Contents of the 60TH Anniversary Series, Volume 6, Advances in Research on Stability and Rolling of Ships

The Society of Naval Architects of Japan

60TH ANNIVERSARY SERIES

V O L U M E 6

ADVANCES IN RESEARCH ON STABILITY

AND ROLLING OF SHIPS

By

Shin

TAMIYA

Seizo

MOTORA

with the collaboration of

Masayoshi

K A N O

Kazuo

SuGAI

Toshio

HISHIDA

Norio

TANAKA

Daikaku

M A N A B E

Yasufumi

YAMANOUCHI

Yoichi

OGAWARA

The Society of Naval Architects of Japan

Tokyo, 1960

C O N T E N T S

PREFACE , .

Page

C H A P T E R 1. Rolling Characteristics of Ships 1 § 1 . 1 Period of Roll and Added Moment of Inertia f o r Rolling Motion 1

1.1.1 A n approximate method of calculating the period of r o l l of ships 1

1.1.2 Additional moment of inertia 3

§ 1 . 2 Damping 5 1.2.1 Frictional damping 5

1.2.2 Wave-making damping 7 1.2.3 E f f e c t of bilge keels 13 1.2.4 Semi empirical formulae of extinction coefficient 21

1.2.5 Damping of roll at large amplitude 25

1.2.6 L a w of similarity 29 C H A P T E R 2. Problems of Statical Stability 33

§ 2 . 1 Measuring Devices of GM 33 2 . 1 . 1 Optical clinometer 33 2.1.2 H i g h sensibility clinometer 38

2.1.3 m e t e r . 38 § 2 . 2 E f f e c t of T r i m on Statical Stability 41

§ 2 . 3 E f f e c t of Free Water i n a Rectangular Tank 42

2 . 3 . 1 Closed tank 42 2.3.2 Open t a n k 44 2.3.3 R i g h t i n g lever 47 § 2 . 4 E f f e c t of Erections on the Statical Stability 48

§ 2 . 5 Approximate Formula of R i g h t i n g Lever GZ 50

2 . 5 . 1 Formulae presented hitherto 50 2.5.2 Calculation formulae to obtain a, b, r, m and g 53

2.5.3 Estimation of dr and GZ^ 58

2.5.4 Summary 61 C H A P T E R 3. W i n d and W i n d Pressure Moment 63

§ 3 . 1 Data on Ocean W i n d i n the North-West Pacific and their Analysis f r o m

Marine Meteorological Point of V i e w 63

3 . 1 . 1 Introduction 63 3.1.2 General characteristics of ocean w i n d i n the North-West Pacific 65

3.1.3 M a x i m u m w i n d velocity and m i n i m u m atmospheric pressure 67

3.1.4 Gustiness of ocean w i n d 69 § 3 . 2 Heeling Moment due to W i n d Pressure 72

3 . 2 . 1 W i n d pressure and vertical position of centre of pressure 72

3.2.2 Centre of water pressure 76 3.2.3 W i n d pressure moment 78

C H A P T E R 4. Waves 83 § 4 . 1 Characteristics of the Ocean Waves i n the N o r t h Pacific and their Analysis

f r o m Marine Meteorological Point of V i e w 83

4 . 1 . 1 Introduction , 83 4.1.2 Age, and steepness of ocean wave and w i n d factor of d r i f t current 83

4.1.3 M a x i m u m wave height and most prevailing period of ocean waves 85

CONTENTS 11 Page 4.1.5 Ship's oscillations on r o u g h sea surface

4.1.6 Criteterion f o r safety of ships

S 4 2 Heeling Moment d u ê to Waves • • • • ; ' ' ' ' „

4 2 1 Theoretical expressions of t h e coefficient of the effective wave slope 97 4 . 2 . 2 Experiments on measuring heeling moment due t o waves

C H A P T E R 5. Ship Responses to W i n d and Waves

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§ 5 . 1 Motion i n Regular Waves 105 § 5 . 2 Motion i n I r r e g u l a r Waves

5 . 2 . 1 Linear theory of ship response to irregular waves

5.2.2 Model experiment i n natural irregular waves ' 5.2.3 Analysis of results n " '• " i 1 1 2

5 2.4 Rolling of ship under co-existence of waves and w i n d

§ 5.8 Analysis of Ship's Oscillation as a Time Series '.'. ^ ' ! ' 114

5 . 3 . 1 Introduction -^^^ 5.3.2 Periodogram analysis and discontinuous spectrum

5.3.3 Correlogram analysis and continuous spectrum

§ 5 . 4 Actual Ship Observations ' 5 . 4 . 1 Principal particulars of the ships

5.4.2 Voyage routes and ship conditions 5.4.3 Measuring apparatus

5.4.4 Examples of records and results obtained 5.4.5 Analysis of results and some conclusions

C H A P T E R 6 Special Problems 139 § 6 . 1 Longitudinal Waves ^

6 . 1 . 1 Introduction • -j^gg 6.1.2 Equation of motion and its solution

6.1.3 Experiments '" i " ' ' " 1 4 3 6.1.4 Experimental results and t h e i r comparison w i t h theoretical values . . . • •

6.1.5 Inquiries and conclusions 145 § 6 . 2 E f f e c t of Sipping Water

6 2 . 1 Experimental research on model ships • 6 2 2 Model experiments w i t h special reference to the effect of deck houses

w h i c h w i l l disturb t h e s h i f t i n g of shipped water § 6 . 3 E f f e c t of Free water on Rolling Motion

6 . 3 . 1 Motion of f r e e water i n a rolling rectangular t a n k 6.3.2 I n c h n i n g moment of f r e e water

6.3.3 Equation of r o l l i n g of ship w i t h f r e e water

6.3.4 Results obtained f r o m numerical calculation ' ' ' ' ' " ' ' V ' ' ' ' I K Q C H A P T E R 7. Problems of Capsizing w i t h Special Reference to the Toya M a i u D i s a s t e r . . 159

§ 7 . 1 Introduction 2.59 § 7 . 2 Meteorological Condition at t h e Time of Disaster

7 . 2 . 1 Course, degree of central pressure and speed of typhoon 7.2.2 W i n d velocity, atmospheric pressure and waves at H a k o d a t e . . .

§ 7 . 3 Movements and Circumstances of Each Ship at the Time of Disaster Ibd § 7 . 4 Types and Principal Dimensions of Ships Studied

7 4 1 Principal dimensions of Toya-maru and Tokachi-maru

7'.4.2 Conditions of Toya-maru and Tokachi-maru on t h e day of

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7 . 5 . 1 Case of Toya-maru i n anchoring 173 7.5.2 Case of Tokachi-maru i n anchoring 174 § 7 . 6 Critical W i n d Velocity f o r an Assumed Flooding Condition 176

§ 7 . 7 Model Experiment as to the Relation between Bottom Contact and Capsize

in Case of Toya Maru 180 7 . 7 . 1 Place of bottom contact 184 7.7.2 Reaction due to bottom contact 184

§ 7 . 8 Conclusion 187