W a t e r l o o p k u n d i g L a b o r a t o r i u m
R a a m
61 - DELPT . H A N S T H O L M HARBOUR C O N S T R U C T I O N C O M M I T T E E M I N I S T R Y OF P U B L I C WORKS Slotsholmsgade 10 . Copenhagen K . S U M M A R Y • • OF • M O D E L TESTS ON W A V E I M P A C T FORCES ON H A N S T H O L M B R E A K W A T E R S September 26th 1960. W A T E R L O O P K U N D I Q L A B O R A T O R I U M " D E VOORST" N . O. P. H O L L A N DI n a l e t t e r of May 7, 1 960 the H a n s t h o l m H a r b o u r C o n s t r u c t i o n B o a r d requested the W a t e r l o o p k u n d i g L a b o r a t o r i u m "De V o o r s t " to p e r f o r m a m o d e l i n v e s t i g a t i o n of the wave f o r c e s on the b r e a k w a t e r s of the H a n s t h o l m H a r b o u r .
T h i s task was accepted by the W a t e r l o o p k u n d i g L a b o r a t o r i u m i n a l e t t e r of May 28 , 1960.
Because of the shortage of e n g i n e e r s i n "De V o o r s t " i t was a g r e e d that M r . Hans P. Steenfos, a r e s e a r c h engineer f r o m the C o a s t a l E n g i n e e r i n g L a b o r a t o r y i n Copenhagen should be placed at the d i s p o s a l of the W a t e r l o o p k u n d i g L a b o r a t o r i u m to r u n these t e s t s .
The t e s t s w e r e c a r r i e d out i n the w i n d f l u m e at "De V o o r s t " f r o m June 30th to September 1st, 1960.
T h i s r e p o r t contains a s u m m a r y of the t e s t r e s u l t s as w e l l as a n u m b e r o f p r e l i m i n a r y c o n c l u s i o n s .
1 T E S T C O N D I T I O N S
1 . 1 S C A L E
The l i n e a r scale i n a l l the t e s t s was 1:40. I n a c c o r d a n c e w i t h the P r o u d e m o d e l l a w the t i m e s and the v e l o c i t i e s w e r e r e p r o d u c e d at the scale 1: I n the i n t e r p r e t a t i o n of the r e s u l t s i t was assumed that a l l p r e s s u r e s f o l l o w the l i n e a r scale 1:40, Thus the scale! of
f o r c e s w i l l be 1:40^..
1 . 2 W A V E C O N D I T I O N S
The t e s t s w e r e r u n w i t h two d i f f e r e n t sets of wave c o n d i t i o n s : ïï" H , . , = H „ , / H „ „ . T
sign 85 o / o 90 o/o
W 1 • 1,4 m 2, 2 m ^ 2,7 m 5,0 sec W 2 3,0 m 4 , 7 m 5,0 m 6, 6 sec
These t e s t c o n d i t i o n s w e r e intended to s i m u l a t e the f o l l o w i n g p r o t o t y p e c o n d i t i o n s s p e c i f i e d by the Coastal E n g i n e e r i n g L a b o r a t o r y of Copenhagen:
W i n d . . . .
W P 1 15 m / S Q C 1 , 4 m 2 , 2 m 2, 7 m 8 sec
Since i t i ë e s p e c i a l l y inaportant to o b t a i n a c o r r e c t r e p r o d u c t i o n of the c o m p o s i t i o n o f the h i g h e s t waves w i t h i n the wave s p e c t r u m , PI , was chosen as the s i g n i f i c a n t v a l u e to be r e p r o d u c e d c o r r e c t l y
yu oj o t o s c a l e .
P r e l i m i n a r y t e s t s have shown that the average v a l u e s of the
i m p a c t p r e s s u r e s a r e independent of the wave p e r i o d i f the s i g n i f i c a n t . wave height i s h e l d constant,. On the o t h e r hand, the wave height
s p e c t r u m has been shown to be of g r e a t i m p o r t a n c e f o r the f r e q u e n c y of the wave i m p a c t s . Consequently, the t e s t s w e r e made w i t h p u r e l y w i n d - g e n e r a t e d waves f o r w h i c h the wave height s p e c t r u m i s
a p p r o x i m a t e l y c o r r e c t , • • I n a l l t e s t s the w a v e s w e r e a p p r o a c h i n g the b r e a k w a t e r at a r i g h t
angle. ' • .
T o get a s u f f i c i e n t a m o u n t o f t e s t data each t e s t c o m p r i s e d 8.bout 2000 w a v e s .
1. 3 O T H E B T E S T CONDITIONS_
Since the sea l e v e l d u r i n g w e s t e r l y s t o r m s at H a n s t h o l m i s about one m e t e r above m e a n sea l e v e l a l l the t e s t s v/ere made w i t h a sea l e v e l of + 1,0 m .
The b o t t o m i n the m o d e l was p l a c e d at - 11 m to a d i s t a n c e o f about 200 m f r o m the b r e a k w a t e r . I n the r e s t of the f l u m e the b o t t o m was placed at - 1 3 m .
I n a l l the t e s t s the t o p of the b r e a k w a t e r s t r u c t u r e was placed at + 4, 0 m .
h 4 TESTS' W I T H ^ T O E I N N E R B R E A K W A T E R .J¬
I n a d d i t i o n t o the m a i n t e s t s w i t h the o u t e r b r e a k w a t e r s some t e s t s w e r e made w i t h the i n n e r b r e a k w a t e r to d e t e r m i n e the i m p a c t p r e s s u r e s o n a p r o p o s e d h o r i z o n t a l l y p r o t r u d i n g wave s c r e e n .
The waves used i n these test.s had a s i g n i f i c a n t wave h e i g h t Hg = 3, 1 m . The waves w e r e a t t a c k i n g the s t r u c t u r e at a r i g h t a n g l e .
The b o t t o m l e v e l at the s t r u c t u r e was at e l e v a t i o n - 7 m and the sea l e v e l at + 1 m .
1. 5 M E A S U R I N G I N S T R U M E N T S A N D RECORDING A P P A R A T U S
The i m p a c t p r e s s u r e s w e r e m e a s u r e d w i t h c a p a c i t y p r e s s u r e c e l l s and the t o t a l f o r c e s on the s t r u c t u r e s w e r e m e a s u r e d w i t h c a p a c i t y f o r c e m e t e r s . The wave h e i g h t s w e r e m e a s u r e d w i t h r e s i s t a n c e gages.
The r e c o r d i n g a p p a r a t u s was a V i s i c o r d c h a n n e l l i g h t b e a m r e c o r d e r w o r k i n g w i t h u l t r a v i o l e t l i g h t .
1.6 ^ E g T P R O G R A M M E
The t e s t p r o g r a m m e c o m p r i s e d t e s t s w i t h v e r t i c a l w a l l b r e a k -w a t e r s , b r e a k -w a t e r s -w i t h v e r t i c a l -w a l l s c o m b i n e d -w i t h a slope at the top, and b r e a k w a t e r s of c i r c u l a r caissons.
The f i r s t s e r i e s of t e s t s w i t h these s t r u c t u r e s w e r e made w i t h p r e s s u r e c e l l s g i v i n g the v a r i a t i o n of the l o c a l p r e s s u r e s at v a r i o u s h e i g h t s . L a t e r on, the t o t a l h o r i z o n t a l and v e r t i c a l f o r c e s on the s t r u c t u r e s w e r e m e a s u r e d by means of f o r c e m e t e r s .
1. 7 I N T E R P R E T A T I O N OF RESULT^S
I n the t a b l e s below a r e g i v e n the m e a s u r e d m a x i m u m i m p a c t -p r e s s u r e s as w e l l as the s t a t i s t i c a l values of the i m -p a c t - -p r e s s u r e p e r 5000, 1 000 and 1 00 waves.
The s t a t i s t i c a l values are obtained by d r a w i n g a smooth c u r v e t h r o u g h the data p l o t t e d on s e m i l o g a r i t h m i c p a p e r . Since the l e n g t h of the m e a s u r i n g s e r i e s i s a l w a y s about 2000 w a v e s , ' t h e value o f the m a x i m u m p r e s s u r e m e a s u r e d n o r m a l l y w i l l be somewhat d i f f e r e n t f r o m the s t a t i s t i c a l value p e r 2000 w a v e s .
2 T E S T S W I T H P R E S S U R E C E L L S 2 . 1 I M P A C T PRESSURES ON B R E A K W A T E R S NO 1 , 2 . 3 A N D 4 . ( B r e a k w a t e r s w i t h a v e r t i c a l f a c e and a v e r t i c a l + a sipping f a c e , c f . F i g . s 1 and 2 ) . W A V E S : W 1 , Hp, = 2 . 2 m . M o d e l No C e l l at l e v e l Ï 5 T A T I S T I C A L V A L U E S OF I M P A C T P R E S S U R E " i M o d e l No C e l l at l e v e l M a x .
pressure
measured
Der 5 0 0 0 wavest / m ^
per 2 0 0 0 wavest / m '
per 1 0 0 0
wavest / m ^
p e r 1 0 0 w a v e st / m '
+ 2 . 5 7 . 2 1 0 . 1 8 . 8 7 . 7 4 . 4. i
l A ' - 0 . 5 - 3 . 0 - 8 . 0 3. 2 2 . 4 2 , 0-3 . 2 2 . 9 \ + 1 . 5 1 5 . 7 I 5 . b 1 4 . 0 1 2 . 9 6 I B ' - 0 . 5 - 3 . 0 - 8 . 0 2 . 8 2 . 4 0 3 . 5 3 . 2 2 . 9 2 . 1 + 2 . 5 7 . 2 1 9 . 2 7 . 2 3 . 4 3 A - 0 . 5 2 . 4
-
3 . 8 3 . 5 2 . 4 - 3 . 0 4 . 0 ( 2 1 . 3 ) ( 2 3 . 0 ) - ( 2 1 . 0 ) - ( 1 9 . 8 ) - ( 1 5 . 4 ) - 8 . 0 0 ( 6 . 4 )-
-
-
— + 2 . 5 1 3 . 7 1 4 . 3 1 3 . 6 1 3 . 2 1 1 . 3 3 B - 0 . 5 3. 2 ( 9 . 6 ) 4 . 5 4 . 2 • 3. 7 2 . 0 - 3 . 0 4 . 0 ( 2 2 . 8 ) ( 2 2 . 0 ) ( 1 8 . 0 ) ( 1 0 . 5 ) - 8 . 0 1 . 2 ( 4 . 8 )-
-
-
-+ 2 . 5 3 . 2 0 4 A - 0 . 5 6 . 0 ( 5 . 6 )
•-
3 . 9 2 . 8 • 0 - 3 . 0 4 . 0 ( 1 3 . 3 ) ( 1 3 . 2 ) ( 1 1 . 4 ) ( 1 0 . 3 ) ( 6 . 6 ) - 8 . 0 1 . 2 ( 1 . 2 )-
-
-
— + 2 . 5 1 6 . 1 1 8 . 0 1 5 . 8 1 4 . 9 8. 6 4 B - 0 . 5 4 . 0 ( 6 . 0 ) 4 . 4 3 . 5 3 . 2 1 . 4 - 3 . 0 3 . 2 ( 1 2 . 4. ( 1 3 . 8 ) ( 1 2 . 2 ) ( 1 1 . 9 ) ( 8 . 5 ) - 8 . 0 1 . 6 ( 3 . 6^-
-
-
-W A V E 3 : -W2, H s = 4 . 7 m M o d e l No C e l l at L e v e l Max. p r e s s u r e m e a s u r e d t / m ' S T A T I S T I C A L V A L U E S OF I M P A C T PRESSURE M o d e l No C e l l at L e v e l Max. p r e s s u r e m e a s u r e d t / m ' p e r 5000 w a v e s per 2000 waves p e r 1000 waves per 100 w a v e s C e l l at L e v e l Max. p r e s s u r e m e a s u r e d t / m ' t / m ' t / m ' t / m ' t / m ' +2. 5 16. 7 19. 0 16. 7 15. 1 9. 3 1A - 0 . 5 - 3 . 0 - 8 , 0 4. 4 3. 2 2. 8
-
4. 0 - 3. 6 2. 0 +2. 5 21 24 2 1 . 2 19. 5 13. 3. I B - 0 , 5 - 3 . 0 - 8 . 0 10. 0 6.4 1.6-
10.0 8. 5 4. 0 +2. 5 8.8 ' 9. 6 9. 2 8. 9 6. 8 3A - 0 . 5 3. 2. 4. 3 4. 0 3. 5 1.9 - 3 . 0 2.8 ( 1 7 . 7 ) - ( 1 9 . 5 ) (17.5) ( 1 6 . 6 ) ( 1 1 . 5 ) - 8 . 0 1.2 ( 4 . 0 )-
-
-
-+2. 5 14. 5 14.8 14. 3 13. 4 10. 9 SB - 0 . 5 4. 0 4. 3 3. 9 3. 5 2. 2 - 3 . 0 4. 8 ( 1 1 . 3) - ( 1 6 . 0 ) ( l i . O ) ( 1 3 . 0 ) ( 6 . 4 ) - 0 . 8 2.8
- •
-
-
-+2. 5 12. 9 14. 8. 12. 8 8 . 2 4. 3 4A - 0 . 5 7 . 2 , (3. 3) 8. 6 7. 4 5.9 1. 3 - 3 . 0 4. 8 ( 1 1 . 2 ) - ( 1 3 . 6 ) ( 1 2 . 5 ) ( 1 1 . 3 ) ( 7 . 4 ) - 8 . 0 •1..6 (f2-:.. 0))
-
-
-
-. +2-. 5 19. 6 21.9 20. 7 19. 8 16. 7 4 B - 0 . 5 8.0 , ( 4 . 0 )
-
7. 5 6 . 4 3. 9 - 3 . 0 3. 2 (17. 3) ( 1 9 . 0 ) (17.1) (15, 6) ( 1 0 , 6 ) - 8 . 0 0.8 ( 3 . 6 )-
-
-N B The f i g u r e s i n p a r e n t h e s e s a r e r e l a t e d to the i m p a c t s o c c u r r i n g when the w a t e r r u n n i n g back f r o m the s l o p i n g face of the s t r u c t u r e h i t s the w a t e r s u r f a c e , when t h i s i s j u s t r i s i n g due to the a p p r o a c h of the next w a v e . These i m p a c t s can be d i s t i n g u i s h e d f r o m the n o r m a l ones by the m o m e n t of o c c u r r e n c e . These i m p a c t s o c c u r o n l y on the l o w e r c e l l s i n a n a r r o w zone a r o u n d - 3 . 0 m .
The r i s i n g t i m e s o f the i m p a c t p r e s s u r e s i n the above m e n t i o n e d t e s t s are i n the p r o t o t y p e about 0. 05 sec, but the r i s i n g t i m e s v a r y f r o m 0, 15 sec to 0. 015 f r o m the s m a l l peaks to the highest ones.
The r i s i n g t i m e s o f the i m p a c t s i n the p a r e n t h e s e s a r e somewhat l o w e r , about 0, 03 sec i n the p r o t o t y p e ( v a r y i n g f r o m 0, 1 sec to 0. 01 sec).
2. 2 I M P A C T PRESSURE O N T H E I N N E R B R E A K W A T E R , M O D E L S N O . 8, 9 A N D 10 ( F i g . 4). — — ^ • — W A V E S : H = 1 • 85 m Hg = 3. 1 m Model No C e l l No M a x i m u m p r e s s u r e m e a s u r e d t / m ' S T A T I S T I C A L V A L U E S O F I M P A C T PRESSURE Model No C e l l No M a x i m u m p r e s s u r e m e a s u r e d t / m ' p e r 5000 w a v e s p e r 2000 waves p e r 1000 waves p e r 100 waves p e r 10 w a v e s • M a x i m u m p r e s s u r e m e a s u r e d t / m ' t / m ' t / m ' t / m ' t / m ^ t / m ' I 0 0 0 9 0 0 8 I I 52 54 52 • 51 44 22 ; I I I 9. 3 9; 4 8. 7 8. 0 6. 4- 3. 4 I 40 48. 0 42 38 25 12 9 I I 55 51 45 40 25 10 I I I 46 50. 5 45 43. 28 , 15 I I 37 41 36 34.
i
24 11 10 I I I 48 53 48 44I
32 19The r i s i n g t i m e s of the above m e n t i o n e d i m p a c t p r e s s u r e s a r e about 0. 04 sec i n the p r o t o t y p e , but r i s i n g t i m e s v a r y f r o m 0. 09 sec to 0. 01 sec.
I t should be n o t i c e d t h a t the above m e n t i o n e d i m p a c t p r e s s u r e s at the f o u r p r e s s u r e c e l l s a r e not n e c e s s a r i l y r e l a t e d to the same wave.
T E S T S W I T H W A V E I M P A C T S O N B R E A K W A T E R S O F C I R C U L A R C A I S S O N S . M O D E L S N O . 5 , 6 A N D 7 . T O T A L I M P A C T F O R C E S ON C I R C U L A R CAISSONS. ( F i g . 3) D i a m e t e r of the caissons; 1 5 m . W A V E S : W 1 , Hg = 2. 2 m M o d e l M a x . S T A T I S T I C A L V A L U E S OF T O T A L I M P A C T F O R C E ( N o . f o r c e p e r 5000 p e r 2000 p e r 1000 p e r 100 Re sul' tant f o r c d
m e a s u r e d waves waves waves w a v e s L e v e l at I n c l i -t/ c t / C t / C t / C t / C f a c e . n a t i o n 5 640 700 621 578 400 - 1 . 8 0 ° 6 41 5 492 456 433 334 - 1 . 0 • 0 ° 7 640 670 620 547 356 - 1 . 8 0 ° W A V E S : W 2 , H s = 4, 7 m 5 1280 1422 1276 1170 808 - 1 . 8 0 ° 6 1005 1 160 1075 1015 785 - 1 . 5 Q O 7 900
-
1100 990 582 - 2 . 7 O O Note: t / C m e a n s : tons p e r c a i s s o n .The r i s i n g t i m e s of the m e a s u r e d t o t a l i m p a c t f o r c e s a r e about 0. 25 sec i n accordance w i t h the r e s u l t s f o r the v e r t i c a l w a l l .
M A X . I M P A C T PRESSURES O N C I R C U L A R CAISSONS:
T o d e r t e r m i n a t e the highest i m p a c t p r e s s u r e s on the c i r c u l a r c a i s s o n s 3 p r e s s u r e c e l l s w e r e placed at e l e v a t i o n + 1 . 0 m . The h o r i -z o n t a l p o s i t i o n s of the p r e s s u r e c e l l s a r e s h o w n , i n F i g . 3. The h i g h e s t i m p a c t p r e s s u r e s m e a s u r e d w e r e : W A V E S : Hg = = 2. 2 m r 1 1 WAVES- Hg = .4. 7 m •Model . M A X . I M P A C T PRESSURE M E A S U R E D No. c e l l c e l l c e l l c e l l c e l l c e l l I I I I I V I I I I I V t / m ^ t / m ^ t / m ' t / m ' t / m 2 t / m ' 5 4. 0 2. 0 ' ' • 10. 0 7. 0
-6 5. 2 4. 4-
14. 0 7. 0-7 6 . 0 4. 2 9. 2 6. 0 1 2. 0 5. 2
V e r t i c a l f o r c e s on the t o p of the s t r u c t u r e s o c c u r w h e n w a t e r f r o m ' the u p - s p l a s h f a l l s down on the h o r i z o n t a l deck of the c a i s s o n s .
These f o r c e s a r e not r e a l i m p a c t s , but the r i s i n g t i m e s a r e as s m a l l as about 0, 6-0, 7 sec i n the p r o t o t y p e .
W A V E S : W 1 . Hg = 2. 2 m M o d e l W i d t h o f S T A T I S T I C A L V A L U E S O F V E R T I C A L F O R C E S No, s t r u c t u r e p e r 5000 w a v e s t / m p e r 2000 w a v e s t / m p e r 1000 w a v e s t / m p e r 100 w a v e s t / m p e r 1 0 waves t / m 1A 14. m 13. 7 1 2. 1 11.0 7. 2 W A V E S : W 2 , Hg = = 4. 7 m 1A I B 14 m 14 m 40 • ' 29. 5 39 28. 5 38 28 3 1 , 5 23. 5 17, 7 14. 5 W A V E S : W 2 , Ho = 4. 7 m M o d e l No.. D i a m e t e r of c a i s s o n p e r 5000 waves t / C • p e r 2000 waves t / C p e r 1000 w a v e s t / C p e r t o o w a v e s t / C p e r 1 0 wave s t / C 5 15 m 705 665 630 480 315 Note: t / C m e a n s tons p e r c a i s s o n .
6 O V E R T O P P I N G
I n a l l the t e s t s the a m o u n t of o v e r t o p p i n g was m e a s u r e d .
W A V E S : W 1 , H ^ = 2 , 2 m ^ W A V E S : W 2 , H.c;=4, 7 m WAVES:.H=r., 8 5 m Hg=3, 1 m M o d e l O v e r t o p p i n g M o d e l O v e r t o p p i n g M o d e l ! O v e r t o p p i ng N o . m ^ / s e c / m No. m ^ / s e c / m No. . m ^ / s e c / m 1A 0,021 1A 0, 395 8 rsjO I B 0, 017 . ' I B 0, 340 9 0,007 , , 3A 0, 045 3A 0, 400 0,014 3B 0,031 3B 0, 305 4A 0,038 4A 0, 360 4 B 0,014 .
j
4B 0, 260 5 0, 049 1 5 0, 450C O N C L U S I O N S , S ,
The f o l l o w i n g p r e l i m i n a r y c o n c l u s i o n s m a y be d r a w n f r o m the • r e s u l t s o f the w a v e - i m p a c t t e s t s :
1. A m o n g the s t r u c t u r e s tested i n t h i s i n v e s t i g a t i o n the f o l l o w i n g t h r e e types have the best p r o p e r t i e s With r e g a r d to i m p a c t f o r c e s :
a. The b r e a k w a t e r w i t h a c o m b i n e d v e r t i c a l and 4 5 ° s l o p i n g f a c e , m o d e l N o . 3.
b . C i r c u l a r c a i s s o n s closed 1, 5 o r 3, 0 m i n f r o n t of the centre-l i n e , m o d e centre-l s N o . s 5 and 6.
c. The b r e a k w a t e r w i t h a v e r t i c a l , plane f a c e , m o d e l N o . 1. M o d e l N o . 3 m e n t i o n e d u n d e r a g i v e s i m p a c t f o r c e s ' t h a t a r e o n l y about 50 o / o of the v a l u e s f o r the type m e n t i o n e d u n d e r c, w h e r e a s the t y p e s b give i m p a c t f o r c e s about 80 - 90 o / o of the v a l u e s f o r the type m e n t i o n e d u n d e r c. A f u r t h e r advantage o f the type m e n t i o n e d u n d e r a, i s that the r e s u l t a n t i m p a c t f o r c e has an i n c l i n a t i o n of about 2 5 ° ,
The 1.0 - 1 . 0 m p r o t r u s i o n s tested do not i n f l u e n c e the i m p a c t f o r c e s on the v e r t i c a l w a l l .
2. On the sections w h e r e p e r p e n d i c u l a r w a v e - a t t a c k can be expected the b r e a k w a t e r s should not be p r o v i d e d w i t h a l i p , because the l i p w i l l i n c r e a s e the m a x i m u m i m p a c t s w i t h a f a c t o r of 1. 5 and the f r e q u e n c y of i m p a c t s w i t h a f a c t o r of 8-10.
3. The s t r u c t u r e s tested f o r the i n n e r b r e a k w a t e r ( m o d e l s N o . s 8, 9 and 1 0) a r e not s a t i s f a c t o r y because of f r e q u e n t o c c u r r e n c e o f v e r y h i g h i m p a c t p r e s s u r e s .
Because of the shortage of t i m e , t e s t s w i t h bed p r o t e c t i o n have not been c a r r i e d out.
W A T E R L O O P K U N D I G L A B O R A T O R I U M I r . E . W . B i j k e r
• M O D E L M O . I A
•«•4M O D E L NO. 1B
^4 V E R T I C A L W A L LMODEL NO. 2A
4-4 V E R T I C A L WALL W I T H 0 , 5 ^ 0 . 5 m LIPM O D E L NO. 2 B '
. +4 V E R T I C A L W A L L W I T H 1 . 0 x 1 . 0 m V E R T I C A L P R O T R U S I O N S V E R T I C A L W A L L ' W I T H 1.0X 1.0 m V E R T I C A L P R O T R U S I O N S AND LIPOUTER BREAKVi/ATER
CAISSONS WITH .VERTICAL WALLS
1 = 2 5 0
OUTER BREAKVi/ATER
CAISSONS WITH .VERTICAL WALLS
HANSTHOLM
45
W I T H 0.5x0.5mLIP
MODEL NO. 4A
W I T H 0.5X 0.5m L I P
OUTER B R E A K W A T E R
'ERTICAL CAISSONS-^SLOPING FACE
1'.250
ISTF
MODEL NO. 5
-15mMODEL NO. 6 •
MODEL NO. 7
-11 W A V E S . WAVES 0 . 5 mC E L L H WAS NOT MOUNTED
O U T E R ' B R E A K W A T E R
C I R C U L A R C A I S S O N S
1: 5 0 0
!["Le fragment de loi ptolemaïque P. Petrie III 26 (Bodl. Ms. Gr. Class. D 27 [Ρ])", M. T. Lenger, "Studi in on. di U. E. Paoli", 1955 : [recenzja]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==)