2, 1611

Sanriku Offing

8.1

4

Sanriku/Hokkaido

6,800

Nov.3, 1677

Boso Offing

8

3

Miyagi to Boso

500

Damaged Areas
Tokai to Nankaido

1,000

Dec.31, 1703

Near Boso

8.2

3

Southern Area of Kanto

5,233

Oct. 28, 1707

8.4

4

Tokai/Nankaido/Osaka

4,900

7.5?

3

Oshima/Tsugaru/Sado

1,467

7.4

4

Ishigakijima/Miyakojima

11,861

Dec. 23, 1854

Tokai/Nankaido Offing
South East Offing of
Hokkaido
Ishigakijima Offing,
Okinawa
Tokai Offing

8.4

3

Tokai/Ise/Kumano900

Dec 24, 1854

Nankaido Offing

8.4

3

Nankaido/Osaka

3,000

Aug. 29, 1741
Apr. 24, 1771

Jun. 15, 1896

Sanriku Offing

7.6

3 to 4Sanriku/Hokkaido

27,172Mar. 3, 1933

Sanriku Offing

8.3

3

Sanriku/Hokkaido

3,008

Dec. 7, 1944

Kumano-Nada

8

2.5

Mie

998

Dec. 21, 1946

Kii Offing

8.1

2.5

1,330

May 24, 1960

South Offing of Chile

9.4

4

May 26, 1983

Akita/Aomori Offing
South West Offing of
Hokkaido

7.7

3

Shikoku/Wakayama
Whole of Pacific Coast ofJapan
Tohoku/Hokkaido

7.8

3

Okushiri-Island/Hokkaido

230

Tohoku/Kanto Offing

94

Aomori to Ibaraki

Jul. 12, 1993
Mar. 11, 2011

142
100

Approx.
20,000Source: “Natures and Disasters of the Sea,” by Sanae Unoki-39-

2-2. Tohoku Pacific-Offing Earthquake
The following is the summary of the Tohoku Pacific-Offing Earthquake (Widely known as"the Great East Japan Earthquake"), based on releases by the Meteorological Agency:

1. Summary of the Earthquake (by the Meteorological Agency)
2011 Tohoku Pacific Offing Earthquake(1) Date of Occurrence: Around 14:46 , March 11, 2011(2) Source and Magnitude (estimated)
Location: Sanriku Offing (38.1 degrees N, 142 degrees E, at around 130 km ESEof Oshika-Peninsula), approx. 24 km deep
Magnitude: Mw 9.0 (Moment Magnitude)
Fault Dimensions: Approx, 450 km long and 200 km wide
Fault Slip-Distance: Approx. 20 to 30 m (maximum)
Ocean-Bed Displacement (directly above the earthquake source):
Approx. 24 m to ESE, Approx. 3m Lift (Japan Coast Guard’s Releases: April 6, 2011)(3) Seismic Intensity Observations
The intensity observations of more than upper-5 are listed below:
Intensity 7: Northern Miyagi

Intensity 6 upper: Southern/Middle Miyagi;
Naka-dori/Hama-dori, Fukushima;Northern/Southern Ibaraki;Northern/Southern Tochigi

Intensity 6 lower: South Coast/Northern Inland/Southern Inland, Iwate;
Aizu, Fukushima;
Southern Gunma:
Southern Saitama;
North-West Part of Chiba

Intensity 5 upper: Sanpachi-Kamikita, Aomori;Northern Coast, Iwate;
Southern Coast/Inland, Akita;
Murayama/Okitama, Yamagata;
Northern Gunma; Northern Saitama;
North-East Part/South Part of Chiba;
Tokyo’s 23 Wards;
Niijima-Island, Tokyo;
Eastern Kanagawa;-40-

Middle/West Part of Yamanashi;
Eastern/Fuji-Five-Lake Area, Yamanashi(4) Tsunami
・1449 hrs, March 11: Major Tsunami Warning Issued
・1758 hrs, March 13: All warnings/advisories, Cancelled
Tsunami Observations (at Tide Stations)
Shoya, Erimo:

3.5 m Maximum, at 1544 hrs

Miyako:

8.5 m or over Maximum, at 1526 hrs

Ofunato:8.0 m or over Maximum, at 1518 hrs

Kamaishi:

4.1 m or over Maximum, at 1521 hrs

Ayukawa, Ishinomaki:

7.6 m or over Maximum, at 1525 hrs

Soma:

9.3 m or over Maximum, at 1551hrs

Oarai:

4.2 m Maximum at 1652

Source: Compiled from “Handout 1 at the May 28, 2011, 1st Expert Panel on Earthquake/Tsunami Measures
Reflecting the Lessons of Tohoku Pacific Offing Earthquake”-41-

3. Earthquakes Predicted in Future
Figure 5 shows the earthquakes that have been subjected to discussion at the Central
Disaster Prevention Council. Their future occurrence in the vicinity of Japan has been predicted.

Tokai Earthquake
Occurrence Probability in 30 Years: 88 %Chishima Trench
Tonankai / Nankai Earthquake
Occurrence Probability in 30 years:
Around 70 % for Tonankai Earthquake,
Around 60 % for Nankai Earthquake

Trench-type Earthquake
around Japan Trench /Chishima TrenchJapan
TrenchNear-Field Earthquake in Chubu /Kinki Area

Occurrence Probability in 30 years:
Unknown(99 % for an earthquake in Miyagi offing,estimated before the occurrence of
Tohoku Pacific Offing Earthquake)

Near-Field Earthquake inMetropolitan Area
Occurrence Probability in 30 years:
Around 70 % for an M7-class earthquake
Trench-Type Earthquake in South Kanto Area

Nankai TroughNear-Field Earthquake

The earthquake-occurrence probabilities shownin the map above are those released by the
Headquarters for Earthquake Research
Promotion (as of January 1, 2012)

Source: Cabinet Office Webpages

Figure 5: Large-Scale Earthquakes Subjected to Discussion at the Central Disaster Prevention
Council-42-

4. Understanding of Mooring Criteria (Critical Conditions)
Table 4 shows the mooring criteria presented at the “Research Committee of Navigation
safety Measures at the time of tsunami strike” (held in FY2012 and 2013). The criteria were derived
from the output of simulations on quay models and vessels (large vessels carrying dangerous cargo(VLCCs and LNG tankers) and general vessels (10,000 DWT-class and 3,000 DWT-class) moored at
the quays) for the various values of tsunami height or flow speed.
Summary:
The simulations were conducted for determining mooring criteria on a port model(Shimizu Port was used as the model) applying hypothetical waves of tsunami
wave-form or sine waves. The derived mooring criteria of tsunami height areapproximately 1 to 3 meters for VLCCs or large LNG tankers, and approximately 3
to 6 meters for 10,000 or 3,000 DWT-class vessels.
The findings of these tsunami simulations, where various tsunami waves—hypotheticaltsunami-waves or sine waves (period of 5, 10, and 15 minutes)—of different combinations ofwave-height and flow speed were applied to the Shimizu-Port model. The findings were as follows:(a) Mooring criteria for tsunami height goes down when the effect of flow speed, in addition tothat of tsunami height, is not negligible;(b) Mooring criteria gets lower for a shorter tsunami period; it indicates that the rapid rate ofwater-level rise, as well as the tsunami height, influences the mooring criteria.
With regard to the conditions—sea-level lift or the form (tsunami wave or sinewave)/amplitude/ period of tsunami—where the mooring force of model ships reaches its criticalvalues, the results of the simulations are summarized as follows:
For VLCCs or large LNG tankers, in the case where waves of tsunami wave-form wereapplied, the mooring force reaches its critical value for the sea-level lift of 3 meters in the directionof ship center-line, and for the sea-level lift of 1 meter in ship-beam direction. In the case where sine
waves are applied, the mooring force reached its critical value for waves of amplitude of 1 meter anda period of 5 minutes; for waves of amplitude of 2 meters and a period of 10 minutes; and, for awave of amplitude of 3meters and a period of 15 minutes.
For 10,000 DWT or 3,000 DWT-class vessels, in the case where waves of tsunami
wave-form are applied, the mooring force reached its critical value for sea-level lift of 6 meters inship center-line direction; and in the case where sine waves were applied, the mooring force reached
its critical value for waves of amplitude of 3 meters and a period of 10 minutes and for the waves ofamplitude of 6 meters and a period of 10 or 15 minutes.
When the mooring criteria are applied to practical situations, the following should be
noted:-43-

In general, the period of tsunami wave is within the range of several minutes to several
tens of minutes, and tends to become shorter as the observation point comes closer to the wave
source—meaning that the rate of water level rise is larger, and longer as the observation point gets
further away— meaning that the rate of water level rise is smaller.
Take the Nankai Trough Earthquake as an example: the three major bays, Tokyo Bay, Ise
Bay, and Osaka Bay, are far enough away from the possible earthquake source so that the periods oftsunami will be longer. This means that the rate of water-level rise will be small. Consequently,
mooring criteria are expected to be larger than the values shown above.
In addition, it should be noted that the mooring criteria introduced above were derived
from simulation output based on the assumptions that vessels are moored by regular mooring
methods. Therefore, in actual situations, the measures for enhancing mooring forces, such as the
addition of mooring lines, particularly breast lines/spring lines, and tightening of the mooring-drumbrakes, are expected to raise the mooring criteria (critical values).
Figure 6 shows “Critical Conditions Causing Spring-Line Break-Downs,” presented in the“Research Report on the Measures for Securing Vessels in a Situation of Tsunami Risks” released in
FY2003; the diagram shows the critical water-level lift and the critical tsunami-water flow-speed, fordifferent types of vessels that are moored by usual mooring methods and suffering water-level lift

Water-Level Liftand flow pressure at the same time, due to a tsunami of a period of 10 minutes.

Water-Flow Speed

Figure 6: Critical Conditions for Causing Spring-Line Break-Down-44-

Table 4: Mooring Critical Conditions of Vessels Caused by Hypothetical Sine-Wave Tsunami
Large LNG Tankers-45-

5. Understanding of Anchoring Criteria (Critical Conditions)
In addition to the mooring criteria previously described, the “Research Committee of
Navigation safety Measures at the time of tsunami strike” held in FY2012 and 2013 presented the“Anchoring Criteria” (critical conditions for anchoring). The criteria were derived from calculationsof critical tsunami-flow speed, at which the external force that the tsunami places on the vessel
overcomes the anchor force and the vessel begins to move dragging its anchors. The criteria (criticalconditions) are presented below and summarized in Table 5 and Table 6. Equation 2-1 and Equation
2-2 are the equations that were applied to the calculations of such critical conditions; the parametersthat were set for the calculations are summarized in Table 7.
Conclusions:
In the case where an anchoring vessel is hit by tsunami, the critical conditions foranchoring are the following: tsunami-water flow speed is approximately 3 to 6
knots, and approximately 2 to 4 knots on the assumption that swinging angle issupposed to 15 degrees.

Table 5: Anchoring Criteria for Tsunami-Water Flow Speed
Unit: knots

TsunamiHeight: 0
meters

TsunamiHeight: 5
metersAnchor:
JIS-Type
Anchor:
AC14Type
Anchor:
JIS-Type
Anchor:
AC14Type

500DWT

3,000DWT

10,000DWT 30,000DWT 60,000DWT 200,000DWT 100,000DWT 300,000DWTGeneralVesselGeneralVesselGeneralVesselGeneralVesselGeneralVesselGeneralVessel

Mud

4.62

4.02

3.60

3.38

3.15

3.17

3.28

3.28

Sand

4.83

4.21

3.77

3.54

3.29

3.32

3.45

3.43

Mud

( 6.70 )

5.87

5.24

4.91

4.53

4.57

4.75

4.73

Sand

( 5.72 )

5.00

4.47

4.20

3.89

3.92

4.08

4.06

Mud

4.51

3.93

3.53

3.31

3.10

3.12

3.23

3.23

Sand

4.74

4.14

3.72

3.49

3.25

3.28

3.41

3.39

Mud

( 6.59 )

5.77

5.16

4.84

4.48

4.51

4.70

4.67

Sand

( 5.63 )

4.93

4.41

4.14

3.85

3.88

4.04

4.02

-46-

Vessels
Vessels
Carrying
Carrying
Dangerous Dangerous
Cargo (LNG
Cargo
Tanker)(VLCC)

Table 6: Anchoring Criteria for Swinging Situation
Unit: knots

Anchor:
JIS-Type
Swing:
0 deg

Anchor:
AC14Type
Anchor:
JIS-Type

Swing:
5 deg

Anchor:
AC14Type
Anchor:
JIS-Type

Swing:
10 degAnchor:
AC14Type
Anchor:
JIS-Type

Swing:
15 degAnchor:
AC14Type

500DWT

3,000DWT

10,000DWT 30,000DWT 60,000DWT 200,000DWT 100,000DWT 300,000DWTGeneralVesselGeneralVesselGeneralVesselGeneralVesselGeneralVesselGeneralVesselVessels
Carrying
Dangerous
Cargo (LNG
Tanker)

Vessels
Carrying
Dangerous
Cargo(VLCC)

Mud

4.51

3.93

3.53

3.31

3.10

3.12

3.23

3.23

Sand

4.74

4.14

3.72

3.49

3.25

3.28

3.41

3.39

Mud

( 6.59 )

5.77

5.16

4.84

4.48

4.51

4.70

4.67

Sand

( 5.63 )

4.93

4.41

4.14

3.85

3.88

4.04

4.02

Mud

4.20

3.66

3.29

3.08

2.88

2.90

3.01

3.00

Sand

4.41

3.85

3.46

3.25

3.03

3.05

3.17

3.16

Mud

( 6.14 )

5.37

4.81

4.51

4.17

4.21

4.38

4.35

Sand

( 5.25 )

4.59

4.11

3.86

3.58

3.61

3.76

3.74

Mud

3.54

3.08

2.77

2.60

2.43

2.45

2.53

2.53

Sand

3.72

3.25

2.91

2.73

2.55

2.57

2.67

2.66

Mud

( 5.17 )

4.52

4.05

3.80

3.51

3.54

3.69

3.67

Sand

( 4.42 )

3.86

3.46

3.25

3.02

3.04

3.17

3.15

Mud

2.98

2.60

2.34

2.19

2.05

2.06

2.14

2.14

Sand

3.14

2.74

2.46

2.31

2.15

2.17

2.26

2.25

Mud

( 4.36 )

3.82

3.42

3.20

2.97

2.99

3.11

3.09

Sand

( 3.73 )

3.26

2.92

2.74

2.55

2.57

2.68

2.66

Note: In the table above, the parenthesized values are shown for a 500 DWT-class vessel with AC14-type anchors,
only for the purpose of comparing them to those of other combinations of vessel-class and anchor-type; however, it israre for a 500 DWT-class vessel to have AC14-type anchors.

-47-

[Equation for Vessel Holding Power]

P=ωa・λa+ωc・λc・l（Eq. 2-1）

where
P (tons): Vessel Holding Power(calculate Tsunami Flow Speed (V) assuming P as Fx)
ωa(tons)：Anchor Weight
λa：Anchor Holding Power Coefficientωc（tons /m）：Unit Anchor-Cable-Weight (tons/m)
λc：Anchor-Cable’s Frictional Resistance Coefficientl(m): Anchor-Cable’s Contact Length to the Bottom
Source: “Navigation Handbook” by Keinosuke Honda[Equation for Fluid Pressure]

Fx=Cxc・（ρc／7600）
・Lpp・D・V2（Eq. 2- 2）

whereFx(tons)：Tsunami Fluid Pressure on the Hull Front-Surface
Cxc：Longitudinal Fluid Pressure Coefficientρc（kg・sec2/m4）：Water Density（＝0.1248）
Lpp（m）：Length Between Perpendiculars
D（m）：Draft
V（m/sec）：Tsunami Flow Speed
Source：Prediction of Wind and Current Loads On VLCCs（by OCIMF）
With regard to the behaviors and characteristics of an anchor while the vessel is anchoring,
the research so far has reported the following:(a) JIS-type ship anchors, after moving on the bottom for a distance of 10 to 20 times longer
than its fluke length, are prone to tumble upside-down with its flukes up off the bottom. Herethe anchor’s holding power coefficient is drastically decreased and the vessel is likely to movedragging its anchors. (see Ref. (1))(b) Ship anchors, for example AC14-type anchors, that have stabilizers with proper areas, after
moving for a distance approximately 6 times longer than its fluke length with any attitude on
the bottom, easily cut into the bottom to gain stability and the state of maximum holding
power is secured. (see Ref. (2))(c) Anchor holding power depends on characteristics and strength of the sea bottom. Sandbottom will, as easily predictable, lends very low holding power to an anchor. On the other-48-

hand, mud bottom, because its dynamic characteristics heavily depend on the stiffness of mud,gives an extremely strong grip to an anchor in some cases, and insufficient grip in other cases.
(see Ref. (3))<<References>>(1): URA, Tamaki; and YAMAMOTO, Yoshiyuki: “A Basic Study on the Stability of Anchors”: Journal of
the Society of Naval Architects of Japan; Vol. 140, 1976; pp. 279-285(2): URA, Tamaki; and YAMAMOTO, Yoshiyuki: “A Basic Study on the Stability of Anchors (3 rdReport)”: Journal of the Society of Naval Architects of Japan; Vol. 146, 1978; pp. 196-200(3): URA, Tamaki: “How can we rely on anchors? (1st)”: Kaigi-to-Juken (Maritime Technology and Ship
Officer’s Certification Test Preparation): No.1, 1981; pp. 34-39-49-

Table 7: Parameter Settings for Calculating Vessel Holding Power
Vessel Class (DWT)

500

3,000

10,00030,00060,000200,000

Vessel Type

GeneralVesselGeneralVesselGeneralVesselGeneralVesselGeneralVesselGeneralVessel

50
45
11
5
1
3
460
1,100
0.08
900
675
12.6

80
75
13
6
0.5
5
1,600
3,700
0.08
1,920
1,440
25.3

113
107
19
10
1
8
6,000
13,500
0.08
3,540
2,655
46.3

170
164
27
14
2
10
18,00036,800
0.08
6,000
4,500
78.8

200
190
32
18
2.5
13
35,00051,700
0.08
7,800
5,850
101.3

3.5/3.0

3.5/3.0

3.5/3.0

3.5/3.0

7/10

7/10

7/10

0.75/1.0

0.75/1.0

135
15
5.0

Length (m)Length Between Perpendiculars (m)Molded Breadth (m)Molded Depth (m)Bell-Mouth Height (m) *1
Full-Load Draft (m)Gross Tonnage (GT)
Full Load Displacement (MT)Longitudinal Fluid Pressure Coefficient *2
Weight of JIS-type Anchor (kg) *3
Weight of AC14-type Anchor (kg) *3
Unit Anchor Cable Weight (kg/m)
Holding Power Coefficient of JIS-type Anchor(Sand/Mud) *5
Holding Power Coefficient of AC14-type
Anchor (Sand/Mud) *5
Frictional Resistance Coefficient (Sand/Mud)*6
Length of Anchor Cable (m) *7
Water Depth (m)Draft to Water-depth Ratio (Full-Load
Draft/Water Depth)

300
292
50
24
3
18
102,000
235,600
0.08
16,90012,675219.0

100,000
Vessel Carrying
Dangerous Cargo(LNG Tanker)
315
302
50
27
7.5
12
135,000
143,400
0.08
12,9009,675
165.8

300,000
Vessel Carrying
Dangerous Cargo(VLCC)
333
324
60
29
4.3
20.5
160,000
342,000
0.08
23,00017,250299.8

3.5/3.0

3.5/3.0

3.5/3.0

3.5/3.0

7/10

7/10

7/10

7/10

7/10

0.75/1.0

0.75/1.0

0.75/1.0

0.75/1.0

0.75/1.0

0.75/1.0

135
15

150
20

150
20

180
30

180
30

180
30

180
30

3.0

2.5

2.0

2.3

1.7

2.5

1.5

Notes:*1: Calculated on the assumption that the bell-mouth height is (molded depth – full load draft)/2.
*2: Referencing the OCIMF-proposed longitudinal fluid-pressure coefficient at the relative flow direction (bearing angle from ship bow) of 0 degrees*3: Referencing the anchor weight designated in C27.1 of Class NK. The weight of an AC14 type anchor is assumed (as a high holding-power anchor) to be 75 % of a JIS-type anchor.
*4: Calculated by applying the value of a cable diameter derived through referencing the nominal diameter “dc” specified in C27.1 of Class NK to the anchor-cable unit weight (kg/m)
formula specified in JIS F 3303 (chain specification), W = 0.0219 dc2 , where W is the anchor-cable unit weight (kg/m), and dc is the nominal diameter of anchor cable.
*5: Using, as a reference, the nominal value of holding-power coefficient for an anchor of different type shown in the “Navigation Handbook.”*6: Using, as a reference, the frictional resistance coefficients of sand or mud against a vessel in a holding state, which are shown in the “Navigation Handbook”*7: Calculated by using an equation for the determination of anchor cable length for a vessel to anchor—S = 3D + 90, where “S” is the anchor-cable length in meters and “D” is the water
depth in meters; the formula is shown in the “Navigation Handbook.”-50-

6. Guide to the Estimation of Critical Maneuvering Conditions
When a vessel is caught in a situation where it is hit by tsunami waves, it is important tobe able to judge whether it can afford to make a sheltering in the offing. Thus it is important to know
the impact tsunami waves will have on a vessel proceeding in relatively shallow waters
inside/outside port toward the offing to evacuate. For instance, the vessel may risk touching bottom
because the occurrence of touching bottom depends on the height of back-drawing tsunami, thevessel’s draft, or water depth. Alternatively, the vessel may lose control or be put into a situation
where it has to override breaking waves.
(1) Rough estimation on the critical conditions for course keeping
Figure 7 shows the results of calculations on critical tsunami-wave relative direction andflow speed within the range marked-out by the line showing the relation between the critical tsunami
relative direction-angle and the flow speed. A vessel trapped in tsunami in this way may be able tomaintain its course, given the following assumptions:
The vessel is an general cargo vessel;
The tsunami, coming diagonal onto the vessel’s bow, causes a rotational moment on thevessel;The vessel, using its rudder, tries to keep its course;
The vessel uses its usual rudder angle of 15 degrees, because it has to leave room for
rudder angle so that it is able to change, as well as to keep, its course;
Tsunami flow speed is represented by its ratio to the vessel speed, because, against atsunami wave of the same flow speed, a vessel proceeding at a faster speed is able toeasily keep its course.
Note: A tsunami wave with a height of 2 meters, when travelling in water of a depth of 10
meters, will flow at a speed of 1.98 m/s (approx. 3.85 knots). The diagram indicates that a vessel
proceeding at 11.55 knots—3 times faster than that of tsunami flow speed—will be unable to keep
its course by a steering of a rudder angle of 15 degrees, against a tsunami coming from the direction
angle of 78 degrees. An angle of 7 to 8 degrees is similar to the heading fluctuation, even in a normal
situation, that vessels, when proceeding straight with an attitude of receiving waves from a diagonal
direction, are likely to experience. Therefore, vessels in tsunami waves are recommended to proceed
at a faster speed and as parallel as possible to the tsunami wave flowing direction.

-51-

(Vessel Speed)(Flow Direction)(Flow Speed)

Water Flow Direction α (deg)Keeping Course Unattainable

Keeping-Course Attainable

Ratio of Vessel Speed to Flow Speed (V / U)
Figure 7: Critical Conditions for Vessel Course Keeping

where
U

∙

⁄H

U: Tsunami water flow speed (m /sec)
η: Wave-surface elevation above still-water level,g: gravitational acceleration (9.8 m/sec2),
H: Water depth (m)With regard to small vessels, it can be said that, while fishing boats or pleasure boats havegood maneuverability, working boats or boats towing others lack maneuverability or speed so thatthey are likely to get trapped in critical situations and be unable to keep their course in much lesssevere conditions of tsunami flow direction or speed than general cargo vessels.

-52-

In addition, low-speed vessels, in particular, when encountering unbroken tsunami waves
may lose ground speed being carried back by flowing tsunami, even if they, intending to override
tsunami waves, try to proceed in a direction perpendicular to the tsunami wave-lines; and as a result
get trapped in a dangerous situation.
(2) Guide to the estimation of critical conditions for small vessels in broken waves(Skipped)-53-

7. Tsunami Information
7-1. Information released by the Meteorological Agency
The Meteorological Agency, when an earthquake occurs in Japan or in the vicinity ofJapan, immediately analyzes the seismometer data that is transmitted to the agency on a real timebasis, and then promptly releases an earthquake early-warning, a tsunami warning/advisory,
earthquake information, or other. Such information is delivered to the authorities or organizations
that are in charge of disaster prevention through ground-based commercial communication lines thaton-line connect the agency to those organizations or the EM-Net. Then, local residents or vessels get
informed of such tsunami information through such organizations or by news media.
With regard to a tsunami induced by an earthquake occurring in a foreign country, theagency, closely communicating with the Pacific Tsunami Warning Center (PTWC) in Honolulu,
releases a tsunami warning/advisory. In addition, with regard to a tsunami induced by an earthquakethat occurs in the Japan Sea, the agency provides foreign organizations or governments with tsunami
information including its predicted height and arrival time.
Because earthquake early-warnings or tsunami warnings/advisories need to be released as
early as possible the agency has installed the Earthquake Phenomena Observation System (EPOS) at
its headquarter (Tokyo) and Osaka District Meteorological Observatory for the purpose of enabling
the start of analyses and identification of earthquake-source location and magnitude automatically
immediately after earthquake occurrence.
7-1-1. Tsunami Forecast System(1) Tsunami forecast release scheme
As early as in 1952, the tsunami forecast scheme was established by law for the purpose of“tsunami judgment” (identification or prediction of tsunami magnitude or risk) and the delivery oftsunami forecasts.
By 1986, the development of a data-communications network for the delivery of tsunami
information was completed.
In 1987, the Meteorological Agency installed the Earthquake Phenomenon Observation
System (EPOS). In the system computers fully-automatically conduct a full sequence fromearthquake detection to the identification of source.
In 1999, the system was enhanced through the employment of tsunami numericalsimulation technologies. The enhanced system enabled the agency to release tsunami information
including specific numerical vales on tsunami height and to release highly accurate quantizedtsunami information to the 66 forecast-areas nationwide, which were determined based on prefecture.
The previous 18 forecast areas were more finely segmented into these 66 areas.

-54-Moreover, in 2009, the whole tsunami-forecast operation scheme was transformed so thatthe two headquarters, Tokyo and Osaka, were responsible for tsunami forecast operations. Previously,
six forecast units, located in Sapporo, Sendai, Tokyo (Headquarter), Osaka, Fukuoka, and Okinawa,
had been in charge of the forecasts for the regions assigned to them.
Generally, tsunami forecasts are released according to the following sequence: in the firstpreliminary stage, tsunami databases are created identifying faults that are likely to cause tsunami;
numerical simulations are applied to those fault examples and the results are stored in a database;when an earthquake occurs, the database is consulted to immediately retrieve instances of tsunami
behaviors (simulation results) sharing similarities with the actual earthquake in terms of source andmagnitude. In such a way, prompt releases of tsunami warnings/advisories to coastal areas facing
tsunami risk are enabled.
(2) Tsunami forecast area and Tsunami Forecast Center, the section in charge of tsunami forecast
The Meteorological Agency, at the same time when releasing a tsunami warning/advisory,
makes a notice on the predicted tsunami height and arrival time at each of the 66 tsunami-forecast
areas nationwide—covering Japan’s entire coast line. Those tsunami forecast areas are set based onstudies on the areas’ specific tsunami behaviors that are significantly affected by the geographicalconditions of coast areas. Then, considerations are made on what actions the local authorities andorganizations in charge of disaster prevention should take.

-55-

7-1-2. Tsunami forecast and tsunami information[1] Types, timing, and content of tsunami information
Release of Earthquake / Tsunami Information
Event: Outbreak ofan Earthquake
Releasing: Earthquake Early Warning
In case of seismic intensity 5 or greater

Releasing: Early Report on
Seismic Intensity *1
In a case of seismic intensity 3
or greater

Situation: No risk of tsunami
disaster

Situation: Risk of Tsunami
Disaster Predicted

Case: Sea-Level
Change Predicted

Releasing: Tsunami Warning /Advisory *1
Releasing: Tsunami Forecast *3
Adding: Small Sea-level Changes
Predicted

Releasing: Predicted Tsunami
Arrival Time / Height
Releasing: Specific Places’ High
Tide Time / Estimated Tsunami
Arrival Time

Releasing: Seismic
Source / Intensity
Even in a case of noobservations of seismic
intensity 1 or greater
Specific Places’
Seismic Intensity
In a case of seismic
intensity 1 or greater

Releasing: Estimated Seismic
Intensity Distribution Map
In a case of seismic intensity 5
or greater

Releasing: Tsunami Observationsin the Offing
Releasing: Tsunami Observations

Case: No Tsunami
Predicted

Releasing: Earthquake
SourceIn a case of seismic intensity
3 or greater
Adding: Small Sea-level
Changes *2

Releasing: Earthquake
Source,In a case of seismic intensity
3 or over
Adding: No risk of
Tsunami Predicted

Releasing: Earthquake
Source / Seismic Intensity
Even in a case of noobservations of seismic
intensity 1 or greater

Releasing: Earthquake
Source / Seismic Intensity
In a case of Seismic
intensity 3 or greater

Adding: Small Sea-level
Changes *2
Releasing: Specific Places’
Seismic Intensity
In a case of seismic intensity
1 or greater,
Adding: Small Sea-level
Changes *2
Releasing: Tsunami
Forecast *2
Adding: Small Sea-level
Changes Predicted

Adding: No risk of
Tsunami Predicted
Releasing: Specific Places’
Seismic Intensity
In a case of seismic
intensity 1 or greater
Adding: No risk of
Tsunami Predicted

Releasing: Estimated Seismic
Intensity Distribution Map
In a case of seismic intensity 5
or greater

Releasing: Estimated Seismic
Intensity Distribution Map
In a case of seismic intensity 5
or greaterNote:*1: A tsunami warning / advisory can be released earlier than early seismic intensity reports
according to the situation*2: In this situation, the announcement should be made as follows: at first, the earthquake
information with a comment stating that, although small changes in the sea level may beobserved, no risk of tsunami damage is expected; and, then, in the tsunami forecast that
follows the earthquake information, the names of tsunami-forecast areas where sea-levelchanges are predicted.
*3: In this situation, the comment “small sea level changes are predicted” is delivered evento the tsunami forecast areas that are not the targets of tsunami warning / advisory.

Source: Meteorological Agency’s web pages
Figure 8: Information on tsunami and earthquakes-56-[1] Tsunami warning/advisory
Tsunami warnings (major tsunami warning/tsunami warning) or tsunami advisories are
released in a situation of tsunami-disaster risk predicted, within a rough target range ofapproximately 3 minutes (according to the situations of earthquake, within 2 minutes).

Table 8: Standards for Tsunami Warnings/Advisories: Release Criteria, Contents, andAnnouncement Phrase
Tsunami Height
Type of
Information

Major
TsunamiWarning*

TsunamiWarningRelease Criteria

Tsunami-height ofover 3 meters atthehighest,predicted

Predicted
maximumtsunami height ismore than 1 m
and less than orequal to 3 m

Numerical Expression(Class of Predicted
Tsunami Height)“Over 10 meters”( 10 m < P.H. )P.H.: Predicted Height“10 meters”(5 m < PH ≦10 m)

VerbalExpression
for Major
Earthquakes“Major”“5 m”(3 m < P.H. ≦5 m)“3 m”(1 m < P.H. ≦3 m)“High”

Announce Phrases for Predicted
Damage and Recommended
Actions“ Wooden houses will becompletely destroyed or swept
away. Humans will be caught intsunami-water flow.
People in coastal areas or on
river
banks,
immediately
evacuate in safe places. Hurry
to
high
land
or
a
tsunami-shelter building.”“Low elevation areas will be
flooded by tsunami water andsuffer inundation damage.
Humans will be caught up in
tsunami-water flows. People incoastal areas or on river banks,
immediately evacuate in safe
places. Hurry to high land or atsunami-shelter building.”

Predicted“People at sea may be caught
maximum
up in fast flowing tsunami
tsunami-height iswater; farming rafts may be
more than 0.2 m“1 m”
Tsunami( Not
washed away; small vessels
and less than orAdvisory
Applied)may be capsized.
(0.2 ≦P. H. ,≦ 1 m)
equal to 1m; andPeople at sea, immediately
risk of tsunami
return to land, and go awaydamageisfrom the coast.”
expected* A Major Tsunami Warning is designated as “special warning.” The Meteorological Agency, on Friday August 30,
2013, initiated the operation of “special warning”; the agency releases a special warning for an extraordinary natural
phenomenon that the usual waning release criterion is unable to cover. The release criteria of a special warning aredetermined through consultation with governors, and municipal mayors who are in charge of disaster prevention in
local areas.

Source: Meteorological Agency’s web pages-57-[2] Tsunami advisory
A tsunami advisory is released where a risk of tsunami disaster is no longer expectedfollowing the earthquake occurrence; a tsunami advisory includes the information shown in Table
15.

Situation of Release
No tsunami risks are expected.
A sea-level change of less than
0.2 m is predicted.
Sea-level changes have lasted
even after the tsunami advisory
was canceled.

Table 9: Tsunami Advisory
Announce Phrase“Earthquake information is released as follows, including thestatement that no tsunami risk is expected.”“No special care against tsunami disaster is required;sea-level change is predicted less than 0.2 m at the highest.”“Sea-level changes due to tsunami have been observed, andare predicted to last; people working at sea, fishing, orbathing are recommended to pay sufficient attention.”
Source: Meteorological Agency’s web pages(2) Types and announcement of tsunami information
Tsunami warnings/advisories, when released, must be followed by tsunami informationthat includes the predicted arrival time, tsunami height, and other information.

Table 10: Types and Announcement of Tsunami Information
Information Category
Announce Phrase“Predicted arrival time and height at the individual
tsunami-forecast areas, is released as follows.” (Note: theInformation on predicted tsunami items of announcement are specified in Table 8)
arrival time/height“The predicted tsunami arrival time is the earliest for thetsunami-forecast areas. Tsunami may arrive more than one
hour later to some areas.”
Time of high tide and predicted“Time of high tide and predicted tsunami arrival time attsunami arrived time at specificrepresentative points is released as follows.”
places“Tsunami height observations and time at coasts are released
Tsunami observations (*1)
as follows.”“Tsunami height observations and time in the offing, andTsunami observations in the estimated tsunami arrival time and height from suchoffing (*2)
observations is released as follows for the individual
tsunami-forecast areas.”Note:*1: The tsunami-observation information includes the following: the arrival time and behavior (forwarding orback-drawing) of the tsunami first strike, and the maximum height and time of tsunami observations by the timeof the information release.
*2: The information on tsunami observations in the offing includes the following: the observation time of the tsunami
first strike observed in the offing and its behavior (forwarding or back-drawing), and the observation time andheight of the maximum tsunami-wave observed in the offing at each observation point by the time of theinformation release. In addition, the arrival time of the first strike on coast/the arrival time and height of the
maximum wave estimated from the observations in the offing is released for the individual tsunami-forecast
area.

Source: Meteorological Agency’s web pages-58-

7-1-3. Distribution of Tsunami Forecast/Information and Channels
The Meteorological Agency, for the purpose of alleviating the impact of earthquake
disasters, monitors earthquakes and tsunami on an around-the-clock basis, releases information
promptly on the occurrence of earthquakes or tsunami, and releases predictions for and observationsof the earthquake or tsunami. Such early information immediately after the occurrence of anearthquake ensures the authorities or organizations in charge of disaster prevention can take action.
In addition, the agency, following the Basic Act on Disaster Control Measures and theMeteorological Service Act, promptly distributes such information to the organizations concernedand news media to local residents and vessels for their information.
Creation Flow and Distribution Channels of Earthquake/Tsunami Information
Seismic Intensity
Earthquake Wave-Form
Tsunami Wave-Height(Tide Level)

Observation Facilities,
Meteorological Agency

Satellite

Approx. 660 Sites

Earthquake
Observation Facility* Monitoring earthquake
activities / tsunami* Issuing and releasing
Tsunami tsunami warnings / advisories
Wave-Heig and earthquake early
Tide Station
Off-the-Coast Water
ht (Tidal warnings
Pressure Gauge
Level)* Compiling and releasing
earthquake information,
Tsunami Observation
tsunami information, etc.
Facility
Seismic Intensity
Earthquake
Observations
Wave-FormApprox. 3,700 Sites

Seismic Intensity
Observation Facility
Belonging to Municipalities,
National Research Institute for
Earth Science and Disaster
Prevention, or others
Tsunami-Wave Height(Tide Level)
Approx. 100 Sites
Tide Stations orothersTide Level Observation
Facilities
Belonging to the Ports and Harbors
Bureau, MLIT; the Geospatial
Information Authority; the Japan
Coast Guard, and others
Arrow Symbols

In-collaboration
with
TsunamiUniversities,
Observation
Research
Data
Institutes, etc.

Earthquake
and tsunami
information

Approx. 40 Sites
GPS-type
Wave Gauge

Seismic Intensity
Information

meteorological offices

TsunamiWarning /Advisory

Approx. 80 Sites

Municipalities

Earthquake
Wave-Form

Local Residents, etc.

Earthquake
Early
Warning

Seismic Intensity
Observations

Broadcasting Companies,
Mobile-phone Service
Companies, etc.

Approx. 280 Sites

News Media. Prefectures, Police, Coast Guard, NTT

Seismic Intensity
Observation Facility

Local Residents,
etc.

Earthquake Phenomena
Observation System(EPOS), Tokyo and Osaka

Ports and Harbors Bureau, MLIT; Japan
Agency for Marine-Earth Science
Technology; National Research Institute for
Earth Science and Disaster Prevention

In Cases of Seismic Intensity 6 or greater (upper-5 or greaterfor Tokyo’s 23 Wards)
Call for Cabinet Team-Conference for Emergency
In Cases of Seismic Intensity 4 or greater
Initiation of Early Earthquake-Damage Estimation using
Cabinet Office DIS

Delivery of Data
Delivery of Information

Number of site: as of March
31, 2013

In Cases of seismic Intensity 4 to lower 5 or greater
Initiation of Damage-Investigation using Aircraft from the
Ministry of Defense, Japan Coast Guard, Police, etc.
In Cases of Seismic Intensity 3 or greater
Early Earthquake Report on Radio / TV Broadcast.

Source: Meteorological Agency’s Web Pages
Figure 9: Creation/Delivery Flow of Earthquake/Tsunami Information by the Meteorological
Agency-59-

(1) Gathering of earthquake data
[1] Earthquake monitoring
The Meteorological Agency monitors earthquake activities on a 24-hour basis bycompiling the observations obtained from the 280 seismometers located nationwide that belong to
the agency and the observations obtained by the seismometer belonging to the National ResearchInstitute for Earth science and Disaster Prevention, etc.
In addition, the agency, at the time of an earthquake occurrence, integrates the dataobtained by their own seismometers with a function of measuring ground motions installed at 660
locations nationwide and the data from the seismometers that belong to local authorities, theNational Research Institute for Earth Science and Disaster Prevention, etc. The number of available
observation facilities installed nationwide is approx. 4,700 in total.
[2] Earthquake early warning
The agency, immediately after an earthquake occurrence, analyzing the observation datafrom the seismometers located in the vicinity of the epicenter, estimating the location of theearthquake source and its magnitude, predicting the arrival time of the earthquake principal motions
to places around Japan based on the results of such analyses, releases an earthquake early warning as
promptly as possible.
(2) Gathering of tidal data
The agency, using the tidal data from the 80 tsunami observation facilities nationwide thatthe agency has built, and the data from observation equipment belonging to other organizations suchas GPS-type wave gauges deployed by the Ports and Harbors Bureau MLIT and so on, monitors
tsunami phenomena at approx. 220 locations nationwide.
(3) Release of tsunami forecasts or earthquake/seismic-intensity information
On the occurrence of an earthquake, the agency, using data from seismometers andtsunami monitoring data, identifying the earthquake source location and estimating its magnitude
and tsunami scale, creates and releases tsunami forecast statements.
(4) Distribution of meteorological information for disaster prevention
Meteorological information such as tsunami warnings/advisories released by the agency is
distributed to local residents via mass-media such as TV/radio broadcasts, as well as through thenational organizations in charge of disaster prevention or the local authorities. This has contributed
to the prevention /alleviation of the impact of disasters.

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Such information is directly delivered in a secure way through administrative authorities
such as prefectures or NTT primarily to the municipalities, which are directly involved in disasterprevention activities on the frontline. In addition, such information is distributed by multiple means,for instance delivered via the Internet or the Nationwide Warning System (J-ALERT) administeredby the Fire and Disaster Management Agency.
Meteorological Agency(Head Office / Observatory)

Prefectures
Municipalities
Police / Fire-Fighting
Department

Citizens

RelatedOrganizations

Water and Disaster Management Bureau, MLIT

Involved in disasterprevention activities

Japan
MeteorologicalBusiness
Support Center

Power Companies

News Media
Meteorological Business Operators

Subscribers
Vessels

Japan Coast Guard

Release of Meteorological
Information for Disaster
Prevention

Aircraft

Civil Aviation Bureau, MLIT

http://www.jma.go.jp, Meteorological Agency’s web pages

Source: Meteorological Agency Brochures

Figure 10: Distribution Flow of Meteorological Information for Disaster Prevention
7-2. Distribution of Tsunami Information by Japan Coast Guard
Japan Coast Guard, basing procedures on the Disaster Prevention Basic Act and the Act on
Special Measures concerning Countermeasures against Large-scale Earthquake for the purpose of
conducting their anti-disaster operations in an integrated way and following well-prepared plans, has
prepared the “Japan Coast Guard Disaster Prevention Operation Plan” that stipulates the appropriate
actions for them in a time of disaster-risk. Tsunami information is distributed following the plan and
the Meteorological Service Act.
In addition, Japan Coast Guard delivers to vessels, as a navigational warning, information
on abnormalities in navigation aids due to earthquakes or tsunami and information on obstacles
drifting on the surface.
Note: because, while the Meteorological Agency classifies their tsunami information into
“Tsunami Forecast” and “Earthquake/Tsunami Information,” the modes of information delivery are
not specified. Those two types of information are, hereinafter, uniformly referred to as “Tsunami
Information,” except in the case where differentiation is necessary.

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Information delivery measures to vessels and others in different situations are shown
below.
(1) Proceeding vessels
・International Marine VHF Radio Channels: Tsunami information is broadcast on VHF
Channel 16 as emergency information
・NAVTEX Navigational Warning
・Japan Navigational Warning
・NAVAREA Navigational Warning
・AIS’s (Automatic Identification System) information
・MICS’s (Maritime Information and Communication System) information(2) Anchoring vessels
・Sending patrol vessels/crafts or aircraft to cover anchorage area and inform by means ofloud speakers or banners
・Sending Coast Guard Office/Station staff to visit vessels or use ship telephones(3) Local residents in coast areas or sea-bathing visitors, etc.
Sending patrol vessels/crafts or aircraft to cover coastal areas and inform by means ofloud speakers or banners.
(4) Information delivery by parties concerned with vessels
Significant port business operators such as ship agents, major fisheries cooperative
associations (marine radio stations), marinas, marine clubs, port construction-work safety
associations, and others are supposed to relay tsunami information that is delivered to themby Coast Guard Office/Station to the vessels, fisheries cooperative associations, port
construction-work companies (construction work vessels), or pleasure boats that belong tothem via telephone, FAX, mobile phone, marine band, or construction-workers’ radio, or bydirect visit to vessel.
(5) Delivery of earthquake information to vessels
Reports on earthquakes that occurred in the vicinity of Japan including the coasts ofJapan, of a seismic intensity lower 5 or greater, are distributed by the Meteorological
Agency to vessels as a NAVTEX Navigational Warning, a Regional Navigational Warning(for which the Coast Guard regional headquarters are responsible), and a Japan Navigational
Warning.
(6) Delivery of information on abnormalities in navigation aids or surface obstacles
Information on abnormalities in navigation aids or surface obstacles is distributed as a
NAVARIA XI Navigational Warning, a NAVTEX Navigational Warning, a Regional
Navigational Warning, and a Japan Navigational Warning. In addition, the graphically
mapped information is available on the Internet.

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7-3. Tsunami Information Delivery by Regional Tsunami Disaster Management Organizations
While the tsunami information released by the Meteorological Agency is delivered to theregional organizations involved in tsunami disaster management, such as prefectures, Cost Guard
Offices, police offices, fire departments, regional development bureaus, news media, JR, and NTT,
responsibility for delivering such information to local residents rests on municipalities and news
media.
However, while the Meteorological Service Act stipulates in Article 23 that others than the
Meteorological Agency are not permitted to make warnings on weather, tsunami, high tides, waves,or floods, according to the Disaster Management Basic Act Article 56 and the Meteorological
Service Act Enforcement Order No.10, municipal mayors are permitted to independently release
their own tsunami warnings in remote areas where the prompt recipient of the Meteorological
Agency’s tsunami information is difficult or where the receipt of such tsunami warnings is no longer
possible.
7-3-1. Information delivery through municipalities
Municipalities, by broadcasting on municipal emergency radio, blasting sirens, ringing firebells and loudspeaker vans, inform the local coast-area residents, people staying on the coast, and themaritime organizations of the earthquake/tsunami information delivered by prefectures, police
stations, NTT, and news media.
7-3-2. Information delivery by news media(1) Emergency warning broadcast
Major news media companies, on the release of large-scale earthquake warning or tsunami
warning, or at the request of local authorities for broadcasting evacuation orders, broadcast
emergency warnings. Television-sets/radios with emergency broadcast receiving function, even if
their power switched off, but connected to a power receptacle, are able to receive such emergency
broadcast on NHK’s ordinary TV channel and NHK radio No.1 and on the channels/frequencies ofthe private broadcast companies participating in the Emergency Broadcasting Network System.
(2) News-media’s position in the regional disaster prevention plans prepared by prefectures
Prefectural regional disaster prevention plans stipulate the actions that news media aresupposed to take as follows: “News media should voluntarily raise audience attention, on radio byinserting the announcement of an emergency warning in program intervals or by interrupting
programs, or on TV by displaying tickers on screen or interrupting programs. In addition, when atsunami warning is released news media must, at the request of local authorities and broadcasting-63-

evacuation orders, etc. based on the Basic Act on Disaster Control Measures, broadcast theiremergency programs.”-64-

8. Laws and Regulations on Measures against Tsunami Disaster
The laws and regulations concerning measures against tsunami disasters are summarized
below.
8-1. Basic Act on Disaster Control Measures(1) Basic Act on Disaster Control Measures“Disaster Countermeasure Basic Act” (hereinafter referred to as “Disaster Control Act”)
was enacted in 1961 in the wake of the disaster caused by a typhoon that hit Ise-wan area (Ise-wan
Typhoon) in 1959. The act represents the general law for rules and regulations concerning disasters.
The Act stipulates in its Article 60 as follows:
When a disaster has occurred or is expected to occur, the mayor of a municipality may
make an evacuation recommendation to the residents or others or make an instruction of evacuation
eviction if urgently necessary.
In Article 61, the Act stipulates as follows:
When the mayor is unable to make a request or instruction of evacuation, a Police or Coast
Guard officer may make such an instruction towards persons the officer considers as needing toevacuate.
In Article 63, the Act stipulates as follows:
The mayor, when he/she considers it necessary, may establish a warning zone, restrict or
prohibit access to the zone by persons except those who have permission, and make instructions ofevacuation.
Furthermore, in its Article 63 Item 2, the Act stipulates as follows:
When the mayor of a municipality, etc. is not present on-site or on the request of the mayor,
etc., a Police/Coast Guard officer may exercise the mayor’s authority.
(2) Basic Plan for Emergency Preparedness
The Basic Plan for Emergency Preparedness is the government basic plan that the Central
Disaster Management Council prepares pursuant to the Disaster Countermeasure Act.
The Central Disaster Management Council amended the Basic Plan for Emergency
Preparedness on December 27, 2011, based on the final report of the “Expert Group on the
Earthquake/Tsunami Countermeasures in the light of the lessons of Tohoku Pacific Coast
Earthquake,” dated September 28 2011, for the purpose of realizing what the Expert Group proposedin the report.
The main points of the amendment are the addition of a new chapter “Tsunami Disaster
Management” and the improvement of the description for the purpose of enhancing
earthquake/tsunami countermeasures, as follows:-65-[1] For the purpose of managing all possible situations, assume maximum-scale earthquake
and tsunami.
[2] Setting two levels of target tsunami and corresponding measures
・Against a maximum-scale tsunami, preparing comprehensive measures focusing on
evacuation of residents;
・Against a relatively often-occurring tsunami, improving coast-guarding facilities, etc.
[3] Building highly tsunami resistant towns
・Promotion of land utilization so that low-inundation risk areas are used for residency, andaccording-to-plan development of evacuation spaces or evacuation buildings, etc.
[4] Properly equipping citizens with disaster prevention knowledge
・Familiarizing citizens with disaster prevention actions, such as “when sensing a strong
earthquake motion, evacuate without hesitation, immediately and independently;
・Executing disaster prevention education programs and developing education programs
concerning tsunami;
・Development of tsunami hazard maps and familiarizing residents with the plans.
[5] Improvement of research and observation systems for earthquakes/tsunami[6] Establishing or securing systems for delivering information of tsunami warnings andevacuation execution(3) Regional Disaster Prevention Plan
Each of the heads of local authorities, pursuant to the Disaster Countermeasure Act,prepares its own Regional Disaster Prevention Plan through consultation with its regional disastermanagement council. Such plans stipulate specific actions or operations of disaster management.
The ministries concerned, for the purpose of supporting the local government’s activities
for preparing such plans, prepared the “Guides to the Enhancement of Tsunami Measures inRegional Disaster Prevention Plan” in 1998 and the “About promoting the activities for preparing
against tsunami in coast areas” (note of consent of the ministries concerned) in 1999, and notified
local governments of those documents. The points of those documents are as follows:[1] Guides to the Enhancement of Tsunami Measures in Regional Disaster Prevention Plan
In March, 1998, the ministries concerned (National Land Agency, Ministry of Agriculture,
Forestry and Fisheries, Fisheries Agency, Ministry of Transport, Meteorological Agency,
Ministry of Construction, and Fire and Disaster Management Agency) presented the Guide to
the Enhancement of Tsunami Measures in Regional Disaster Prevention Plan, introducing thebasic concepts and procedures for prefectures or municipalities in preparing their Regional
Disaster Prevention Plans.

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The document shows the following as the basic ideas for tsunami measures involving
vessels:
・ Measures for securing the safety of vessels in ports, harbors, and fishing ports
While Coast Guards, in cases where they, on a recipient of tsunami warning, judge
whether the water areas are facing risks, take actions such as delivering tsunami warnings tovessels, making recommendations, controlling the area, and making restrictions, port
administrators are recommended to request concerned parties on vessels to take appropriate
actions to secure vessels’ safety in cases where they deem it necessary.
Note: with regard to ports, harbors, or fishing ports that are not subject to the Act on Port
Regulations, the administrators should have meetings in advance with ship owners andfisheries cooperative associations and request them to prepare appropriate measures forsecuring vessels’ safety.
・Measures for fishing boats
In a situation with a risk of tsunami strike, measures for fishing boats should beexecuted within a range where such execution will not risk human life.
[2] About the enhancement of awareness of tsunami in coastal areas
The Liaison Conference of Ministries and Agencies on Tsunami measures in July 1999
(participated in by the Cabinet Secretariat, Cabinet Office, Police Agency, Ministry of Defense,
Ministry of Internal Affairs and Communications, Fire and Disaster Management Agency,
Ministry of Agriculture, Forestry and Fisheries, Ministry of Land, Infrastructure and Transport,
Meteorological Agency, and Japan Coast Guard), recognizing the importance of advance
preparation for tsunami measures and evacuation/rescue operation arrangements, agreed oncomprehensively promoting tsunami measures.
The conference agreed on vessels’ tsunami measures as follows:
・The enhancement of awareness of tsunami
The awareness of the necessity of being precautious against tsunami should beenhanced as stated in the following attachment, where the instruction is: “When having sensed
a strong earthquake motion, residents must evacuate to safe places away from the coast; vessels
evacuate offshore.”・“Instructions for preparing against tsunami” (an attachment to the announcement)<Instructions for Vessels>-67-

1. When having sensed a strong earthquake motion (intensity 4 or greater) or long lastingslow motions, even if the earthquake was small, vessels must immediately leave theport to evacuate offshore.*
2. Even if not having sensed earthquake motions, when a tsunami warning/advisory isreleased, vessels must leave the port to evacuate offshore.*
3. Vessels must try to receive correct information via TV/radio broadcasts or radio
communications.
4. Small boats unable to evacuate offshore,* must be pulled up out of water to a highplace and be firmly tied down if possible.
5. Vessels must be on-alert until the tsunami warning/advisory is cancelled, as tsunami
can strike repeatedly.
* Note: choose wide-open and deep areas for offshore evacuation; pulling-up of a small
boat must be executed only in the case where sufficient time is available.
(4) Japan Coast Guard Disaster Management Action Plan
The Japan Coast Guard (hereinafter referred to as “Coast Guard”) Disaster Management
Action Plan, pursuant to the Disaster Control Act, stipulates as follows the operations that the Coast
Guard should execute at the time of disaster.
[1] Delivery of disaster information: conducted toward the residents and vessels in the vicinityof the tsunami risk area, the Coast Guard sends patrol vessels/crafts or aircrafts to patrol
the area and inform by means of loud speakers and banners, in addition to visiting vessels;
toward proceeding vessels, the Coast Guard informs them by means of navigational
warnings or safety messages; toward the residents or visitors sea-bathing in thetsunami-risk coastal areas, the Coast Guard sends patrol vessels/crafts or aircrafts to
inform them by means of loud speakers or banners.
[2] Delivery of warning to vessels, etc.: when receiving warnings on weather, tsunami, hightide, or waves, or information on disasters, the Coast Guard immediately informs thevessels of the warning/information by means of navigational warning, safety message,
signage, and/or visit by patrol vessels/boats/aircrafts, and at the same time informs
business operators concerned if necessary; when detecting navigation hazardous debris orabnormalities in navigation aids that could severely risk of navigation safety, or to set
restrictions/prohibitions on vessel traffic, the Coast Guard promptly raises navigational
warnings or sends message on navigation safety, or informs by means of Notice toMariners if necessary.
[3] Evacuation recommendation: toward the ports in the tsunami risk areas or vessels close to
the coast, the Coast Guard makes recommendations of evacuation to safe waters such as in-68-the offing, and, if necessary, restricts port-entry or impose controls to the vessels in the port
to move.
[4] Actions to vessels carrying dangerous cargo: the Coast Guard, if necessary, instructs to leaveor restricts/prohibits their navigation, and with regard to vessels in the middle ofloading/unloading dangerous cargo, makes necessary guidance, such as suspension ofloading/unloading, for the prevention of accidents.
[5] Setting up warning zones: the Coast Guard, if necessary, pursuant to Article 63 of theDisaster Control Act, makes instructions for leaving the warning zone and restricts/prohibits
entry to the zone.
8-2. Act on the Prevention of Disaster in Petroleum Industrial Complexes and Other Petroleum
Facilities, and others(1) Act on the Prevention of Disaster in Petroleum Industrial Complexes and Other Petroleum
Facilities
The Act on the Prevention of Disaster in Petroleum Industrial Complexes and Other
Petroleum Facilities (hereinafter referred to as Petroleum Disaster Act) was effected in 1975 for the
purpose of protecting citizens’ life/physical integrity and property from disasters in speciallydesignated disaster prevention zones such as petroleum industrial complexes (hereinafter referred toas special disaster prevention zone) through promoting comprehensive policies concerning theprevention of disaster occurrence or expansion related to special disaster prevention zones incombination with the Fire Service Act, High Pressure Gas Safety Act, Disaster Countermeasure Act,and other laws concerning disaster prevention.
(2) Disaster prevention plan for Petroleum Industrial Complexes and Other Petroleum Facilities
In the prefectures that have special disaster prevention zones—as of April 1, 2011, 85
zones in 33 prefectures and 104 municipalities are designated special disaster prevention zones,
pursuant to the Petroleum Disaster Act. The prefectural headquarter for the prevention of petroleum
disasters, playing the central role in collaboration with organizations concerned, promotes, in acomprehensive way and following the plans for activities for the establishment of disastermanagement systems. The headquarters conducts the following as their responsibility: thepreparation of Plans for the Prevention of Disaster in Petroleum Industrial Complexes and Other
Petroleum Facilities (hereinafter referred to as disaster prevention plan); coordination between
organizations in time of disaster; and the promotion of research and study.
Disaster prevention plans, required by the Article 31 Item 2 of the Petroleum Disaster Act,
must include the items on “the execution of emergency measures against disasters caused byextraordinary natural phenomena including earthquakes or tsunami,” and “the control and-69-

management of evacuation, traffic, and setting-up warning zones.” Hence, such plans stipulate
emergency measures for vessels including the giving of instructions/recommendation of suspensionof loading/unloading work and controlling/restricting vessels' evacuation/traffic.
8-3. Meteorological Service Act and others
The Meteorological Service Act stipulates in Article 15 as follows: the agency, whenreleasing warnings of tsunami or other, must notify designated administrative organization such as
Coast Guard, prefectures, etc. Coast Guard that received such a notification from the Meteorological
Agency must endeavor to inform the relevant vessels proceeding/anchoring in ports.
8-4. Maritime Transportation Act and others
The Maritime Transportation Act, in Article 10-3, obligates all passenger transportbusiness operators to prepare their own “Safety Management Rules” describing the items that theoperator and its employees must follow for securing transport safety.
In addition, the act obligates business operators (the transport business operators permitted
to operate in the designated areas) designated by the “Act on Special Measures for Large-scale
Earthquakes,” “Act on Special Measures for Tonankai/Nankai Earthquake” or the “Act on Special
Measures for Promotion of Earthquake Disaster Prevention Measures against Trench-type
Earthquake in Japan Trench or Trenches in the Vicinity of Chishima Trench” to prepare/observe their“standards for earthquake disaster prevention.”
8-5. Act on Port Regulations
The Act on Port Regulations stipulates, in Article 37 Item 4, that the Captain of the port ofthe specific port, when expecting a risk to vessel traffic safety due to tsunami and other phenomena,
may recommend the vessels in the port to take necessary measures.
And, the act, in Article 37 Item 3, stipulates that the Captain of the port, within the rangeof necessity for preventing risks to vessel traffic or alleviating traffic congestions, may
control/restrict or prohibit the navigation of vessels entering specific areas, or make an instruction on
where to anchor, restrict a vessel’s shift, or make an instruction for vessels to leave outside from theport.
Furthermore, such stipulations on the port are subject to legal enforcement, even when notdesignated as a special port. In such a case, the head of the Coast Guard Office/Station may exercise
the authority of the Captain of the port.

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II Safety/Disaster Prevention Measures for Large Vessels Carrying
Dangerous Cargo
1.1. Objectives
With regard to the safety/disaster prevention measures for large vessels carrying
dangerous cargo, while such safety measures as emergency unberthing have been proposed, thestudies have been conducted for the purpose of reflecting the lessons from the Great East Japan
Earthquake; in this section, the reviews of the conventional safety/disaster prevention measures are
introduced as shown below.
Note that, in light of the severe damages on petroleum industrial complexes, etc.
experienced in the Great East Japan Earthquake, studies and reviews on earthquake/tsunami
countermeasures with regard to on-land facilities have so progressed that new standards fortsunami-countermeasures compliant with the Fire Service Act have been proposed.

1.2. Safety/Disaster Prevention Measures for Large Vessels Carrying Dangerous
Cargo

1.2.1. Current Status of Earthquake/Tsunami Safety Measures for Large Vessels
Carrying Dangerous Cargo
Currently, large-sized oil carriers with dimensions larger than a designated size, and theberths used for loading/unloading by such carriers, are subject to the regulations for safety/disasterprevention measures for loading/unloading operations, according to the “Standards for the
Preparation of Safety/Disaster Prevention Measures for Large-sized Oil Carriers and Berths used bysuch Carriers (Coast Guard Administrative Guide Line, dated January 17, 2011)”; furthermore, LNG
berths, of liquefied-gas berths, have been equipped with emergency shut-down systems, etc. thathave proactively employed the recommendations by the Marine Disaster Prevention Center.

1.2.1.1. Standards for Safety/Disaster Prevention Measures for Large-Sized Oil
Carriers and Berths(1) Target vessels or berths[1] An oil carrier of 50,000 DWT or over, or a berth used by such a vessel for
loading/unloading.
[2] A liquefied-gas (petroleum/natural) carrier of 25,000 gross tonnages or over, or a berthused by such a vessel for loading/unloading-71-

(2) Safety/disaster prevention measures concerning emergency unberthing
The standards for the safety/disaster prevention measures have been prepared as thetechnical standards concerning the port entering/leaving or loading/unloading of a large vessels
carrying dangerous cargo; the standards include the requirements covering a wide range fromfacility to operation. Of the standards, the following are the requirements with regard to
emergency unberthing at the time of earthquake or tsunami.
[1] Requirements for facilities
Quays are required, for the purpose of ensuring that a vessel can make safe
emergency unberthing, to be equipped with sufficiently strong quick release hooks if
possible.
[2] Requirements for the preparation and strictly carrying out of the manuals forberthing/unberthing and loading/unloading operations
Manuals for berthing/unberthing or loading/unloading, and the checklists forindividual operations must be prepared and strictly observed.
[3] Pre-arrangement concerning the means of the suspension of loading/unloading operations
at the time of emergency
Berth operators and tanker operators must, in advance, mutually confirm theprocedures for safely stopping their operations of loading/unloading or the release of arms
or hoses at the time of an emergency situation.
[4] Countermeasures for extraordinary weather or sea-conditions
When a tsunami warning or a major earthquake alert is issued, loading/unloading
operations must be suspended immediately, and, as a general rule, the vessel must be
evacuated to a safe water-area off the port. Note: in a case where the procedures for anindividual vessel to follow have been pre-agreed in the tsunami countermeasuresconference, etc., the vessel should follow such procedures.

1.2.1.2. Safety/disaster prevention measures for LNG berths
With regard to LNG berths, the individual berths have employed not only
safety/disaster prevention measures for general oil carrier berth, but also the following safetymeasures for emergency unberthing, through proactively applying the recommendations by the
Maritime Disaster Prevention Center:[1] Employment of Emergency Shut Down System (ESDS)The system has such functions as automatically or manually stopping theloading/unloading pump promptly in an emergency situation and closing the
emergency shut-down valves.

-72-[2] Employment of Emergency Release System (ERS)
The system has such functions as remotely releasing the loading arms promptly inan emergency situation even in the middle of loading/unloading operations.
[3] Employment of arm angle irregularity detection and alarm system
The system monitors the loading arm angle, and activates ESDS and ERS, when
detecting irregularity in the angle.
[4] Employment of mooring-line load monitoring equipment
The equipment, using the outputs of the sensors attached to the quick release hook,monitors the load on mooring lines.

1.2.2. Earthquake/Tsunami Countermeasures for Large Vessels Carrying Dangerous
Cargo: Improvement through Reflecting the Lessons from the Great East Japan
Earthquake

1.2.2.1. Damage Situations of Large Vessels Carrying Dangerous Cargo in the Great
East Japan Earthquake(1) Sendai-Shiogama Port
VLCC (150,000 DWT: in the middle of unloading)
The vessel, while executing emergency unberthing operations, received tsunami-flowpressure that caused its mooring lines to be cut off; the vessel, although executing an emergency
dropping anchor but being swept around by tsunami waves, made offshore evacuation by
self-maneuvering and navigation, after having collided with other vessels
In addition, the vessel, during executing the required emergency shut down operations
for dangerous cargo facilities, suffered 4 casualties: the casualties were induced by the delay ofthe delivery of retreat instructions to the staffs working on the unberthing operation on the quay;
the delay of instruction delivery was induced by the unavailability of the vessel’s PA system dueto the insufficient capacity of the emergency batteries.
Note 1: The Fire and Disaster Management Agency, Ministry of Internal Affairs andCommunications, considering such risks during emergency operations, has revised the laws andregulations on fire and disaster management, so that, with regard to the facilities having the riskof inundation due to tsunami flooding, such stipulations were added regarding the actions for
emergency stop taking into account the time allowance for tsunami arrival, and the security of
employees’ safety. (Notice No.197 “Sho-bou-ki” dated August 21, 2012)-73-

Note 2: Tsunami observation at Sendai-Shiogama Port (Sendai Port-Area) (Brochure released by
the Ports and Harbors Bureau, Ministry of Land, Infrastructure, Transport and Tourism)
Maximum Wave:+ 7.7 meters(2) Onahama Port
VLCC (100,000 DWT: in the middle of unloading)
The vessel, although suffering tsunami waves with the loading/unloading facilities
including “Chikusan Arm” connected, survived the tsunami while moored at the crude oil berth.
The staff working on mooring or unloading operations, although on a sea-berth off theland, made evacuation into the vessel following the berth master’s timely and proper advice:none of them suffered damages.
Note: Tsunami observation at Onahama (release by the Meteorological Agency)
First Wave

: + 2.6meters, 1508 hrs

Maximum Wave

: + 3.3 meters, 1539 hrs(3) Kashima Port
VLCC (160,000 DWT, in the middle of unloading)
The vessel was pushed by tsunami-water flow and its mooring line was cut-off;however, the vessel, by self-maneuvering and navigation, made offshore evacuation.
LPG Carrier (47,000 GT, during preparation for unloading)
The vessel had its mooring line cut-off by the tsunami; however, the vessel, by
self-maneuvering and navigation, made offshore evacuation.
Note: Tsunami observation at Kashima Port (Brochure released by the Ports and Harbors Bureau,
Ministry of Land, Infrastructure, Transport and Tourism)
Maximum Wave:+ 5.7 meters1.2.2.2. Lessons from the Great East Japan Earthquake
Following the Great East Japan Earthquake, in FY2012, the Japan Association of Marine
Safety determined the items that require the revision in the current tsunami measures, based on thepast reports and interviews with people engaged in maritime affairs, and outlined approaches forsuch items in Table 2.

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Out of the table, dos and don’ts that large vessels carrying dangerous cargo should follow
are shown in a form of lesson, as follows.
✓ Make sure to equip berth facilities with auxiliary/emergency power supplies for berthfacilities, and equip operable communication means for emergency situations with vessels.
✓ Make pre-agreements on how and what decisions to make for evacuation with parties
concerned, in the situation of a tsunami strike.
✓ Keep in mind that vessels are forced to unberth by themselves in a situation where no
assistance (land nor offshore) is available.
✓ Share the information on the safe areas on the water that will experience less tsunami
impact.
✓ Evacuation of vessels carrying dangerous cargo
・Take it into consideration that a secondary disaster, breaking-out in port areas, will havetremendous impacts. Such vessels should choose offshore evacuation as an emergency
measure, if allowed by the time allowance for tsunami arrival and the required time toreach a safe area.
・Generally speaking, head-out berthing is desirable for a vessel to berth,

1.2.2.3. Safety/disaster-prevention measures for large vessels carrying dangerous
cargo, reflecting the lessons from the Great East Japan Earthquake
The evacuation methods of large vessels carrying dangerous cargo should be reviewed andrevised based on simulation-assessment on vessel maneuvering and navigation from the standpointof safety preservation, putting emphasis on the following:✓ There is a risk of the break-out of severe secondary disasters induced by the vast amount ofinflammable dangerous cargo on-board of such vessels;✓ Such vessels should evacuate outside the port, except for cases when they are in somespecial situations;✓ Facilities, methods, procedures and systems for emergency unberthing must be developed.
If a large carrier loaded with vast amount of crude-oil or liquefied gas collides with orgoes aground, it may induce the loss of port functions due to the closing of water areas, as well aslarge-scale disasters such as run-off of the load and fires caused by ignition of the load.
From the stand point of the prevention of such secondary disasters and the limitation ofdamages, large vessels carrying dangerous cargo are required to take prompt actions and evacuate tosafe areas as swiftly as possible.

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As described earlier, the safety measures of emergency unberthing have been employed
as a part of the safety measures for large vessels carrying dangerous cargo. However, studies are
required on the following for reflecting the lessons from the Great East Japan Earthquake:(1) Action items for berth master[1] Studies on berthing methods for large vessels carrying dangerous cargo
With regard to the berthing method, berth masters should consider a berthing
method that is suitable for the berth’s situation, taking into account the effectiveness ofhead-out berthing.
On the other hand, in some specific berth situations, head-in berthing may lead tosafer and quicker unberthing.
Therefore, berth masters must determine how a vessel should berth, throughcomprehensive and systematic consideration on the time required for unberthing,whether safety will be preserved at the time of berthing/unberthing, and how easy the
maneuvering will be, etc., in addition to considering the following matters:
・How the port facilities are located around the berth;・In which direction from the berth, the port exit is located;
・How wide and deep, and in what shape, the available water route and thevicinities are;
・How many towing boats are available and their performance;
・Whether pilots are available;
・Whether the vessel is equipped with thrusters:
・How loading/unloading facilities are arranged on the berth or on the vessel;
・What are the characteristics of weather or sea conditions around the berth orport;
・How much vessel traffic is around the berth.
What is stated above must be considered when berths are to be newly constructed;
and in addition, with regard to the existing berths, these factors must be consideredwhen such berths are undergoing large-scale re-construction or when, along with suchreconstruction, alteration to the operations are to be made.
However, it should be noted that tug-boat arrangements or thruster facilities are
effective for ensuring safe and prompt unberthing, regardless of berthing
methods—head-in or head-out.

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[2] Facilities on quaya) Quick release hook
As a lesson from the Great East Japan Earthquake, it is desirable to duplicate, if allowed,
the power sources by means of installing emergency generators, and install, if allowed,
remote-controllable facilities. The staffs working on unberthing operations for an oil-carrierat an oil-refinery’s berth suffered damages by tsunami; in some cases, staffs for unberthing
operations were not available.
b) ESDS and ERSESDS and ERS, effective for ensuring that a vessel
can make its emergency unberthing promptly and withless difficulty, should be employed; and for them, thepower system should be duplexed, such as installing
emergency generators.
With regard to the application of ERS to VLCC, thepossibility of oil run-off at the time of releasing has beenfeared; however, if an equipment which is able to purge
nitrogen is added, such oil run-off will be suppressed
when the ERS is manually operated.
Note that there is a risk of oil run-off of a certain
amount when the ERS is automatically activated when

Photo 1: ERS

the vessel hull is displaced due to the mooring-line
break-down, although this depends on the rate of hull
movement off the berth.

Photo 3: Actually Activated ERS (On-board
Equipment) on March 11

Photo 2: Actually Activated ERS*Source of Photo 1 to 3: CHUBU Electric Power Co., Inc.

-77-c) Emergency PA system
As the lessons from the Great East Japan Earthquake show, the power supply for
emergency PA systems must be duplexed with emergency power generators, etc.
[3] Suspension of loading/unloading
Loading/unloading operations must be suspended when the information on a major
tsunami warning, a tsunami warning, or a tsunami advisory released by the Meteorological
Agency is obtained.
Furthermore, there is a risk that, in a case where the earthquake occurred at a
close-to-coast point, a tsunami will arrive before the agency releases a tsunami warning,
etc.: therefore, the parties engaging in the loading/unloading operation must make efforts togather information when sensing a strong earthquake (intensity 4 or greater) or slow but
long-lasting motions even if the earthquake itself is not strong.
[4] Oil fence
In some cases in the Great East Japan Earthquake, many difficulties were experienced
when works to remove oil fences for emergency unberthing of oil carriers were operated
from the land side as working boats could not approach the location.
Therefore, it is necessary to establish a system for prompt collection of oil fences so thatthey do not obstruct works for emergency unberthing.
In addition, measures should be taken to keep the oil fences from floating away so thatthey do not interfere with vessel traffic.
[5] Emergency manuals
Emergency manuals for the procedures of emergency suspension of loading/unloading or
emergency unberthing should be prepared; in addition, training or drills should be executed
periodically on such operations.
Such drills should be executed focusing on the following items and the order listed
below:a) (On the outbreak of earthquake/tsunami) Gathering information/investigation on
damage situationsb) Distributing informationc) Discussing with parties concernedd) Distributing the result of such discussionse) Suspending loading/unloading operations, and standing-by main enginef) Releasing loading arm (using ERS)g) Unberthing-78-h) Arriving at safe water
For the purpose of preparing the cases where the vessel-to-land or land-to-vessel
communications are blocked due to power losses or communication traffic
congestions as were often seen in the Great East Japan Earthquake, the training on
the items from a) to d), should be executed following the “pre-arrangement” for thecases of communication shut-down, based on the scenario where such power is lost.

(2) Actions taken by vessels[1] Moored sheltering
There will be a risk that a vessel cannot afford to make its emergency unberthing
due to physical obstacles or difficulties in securing safety; vessels must prepare theprocedures for enhancing mooring force and other measures for making mooredsheltering.
[2] Emergency unberthing of a membrane-type LNG vessel
A membrane-type LNG carrier has a risk of suffering damages on the tank due tosloshing, although the occurrence of such phenomenon depends on the LNG level in thetank; on the other hand, a MOSS-type LNG carrier rarely suffer such damages.
A membrane-type LNG carrier, in a case where having the sufficient time allowance
for measures such as taking countermeasures against a typhoon that is coming closer, canadjust its tank level by transferring the cargo from one tank to another to prevent the tanklevel from reaching its critical range. However, the following actions would be practicalfor such vessel to take in the situation where it is being forced to unberth due to theoccurrence of an emergency situation such as being struck by a tsunami or having a fire
during its loading/unloading operations: the vessel should at first leave the berth; thenmake such maneuvering that could alleviate as much as possible the vessel’s motion
caused by tsunami waves, winds, wind-waves or heaves; and then, shift its cargo with thetank level being kept within the allowance range of loading.
(Reference 1)
Sloshing is a phenomenon where, due to the vessel’s hull motions during navigation,
its cargo (LNG) in the tank moves synchronously with the vessel motions to strike hardagainst the tank walls.
(Reference 2)
The tank structure of a LNG carrier is designed according to the International Gas
Carrier Code (IGC Code: International Code for the Construction and Equipment ofShips Carrying Liquefied Gases in Bulk); therefore, a vessel with such tank structure isrequired to execute cargo handling operations that satisfy the IGC Code requirements.

-79-

The International Safety Management Code (ISM Code) requires the preparation ofmanuals to ensure operations that meet the IGC Code requirements.
Gaztransport & Technigaz SAS (GTT), the licenser, specifies the inhibited range ofload-level during navigation (for instance, the range of 10 to 70 percent of the tank’sheight) in order to prevent sloshing damages.
Vessel management companies prepare a manual, referring to such materials astechnical documents concerning cargo storing facilities issued by the licensor, theClassification Society Guidance, technical specifications issued by the ship builders; andthe navigation guidance issued by the vessel operators. An ISM certificate is issued by
the maritime authorities of the flag state (in Japan, Inspector Ministry of Land
Infrastructure, Transport and Tourism (JG), and Nippon Kaiji Kyokai (NK) are in charge).
A procedural manual should be prepared taking into account the limitations in the eventof tsunami arrival, such as low vessel speed.

(3) Arrangement of assistance[1] Pilot arrangement
The following are considered effective:
Agreeing on pilot-arrangement in emergency situations with pilot associations;
Studying the procedures for emergency unberthing in a situation where pilotage
services are unavailable.
Requiring berth masters to fully discuss and share information with vessel
masters.
[2] Tub-boat arrangement
Tug boats are required to maintain the same capability as that is obtainable undernormal conditions, if at all possible. To this end, it is effective to coordinate with theships and make pre-arrangements with the vessel's operator.
If such arrangements are made case-by-case according to conditions, such as theamounts of time before tsunami arrival and the expected height of the tsunami, they
will allow for practical actions that fit the actual situations.
(Example of pre-arrangement, note: “X” means time, “Y” means length, and “Z” means
number of vessel )・Time allowance is X minutes or longer: Z tug-boats will be available.
・Time allowance is X minutes or shorter, and the predicted tsunami height is Y meters or
lower: Z tug-boats will be available.
・Time allowance is X minutes or shorter, and the predicted tsunami height is Y meters or
higher: No tug-boats will be available.

-80-With regard to the cases where the situation is predicted to prevent thearrangement of sufficient number of tug-boats from being available as prearranged, it isnecessary to specifically study in advance, by using the assumptions (ex. “X number oftag-boats are available”; or “No tug-boats are available”), the details of the actions totake (such as how to unberth or how long will it take to make the unberthing); for suchstudies, making reference of the investigation reports on the past incidents will beeffective, or conducting simulations on the individual berth will be desirable.
If the patrol boats or fire boats deployed at the loading/unloading site of a large
vessel carrying dangerous cargo have towing capability, those boats will be used forassisting the vessel’s emergency unberthing.
Table 1 Overview of the safety measures for large-scale tanker berth (skipped)

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-82-

Table 2: Conventional Tsunami Countermeasures or Navigation Safety Measures and Points of Revision, Part 1
Item
1. Securing PowerandCommunication
Means

Challenge(1) Securing the power for berthfacilities

Experienced Incidents and Necessity of Revision(2) Securing communication means
with ships











2. Voluntaryevacuation at thetime of tsunami
strikeLoading/unloading facilities lost functions due to power loss, not released, prevented the vessel from 
unberthing.
A vessel, even having approx. 40 minutes allowance for unberthing if the unloader is released, wasunable to do anything due to power shut-down, and failed to unberth.

Keeping auxiliary power supplies or effective communication means available is indispensable,
for emergency situations.

Very limited number of business operators had prepared tsunami countermeasures on the assumption of 
power loss.
On-board generators or others might be used for supplying power, when technically possible.
Communications between the vessel and land was interfered with by power-loss or telephone line 
congestions that blocked the use of telephone or facsimile.
VHF radio systems were working well to secure vessel-to-vessel communication.
CB-Radio equipment (transceivers) were useful for vessel-to-land communications.

MCA Radio systems were effectively working.
Battery-powered radios were helpful for information gathering.
TV sets, rarely able to receive digital TV broadcasting on board in the off-coast areas, were not available
for getting the information on the tsunami or damage situations.
Some of the business operators, in the wake of the earthquake disaster, equipped their unloaders withemergency power supplies, relocated such unloaders onto higher places, or installed satellite telephonesystems, for preparing the tsunamis in future.

Preparing manuals specifically for the individual business operators on the assumption that there isa risk of the shut-down of power or communication means, and periodically executing drills, isindispensable.
Multiplexing the communication means is indispensable for preparing against the shut-down of
information infrastructures, for the purpose of securing the distribution means ofrecommendations or other information as an alternative to the telephone or facsimile.
Improving of on-board reception and transmission equipment is necessary; and along with that,requesting broadcasting business operators to expand their broadcast areas is necessary. Also
employing BS receivers on board will be effective.

The Regional Coast Guard Office, responsible for the issuance of evacuation recommendation, suffered damages (loss of power, inundation , or others), and the ship agents lost their communication means(VHF, telephone, or facsimile) due to power shut-down; as a result, the tsunami-information or
evacuation-recommendations were not delivered.

Vessels were not able to communicate with cargo owners or ship-agents, due to the power shut-downthat the land facilities suffered.
Pre-arrangements should be established on the actions when a tsunami warning is released—for
example, take the same actions as those for the case where an evacuation recommendation isissued.

(1) Pre-arrangements for the casewhere the secure delivery of atsunami warning or evacuation
recommendation is not be expected(2) Pre-arrangements with regard todecision-making on evacuation

(3) Smooth evacuation of a large
number of vessels

A large number of vessels rushed to the area around the entrances to evacuate off the port; as a result,
such areas got congested; in some cases, on the other hand, vessels approaching a point where
navigation route meet, communicating on VHF radio with the vessels coming-down on the other channel, made the arrangement on the passing order, formed a line and made the merge in safety.

(4)Let non-Japanese speaking crew
know what to do when tsunami
warnings have issued

Some ports have arrangements on evacuation orders for the situation where an earthquake or tsunami ispredicted to occur.

Non-Japanese speaking crew members did not understand what happened and what they were supposed
to do.


Basic Ideas of Solution

Pre-arrangements should be established between the cargo owner, the ship-agent, and the vessel,
too—for example, vessels may evacuate without making announcements.
The issue of the evacuation of on-quay staffs and vessel crew-members should be treated as one ofthe voluntary safety-measures for the tsunami-measures conference, etc. to discuss. The issue ofthe evacuation method of on-quay staffs, in particular, should be discussed so that their evacuation
into the vessel is considered one of the options.
Because, in a case where the time allowance of the tsunami arrival is short, if taking offshore
evacuation without a particular reason, a vessel may have an accident, the evacuation methods forsmall vessels at berth in port areas should be discussed so that such small vessels may be excluded
from the targets of evacuation.
Pre-arrangements on evacuation methods and others should be discussed by the parties concerned,
because ports are often congested by the vessels that conducted their emergency unberthing andgoing offshore.
The education and information delivery of the general knowledge on tsunami and thecountermeasures to non-Japanese speaking crew members is important and indispensable.

-83- ～-84--84- ～-84-

Table 2: Conventional Tsunami Countermeasures or Navigation Safety Measures and Points of Revision, Part 2
Item

Challenge

3. Evacuation
assistance fromthe land and on
the sea

Evacuation in the situation where
tug-boat or pilot assistance are notexpectedExperienced Incidents and Necessity of Revision

Basic Ideas of Solution

The arrangement of pilots, tug-boats, or mooring line workers was difficult during tsunami situation.

There was seen a case where several tug-boats tried in vain to assist a large vessels carrying dangerous
cargo that was drifting due to being pushed by the tsunami wave during its offshore evacuation.


4. Identifying thelocations of safe
evacuationwater-area
5. Evacuation ofvessels carrying
dangerous cargo

Conventionally, on the assumption that pilots, tug boats, and mooring-line workers are arranged,
the studies have been conducted on offshore evacuation; however, the actions or measures should
be made for a situation where no arrangement is made.
It is indispensable to have knowledge on the number and performance of the tugs that can bearranged in an emergency situation, and to have conducted the studies on the unberthing methodby which their assistance works effectively.
It is desirable to agree on the pre-arrangements with regard to the actions and communication
arrangement in an emergency situation with tug-boat operators and pilots.

Information sharing on safe offshore
evacuation water-areasWith regard to offshore evacuation, there was no information available on how far off the port to 
evacuate for securing safety.

Clarifying and sharing information on the safe evacuations areas where tsunami impacts would beless for individual vessel types, is indispensable.

(1) Criteria of the suspension ofloading/unloadingConventionally, a tsunami forecast is released within approx., 3 minutes

Laws and regulations, targeting some kinds of operation sites, specify the earthquake intensities forwhich pumps must be stopped and emergency-shut-down valves must be closed.
Studies on the timing of the suspension of loading/unloading are required, including it as one ofthe options that loading/unloading must be suspended, not waiting for the release of tsunami
forecast, and the actions must be initiated for the preparation against the coming tsunami.
Between-land-and-vessel pre arrangement is necessary on the criteria for the suspension ofloading/unloading at the time of earthquake occurrence.

(2) Evacuation methods (offshore,anchored sheltering, mooringenhancement, or on-terrene
evacuation)

Evacuation methods must be decided according to the time allowance to tsunami arrival, the timerequired to choose between the evacuation to a safe water area, offshore evacuation, anchored sheltering,
mooring enhancement, and on-land evacuation.
A vessel carrying dangerous cargo, if causing a secondary disaster in port areas, will give exert severe
impact on vessel-traffic safety.
No assistance by pilots, tug-boats, or mooring line workers is expected, or the power required to un-berth
will be lost due to the power shut-down that occurred on terrene, in the situation where a vessel is forced
to unberth.
Looking into the situations of the vessels that chose anchored sheltering, it is clear that the vessels thathave completed anchoring before the tsunami arrival suffered relatively less damages.
A vessel that chose moored sheltering should keep its main engines ready as well as enhancing themooring force by adding mooring lines.
The oil fences had to be removed for a vessel to unberth; however, working boats failed to come close;
although oil fence releasing was tried from the land, such work was difficult due to strong tension at theconnecting section; finally, the connecting section was cut-off with knives.

With regard to enhanced mooring, hull motions simulations should be conducted to estimate themooring critical conditions (mooring limit), and then the studies should be conducted on what
actions should be taken, based on such estimations of critical mooring conditions.
With regard to anchored sheltering and offshore evacuation, what actions should be taken should
be figured out with the assessment of the impact on the vessel by the tsunami.,
It is necessary to establish a system for prompt collection of oil fences so that they do not obstructemergency unberthing works.
As regards emergency response such as stoppage of cargo handling and unberthing, it is necessary
to develop a manual for such operations and to conduct regular training exercises.











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-85- ～ -86-

Table 2: Conventional Tsunami Countermeasures or Navigation Safety Measures and Points of Revision, Part 3
Item

Challenge

Experienced Incidents and Necessity of Revision

5. Evacuation ofvessels carrying
dangerous cargo(3) Moorage method for large 
vessels carrying dangerous cargo

6. Evacuation
methods for othervessels than vessels
carrying dangerous
cargo(1) Criteria for the suspension ofloading/unloading (except forpassenger vessels and pleasureboats)(2) Evacuation methods (offshore
evacuation, anchored sheltering,
mooring enhancement, or on-terrene
evacuation)(3) Mooring methods for large
vessels

7. Post-tsunami(1) Necessary information to
information-delivery damaged vessels or vessels into vessels
evacuation

Time required for offshore evacuation must be reduced.
Emergency self unberthing must be taken into consideration.
In the middle of an emergency shut-down operation in an oil refinery, a casualty case occurred inducedby the tsunami.

In general, vessels should be berthed with head-out that the difficulty of emergency self unberthingis reduced, and the time required for making an offshore evacuation is shortened; however,whether to berth head-in or head-out must be decided case by case according to the conditions orsituations of the berth or the vessel—how deep and wide is the water area surrounding the berth,
how heavy is the vessel traffic around the berth, what kind of loading/unloading facilities areavailable on the berth, what kind of singularity the weather or sea conditions around the berthhave, and what condition the vessel is in. If the vessel decided to berth head-in, the measures for
reducing the time required for unberthing must be prepared if necessary, such as arranging
tug-boats for unberthing assist, or applying the equipment (must be remote-controllable) with thecapability of quick release. ESDS or ERS is equipment that ensures that a vessel can make its
emergency unberthing even in the middle of loading/unloading.
Assessment using simulations on vessel navigation or maneuvering is required.
Studies and discussions should be conducted through referencing the cases of vessels carrying
dangerous cargo.



Same as the backgrounds with regard to vessels carrying dangerous cargoSame as the backgrounds with regard to vessels carrying dangerous cargoStudies and discussions on the appropriate evacuation methods, by the type andSize of vessel must be conducted, in addition to those for vessels carrying dangerous cargo.



Same as the backgrounds with regard to vessels carrying dangerous cargoStudies and discussions should be conducted through referencing the cases of vessels carrying
dangerous cargo.



Ship agents and other suffered damage or lost power; no information on the situations of the ports 
including the availability of port infrastructures or water route in the ports were available; those vessels
were trapped in a situation where they had no way to make decisions.
The information was also unavailable on obstacles drifting on the surface in the ports or in the coast
offing.
The navigation safety information that was issued by the Coast Guard Office represented positions bylatitude and longitude; however, such representation was not easy to understand; such position
representation as “X degrees Y miles from Z” will be easier to understand.
Although the ministries or agencies concerned posted the information related to the earthquake on the Internet, such information was not delivered to the damaged vessels or sheltering/evacuated vessels
Hydrographic and Oceanographic Department posted on their web pages their graphical informationthat represents on a map the navigational warnings with regard to the situations of the obstacles drifting 
in the offing of the coasts damaged by the tsunami.
General vessels having the capability of Internet connection are rare; almost all the general vessels
staying in the offing had no other way of information gathering than getting information via their ship
agent, etc. using facsimile and others.

With regard to the availability of port infrastructures, situations in the port such as water depth orchannel availability, and the obstacles drifting around the offing of the coast, easy to understandinformation should be delivered.

(2) Means for information provision

Basic Ideas of Solution

It would be reasonable to assume that, as the information delivery means to the vessels staying in
the offing for evacuation, the navigational warning or the Internet will be playing a central role;
however, the delivery of information should desirably be done in an easy-to-understand way.
Foreign vessels, in particular, must be given such information in an easy-to understand way.

-87- ～ -88-

-87- ～ -88-

III. Conclusion
In this part, the summary of the following is introduced: the “Questionnaire/Interview
Survey on the Great East Japan Earthquake” conducted by the Japan Association of Marine Safety in
FY2011; and the “Research and Study on Navigation Safety Measures at the time of Major
Earthquake and Major Tsunami” conducted by the same association in FY2012 and 2013.
The survey in FY2011 was conducted mainly by means of questionnaire or interview of
the crew members who were on-board the vessels that stayed in the ports that were affected by the
Tohoku Pacific Offing Great Earthquake on March 11, 2011, and also to the organizations and theirmembers having involvement to such ports
On the other hand, the research conducted in FY2012, through compiling and analyzing
the lessons and problems that were found during the survey by the Central Disaster Management
Council and the previous fiscal year’s survey, presented a general view of the damages due to theGreat East Japan Earthquake; furthermore, the research, through compiling and analyzing of theincidents related to the current tsunami measures/navigation safety measures, extracted the problems
to review and study concerning such measures; finally, the research showed basic ideas for the
improvement and enhancement of such measures.
Moreover, the association, picking up Shimizu Port as a model, conducted the surveys on
the current Tsunami Safety Measures for the port; in addition, the association executed tsunami
simulations applying the Nankai Trough Major Earthquake Fault Model and made the assessment of
the impacts that the port is expected to suffer; then, the association conducted the studies on themeasures applicable to the port. In addition, the association, for the purpose of determining thecritical mooring conditions for large vessels carrying dangerous cargo (VLCCs or LNG tankers),
made assessments on tsunami impacts by executing hull-motion simulations.
In FY2013, the association studied the critical mooring/anchoring conditions for large
vessels carrying dangerous cargo and general vessels (3,000 DWT class and 10,000 DWT class). At
the same time, the association conducted simulations for the following: the studies on the behaviorsof large vessels carrying dangerous cargo during their emergency unberthing maneuvering, byapplying a hypothetical quay; a large cargo vessel’s emergency unberthing under tsunami forces, byapplying simulated tsunami forces in the model port; the maneuvering of cargo vessels (of 3,000
gross tonnage, and of 500 gross tonnage) from their outgoing berthing. In addition, the association,
based on the findings from such simulations and others, studied the safety/disaster prevention
measures for large vessels carrying dangerous cargo.
The association has reflected the outputs of the studies/discussions at the researchcommittee, the basic concepts, and the experiences or findings in the “Appendix: Guides to the- 89 -

Preparation of Tsunami Safety Measure in a port,” which is believed to contribute to the preparation
or review of tsunami measures for individual ports.
With regard to the assignment of roles to the individual parties concerned, the parties
concerned are required to discuss and agree on pre-arrangements, at the conference of Tsunami
Safety Measures for vessels, along with the discussions or review of Tsunami Safety Measures.

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(1) Securing electric powers and communication means
Summary: It is required to keep the emergency power sources prepared forloading/un-loading facilities or mooring so that they work well in emergency situations
caused by power shut-downs.
In the Great East Japan Earthquake, power loss caused by the earthquake madeloading/unloading facilities go down and prevented them from being cut off from the vessel, and as aresult the vessel failed to conduct emergency unberthing. For instance, a vessel, although having atime allowance of about 40 minutes until the tsunami strike, was unable to do anything because of
power loss.
In addition, with regard to emergency power supplies, it is recommended to take tsunami
countermeasure such as relocating the emergency power supplies on the upper floors because if
installed on the ground floor, they may face a risk of function loss due to the inundation caused bytsunami water.

Summary: Emergency communication system should have a multiplexed configuration
where means other than telephones or facsimiles, so that the system is able to function
even in a case where the communication infrastructures have lost their functions due todamages.
With regard to the multiplexing of communication means, the utilization of the satellite
telephone systems or MCA Radio system* which have been used by some business operators will be
the candidates for the alternative communication channel; furthermore, the utilization of port radios
for relaying instructions of the Captain of the port, such as evacuation recommendation, is feasible,
and it will be another form of multiplexing of communication means.
* Note: MCA Radio system is a business-user oriented mobile communication system where a number ofusers share multiple channels; MCA has been permitted as an alternative communication system to theemergency municipal radio communication system. Some vessels use MCA Radio system because it
covers coastal areas.

(2) Pre-arrangement[1] Pre-arrangement for a case where the evacuation recommendation is not delivered
Summary: Parties concerned should agree on the actions for disaster prevention, such as“In a case where a tsunami warning, etc. is released, by taking the same actions as agreed
for the case of an evacuation recommendation.
In the case of the Great East Japan Earthquake, situations were seen as follows: Coast
Guard Offices/Stations, which was responsible for issuing orders, lost such functions due to power
loss or inundation, and also the ship agents were not able to use communication means such as VHF,
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telephone or facsimile due to power shut down. As a result tsunami information or evacuation
recommendations were not delivered; hence, prompt and proper actions were not taken.
[2] Pre-arrangement on vessel’s decision of evacuation
Summary: Pre-arrangement should desirably be done in advance on the decision making
procedure of vessel evacuation method; and available assistance, etc., so that, in thesituation where a tsunami warning has been released. The vessel master, making proper
judgments on the vessel actions in the tsunami-strike situation, prompts speedy and proper
actions under the pre-arrangement described.
In the cases of the Great East Japan Earthquake, such incidents described in the following
were often seen: the vessel master solely by his judgment has to decide every action because
communications to cargo-owners, vessel operators, or ship agencies had been blocked due to thepower-loss and communication congestions that occurred in the land facilities.
[3] Pre-arrangement on vessel-evacuation support scheme
Summary: On the vessel master’s evacuation decision including an emergency unberthing,
the availability of the assistance by pilot, tug-boat, or mooring-line worker will have asignificant impact; therefore, it is desirable for parties concerned to agree on
pre-arrangement on such matters.
The following should be remembered: in the cases of the Great East Japan Earthquake,around the ports that suffered severe damages, the vessels rarely received assistance from pilots,
tug-boats or mooring-line workers.
[4] Pre-arrangement by parties concerned on offshore evacuation
Summary: Because, vessel traffic in the port is expected to be congested by the vessels on
their way to the offing, it is recommended for the parties concerned to agree on
pre-arrangement on emergency evacuation.
In the cases of the Great East Japan Earthquake, severe vessel traffic congestions occurred
around the levees at the port entrance by many vessels rushing to the entrance.
On the other hand, there was an instance that vessels approaching a channel meeting point
on one of the passage, having VHF radio contact to the vessels coming on another passage,
determined the order of passing the cross-point, formed lines according to the passing order madesuccessful evacuations(3) Keeping non-Japanese speaking crew members informed of tsunami general knowledge anddelivering tsunami information to them
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Summary: Non-Japanese speaking crew members must be kept informed of tsunami
general knowledge and countermeasures.
In the case of the Great East Japan Earthquake, non-Japanese speaking crew members, atthe time of the earthquake occurrence did not understand what happened or did not know what they
were supposed to do
Therefore, it is essential to keep non-Japanese speaking vessel-masters informed of thefollowing items by means of distributing brochures or leaflets so that they properly execute thefirst-hand actions or the countermeasures in the situation of tsunami strikes:
・General knowledge of earthquake (likelihood of occurrence, expected scale, etc.) that are
expected in the vicinity of their way ports;
・How to collect information at the time when an earthquake or an tsunami breaks out;
・Hazard map
・The pre-arranged emergency countermeasures in the port; such as first-hand actions,
Tsunami Safety Measures and safe offing areas to evacuate;・Recommendation of the Captain of the port’s and others.
(4) Sharing information on the evacuation areas where vessel safety is secured
Summary: Information on the safe areas that will receive less tsunami impacts must be
shared in advance.
It is recommended, through executing tsunami simulations, that knowledge on tsunami
impacts on the areas that are used for offshore evacuation/stand-by; is shared by the parties
concerned including vessels.
The tsunami simulations executed on the Shimizu-Port model shows the following:
In the offing areas with a water-depth of deeper than approx. 200 meters, although thesea-level changes may be observed there, the tsunami-water flow-speed is less than 0.5 meters(approx. 1 knot); it indicates that in such areas, tsunami impacts are expected to be relatively small.
(5) Critical mooring conditions and critical anchoring conditions
Summary: The mooring hull-motion simulations in the model port (Shimizu-Port) by applying
waves of tsunami-wave form or sine wave form revealed that the critical mooring conditionof tsunami-height is approx. 1 to 3 meters for VLCCs or large LNG vessels, and is approx. 3
to 6 meters for10,000 DWT class or 3,000 DWT class vessels.
The magnitude of moored vessels’ motion, under different combinations of tsunami height
and tsunami flow speed, was obtained through executing tsunami simulations on the Shimizu-Portmodel for the waves of tsunami wave-form or sine-wave (with a period of 5/10/15 minutes); thefindings are shown as follows:- 93 -

(a) Critical mooring condition of tsunami height becomes lower when both the impact oftsunami height and the impact of tsunami-water flow are exerted at the same time.
(b) Critical mooring conditions become lower (meaning more severe) as the tsunami period
gets shorter; it indicates that not only a tsunami height but also a rapid rise in water level
affects critical mooring conditions.
In addition, the following findings were obtained:
With regard to VLCCs and large LNG tankers, when waves of tsunami-wave-form areapplied to the mooring vessel, the mooring reaches its critical situation at the tsunami-wave height of
3 meters if the tsunami wave is hitting the vessel from the direction along the ship center line, and at
the height of 1 meters if the tsunami wave is hitting from the beam direction; and for the waves ofsine-wave form, the mooring reaches its critical situation at the tsunami-wave height of 1 meters fora period of 5 minutes, 2 meters as for a period of 10 minutes, and 3 meters for a period of 15
minutes.
With regard to the vessels of 10,000 DWT class or 3,000 DWT class. the mooring reaches
its critical situation for a wave of tsunami-wave-form at the height of 6 meters if the tsunami is
hitting the vessel from the direction along the ship center line; and for a sine-wave tsunami, themooring reaches its critical situation at the tsunami height of 3 meters for a period of 5 minutes, and6 meters for a period of 10/15 minutes.
Generally, a tsunami period is in the range of several minutes to several tens of minutes,
and the period becomes shorter— it means the water level rises rapidly—at the point closer to theearthquake source, and longer —it means the water level rises relatively slowly—at the point fareraway from the earthquake source.
For instance, with regard to the tsunami-waves that would be caused by the Nankai
Trough, at one of the three major bays (Tokyo-wan, Ise-wan, and Osaka wan), because it’s far awayfrom the expected earthquake source, the tsunami-wave period is relatively long (meaning that thewater level rises slowly); therefore the critical mooring conditions are expected to be larger(meaning more moderate) than the values shown above.
It should be noted that, because the simulations mentioned above assumed that vessels aremoored with usual mooring methods, the proposed mooring conditions should be applied to the casewhere vessels are moored with usual mooring methods; therefore, the mooring-force improvement
method such as the addition of mooring lines, in particular breast lines and spring lines or the
retorquing of mooring-drum brakes is expected to raise (meaning alleviate) the critical mooring
conditions.

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Summary: With regard to the vessels in anchored sheltering, the critical mooring conditionof tsunami-water flow speed when the vessel is hit by tsunami waves is approx. 3 to 6 knots;
when assuming swing angle is 15 degrees, the critical condition is approx. 2 to 4 knots.
Note that the critical tsunami-water flow speed shown above was obtained when thefollowing conditions were assumes:
Type of anchors: JIS or AC14;
Anchoring method: single anchor;
Vessel type: 500 DWT class to 300,000 DWT class
Water depth: 15 meters for 500 DWT class and 3,000 DWT class; 20 meters for 10,000
DWT class and 30,000 DWT class; 30 meters for 60,000 DWT class, 200,000 DWTclass and 300,000 DWT class;Anchor cable extension length: obtained from the equation,S (m) = 3D + 90 (where, D isthe depth of water)(6) Feasibility of the emergency unberthing of a large vessels carrying dangerous cargo
Simulations were conducted with regard to the situations where large vessel carrying
dangerous cargo is trying to make an emergency unberthing off a hypothetical quay, on the different
assumptions as follows:
Berthing head-in or head-out;
Assisted by a tugboat or not;Equipped with thrusters or not..
The outputs of the simulation indicate the following:
Summary: A single tug-boat is able to assist a vessel to make an emergency unberthing
under on-shore wind of 5 m/sec.
(a) Assumption: the vessel is using stern-kick maneuvering; wind is on-shore of 5 m /sec;
the vessel is not using a thruster; the vessel is not assisted by a tug-boat.
The vessel does not make an emergency self unberthing, because of provabilityof damage on quay and/or hull.
(b) Assumption: the vessel is assisted by a single tug-boat; the vessel is using stern kick;the tug-boat is pulling the bow.
The vessel makes a transfer with a low risk of damages to the hull or the fenders.
Furthermore, during the vessel’s turning, the tug-boast makes an effective assist

Summary: A large LNG tanker, if equipped with a thruster, makes an emergency
unberthing under on-shore wind of 5 m/sec.

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(a) Assumption: the vessel is a LNG tanker equipped with a thruster; stern-kick is appliedon the stern, and the bow thruster is used.
The vessel is able to make a transfer off the quay. The risk of damages to thehull and fenders is low. The vessel makes an emergency unberthing.
(b) Assumption: assistance by a tug-boat is available; the vessel is using thrusters:
Such method makes vessels maneuvering easier during the vessel’s unberthing:furthermore, while the vessel is turning, it helps the vessel accomplish a relatively large
turning angular speed in a short time.
.
(7) Suspension of loading/un-loading
Summary: Loading/unloading must be suspended when tsunami information such as a
Major Tsunami Warning/Tsunami warning, or Tsunami Advisory is delivered.
In some cases where an earthquake breaks out in a close-to-coast area, there is a chance ofa tsunami arriving before the Meteorological Agency releases the tsunami warning or otherwarnings.
Vessels must make efforts to collect information when sensing a strong (intensity 4 orgreater) earthquake, or even in the case of a small earthquake when sensing slow but long-lasting
motions.
(8) Evacuation: how to choose and execute evacuation method (offshore evacuation, in a port
sheltering, moored sheltering, or on-terrene evacuation).
Summary: Vessels, according to the length of time allowance for the arrival of the tsunami
and the time required to make an evacuation to safe water, must choose most appropriate
evacuation method—offshore evacuation, in a port sheltering, moored sheltering, on-landevacuation, or others.
Among the vessels that were sheltered inside a port using an anchor in the Great East
Japan Earthquake, those that were already anchored before the tsunami arrival suffered less damage.
When strengthening the mooring and sheltering the ship at the port, use extra mooringlines and/or apply additional tightening to the brakes of a mooring drum. At the same time, be readyfor starting the main engine and anchorage.
Large vessels may face a risk of damages to quay or their hull, in a situation where tugboat
assistance or thrusters are unavailable.

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(9) Safety measures for large vessels carrying dangerous cargo[1] Requirements to quay masters
Summary: Quay masters, with regard to the berthing method of large vessels carrying
dangerous cargo, are required to make decisions on the berthing method, while considering
the superiority of berthing with head-out, through comprehensive considerations including
the current berth utilization or situations.
Although, in general situations, berthing with head-out is considered better to make a safeand prompt emergency unberthing, quay masters should decide the berthing method at individual
quays through comprehensive study, as well as the time required for unberthing, safety andconvenience of berthing/unberthing in normal situations.
Note: tugboat arrangement and thruster facilities will be effective for a safe and prompt
unberthing, regardless of berthing direction.

Summary: Quays should desirably be equipped with remote-controllable quick releasehooks, ESDSs, and ERSs(a) Quick release hook: In light of the lessons of the Great East Japan Earthquake that theworker, while engaging in the unberthing operation of a tanker, suffered damages bytsunami, and in addition when considering the case where worker are unavailable, quays
should desirably be equipped with remote-controllable hooks if allowed.
(b) ESDS or ERS: they are so effective that the execution of emergency unberthing will becompleted with less difficulty and in less time, and should be installed with emergency
powers.

Summary: with regard to oil tankers, etc., the preparation of such arrangement of housing
oil-fences, which have been expanded prior to loading/unloading, so that such fences will
not interfere with emergency unberthing, is required. In addition, oil fences, etc. should be
expanded in such a way that they will not, due to run-off by tsunami, interfere with vessel
traffic.
In a case of the Great East Japan Earthquake, such oil fence removing, which wasnecessary for a tanker to unberth, was not executable because the working-boat had no chance ofcoming close to the fence; hence, the operation, done by the work from the land, involved
considerable difficulty.

Summary: with regard to the emergency procedures of loading/unloading suspension or
unberthing, quay masters are required to prepare manuals and periodically execute drills.

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With regard to training, the involvement of vessels will improve the training effectiveness;quay masters should not miss any chance of training—table top exercises, dry-run drills or
drill-execution at the time of usual unberthing will be effective.
[2] Vessel-side arrangement
Summary: Though there is a possibility of difficulty in unberthing caused by physicalobstacles or problems of safety, vessels are required to prepare, in collaboration with quay
masters, the procedures such as mooring-force enhancement which is required for mooredsheltering.

Summary: Membrane-type tankers, during their emergency unberthing, must at first makeefforts to leave the quay regardless of tank load level, and then start maneuvering so thatvessel motions due to tsunami-waves, winds, or heaves will be alleviated to be as small as
possible; and in addition, such tankers are required to consider, as one of the practicalmeasures, shifting cargo within the allowable range of loading criteria.
Membrane-type LNG tankers have a risk of tank damage due to sloshing depending on the
LNG quantity in the tank— sloshing is a phenomenon where the LNG loaded in tank moves in asynchronous way with the hull motions, and as a result strongly hits the tank walls.
[3] Assistance arrangement
Summary: Pre-arrangement with the pilot associations on the pilotage in emergency
situations will be effective. Quay masters are required, for the emergency unberthing where
pilots are unavailable, to conduct preliminary studies on such procedures, and in addition, tohave meetings with vessel masters.

Summary: Tug-boasts should aim to show equivalent performances to those in their usual
operations as much as possible; therefore, it will be helpful for vessels to havepre-arrangement with vessels.
Such pre-arrangement should be made for individual cases classified with thesituations—for example, how much time is allowed before the tsunami arrival, or how high the
expected tsunami height is; making such case-by-case pre-arrangement will ensure practical actions.
(Classification of situations: example)
・If the time allowance is longer than X minutes, Z tug-boats will be available.
・If the time allowance is shorter than X minutes, and the expected tsunami height is lower
than Y meters, Z tug-boats will be available.
・If the time allowance is shorter than X minutes, and the expected tsunami height is higher
than Y meters, no tug-boats will be available.
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Summary: In a case where the escort boats/fire boats deployed at the site ofloading/unloading of a large vessel carrying dangerous cargo have towing capability, they
will be used for emergency unberthing.
(10) Emergency unberthing on the model port (Shimizu Port)
Summary: The tsunami simulations on the model port (Shimizu Port) revealed that, during
the tsunami strike, it was difficult to surely make a series of manoeuvers from emergency
unberthing/turning to leaving port.
The studies on the emergency unberthing feasibility of a large container vessel andmaneuvering methods, on the assumption that the vessel is trapped in a tsunami based on thesimulation outputs on the model port (Shimizu Port), revealed the following:(a) The hypothetical vessel did not make unberthing in onshore tsunami flows; on the other
hand for offshore flows, the vessel made unberthing.
(b) In the situation where the vessel speed had not yet been increased to a fast level, it was
likely for the vessel to lose control against a tsunami flow of a speed of more than approx.
2 knots; furthermore, once the vessel lost control, there was a risk of grounding in shallow
water or a risk of collision with a quay or levee.
(c) Once the vessel had managed to move to the area where the flow situation was relatively
moderate, several cases were seen where the vessel, recovering its turning ability, secured
the steerage by increasing the engine output almost to its maximum and made a safe
evacuation off the port.
(d) Once the vessel managed to make unberthing, the vessel was able to anchor in port
areas; therefore, it was necessary to pre-determine the area for making anchored sheltering,and to stand by for dropping anchors.

Summary: A cargo vessel of gross tonnage of 3,000/500 tons, passing through the port
entry, made offshore evacuation, during the tsunami strike.
Vessel-maneuvering simulations were conducted for the purpose of studying the feasibility
for a cargo vessel of gross tonnage of 3,000/500 tons to proceed from the far end of the port along
the navigation route, pass the port entrance, and make offshore evacuation, in the situation of
forwarding/back-lashing waves and large eddy currents. The results are shown as follows:(a) The vessel made its evacuation off the port if the vessel succeeded in securing its
steerage by raising its engine output to almost its maximum.
(b) The vessel, while passing the port entrance with its maximum engine output at thetiming when the tsunami water was back-lashing, was able to keep its course relatively- 99 -

stable compared with the cases of forwarding flows or large eddy currents, in addition, thevessel’s drifting was small; hence, the vessel made s stable navigation.
(11) Post tsunami-strike information provision
Summary: To the anchored-sheltering vessels in the offing, easy-to-understand and useful
information on the availability of port infrastructures, the situations in port areas including
navigation route and their water depths, and navigation obstacles drifting on the water
surface must be delivered.
In the case of the Great East Japan Earthquake, such vessels were totally unable to get
information on the situations in the port including the availability of port facilities, whether
navigation route were available or not, and the information about navigational obstacles drifting on
the surface in port areas or in the near-by coast areas, because their ship-agents suffered damages orlost powers; such information shut-down interfered with such vessels’ making decisions on go/no-goof port re-entry. In addition, there were many cases observed where, unfortunately due to the shift ofground TV broadcast to the digital broadcast system, the vessels staying in the offing were unable tocollect the information on tsunami information or damage situations via television broadcasts.
Therefore, as well as the improvement of broadcast reception equipment on vessels, it will
be effective to request the broadcast business operators to expand their broadcast range; in addition,
the improvement of satellite-broadcast (called BS) reception environments will be effective.
With regard, in particular, to the information delivery to the vessels anchored sheltering in
the offing, because the Navigational Warning System or the Internet plays the central role for
information gathering, the preparation of systems to enable foreign vessels to understand theinformation delivered via such means will be necessary.
At the same time, vessels sheltering in the offing are recommended to try to inform theparties concerned of the situations of the nearby areas, and, in addition, to try to exchange
information with other vessels staying in the offing.

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Research on Navigation Safety Measuresin the Event of Major Earthquake/Tsunami Strikes
Final Report (Excerpt)
Released on February, 2015
The Japan Association of Marine Safety
6th Floor, Isomura Bldg.,
Toranomon 1-1-3, Minato-ku,
Tokyo, Japan, 105-0001
Contact: +81-3-3502-2233 (phone), +81-3-3582-6136 (fax)Japan Maritime Center
4th Floor, Kaiji Bldg.,
Kojimachi 4-5, Chiyoda-ku,
Tokyo, Japan, 102-0083
Contact: +81-3-3263-9421 (phone), +81-3-3264-5565 (fax)