Ship casualties in the Balitic, Gulf of Finland and Gulf of Bothnia in 1971 - 1975

OTANIEMI FINLAND REPORT Nor

SHIP CASUALTIES IN THE BALTIC, GULF OF FINLAND AND GULF OF BOTHNIA IN 1971-75

BY

VALTER KOSTILA1NEN AND MAIJA HYVXRINEN

Page

ABSTRACT 5

INTRODUCTION 6

DATA COMPILATION 6

TYPES OF CASUALTIES AND THEIR LOCAL AND

TIME-DEPENDENT DISTRIBUTIONS 8

FLAG, TYPE AND AGE OF SHIPS INVOLVED 16

SHIP SPEED, AND CONDITIONS OF VISIBILITY

AND WEATHER 18

THE USE OF NAVIGATIONAL AIDS 24

DIMENSIONS AND LOCATION OF DAMAGE 26

LOSS OF LIFE, NUMBER OF INJURED, AND

TOTAL LOSSES OF SHIPS 29

CAUSES OF CASUALTIES 29

CONCLUSIONS 31

ACKNOWLEDGEMENT 32

SHIP CASUALTIES IN THE BALTIC, GULF OF FINLAND AND GULF OF BOTHNIA IN

_1971-75

by

Valter Kostilainen and Maija Hyvarinen

ABSTRACT

Data relating to a total 707 ship casualties in the Baltic area during

1971-1975

have been compiled and

analy-sed, and a presentation is made of the results obtained. The discussion included concerns local and seasonal distri-bution, along with distribution of the casualties by other time-dependent variables. An account is given of the conditions of weather and visibility, and the use of

navigation equipment at the time concerned. The statistics further cover the type of ship involved, its nationality, age, and speed. Some correlations are discussed, and emphasis laid upon the need for a more efficient casualty reporting system.

HELSINKI UNIVERSITY OF TECHNOLOGY

Ship Hydrodynamics Laboratory Espoo 1976

INTRODUCTION

This study represents a direct continuation of earlier research [11[2]. Notwithstanding the deficiencies

disco-vered in the compilation of casualty data, very little progress can be remarked in this respect. An efficient "on the spot" approach to the compilation of casualty data relating to Swedish ships has been outlined in Sweden [3].

The data compiled for each casualty took the same form as before, and thus the analysis was limited to the same general aspects. The larger size of sample enabled some new conclusions to be drawn.

DATA COMPILATION

For the main part, the first information on accidents was obtained from Lloyd's Weekly Casualty Report. In

addition to this, the Boards of Navigation in Finland and Denmark issued reports on some casualties. It is signifi-cant that in some cases the initial information concerning accidents in Finnish waters was derived from newspapers. To complement this information, Ship Casualty Cards, as

illustrated in [11 were first sent to the captains; if no answers were received, questionnaires were addressed to

the shipowners concerned. Table 1 indicates the percentage proportions of questionnaires returned.

In view of the relative number of ships from the Soviet Union and E. Germany that navigate in the Baltic area, the numbers of casualties sustained by Soviet and German vessels seem low; this is probably attributable to Lloyd's Weekly Casualty Reports providing the initial source of

information. For practical reasons, these reports can not cover all of the casualties to ships from the Soviet Union and E. Germany. In the few cases in which initial infor-mation was derived from Lloyd's Weekly Casualty Reports, little additional information was obtained from the ship or from the shipowner. This one-sided reduction of the

sample exerts an adverse effect upon the reliability of regional statistics of this type.

The damage information was punched on cards for data processing. For the analysis, there was applied the sta-tistical programme system HYLPS, in a computer UNIVAC. 1108. All of the information is stored on magnetic tape.

TABLE 1. FLAG DISTRIBUTION OF QUESTIONNAIRES SENT, AND PERCENTAGE PROPORTIONS OF RESPONSE

W. GERMAN, III 47 FINNISH 89 75 DANISH 74 62 SWEDISH 85 48 POLISH 511 63 NORWEGIAN 42 71 DUTCH, 25 64 BRITISH 39 59' GREEK 38 42 SOVIET UNION 24 17 LIBERIAN OS 611 CYPRIOT 26 19 E. GERMAN _{IR 20} PANAMANIAN O3 31, ICELANDIC 5 60 ITALIAN 3 33 SPANISH 6, 50 FRENCH 4 75 BRAZILIAM 41, MOO PAKISTANI TOO EGYPTIAN, a o BELGIAN / 50 INDIAN I a CUBAN 2' 0 JAPANESE '1, 43 YUGOSLAVIAN I 100 -SINGAPORE

2000'

CZECHOSLOVAKIAN 1 100 UNITED STATES V o LIBYAN ai 0

TOTAL NUMBER OF PERCENTAGES OF

FLAG QUESTIONNAIRES QUESTIONNAIRES

TYPES OF CASUALTIES AND THEIR LOCAL AND TIME-DEPENDENT DISTRIBUTIONS

Fig. 1 presents the types of casualties, of which 42.3 % arose from grounding, 36.5 % collision (ship-to-ship casualty),

11.2 % ramming (ship-to-object casualty), 5.4 % foundering and capsizing, and

3.3

% explosions and fires.

FIG. I. TYPES, NUMBERS, AND PERCENTAGES OF THE 700 CASUALTIES

The local distribution of casualties is indicated in Fig. 2; the local distributions of the different types of casualty are presented in Fig.

3.

The number of cases of grounding is comparatively large in the Sound, Great Belt, Kalmar Sound, Stockholm approach, the Gulf of Bothnia, and in the surroundings of Aland, with collisions being most

frequent in the Fehmarn Belt, Kieler Bucht, and in other parts of the Baltic.

EXPLOSIONS AND/OR FIRES FOUNDERINGS, CAPSIZINGS AND FLOOD INGS HEAVY WEATHER AND ICE DAMAGE (5) 0.7

FIG. 2. LOCAL DISTRIBUTION OF CASUALTIES. LETTERS ON X-AXIS REFER TO THE FOLLOWING DIVISION INTO DISTRICTS

A SOUND D KALMAR SOUND G GLAND WITH SURROUNDINGS GREAT BELT E OTHER PARTS OF THE

HI GULF OF BOTHNIA, BALTIC

C FEHMARN BELT

AND KIELER BUCHT F STOCKHOLM APPROACH I GULF OF FINLAND

_ O GROUND/NGS

COLLISIONS RAMMINGS

El EXPLOSIONS AND/OR FIRES FOUNDERINGS, CAPSI2INGS, FLOODINGS

FIG. 3. LOCAL DISTRIBUTION OF THE DIFFERENT TYPES OF CASUALTY. LETTERS ON X-AXIS REFER TO THE DIVISION INTO DISTRICTS PRESENTED IN FIG. 2

OBELI CZGROUNDINGS OPEH --r OPEN --r-S.OUND, APPROACH--1RORT SEA COAST PASSAGE TO THE PORT AREA W4G. Y. DISTRIBUTION OF CASUALTIES BY

DIFFERENT TYPES OF SAILING AREA

OPEN SOUND, APPROACH FOR

COAST PASSAGE TO THE PORT AREA

EEG, D. DISTRIBUTION OF DIFFERENT TYPES OP CASUALTY BY SAILING AREA

,E3COLLISIONS RAAmINGS

"EaEXPLOSIONS AND/OR FIRES 110 POUNDERINGS, CAPSIZINGS FLOODINGS 9S. S. 65. 26.

It is evident from Fig. 4 that 35 %. of the casualties occurred in sounds and passages, 28 % in port areas, and 22 % in approaches to the port. Fig. 5 indicates that most of the casualties. in the first-mentioned group took the form of

grounding.

The seasonal distribution of casualties is presented in Fig. 6. The main feature of this distribution resembles, that of the distributions presented earlier [11114], with the maximum falling at the beginning of the year and at the end, and with the minimum casualty figures in the summer.

i\

k A

\

_/

z, ,L0

,

Lu

_/

/ - >

r

1\V

O. 2 3 5. 6 7 8

MONTH

FIG. 6. SEASONAL DISTRIBUTION OF CASUALTIES,

9 VD Il 112 18,. YEAR 1971 YEAR 1972 YEAR 1973 YEAR 1974 1G. YEAR 1975 YEARS 1971.:.11975 tM _A

\

e. --1 ₄

Fig. 7 illustrates the seasonal relation between diffe-rent types of casualty; it is appadiffe-rent that most of the cases of foundering and capsizing occurred in the stormy autumn period. The proportion of collisions is highest in spring and early summer, and that of groundings in

autumn. 100 90 BO 70 -60 9,50 '30 20 10

FIG. 7. SEASONAL RELATION BETWEEN DIFFERENT TYPES OF CASUALTY

Fig. 8 illustrates the distributions of casualties by watches. The frequency of casualties is highest during

the midnight watch. The distribution of groundings by watches demonstrates a clear periodic feature, with the minimum at daytime and the maximum at evening and night. The distribution of collisions is more even. This

diffe-rence in the distribution by watches of collisions and

groundings might be attributable to navigational lights and to the increased role of radar navigation. The

possible loss of radar echo at close ranges in two-ship encounters is compensated by the visual observation of navigational lights. However, the coast line and landmarks are difficult to recognize in radar screen and in general

GROUNDINGS COLLISIONS RAMNINGS FIRES, EXPLOSIONS FOUNDER INGS, CAPSIZINGS, FLOOD INGS 6 8 'II

26. N. a. GROUNDINGS N 146 COLLISIONS N , 175 0-4 4-8 8-12 12-16 16-20 70-24

rimeOF THE DAY

ALL CASUALTIES

547

0-4 4-8 8-12 12-I6 16-20 20-24

TIME OF THE DAY

FIG. 8. DISTRIBUTION OF CASUALTIES BY WATCHES

S.

-4 4-8 _{12-16 2024}

z tS. 4u 10. S. 0.. 26. 159. 26. S., lc ° SU, MO TU WE TX FR SA NE 1 14 GROUNDINGS = 298 COLLISIONS 511. 25,7 ALL CASUALTI:ES N = 7051 ! .P

Y.16,.. 9.DTSTRV8UTIONIOF CASUALTIES BY WEEKDAYS

, TM FR

r

2,3 IL, , 51 .1 I, IA, S.,

_'4

1. 0 N. S'u mo TU WE SU MO TU WE TM FR 21.

50

-sector lights and other fairway lighting are inadequate; in combination, these exert an influence upon the distribu-tion on groundings by watches. The situation would be impro-ved by adequate fairway marking by radar reflectors and

lights.

The distribution of casualties by weekdays, presented in Fig. 9 has one striking feature, that which indicates a high collision frequency at the end of the week, and on

Monday. The distribution becomes more even upon the

inclu-sion of all, although the figures in respect of Monday and Friday are still the highest.

ALL CASUALTIES 150 100 -GROUNDINGS /COLLISIONS 1971 1972 1973 1974 1975

FIG. 10. ANNUAL NUMBERS OF CASUALTIES

The annual casualty numbers are presented in Fig. 10; this indicates a slight decrease in the number of groundings. The variation in the annual numbers of collisions is more marked, and irregular. According to the statistics for a

-more lengthy period,

1955-1974 [61,

the number of sion is also decreasing.

FLAG, TYPE AND AGE OF SHIPS INVOLVED

Fig. 11 analyses the flags of ships involved in acci-dents. Mention is due that less information on casualties was obtained from The Soviet Union and from Eastern Germany. Without detailed information being obtained on traffic flows in the Baltic area, no general conclusions can be drawn from Fig. 11. In any event, the relatively large numbers of W. German, Finnish, Swedish and Danish ships involved in accidents is noteworthy. The large number of W. German ships is attributable to nearly one third of vessels passing through the Kiel Canal being W. German; Kieler Bucht is an extremely congested area, in which casualty figures are high.

OTHERS (57) 8 SOVIET UNION (23) 3.3 % U.K. DUTCH (25) 3.5 GREEK LIBERIAN (18) 2.6 CYPRIOT (26) 3.7

FIG. II. NATIONALITIES OF SHIPS INVOLVED IN ACCIDENTS

HI. 0-4 1 GROUNDINGS N = 2130' 15-19 20-24 25

SHIP AGE

COLLISIONS N = 239 OVER ALL CASUALThES N = 624

FIG. g2. AGE DISTRIBUTION OF SHIPS INVOLVED IN I GROUNDINGS, COLLISIONS AND ALL CASUALTIES

z 96. I. laL

r

Sr. jI 5-9 40-14 SHOP AGE 5-9 10-14 15-19 20-24 __I-25--29 'TO AND OVER 5-9, 10-14 15-79 20- 4 25-29

SNIP AGF 30 ANDOVER 30 AND

Fig. 12 presents the age distribution of ships involved in grounding and collision. A slight difference is apparent in these distributions:this is the relatively high number of ships from 5 to 9 years of age involved in groundings. The age distributions of different types of ship involved in accidents are indicated in Fig. 13.

Dry cargo ships dominate in the casualty statistics, as is evident from Fig. 14. The annual casualty figures for the four ship types are presented in Fig. 15, with the indication that the high casualties for the years 1972, 1973 and 1974 derive from the high casualty figures in respect of dry cargo ships.

Fig. 16 indicates that one half of the casualties arising in respect of small ships of lengths less than 60 metres were groundings. With increase in the length of ship, collision becomes the more important type of casualty.

SHIP SPEED, AND CONDITIONS OF VISIBILITY AND WEATHER Fig. 17 concerns the speed distribution of ships

involved in grounding and collision. This figure confirms the earlier finding that the speed of most ships (about 80 per cent) involved in collisions was less than, or equal to 5 knots. This leads to the conclusion that some collisions might have been avoided if the ships had been steered correctly. Nevertheless, this distribution does not provide a true picture of the situation. Fig. 18 presents the speed distributions of one ship concerned with respect to another ship, with the clear indication of over-estimation of the speed of the other ship, and under-estimation of the speed of the ship carrying the observer. The speed distribution of ships involved in groundings indicates that the speed of about 30 per cent of them exceeded 10 knots. High speed means high kinetic energy and extensive damages. A risk of oil outflow and loss of lives is always present in conjunction with high-energy grounding. The proposal is thus made that a speed limit should be adhered to in the most dangerous parts of fair-ways for as long as their markings are inadequate.

I

DRY CARGO SHIPS N = 399 0-, 5-9 10-14 15-19 20-24 25-29 30 AND OVER SHIP AGE 0-4 5-9 10-14 15-19 20-24 25-29 SHIP AGE 5-9 10-14 15-19 20-24 5H2P AGE

FIG. 13. AGE DISTRIBUTION OF DRY CARGO SHIPS, BULK CARRIERS ,ND TANKERS INVOLVED IN ACCIDENTS

He. ; to . IS. MIL IS. 5.. TANKERS, BULK CARRIERS N

TANKERS (73) 11.1 %

PASSENGER SHIPS AND FERRIES

DRY CARGO SHIPS INCLUDING RO-R0 AND CONTAINER SHIPS (428) 65.2

FIG. 14. NUMBER AND PERCENTAGE OF SHIP TYPES INVOLVED IN ACCIDENTS

DRY CARGO SHIPS 10050 -TANKERS BULK CARRIERS CAR FERRIES /I 1 I ' 1971 1972 1973 1974 1975

FIG. 15. ANNUAL CASUALTY NUMBERS OF DRY CARGO SHIPS, TANKERS, BULK CARRIERS AND CAR FERRIES

SHIP LENGTH 60m ioN = 228

/

60 m <SHIP LENGTH < 80 m Nm. 154 91. _

11

m< SHIP LENGTH < 100m

5

N 93

A GROUNDINGS C RAMHINGS E FOUNDERING COLLISIONS D EXPLOSIONS AND FIRE CAPSIZING

FIG. 16. DISTRIBUTION OF TYPES OF CASUALTY IN THE THREE LARGEST GROUPS

Ye.

IR.

60

S.

N . 133

Vs.° Oc Vs!. 5 5,,511 0 1O<V15 1 5,Vsl, 0

Vs= SHIP SPEED IN KNOTS

COLLISIONS N 115

II

90

vs. SHIP ,TED IN KNOTS

FIG. 18. SPEED DISTRIBUT,ON OF OBSERVER'SSHIP AND

ANOTHER SHIP IN COLLISION CASES V5.0 O<VsiS 3kV510 10./515

Vs. SHIP SPEED IN KNOTS

FIG. 17. SPEED DISTRIBUTION OF SHIPS INVOLVED IN GROUNDING AND COLLISION

COLLISIONS

SPEED OF OWN SHIP, N = 115

Wt.

so.

.

I.

SPEED OF ANOTHER SHIP, N

SO. V s 0 I S <V41 0 110<v sl,1

°"s1'

SO.

,0

=

SO. _

GROUNDINGS

N = 164

II

COLLISIONS

GOOD MODERATE POOR

VISIBILITY

FIG. 19. VISIBILITY DISTRIBUTION AT TIME OF GROUNDING AND COLLISION

GOOD MODERATE POOR

VISIBIL I TV

2 .

Di.

0.

The visibility distributions in respect of cases of grounding and collision are indicated in Fig. 19.

About one half of the cases of grounding and collision occurred under conditions of good visibility. No visibi-lity distribution was available for the area, so that no comparison is possible between casualty frequencies.

Ne-vertheless, it is evident from this illustration that Poor visibility can not be regarded as a principal reason for marine casualties in the Baltic area. In this respect the situation as concerns collision cases in the Baltic area differs from the general situation on a world-wide basis; according to Cockeroft 161, 70 per cent of sea collisions occur under conditions of restricted visibility.

The'weather distributions at the times of grounding and collision are indicated in Fig. 20. These distribu-tions are almost the same as those derived in an earlier analysis [11, in which it was established that in

parti-cular the mean frequency of grounding remains constant under all weather conditions.

THE USE OF NAVIGATIONAL AIDS

Fig. 21 presents the percentage proportion of casu-alties with radar in operation. The percentage is high in comparison with other statistical data [51, a trend which is still increasing. Despite this, the initial detection of another ship was made by direct sighting in 63 per cent of the 93 collisions; similarly the initial detection of an unsafe position was made in 62 per cent of the 84 cases of grounding, as is evident from Figures

22 and 23.

In 19 per cent of the 84 collisions, another ship was detected when the distance between the ships was 0, in 27 per cent the distance was between 0 and 0.5 miles, and in 10 per cent it was between 1 and 5 miles.

70 60 50 HO 30 - 2010 -10 GROUNDINGS N 163 4-5.5 6-7.5 8-12 BEAUFORT SCALE

FIG. 21. PER CENT OF CASUALTIES IN 1971-75 WITH RADAR IN OPERATION

70 -COLLISIONS 60- N = 121 . 50 40 -30 -20 0-3.5 9-5.5 6-7.5 8-12 BEAuFORT SCALE FIG. 20. WEATHER DISTRIBUTION AT TIMES OF

GROUNDING OR COLLISION

,AR NOT 111 Pt RA1 ION

RADAR IN (WER ION

1,7 1972 l4 1175

70-

60-z

50-w u - 31- 2010 - 3020 -10 N 93

DIRECT RADAR SOUND RADIO OR

SIGHTING SIGNALS RADIOTELEPHONE

FIG. 22. INITIAL DETECTION OF OTHER OBJECT IN COLLISIONS

70

I

I

N = 84

mm

I

DIRECT RADAR ECHO OTHER

SIGHTING SOUNDING MEANS

FIG. 23. DETECTION OF UNSAFE POSITION OF SHIP IN GROUNDING

DIMENSIONS AND LOCATION OF DAMAGE

Fig. 24 presents the distribution of the location of centres of cases of hull damage , and in Fig. 25 the

distri-bution has been split into two distridistri-butions of damage centres in cases of grounding and collision. The forms of these distributions resemble the distributions arrived at in earlier analysis [11, except as regards the increased number of cases of damage to the extreme bow in groundings. This is obviously attributable to the increasing number of bulbous-bow ships. The distributions of the length of damage on grounding and collision are given separately in

Fig. 26. The distribution of dimensionless penetration

1

5

ALL CASUALTIES'

N 195

FIG. 24. DISTRIBUTION OF CENTRES OF MULL DAMAGES OF ALL CASUALTIES

GROUNDINGS N 99 20" to

imit111111.11

_ao O _30 40 50 60 7 80 l90r 100 COLLITI0NS N NOW

2.5. DISTRIBUTION OF CENTRES OF NULL DAMAGE

OptCASES OF GROUNDING AND COLLISION, ID 20 501 40i 50 so z 5 90 100 BOW STERN 10 20 30 50 60 ,00 STERN FIG. 25 20 15

20 GROUNDINGS N 100 GROUNDINGS N 50 0 1 0 2 0,3 0,4 DIMENSIONLESS PENETRATION -PENETRATION ; DEPTH OF SHIP

G. 7. DISTRIBUTION OF DIMENSIONLESS PENETRATION IN CASES OF GROUNDING 60- 50-u COLLISIONS = 71 N DAMAGE LENGTH IN METRES FIG. 26. DISTRIBUTION OF DAMAGE LENGTH IN CASES OF

GROUNDING AND COLLISION

30- 20-

10-L.

0 10 20 30 40 50 50 100 150

DAMAGE LENGTH IN METRES

60 50 Z 4 a 2010 -10 1

LOSS OF LIFE, NUMBER OF INJURED, AND TOTAL LOSSES OF SHIPS Information on the number of lives lost was derived from 524 casualties; of these, only 11 resulted in the loss of a total of 46 lives. Thirty five of these were lost in 1972, 26 of these in two accidents. In 1973, seven lives were lost, and in 1975 four.

Information on the number of injured was derived from

440 casualties; of these only 7 resulted in 11 cases of

injury.

Casualties resulted in the total loss of ships in 22 of the 545 cases. Four of these were cases of grounding, 7

collisions, 3 fires or explosions, and the remaining 8 resulted from foundering, capsizing or flooding.

CAUSES OF CASUALTIES

For reduction of the number of accidents, it is vital to discover the reason for the accident. In general, people

attempt to find one single cause for a casualty. From the aspect of safety analysis, this is incorrect. It is in-accurate to refer to the single cause of a casualty, when

in reality a casualty is a result of several causes, or more correctly an unwished chain of events. In marine

accidents, as a rule the human being is at least one link in this chain of events. Usually, the presumption is made that this human link is aware that this chain of events will lead to accidents. It is then stated that the cause

of the accident was a human error, without any regard being paid to whether the prevention of an accident was within

the bounds of human capability.

Information compiled by means of questionnaires can not provide the necessary data for reconstruction of a chain of events leading to the accident. It is necessary that data be compiled by an "on the spot" approach, which involves all accidents being investigated by a team; it is intended that this will be done in Sweden [3].

EL

FAILURE STORM, FAULT ON OTHER UNKNOWN

OF ADVERSE OTHER REASON

EQUIPMENT WEATHER VESSEL

ALL CASUALTIES

N 371

FAILURE STORM, FAULT ON OTHER UNKNOWN

OF ADVERSE OTHER REASON

EQUIPMENT WEATHER VESSEL

FIG. 28. DISTRIBUTIONS OF PRIMARY CAUSES OF CASUALTIES GROUNDINGS N = 163 SO. OO. 14. FAILURE STORM, OF ADVERSE FAULT ON OTHER OTHER REASON UNKNOWN EQUIPMENT WEATHER VESSEL

S.

COLLISIONS N = 123 411.

in respect of the causes of casualties. Such information on the causes of casualties was obtained in only 371 of the 707 cases. In about 14 per cent of the cases of groun-dings, and in 9 per cent of collisions, the failure of equipment was stated to be the primary cause.

In 23 per cent of the cases of grounding or collision, the primary cause was stated to be storm or adverse

weather conditions. The high percentage of "other reason" in groundings, and the low percentage in collisions, along with the high percentage of the "fault on other vessel" in collision cases, provide an indication that the causes stated in the questionnaires were made for reasons of

caution.

CONCLUSIONS

A presentation is made in this paper of the results obtained in the analysis of 707 ship casualties in the Baltic area. The necessary information was obtained by the use of questionnaires, sent to the ship after the accident. Most of the casualties occurred in narrow and

congested waterways.

Most of the accidents to passenger ships and ferries occurred in waters which have shown an increase in such traffic during recent years. In view of the higher risk of loss of life in accidents to passenger ships, the situa-tion calls for immediate countermeasures.

The seasonal distribution of casualties indicates a clear periodical feature, with a maximum falling in Novem-ber - March, and a minimum in the summer.

The distribution of groundings by watches and seasons indicates that an improvement in the situation is attain-able by the adequate marking of fairways. The high speeds of most ships involved in grounding calls for speed limits in the most dangerous parts of fairways for as long as their markings are inadequate.

led safety analysis. For a qualitative and quantitative measure of safety, it is necessary to have the logic diagram of all the chains of events. It is practicable to acquire information of this kind by an "on the spot" approach, in which all accidents are investigated by small groups of specialists, as is done in aviation.

In addition to detailed casualty statistics, general information is required on marine traffic. The planning of efficient and economic countermeasures to accidents in the Baltic area could be effected with the aid of safety analysis, for instance, upon the principles put forward by Hammer

[71.

Moreover, additional knowledge is required on the capability of the man-ship system.

ACKNOWLEDGEMENT

This research work was carried out in the Ship Hydro-dynamics Laboratory of the Helsinki University of

Techno-logy. The authors wish to express their gratitude to the

personnel of the Laboratory for their contribution. The

willing cooperation of Maritime Administrations, numerous shipowners and Ship Masters made it possible to compile the necessary data. The investigation has been financially supported by the Jenny and Antti Wihuri Foundation, and the Ministry of Commerce and Industry in Finland.

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in 1971-72.

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7. 1973.

[21 Kostilainen V. & Hyvg.rinen M., Ship Casualties in the Baltic, Gulf of Finland and Gulf of Bothnia in

1971-72.

The Journal of Navigation, Vol.

27,

No

2, 1974.

[31 SjOfarter i "NAdiga luntan". Svensk Sjofarts Tidning.

Vol. 72,

No 4,

1976.

[41 Kostilainen V., Analysis of Casualties to Tankers in the Baltic, Gulf of Finland and Gulf of Bothnia in

1960-69.

Helsinki University of Technology, Ship Hydrodynamics Laboratory, Report No

5. 1971.

[51 Study of Collisions of Radar-Equipped Merchant Ships and Preventine Recommendations. National Transport Safety Board, Department of Transportation. Washington D.C. 1968.

[61 Cockcroft A.N., Statistics of Collisions at Sea. The Journal of Navigation, Vol.

25,

No

3, 1976.

[71 Hammer W., Handbook of System and Product Safety. Pren-tice-Hall. Inc.

1972.