U D C 656.61:347.799.1 Key words:
.ship strength, navigation
P1984
-3
VTT SYMPOSIUM 52
SHIP STRENGTH AND WINTER NAVIGATION
Espoo. Januao' 1 0 - 1 K 1984
Organized by
the Technical Research Centre of Finland
Ship Laboratory
V A L T I O N T E K N I L L I N E N T U T K I M U S K E S K U S
S T A T E N S T E K N I S K A F O R S K N I N G S C E N T R A L
T E C H N I C A L R E S E A R C H C E N T R E O F F I N L A N D
Espoo 1984
C'opyilglU © V a l i i o n teknillinen tutkimuskeskus ( V T T ) 1984
Julkaisija - Utgivare - Publisher
Valtion tekniUinen tutkimuskeskus ( V T T ) , Vuorimiehentie 5, 02150 Espoo 15 puh. vaihde (90) 4561, teleks 122972 vttha sf
Statens tekniska forskningscentral ( V T T ) , Beresmanwagen 5, 02150 Esbo 15 tel. viixel (90) 4561. telex 122972 vttha sf
Technical Research Cenue of Finland ( V T T ) , Vuorimiehentie 5. S F - 0 2 1 5 0 Espoo 15, Finland phone internat. •> 358 0 456 1. tele.x 122972 vitha sf
V T T , Laivatekniikan laboratorio, Tietotie 1, 02150 Espoo 15 puh. vaihde (90) 4561
NTTT, Skeppstekniska laboratoriet, Datavagen 1, 02150 Esbo 15 tel. viixel (90) 4561
V T T , Ship Laborator}', Tietotie 1, S F - 0 2 1 5 0 Espoo 15, Finland phone internat. * 358 0 4561
3
-FOREWORD
The VTT Ship L a b o r a t o r y i n t e n d s t o a r r a n g e a n n u a l l y a symposium on a s u b j e c t b e l o n g i n g t o i t s f i e l d o f a c t i v i t y . I n a d d i t i o n t o
p r e s e n t a t i o n o f the l a t e s t r e s u l t s o f the r e s e a r c h w o r k , t h e purpose c f t h e s e occasions i s a l s o t o g i v e r i s e t o d i s c u s s i o n between the r e s e a r c h people and t h e i n d u s t r y . T h i s k i n d o f d i s c u s s i o n can o f t e n g i v e t h e s c i e n t i s t s s t i m u l i t o p l a n new r e s e a r c h p r o j e c t s on s u b j e c t s , which are f e l t i m p o r t a n t by the i n d u s t r y . The most i n p o r t a n t t h i n g i s , however, open and c o n s t r u c t i v e c r i t i c i s m on the r e s e a r c h r e s u l t s , t o whicn t h i s k i n d o f o c c a s i o n g i v e s a gcod p o s s i b i l i t y . The l e c t u r e r s coming o u t s i d e t h e r e s e a r c h community can a l s o c o n t r i b u t e s i g n i f i c a n t l y t o the outcome o f the symposium.
The s u b j e c t o f t h i s o c c a s i o n i n c l u d e s two s l i g h t l y d i f f e r e n t t o p i c s namely waves and i c e . Both have, however, a common f e a t u r e t h a t they cause loads on s h i p s and s e t c o r r e s p o n d i n g r e q u i r e m e n t s on t h e s t r u c t u r e .
As an i n t r o d u c t i o n t o the s u b j e c t t h e o p e n i n g l e c t u r e g i v e s an o v e r v i e w on s t r e n g t h problems o f s h i p s i n waves and a l s o d e a l s w i t h p o s s i b l e e r r o r s , w h i c h can be made, i f t h e problems are n o t a d e q u a t e l y u n d e r s t o o d .
The two n e x t l e c t u r e s deal w i t h t h e d e t e r m i n a t i o n o f p e r i o d i c and t r a n s i e n t wave l o a d s . The s u b j e c t o f the f o u r t h l e c t u r e i s p r a c t i c a l s t r e n g t h c a l c u l a t i o n s and s t r e n g t h c r i t e r i a .
The f i r s t day ends w i t h a l e c t u r e d e a l i n g w i t h the s p e c i a l f e a t u r e s o f t h e wave loads and s t r e n g t h problems on m u l t i h u l l v e s s e l s .
•started a l r e a d y seven y e a r s ago i n the Ship L a b o r a t o r y by t h e
. ' e c t u r e r . T h i s research program, i n w h i c h a c o n s i d e r a b l e e n t h u s i a s t i c i'csearch team has taken p a r t , has a l r e a d y l e d t o v e r y s i g n i f i c a n t P r S u H s . One outcome of i t i s the d o c t o r a l t h e s i s o f P e t r i V a r s t a .
The n e x t p r e s e n t a t i o n t e l l s about tne e x p e r i e n c i e s , which the VTT Ship L a o o r a t o r y has had when u s i n g the new WARC i c e model b a s i n d u r i n g the l a s t y e a r . The i c e r e s i s t a n c e r e s e a r c h i s a n a t u r a l c o n t i n u a t i o n to the i c e l o a d r e s e a r c h .
A s i g n i f i c a n t problem when n a v i g a t i n g i n i c e i s a l s o caused by the i c e l o a d s a c t i n g on the p r o p u l s i o n m a c h i n e r y . These problems are
d i s c u s s e d i n the t h i r d l e c t u r e o f t h e d a y . T h i s i s a f i e l d , where t h e u t i l i z a t i o n o f model t e s t s seems t o be much more d i f f i c u l t than e . g . i n i c e r e s i s t a n c e t e s t s . C o n s e q u e n t l y , t h e f u l l - s c a l e measurements are o f utmost i m p o r t a n c e . The same i s t r u e a l s o w i t h t h e i c e loads on t h e h u l l . The f i n e s s e s o f measuring i c e l o a d s are d e a l t w i t h i n d e t a i l s i n t h e n e x t p r e s e n t a t i o n .
One i m p o r t a n t f i e l d o f a p p l i c a t i o n o f t h e r e f i n e d methods o f d e t e r m i n i n g i c e loads i s w i t h i n t h e i c e r e g u l a t i o n s . I t has become p o s s i b l e t o develope an a n a l y t i c a l approach t o a more e x a c t l e v e l . T h i s s u b j e c t i s d i s c u s s e d i n t h e n e x t l e c t u r e .
The l a s t p r e s e n t a t i o n i n t r o d u c e s us t o t h e new model i c e - the r e s u l t s o f an i m p o r t a n t development work done by WARC. T h i s mode i c e i s c o n s i d e r e d t o improve s i g n i f i c a n t l y t h e p o s s i b i l i t i e s o f model t e s t s on which innumerous e x p e c t a t i o n s have been p u t i n s o l v i n g i c e p r o b l e m s .
5
-The r e s e a r c h work conducted 1n t h e VTT S h i p L a b o r a t o r y has been s u p p o r t e d by t h e M i n i s t r y o f Trade and I n d u s t r y , the W i n t e r N a v i g a t i o n Research Board and t h e Academy o f F i n l a n d , t o whom we want t o e x p r e s s our g r a t i t u d e .
Espoo, May 1984
J u h a n i S u k s e l a i n e n , D i r e c t o r o f t h e L a b o r a t o r y
T e c h n i c a l Research Centre o f F i n l a n d Ship L a b o r a t o r y
LIST OF CONTENTS
1 FOREWORD
J u h a n i S u k s e l a i n e n
2 RATIONAL APPROACH TO SHIP STRENGTH PROBLEMS
P e t r i V a r s t a
3 THE LONG-TERM FORECAST AND CALCULATION OF WAVE
LOADS ON SHIPS
J e r z y Matusiak A Jukka Vasama
4 J WAVE-INDUCED SLAWING LOADS AND SHIP RESPONSE-CALCULATIONS AND MEASUREMENTS
E r k k i K n u u t t i i a . J e r z y Matusiak i A n t t i Rantanen 5 SHIP STRENGTH ANALYSIS AND STRENGTH CRITERIA
P e n t t i K u j a l a & S a k a r i R i n t a l a 6 SPECIAL FEATURES OF MULTIHULL VESSELS,
DESIGN CONCEPTS OF A CATAMARAN Per T e r j e
7 SPECIAL FEATURES OF MULTIHULL VESSELS P e t r i V a l a n t o
8 DETERMINATION OF ICE LOADS SEMIEHPIRICALLY P e t r i V a r s t a
9 THE LEVEL ICE RESISTANCE - IDEAS STEWING FROM THE MODEL AND THE FULL SCALE TESTS Tapio Nyman « KaJ R i s k a
10 ICE LOADS OF PROPULSION MACHINERY M a t t i J u s s i l a
i n MEASUREMENTS OF ICE LOADS — Jukka V u o r i o
12 UP-DATING OF THE FINNISH - SWEDISH ICE CLASS RULES Gunnar Edelinann
13 THE NEW FINE-GRAIN MODEL-ICE OF WARTSILA ARCTIC RESEARCH CENTRE E r n s t E n k v i s t 1 4 9 157 177 183 201 213
