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Annual report 1974
Foundation
Netherlands Ship Model Basin
Wageningen, the Netherlands
The Netherlands Ship Model Basin is located in Wageningen, Haagsteeg 2, P.O.Box 28,
Telephone: (08370) 19140 Telex: 4 5 1 4 8
Telegrams: Modeltank
Bankers: Algemene Bank Nederland N.V., Wageningen, A c c o u n t : 53.93.39.156 The Depressurized T o w i n g Tank is located in Ede, Niels Bohrstraat 12,
" . i i i l H t i i i i i : ;
-B o a r d o f D i r e c t o r s , M a n a g e m e n t , A d v i s o r y -B o a r d , C o n s u l t a n t s ,
R e p r e s e n t a t i v e s a b r o a d 1
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i n d u s t r i a l s e r v i c e 4 Powering, ship propulsion and its consequences 4
Deep w a t e r t o w i n g tanl< 4 C a v i t a t i o n t u n n e l s a n d special projects 6
Depressurized t o w i n g t a n k 8 P r o p u l s i o n h y d r o d y n a m i c s 1 0 S t r e n g t h and v i b r a t i o n s 1 2 Ocean engineering, ship dynamics 1 4
S e a k e e p i n g basin 1 4 T o w i n g t a n k f o r u n c o n v e n t i o n a l maritime c o n s t r u c t i o n s 1 6 W a v e a n d current basin 1 8 S h a l l o w w a t e r basin 2 0 M a n o e u v r i n g s i m u l a t o r 2 2 Computer centre 2 3 I n s t r u m e n t a t i o n 2 5 P e r s o n n e l 2 7 P r o s p e c t s 2 8 S o m e i m p o r t a n t f i g u r e s 2 9 D i s t r i b u t i o n of t u r n o v e r a n d N S M B research 3 0 M o d e l s of very large tankers tested at t h e N S M B 31
P u b l i c a t i o n s , lectures, m e e t i n g s 3 2 Facilities in W a g e n i n g e n 4 2 O r g a n i z a t i o n s c h e m e a n d principal personnel of t h e N S M B 4 3
Board of Directors, Management, Advisory Board, Consultants,
B o a r d o f D i r e c t o r s Chairman V i c e - C h a i r m a n Secretary IVIembersJ . W . Huplces Shipbuilder (retd.)
Dr. H. J . H. Janssen Under-Secretary of State for Shipping P. E. E. Kleyn van W i l l i g e n Shipowner
R . J . H. Fortuyn Royal Netherlands Shipowners Association P. de Josselin de J o n g Shipowner (retd.)
Prof. dr. W . P. A . v a n Lammeren Former President NSiViB A . Stikker Shipbuilder
0 . J . v a n der V o r m Central Association of Dutch Shipbuilders 0 . W . Vos Ministry of Finance
I V I a n a g e m e n t
President V i c e - P r e s i d e n t s
Prof. dr. J . D. v a n M a n e n
A . H. Pastoor, R e g i s t e r a c c o u n t a n t Administration and Finance Dr. J . P. H o o f t Ship Dynamics - Offshore Technology J . J . M u n t j e w e r f Ship Powering
Dr. M . W . C. Oosterveld Research and Development
A d v i s o r y B o a r d
M e m b e r s A . Laredo Shipbuilder (France)
J . W . M a i n g a y Ship Propeller Manufacturer J . F. Meijer Royal Netherlands Navy
G. Nilsson Shipbuilder (Sweden)
H. M . O u d s h o o r n Ministry of Transport, Hydraulics and Public Works E. M . Q. Roren Det norske Veritas (Norway)
L. P. Ruys Shipowner
C o n s u l t a n t s
Prof. dr. R. T i m m a n University of Technology, Delft Prof. dr. R. W e r e l d s m a University of Technology, Delft
R e p r e s e n t a t i v e s a b r o a d Australia
A n t e l o p e Engineering Pty., Ltd.,
U.S.A., Gulf area
Mr. Blakely S m i t h , H o u s t o n
Japan
M a c G r e g o r Far East L t d . , T o k y o
Ison's Point, N.S.W.
D u r i n g t h e year 1 9 7 4 the activities of t h e NSIVIB have experienced a marked i n f l u e n c e of t h e oil crisis a n d its still l i n g e r i n g consequences.
O n the o n e h a n d research, d e v e l o p m e n t and feasibility studies of 'ocean e n g i n e e r i n g ' projects have received a positive impulse d u e t o t h e increased initiatives t o explore t h e sea b o t t o m for energy sources.
On the other h a n d t h e s h i p b u i l d i n g industry has s t o p p e d its d e v e l o p m e n t of ever increasing tanker d i m e n s i o n s . The g r a p h o n page 3 1 , s h o w i n g tanker m o d e l s tested at t h e N S M B , may be illustrative in this respect - note the decrease in size a n d n u m b e r of models of very large tankers tested in 1 9 7 4 . The i m p o r t a n t industrial maritime centres are reorientating in order t o search the d e m a n d for n e w ship t y p e s a n d ship d i m e n s i o n s t o be d e v e l o p e d . In the l i g h t of these t e n d e n c i e s t h e laboratories in W a g e n i n g e n realized a t u r n o v e r larger t h a n estimated, resulting in a cash f l o w of a p p r o x i m a t e l y 1 4 percent of t h e total i n c o m e . The table on page 2 9 gives some figures on t h e d i s t r i b u t i o n of t h e t u r n o v e r of t h e different departments since 1 9 6 8 , as
percentages of t h e total turnover. The g r a p h on page 3 0 gives an impression of w h e r e t h e orders o r i g i n a t e d f r o m .
A t Ede the depressurized t o w i n g t a n k remained f i n a n c i a l l y b e l o w the estimate. A c o m p e n s a t i o n is t h e remarkable scientific t e c h n o l o g i c a l progress made in t h e course of the year. The results of this progress have been presented at the N S M B - S y m p o s i u m ' H i g h P o w e r e d Propulsion of Large S h i p s ' held in
W a g e n i n g e n f r o m 10 to 13 December. In total 2 6 papers w e r e presented, 7 of w h i c h w e r e prepared by scientific officers of the N S M B . The a u d i e n c e of 2 0 0 visitors representing 19 c o u n t r i e s , c o u l d be c o n s i d e r e d a very h i g h q u a l i f i e d g r o u p of experts in t h e v a r i o u s aspects of ship p r o p u l s i o n .
Further h i g h l i g h t s and positive d e v e l o p m e n t s as w e l l as a sad event in t h e course of the year are m e n t i o n e d b e l o w .
- In J a n u a r y the minister of e c o n o m i c affairs Mr. R. F. M . Lubbers and the minister of science p o l i c y Mr. F. H. P. Trip visited o u r laboratories.
- In t h e M a y - m e e t i n g o f t h e Board of Directors Mr. P. E. E. Kleyn van W i l l i g e n succeeded Mr. P. de J o s s e l i n de J o n g as secretary.
- Prof. dr. J . D. v a n M a n e n w a s a p p o i n t e d a m e m b e r o f t h e ' H o l l a n d s c h e M a a t s c h a p p i j der W e t e n s c h a p p e n ' on M a y 18, 1 9 7 4 .
- In A u g u s t Mr. W . C. den H a r t o g , a m e m b e r of the A d v i s o r y B o a r d , past a w a y . - In t h e N o v e m b e r - m e e t i n g o f t h e Board of Directors Mr. A. Stikker entered as a n e w member.
- In t h e name a n d by the a u t h o r i t y of The State of Texas prof. dr. J . D. v a n M a n e n w a s c o m m i s s i o n e d H o n o r a r y A d m i r a l in t h e Texas Navy on 6th September 1 9 7 4 .
- In O c t o b e r dr. J . P. H o o f t w a s a w a r d e d w i t h the Bronze M e d a l of The Royal Institute of N a v i g a t i o n , L o n d o n .
- The c o - o p e r a t i o n w i t h t h e Delft Hydraulics Laboratory d e v e l o p e d f a v o u r a b l y a n d a j o i n t plan for further e x p a n s i o n has been set up.
- A n agreement has been reached w i t h t h e Reactor Centrum N e d e r l a n d , Petten, t o c o m e t o a close c o - o p e r a t i o n w i t h respect t o c o m p u t e r operations.
Industrial service and research to create new
possibilities for industrial service
Powering, ship propulsion and its consequences
D e e p w a t e r t o w i n g t a n k
This f a c i l i t y w a s , as usual, f u l l y o c c u p i e d w i t h industrial orders d u r i n g t h e w h o l e of 1 9 7 4 . T h e w o r k w a s carried o u t in t w o shifts.
Besides t h e n o r m a l resistance a n d p r o p u l s i o n tests f o r hull o p t i m i z a t i o n f r o m a p r o p u l s i o n p e r f o r m a n c e p o i n t of v i e w , an increasing d e m a n d w a s r e c o g n i z e d t o p e r f o r m tests t o o v e r c o m e v i b r a t i o n p r o b l e m s caused by c a v i t a t i n g propellers. T h r e e - d i m e n s i o n a l w a k e surveys w i t h 5 - h o l e Pitot t u b e s are b e c o m i n g
i n d i s p e n s a b l e f o r s h i p t y p e s w h i c h have t o operate under d i f f i c u l t p o w e r i n g c o n d i t i o n s .
T o i m p r o v e t h e v i b r a t i o n b e h a v i o u r , t h e N S M B d e v e l o p e d a stern t u n n e l c o n f i g u r a t i o n , w h i c h can be a d d e d t o or faired into t h e a f t e r b o d y lines of a ship. T o u n d e r s t a n d t h e effect of s u c h a stern t u n n e l , a 2 - h o l e Prandtl t u b e
a r r a n g e m e n t has been d e v e l o p e d t o measure t h e v e l o c i t y in f r o n t of t h e r u n n i n g propeller. F l o w v i s u a l i z a t i o n t e c h n i q u e s by means of t u f t s , observed by
u n d e r - w a t e r t e l e v i s i o n a n d recorded o n v i d e o t a p e , have also been i n t r o d u c e d . T o s t u d y t h e effect u p o n p r o p u l s i o n p e r f o r m a n c e , c a v i t a t i o n a n d pressure f l u c t u a t i o n s , a 4 - b l a d e d h i g h s k e w - b a c k propeller series has been d e v e l o p e d a n d t e s t e d .
A l t h o u g h t h e e n v i r o n m e n t a l c o n d i t i o n s w e r e d i f f i c u l t , f u l l - s c a l e o b s e r v a t i o n s of t h e c a v i t a t i o n b e h a v i o u r of propeller a n d struts of a large t w i n - s c r e w
c o n t a i n e r s h i p s c o r e d great success. C a v i t a t i o n o n t h e struts can already o c c u r d u r i n g n o r m a l s h i p m o t i o n s at sea a n d under m a n o e u v r i n g c o n d i t i o n s . D u e t o t h e larger d e m a n d of h i g h - p o w e r e d c o n t a i n e r s h i p s , it is necessary t o
c o n s i d e r a b l y i m p r o v e t h e t e c h n i q u e s t o d e t e r m i n e t h e strut o r i e n t a t i o n . A special m e a s u r i n g d e v i c e is b e i n g d e v e l o p e d f o r measuring t h e f l o w d i r e c t i o n at t h e l o c a t i o n of t h e struts. U n d e r - w a t e r t e l e v i s i o n also p r o v e d t o be very useful in t h i s respect.
In close c o - o p e r a t i o n w i t h s h i p o w n e r s , t h e p r o p u l s i o n p e r f o r m a n c e of a c o n t a i n e r s h i p w a s s t u d i e d w i t h a s y s t e m a t i c a l l y varied series of b u l b o u s b o w s .
Development of after body configuration of large t w i n screw tankers.
C a v i t a t i o n t u n n e l s a n d s p e c i a l p r o j e c t s
T h e c a v i t a t i o n t u n n e l w i t h f l o w regulator w a s m a i n l y used f o r industrial orders. In t h i s t u n n e l , t h e axial w a k e field in t h e propeller plane is s i m u l a t e d by means of a f l o w r e g u l a t o r c o n s i s t i n g of a m u l t i p l e of c h a n n e l s w i t h valves. C a v i t a t i o n o b s e r v a t i o n tests are m a d e t o predict t h e risk for e r o s i o n . T h e a m o u n t of orders f o r t h i s t u n n e l s h o w e d an increase of a b o u t 2 0 percent.
T h e large c a v i t a t i o n t u n n e l w a s used for several purposes. T h e m a i n part of t h e i n v e s t i g a t i o n s c o n s i s t e d of c a v i t a t i o n o b s e r v a t i o n tests in a t h r e e - d i m e n s i o n a l w a k e f i e l d s i m u l a t e d by a d u m m y ship m o d e l . In s o m e cases pressure f l u c t u a t i o n s w e r e m e a s u r e d . A n o t h e r part consisted of f l o w tests a r o u n d c u r r e n t p r o t e c t i o n shields, blade spindle t o r q u e m e a s u r e m e n t s o n c o n t r o l l a b l e p i t c h propellers, a n d p e r f o r m a n c e , c a v i t a t i o n and f l o w tests of d u c t e d
c o n t r o l l a b l e p i t c h propellers. A n i n v e s t i g a t i o n w a s initiated t o s t u d y c a v i t a t i o n scale effects w i t h propeller m o d e l s . T h e s t u d y involves b o t h t h e v i s c o u s a n d r o u g h n e s s e f f e c t s . O n e of its purposes is t o correct f o r v i s c o u s effects by c h a n g i n g t h e b l a d e r o u g h n e s s .
In t h e h i g h speed c a v i t a t i o n t u n n e l , a research p r o g r a m w a s carried o u t in c o - o p e r a t i o n w i t h t h e Institute of A p p l i e d Physics T N O - T H . A n e w m e t h o d f o r t h e o b s e r v a t i o n of c a v i t a t i o n i n c e p t i o n p h e n o m e n a w a s i n t r o d u c e d . It c o n s i s t e d of a t h r e e - d i m e n s i o n a l i m a g i n g t e c h n i q u e , called h o l o g r a p h y .
W i t h this m e t h o d a h o l o g r a m is made w i t h a pulsed r u b y laser. T h e h o l o g r a m is p l a c e d in a r e c o n s t r u c t o r a n d i l l u m i n a t e d w i t h a c o n t i n u o u s - w a v e laser. T h e r e c o n s t r u c t i o n is m a g n i f i e d by a m i c r o s c o p e a n d , by f o c u s s i n g , i n d i v i d u a l b u b b l e s or cavities can be s t u d i e d a n d p h o t o g r a p h e d . W i t h t h i s t e c h n i q u e , b u b b l e s h a v i n g diameters d o w n t o 4 [xm can be d e t e c t e d . S i n c e t h e e x p o s u r e t i m e is 2 5 x 1 0 " ' sec. o n l y , t h e l i m i t i n g speed of t h e cavities is v e r y h i g h .
In t h i s s t u d y , t h e l o c a t i o n of c a v i t a t i o n i n c e p t i o n c o u l d be correlated w i t h t h e l o c a t i o n of laminar b o u n d a r y layer separation o n a h e m i s p h e r i c a l n o s e d b o d y .
Photographs s h o w i n g the progressive development of cavitation on a hemispherical nosed body at a Reynolds number of 0.97 X 10^. The f l o w is from left to right. The light patches above the model surface are cavitating areas. The photographs are made from reconstructions of holograms. The light source is a pulsed ruby laser w i t h a time duration of 25 x 1 0 " ^ seconds. The upper photograph (a) is at a cavitation number cr of 0.74 and shows bubble cavitation. The body exhibits a laminar boundary layer separation and the locations of separation and transition to turbulence are marked by S and T respectively. In the middle photograph ( b ) , cr is slightly reduced and the cavitation bubbles tend to adhere to the surface. In the lower photograph (c), a is reduced further and a clear macroscopic cavity (sheet cavitation) is found on the body.
D e p r e s s u r i z e d t o w i n g t a n k
It w a s necessary t o w o r k in d o u b l e shifts because of t h e heavy load of industrial orders a n d t h e activities t o i m p r o v e a n d t o e x t e n d t h e t e s t i n g possibilities. In a d d i t i o n t o resistance, p r o p u l s i o n a n d c a v i t a t i o n o b s e r v a t i o n tests, t h e f o l l o w i n g tests can be carried o u t s u c c e s s f u l l y :
- m e a s u r e m e n t of w a k e field by means of a survey w i t h f i v e - h o l e Pitot t u b e s ; - m e a s u r e m e n t of t h e effect of propeller c a v i t a t i o n o n hull pressure forces and s h a f t f o r c e s ;
- m e a s u r e m e n t of far- a n d nearby s o u n d f i e l d as generated by a c a v i t a t i n g p r o p e l l e r ;
- m e a s u r e m e n t of axial f o r c e o n a rudder or nozzle d u r i n g s e l f - p r o p u l s i o n tests. F u r t h e r m o r e t h e m e a n s for f l o w o b s e r v a t i o n and f o r c a v i t a t i o n o b s e r v a t i o n s have been i m p r o v e d .
T h e industrial orders carried o u t t h e past year in t h e depressurized t o w i n g t a n k c o n c e r n e d m a i n l y large a n d / o r h i g h p o w e r e d ships f o r w h i c h a g o o d s i m u l a t i o n of t h e w a k e f i e l d a n d a correct i n t e r a c t i o n b e t w e e n hull a n d propeller is of u t m o s t i m p o r t a n c e f o r reliable t e s t i n g . In n u m e r o u s cases, c o m p a r i s o n s b e t w e e n s i n g l e s c r e w , d u c t e d propeller, o v e r l a p p i n g t w i n s c r e w arrangements and t w i n -g o n d o l a r a r r a n -g e m e n t s w e r e made. In a d d i t i o n , v a r i a t i o n s in aft b o d y shapes w e r e s t u d i e d .
M u c h e f f o r t w a s g i v e n t o o b t a i n correlation data b e t w e e n t h e c a v i t a t i o n patterns o b s e r v e d o n f u l l scale propellers a n d t h o s e in t h e depressurized t o w i n g t a n k . For a n u m b e r of ships, c o m p r i s i n g large tankers w i t h o p e n s c r e w a n d w i t h d u c t e d propeller, c o n t a i n e r s h i p s a n d naval ships, correlation data are available n o w a n d in general a g o o d agreement b e t w e e n m o d e l a n d f u l l scale data w a s f o u n d . T o s u p p o r t t h e i n t e r p r e t a t i o n of t h e depressurized t o w i n g t a n k test results a n d f o r a proper c h o i c e of t h e parameters t o be tested a n u m b e r of t h e o r e t i c a l studies w e r e carried o u t . S o m e of these studies, w h i c h p r o c e e d q u i t e far, a r e : - t h e d e v e l o p m e n t of a p r e d i c t i o n p r o g r a m for resistance and p r o p u l s i o n of ships, i n c l u d i n g t h e a p p l i c a t i o n of t h r e e - d i m e n s i o n a l e x t r a p o l a t i o n m e t h o d s ; - t h e d e v e l o p m e n t of p r o g r a m s t o calculate t h e i n c e p t i o n speed a n d extent of c a v i t a t i o n of propellers o p e r a t i n g in a w a k e f l o w . Based o n t h e results of these c a l c u l a t i o n s a p r o g r a m has been d e v e l o p e d t o calculate the hull pressure forces g e n e r a t e d by t h e c a v i t a t i n g p r o p e l l e r ;
- t h e d e v e l o p m e n t of a p r o g r a m t o calculate t h e scale effects in w a k e f l o w s . M o r e o v e r , m u c h a t t e n t i o n w a s paid t o f u n d a m e n t a l aspects of c a v i t a t i o n . T h e effect of t h e air c o n t e n t of t h e w a t e r and t h e R e y n o l d s n u m b e r o n c a v i t a t i o n i n c e p t i o n w a s s t u d i e d .
T h e progress m a d e in these theoretical studies c o n f i r m t h a t their results c o m p l e m e n t t h e e x c l u s i v e e x p e r i m e n t a l results of t h e tests in t h e depressurized t o w i n g t a n k t o s u c h an extent t h a t rigorous c o r r e l a t i o n studies into t h e v a r i o u s aspects of s h i p p r o p u l s i o n can be m a d e .
Lines of equal axial velocity of a tanker wake field.
Measured model wake distribution. Predicted full scale wake distribution.
The prediction method for the full scale wake distribution developed at the NSMB is using the model wake as a starting point. In the method a threefold contracting of the wake field in dependency of its harmonics content is considered, while also the scale effect on the bilge vortices is taken into account.
P r o p u l s i o n h y d r o d y n a m i c s
N e w t y p e s of e x p e r i m e n t a l projects have been d e v e l o p e d , s u c h as t h e m e a s u r e m e n t of n o i s e radiated by c a v i t a t i n g propellers, b o t h i n b o a r d a n d o u t b o a r d of t h e m o d e l in t h e depressurized t o w i n g t a n k a n d tests w i t h a i r - f e e d , lift c o n t r o l l e d h y d r o f o i l s in t h e t o w i n g t a n k for u n c o n v e n t i o n a l m a r i t i m e c o n s t r u c t i o n s .
Further d e v e l o p m e n t of major t h e o r e t i c a l p r o g r a m s c o n t i n u e d :
- T h e n u m e r i c a l p r o g r a m for t h e c a l c u l a t i o n of the t y p e a n d extent of c a v i t a t i o n o n propellers in a w a k e , i n c l u d i n g effects of n o n - u n i f o r m i n f l o w a n d v i s c o s i t y , w a s f i n a l i z e d . In a n u m b e r of cases this p r o g r a m w a s s u c c e s s f u l l y used in parametric studies t o d e t e r m i n e t h e effect of various propeller g e o m e t r y parameters o n c a v i t a t i o n p e r f o r m a n c e , t h e r e b y d e t e r m i n i n g a final d e s i g n t o be e x p e r i m e n t a l l y q u a l i f i e d . A t t e n t i o n is n o w b e i n g f o c u s s e d o n t h e d e v e l o p m e n t of an e q u i v a l e n t p r o g r a m f o r h e a v i l y - l o a d e d nozzle propellers.
- I m p o r t a n t progress w a s also m a d e in t h e d e v e l o p m e n t of t h e linearized, u n s t e a d y l i f t i n g surface t h e o r y . A n e w a p p r o a c h for t h e c a l c u l a t i o n of t h e steady propeller loads w a s i n c o r p o r a t e d a n d a start w a s m a d e t o i n c l u d e t h e e f f e c t of rake a n d t h e effect of t h e radial c o m p o n e n t of t h e i n f l o w into t h e propeller. - T h e t h r u s t a n d t o r q u e p o l y n o m i a l s of t h e B - s c r e w series, w h i c h w e r e d e r i v e d f r o m t h e available o p e n w a t e r data, w e r e e x t e n d e d t o i n c l u d e t h e effect of R e y n o l d s n u m b e r . In this w a y it is n o w possible t o predict f u l l scale o p e n w a t e r results. A revised set of o p e n w a t e r and s o - c a l l e d ' B p - d e l t a ' d i a g r a m s , based on t h e p o l y n o m i a l v a l u e s , w a s prepared. A n e w set of ' B p - d e l t a ' d i a g r a m s , d e s i g n e d f o r t h e p u r p o s e of q u i c k l y d e t e r m i n i n g t h e o p t i m u m R P M , is b e i n g p r e p a r e d .
L p IN dB r e 1 [IPA.
-S t r e n g t h a n d v i b r a t i o n s
For a n u m b e r of s h i p s t h e h y d r o d y n a m i c propeller shaft e x c i t a t i o n s have been measured in t h e depressurized t o w i n g t a n k . These m o d e l tests w e r e c o n d u c t e d under a t m o s p h e r i c c o n d i t i o n s ( n o c a v i t a t i o n ) as w e l l as under depressurized c o n d i t i o n ( c a v i t a t i o n n u m b e r correctly s c a l e d ) . The tests i n d i c a t e d t h a t t h e effect of c a v i t a t i o n o n h y d r o d y n a m i c propeller shaft e x c i t a t i o n s is very small for
m o d e r a t e l y c a v i t a t i n g propellers, at least in c o m p a r i s o n w i t h t h e effect of c a v i t a t i o n o n t h e h u l l pressure forces. Further, the tests have s h o w n t h a t o n f u l l vessels t h e d y n a m i c hull pressures are less steady t h a n w a s e x p e c t e d . T h e pressure signals c a n vary s t r o n g l y d u r i n g a series of propeller r e v o l u t i o n s . This u n s t e a d y b e h a v i o u r is c a u s e d by variations in the c a v i t a t i o n b e h a v i o u r . A suitable m e t h o d f o r a n a l y z i n g t h e unsteady h y d r o d y n a m i c hull forces is in d e v e l o p m e n t .
Essential progress has been m a d e in t h e u n d e r s t a n d i n g of t h e nature of d a m p i n g w i t h regard t o t h e f o r c e d hull girder response. T o c h e c k t h e general v a l i d i t y of t h e p h i l o s o p h y , i n v e s t i g a t i o n s o n s o m e ships, s t r o n g l y d i f f e r i n g in c o n s t r u c t i o n a l s e t - u p , have been p l a n n e d .
In c o - o p e r a t i o n w i t h t h e p r o p u l s i o n h y d r o d y n a m i c s d e p a r t m e n t , t h e i m p o r t a n t role of t h e h y d r o d y n a m i c propeller c o e f f i c i e n t s w i t h regard t o t h e f o r c e d v i b r a t i o n s of t h e s h a f t i n g has been d e m o n s t r a t e d . Because of t h e f a c t t h a t t h e d e t a i l e d propeller g e o m e t r y a n d its operational R P M are very decisive in t h e values of these propeller c o e f f i c i e n t s , no s i m p l e f o r m u l a t i o n exists f o r t h e r e l a t i o n s h i p b e t w e e n t h e characteristic propeller values, s u c h as p i t c h a n d b l a d e area ratio.
f r e q u e n c y Hz = = = - undannped response — — full scale response
X effect of viscous stiffness damping X = 0 . 0 0 1 O effect of viscous stiffness damping M. = 0 . 0 0 2
Measured and calculated hull response to given excitation system (from Hylarides doctor's thesis).
Ocean engineering, ship dynamics
S e a k e e p i n g b a s i n
In t h i s f a c i l i t y a t o t a l of 3 0 industrial orders w e r e carried o u t d u r i n g 1 9 7 4 , characterized b y a large diversity in s c o p e a n d o b j e c t i v e s .
C o m p l i c a t e d e x p e r i m e n t a l test s e t - u p s had t o be d e v e l o p e d a n d d e s i g n e d f o r i n v e s t i g a t i o n s , particularly f o r p i p e - l a y i n g barges in f u l l o p e r a t i o n a l c o n d i t i o n , w h e r e as m u c h as 4 0 c h a n n e l s had t o be m o n i t o r e d s i m u l t a n e o u s l y .
Orders d i r e c t l y related t o s o l v i n g p r o b l e m s f o r t h e o f f s h o r e i n d u s t r y a m o u n t e d t o 3 0 percent of t h e t o t a l t u r n o v e r . A n e w aspect in this f i e l d of research b e c a m e t h e d e v e l o p m e n t of s e m i - s u b m e r s i b l e p l a t f o r m s f o r b o t t o m e x p l o r a t i o n a n d e x p l o i t a t i o n in arctic w a t e r s .
7 0 percent of t h e projects w e r e related t o surface vessels, c o m p r i s i n g a n c h o r h a n d l i n g t u g s , s u p p l y a n d s u p p o r t vessels, L N G a n d oil carriers.
A p a r t f r o m t h e e x p e r i m e n t a l w o r k , feasibility studies of n e w d e s i g n s of ships a n d o c e a n p l a t f o r m s w e r e carried o u t by c o m p u t e r c a l c u l a t i o n s .
In 1 9 7 4 i m p r o v e m e n t s w i t h respect t o t h e m e a s u r i n g c a p a c i t y have been e f f e c t u a t e d by c h a n g i n g t h e a n a l o g u e r e c o r d i n g i n s t r u m e n t a t i o n i n t o d i g i t a l e q u i p m e n t .
S i n c e preparations f o r c o m p l i c a t e d test s e t - u p s i m p l y a decrease of e f f e c t i v e t a n k t i m e , plans for f u r t h e r i m p r o v e m e n t of t h e f a c i l i t y are in d e v e l o p m e n t , c o m p r i s i n g a m o d i f i c a t i o n t o t h e e x i s t i n g carriage in order t o m a k e t h e t e s t i n g area more accessible.
Stability test for stinger of a pipe-laying barge.
T o w i n g t a n k f o r u n c o n v e n t i o n a l m a r i t i m e c o n s t r u c t i o n s
In t h i s l a b o r a t o r y m o d e l e x p e r i m e n t s w e r e c o n d u c t e d t o s t u d y t h e b e h a v i o u r a n d p e r f o r m a n c e of v a r i o u s fast m o t o r boats and frigates in o p e r a t i o n a l sea c o n d i t i o n s .
A m o d e l of a c a r g o s h i p d e s i g n e d for carrying heavy loads w a s tested in very r o u g h seas t o investigate w h e t h e r t h e freeboard a n d b o w h e i g h t t o be a p p l i e d w e r e s u f f i c i e n t t o keep d e c k w e t n e s s a n d t h e a m o u n t of w a t e r e n t e r i n g t h e o p e n h o l d at a m i n i m u m .
In c o - o p e r a t i o n w i t h t h e ' I n s t i t u u t v o o r M o r f o l o g i e ' of t h e Vrije Universiteit Brussel, B e l g i u m a n d t h e Royal D u t c h S w i m m i n g A s s o c i a t i o n , systematic studies o n t h e e f f e c t of b o d y shape of s w i m m e r s o n t h e resulting resistance a n d t h e pressure v a r i a t i o n o n t h e hands d u r i n g d i f f e r e n t t y p e s of s w i m m i n g strokes w e r e c o n t i n u e d .
T h e s e c o n d carriage, d e s i g n e d f o r very h i g h speeds up t o 3 0 m / s e c , w a s used t o carry o u t tests w i t h v a r i o u s t y p e s of h y d r o f o i l s . M a n y p r o j e c t s , h o w e v e r , c a m e f r o m t h e o f f s h o r e industry. T o w i n g characteristics of steel j a c k e t - t y p e a n d g r a v i t y structures w e r e d e t e r m i n e d in c a l m w a t e r a n d in w a v e s . M o d e l studies w e r e m a d e of t h e c o m p l e t e s e q u e n c e of t h e l a u n c h i n g of v a r i o u s j a c k e t s f r o m t h e l a u n c h barge in c a l m w a t e r and in w a v e s ; t h e e f f e c t s of t h e f r i c t i o n c o e f f i c i e n t of t h e l a u n c h w a y s a n d t h e ballast pattern of t h e barge o n t h e l a u n c h b e h a v i o u r of t h e j a c k e t w e r e d e t e r m i n e d .
D u r i n g these tests t h e a b s o l u t e a n d relative m o v e m e n t s of t h e j a c k e t a n d barge a n d t h e forces in t h e rocker arms a n d t h e p u l l i n g w i r e s w e r e r e c o r d e d . A s a result, t h e m o s t f a v o u r a b l e l a u n c h i n g p r o c e d u r e c o u l d be selected.
T h e l a u n c h i n g tests w e r e f o l l o w e d by t h e u p e n d i n g of t h e j a c k e t t o d e t e c t t h e m i n i m u m b o t t o m clearance of t h e j a c k e t a n d t o observe t h e b e h a v i o u r of t h e j a c k e t d u r i n g t h e u p e n d i n g . The i n f l u e n c e s of t h e w e i g h t , centre of g r a v i t y a n d f l o o d i n g p r o c e d u r e s w e r e s t u d i e d . A f t e r selecting t h e m o s t f a v o u r a b l e u p e n d i n g p r o c e d u r e , static s t a b i l i t y tests a n d h o l d i n g force measurements w e r e p e r f o r m e d f o r several stages in t h e u p e n d i n g trajectory.
Launching of a 5500 tons jacl<et.
W a v e a n d c u r r e n t b a s i n
D u r i n g t h e year 1 9 7 4 t h e w a v e a n d current laboratory w a s f u l l y o c c u p i e d w i t h industrial w o r k .
T o enable m o d e l tests o n deep w a t e r m o o r i n g systems, w h i c h up t o n o w w e r e n o t possible at t h e n o r m a l l y used m o d e l scales d u e t o t h e w a t e r d e p t h
l i m i t a t i o n , a pit w i t h a diameter of a p p r o x i m a t e l y 3 m a n d a d e p t h of 2.5 m w a s c o n s t r u c t e d in t h e centre of t h e basin. This pit provides t h e p o s s i b i l i t y t o test t h e m o o r i n g properties of single a n c h o r leg a n d oscillatory t o w e r t y p e s of d e e p sea m o o r i n g systems.
A very extensive m o d e l test p r o g r a m w a s carried o u t o n single p o i n t m o o r i n g t e r m i n a l s f o r s o m e of t h e p l a n n e d super ports in t h e G u l f of M e x i c o . D u r i n g these tests, w h i c h lasted a p p r o x i m a t e l y three m o n t h s , m u c h a t t e n t i o n w a s paid t o t h e m o d e l l i n g , t e s t i n g a n d o p t i m i z a t i o n of various u n d e r w a t e r hose systems f o r t h e t r a n s p o r t a t i o n of c r u d e o i l .
Use of u n d e r w a t e r t e l e v i s i o n e q u i p m e n t a n d v i d e o tapes appeared t o be very i m p o r t a n t . V i d e o t a p e s can n o w be prepared in a c c o r d a n c e w i t h U.S. standards.
A t o t a l of 7 5 % of t h e m o d e l test studies consisted of tests o n m o o r e d f l o a t i n g
o b j e c t s ; 1 5 % o n t h e d e t e r m i n a t i o n of m a n o e u v r i n g properties of ships. S o m e i n t e r e s t i n g m o d e l a n d full scale e x p e r i m e n t s w e r e p e r f o r m e d o n t h e l i g h t e r i n g of V L C C ' s by smaller o f f - t a k e tankers.
T h e p r o b l e m s met d u r i n g t h e past year have clearly i n d i c a t e d t h a t a deep w a t e r basin, in w h i c h w a v e s a n d current can be g e n e r a t e d , w i l l be necessary f o r proper assistance in t h e d e s i g n of o f f s h o r e c o n s t r u c t i o n s by means of m o d e l tests. Preparations t o b u i l d s u c h a f a c i l i t y have been started.
Various single point mooring systems tested in the wave and current basin.
S h a l l o w w a t e r b a s i n
T h e order s i t u a t i o n d u r i n g t h e year 1 9 7 4 w a s satisfactory. T h e m o s t i m p o r t a n t a c t i v i t y w a s t h e t e s t i n g of o f f s h o r e structures, for t h e m a j o r i t y c o n c r e t e g r a v i t y p l a t f o r m s f o r oil a n d gas p r o d u c t i o n in t h e N o r t h e r n part of t h e N o r t h Sea. M o d e l tests w e r e carried o u t t o investigate t h e b e h a v i o u r of several p l a t f o r m s d u r i n g t o w i n g a n d i n s t a l l a t i o n , w h i l e t h e w a v e loads on t h e s e p l a t f o r m s w e r e d e t e r m i n e d e x c l u s i v e l y by means of c o m p u t e r c a l c u l a t i o n s .
A n o t h e r i m p o r t a n t t o p i c w a s t h e m o o r i n g of large t a n k e r s . D u r i n g these tests, t h e pits, o r i g i n a l l y b u i l t in the basin for t a k i n g u n d e r w a t e r p h o t o g r a p h s , w e r e used several t i m e s t o create locally a greater w a t e r d e p t h .
In t o t a l , a l m o s t 7 0 percent of t h e w o r k carried o u t d u r i n g t h e year under review, w a s related t o e x p l o r a t i o n , e x p l o i t a t i o n a n d t r a n s p o r t a t i o n of o i l .
T h e s t a n d a r d m a n o e u v r i n g tests ( o v e r s h o o t tests) s h o w a t e n d e n c y t o decrease. M o s t m a n o e u v r i n g tests carried o u t in t h e s h a l l o w w a t e r l a b o r a t o r y n o w a d a y s serve t o gather i n p u t f o r t h e m a n o e u v r i n g simulator. These tests c o v e r t h e d e t e r m i n a t i o n of h y d r o d y n a m i c characteristics of ships as w e l l as t h e m e a s u r e m e n t of d i s t u r b a n c e s , as for instance, forces exerted by passing or o v e r t a k i n g ships. T h e t h e o r e t i c a l c o m p u t a t i o n of w a v e loads w i t h the d i f f r a c t i o n t h e o r y s h o w s a f u r t h e r g r o w t h . T h e s p e c i f i c a t i o n of industrial w o r k is as f o l l o w s : Tests o n o f f s h o r e p l a t f o r m s 3 4 percent M o o r i n g tests 2 4 percent M a n o e u v r i n g tests 2 2 percent Resistance a n d p r o p u l s i o n tests 1 2 percent T h e o r e t i c a l c a l c u l a t i o n s 5 percent Special projects 3 percent
O s c i l l a t i o n tests have been p e r f o r m e d t o d e t e r m i n e t h e i n f l u e n c e of t h e w a t e r d e p t h a n d t h e presence of a q u a y o n t h e h y d r o d y n a m i c c o e f f i c i e n t s of a large tanker.
T h e prospects for 1 9 7 5 are g o o d . It is e x p e c t e d t h a t m o d e l t e s t i n g o n g r a v i t y p l a t f o r m s w i l l c o n t i n u e , in v i e w of t h e n u m b e r of p l a t f o r m s n o w under c o n s t r u c t i o n or o r d e r e d .
Model of Sea Deck gravity platform.
M a n o e u v r i n g s i m u l a t o r
M a n o e u v r i n g courses for pilots, masters and senior officers o c c u p i e d t h e s i m u l a t o r a b o u t o n e t h i r d of t h e t o t a l t i m e . The rest of t h e t i m e w a s d e v o t e d t o research projects a n d their p r e p a r a t i o n .
T h e research p r o j e c t s w e r e f o c u s s e d m a i n l y o n c o m p a r i s o n s b e t w e e n
alternative s h i p d e s i g n s , t h e d i m e n s i o n i n g a n d s h a p i n g of a p p r o a c h c h a n n e l s a n d t h e c o n t r o l l a b i l i t y of V L C C ' s in c o m p l i c a t e d situations.
D u r i n g t h e e x p e r i m e n t s , a n d w i t h t h e c o - o p e r a t i o n of o u r clients, a start w a s m a d e t o d e v e l o p t e c h n i q u e s t o measure t h e degree t o w h i c h t h e mariner's c a p a c i t y is o c c u p i e d by t h e n a v i g a t i o n . This w a s d o n e by i n t r o d u c i n g and m e a s u r i n g t h e p e r f o r m a n c e of a s e c o n d a r y task besides t h e primary t a s k : sailing t h e s h i p . T h e results w e r e very e n c o u r a g i n g a n d w a r r a n t e d c o n t i n u a t i o n of t h i s research.
In a d d i t i o n t o w o r k carried o u t for clients, research w a s d o n e t o create n e w possibilities f o r industrial service. This i n c l u d e d the i n f l u e n c e of cross c u r r e n t variations o n t h e p e r f o r m a n c e of m a n o e u v r e s w i t h very large tankers. A l s o an e x p e r i m e n t w a s d o n e t o c o m p a r e d i f f e r e n t m e t h o d s t o steer a s h i p : by sailing w i t h rudder c o n t r o l , rate c o n t r o l , rudder c o n t r o l w i t h f e e d - b a c k of t h e rate, and w i t h a t r a c k p r e d i c t o r , s u p e r - i m p o s e d o n the radar-display. D e m a n d f o r t h e i n v e s t i g a t i o n of t h e effects of t w o large ships sailing close t o g e t h e r a n d t h e effect of t h e p r o x i m i t y o n t h e masters or pilots gave rise t o t h e plans for
e x t e n d i n g t h e possibilities of t h e simulator. In order t o s i m u l a t e t h e t o w a g e a n d t h e p o s i t i o n i n g of heavy structures t h e s i m u l a t i o n of t u g forces w a s f u r t h e r d e v e l o p e d . T o i m p r o v e t h e m e t h o d s of registration, r e c o r d i n g a n d analysis of t h e m a n o e u v r e s , n e w e q u i p m e n t , like v i d e o recorders a n d a visual display u n i t , w e r e installed. In 1 9 7 5 m e t h o d s w i l l be d e v e l o p e d for s t u d y i n g t h e b e h a v i o u r of m a n a n d ship r e a c t i n g t o a n o t h e r steered ship. For this t y p e of research it w i l l be necessary t o b u i l d a s e c o n d b r i d g e s i m u l a t o r a n d t o e x t e n d t h e p r o g r a m a n d registration capacities.
Genera/
In t h e course of 1 9 7 4 it became necessary t o operate t h e d r a w i n g m a c h i n e s In t w o shifts.
The d e m a n d for c o m p u t e r facilities also kept increasing. In February t h e PDP 11 / 4 5 c o m p u t e r w a s installed. It s o o n w a s in o p e r a t i o n as a b a t c h t e r m i n a l on a C D C 6 6 0 0 c o m p u t e r , and as a pre-processor of laboratory
recordings. A b o u t 1 5 % of t h e N S M B c o m p u t e r w o r k w a s d o n e on t h e C D C 6 6 0 0 , w h i l e the N S M B C D C 3 3 0 0 system w a s in o p e r a t i o n for an average of 21 hours a day.
The overall increase in c o m p u t e r usage a m o u n t e d t o 4 0 % as c o m p a r e d t o 1 9 7 3 . T h e i m p o r t a n t d e c i s i o n w a s taken t o a c c o m p l i s h the necessary increase in c o m p u t e r c a p a c i t y in c o - o p e r a t i o n w i t h the c o m p u t e r centre of R C N , the D u t c h Nuclear Research Institute.
The N S M B P D P 11 / 4 5 system w i l l be t r a n s f o r m e d into a h i g h speed terminal station on the R C N e x p a n d e d C D C 6 6 0 0 c o m p u t e r . W h e n this u n i q u e project is e f f e c t u a t e d by t h e end of 1 9 7 5 , N S M B w i l l have access t o a very p o w e r f u l c o m p u t e r system at c o m p e t i t i v e costs, and w i l l start t o benefit f r o m the possibility t o a c q u i r e s o f t w a r e systems in c o - o p e r a t i o n w i t h another large c o m p u t e r user.
Software development
In t h e past year, part of t h e w o r k carried o u t c o n s i s t e d of an i n v e s t i g a t i o n i n t o the possibilities of the n e w c o m p u t e r system and t h e s o f t w a r e available on this system. The p r o g r a m s f o r shipyard p r o d u c t i o n are i m p l e m e n t e d on this system t o be able t o c o p e w i t h p r o b l e m s of overload on our C D C 3 3 0 0 system as w e l l as t o p r o v i d e f o r the possibility of terminal use by N S M B c u s t o m e r s .
T o g e t h e r w i t h R C N , a start has been made t o s t u d y s o f t w a r e packages in t h e fields of m a t h e m a t i c s , p l o t t i n g and d r a w i n g a n d data m a n a g e m e n t t o be able t o o b t a i n libraries of standard s o f t w a r e for t h e d e v e l o p m e n t in the f u t u r e .
S o f t w a r e d e v e l o p m e n t on t h e C D C 3 3 0 0 system m a i n l y consists of the e x t e n s i o n of the possibilities of t h e packages for data r e d u c t i o n a n d m o d e l c o n s t r u c t i o n .
A n e w storage a n d retrieval system w h i c h w i l l be t h e base for the data r e d u c t i o n s o f t w a r e has been analyzed and the i m p l e m e n t a t i o n of this system is initiated. T h e first P D P 1 1 / 1 0 data c o l l e c t i o n system for o n e of t h e laboratories has been installed t o g e t h e r w i t h the necessary s o f t w a r e .
Services to tlie sfiipbuiiding industry
M o s t of t h e c o m p u t e r programs available for service t o the s h i p b u i l d i n g i n d u s t r y w e r e e x t e n s i v e l y used d u r i n g this year. The expertise b u i l t up in t h e course of several years as expressed by the c o m p u t e r programs a n d t h e trained people w o r k i n g w i t h t h e m is still an i n d u c e m e n t f o r several yards t o have
t h e i r c a l c u l a t i o n s p e r f o r m e d at t h e N S M B .
M e a n w h i l e t h e c o m p u t e r p r o g r a m s are c o n s t a n t l y b e i n g u p g r a d e d a n d i m p r o v e d as a result of t h e stricter d e m a n d s f r o m t h e industry a n d t h e a p p e a r a n c e of more c o m p l i c a t e d s h i p f o r m s .
A l m o s t at t h e e n d of t h e year t h e first remote entry b a t c h - t e r m i n a l w a s c o n n e c t e d t o t h e p o w e r f u l C D C 6 6 0 0 - c o m p u t e r , t h u s e n a b l i n g t h e yard i n v o l v e d t o process its o w n N A L S c o d i n g s for part g e n e r a t i o n a n d N / C t a p e p r e p a r a t i o n . It is e x p e c t e d t h a t more yards w i l l f o l l o w this e x a m p l e in t h e course of 1 9 7 5 .
D i s c u s s i o n s w i t h i n d u s t r y have started t o c o m p l e t e a n e w version of t h e N A L S suite of p r o g r a m s , i n c o r p o r a t i n g experience g a i n e d d u r i n g t h e use of t h e e x i s t i n g p r o g r a m s a n d users' s p e c i f i c a t i o n s t o be d r a w n up by t h e n o w more e x p e r i e n c e d users.
II hiSïiiiihiifiriitafiuri
Several i m p o r t a n t d e v e l o p m e n t s o n i n s t r u m e n t a t i o n t o o k place. First of all t h e design of n e w e q u i p m e n t for t h e seakeeping basin has t o be m e n t i o n e d . The n e w i n s t r u m e n t s are a d a p t e d t o t h e c o m p u t e r based data a c q u i s i t i o n system t h a t has been c h o s e n for this basin.
The system w i l l i n c l u d e 4 8 channels, but can be easily enlarged t o 9 6 channels. The final version w i l l be c o p i e d in t h e next years for the other laboratories. A n o t h e r i m p o r t a n t d e v e l o p m e n t w a s started t o g e t h e r w i t h t h e T e c h n i s c h Physische Dienst T N O - T H at Delft. The aim of the research w a s t o adapt their l a s e r - d o p p l e r v e l o c i t y meter for measuring t h e 3 - c o m p o n e n t s of t h e w a k e field b e h i n d a m o d e l . A t t h e e n d of the year it has been proven t h a t it is possible t o measure in one test t h e 3 c o m p o n e n t s . The advantages of this expensive system are its p o s s i b i l i t y of measuring very l o w speeds, the possibility of an a b s o l u t e c a l i b r a t i o n , the f a c t t h a t no d i s t u r b a n c e of t h e w a k e field o c c u r s a n d t h e possibility t o measure t h e w a k e field just in f r o n t of an o p e r a t i n g propeller
(see p h o t o o n p a g e 2 6 ) .
A l s o in 1 9 7 4 , an o p t i c a l , a n d hence contactless, X - Y - Z measuring system w a s built. W i t h this apparatus t h e translations of very small models can be
measured w i t h o u t a p p l y i n g forces t o the models. The space covered is 1 X 1 X 1 m, in w h i c h a measuring accuracy of 0.5% is o b t a i n e d . The system operates up t o 5 Hz. w i t h peak t o peak a m p l i t u d e of 2 0 c m (see p h o t o o n page 2 6 ) . A lot of t i m e w a s s p e n t t o further i m p r o v e t h e existing e q u i p m e n t in order t o m i n i m i z e t h e t i m e needed f o r m a i n t e n a n c e and the t i m e lost d u e t o repair.
P ' ^ i f i D M i i i r i H t
The c h a n g e s in t h e staff can be seen f r o m t h e table b e l o w :
1971 1 9 7 2 1 9 7 3 1 9 7 4 M a n a g e m e n t 6 5 5 5 University graduates 33 33 3 8 4 5 College graduates 3 5 3 2 3 2 3 7 T e c h n i c i a n s 2 1 6 2 1 1 2 3 4 2 7 3 Clerical staff 2 6 2 3 2 5 31 Other personnel 21 19 21 21 Total 3 3 7 3 2 3 3 5 5 4 1 2
D u r i n g t h e year, several guests j o i n e d the N S M B staff f r o m t h e Helsinki University, t h e T w e n t e University of T e c h n o l o g y , t h e Delft University of T e c h n o l o g y , t h e Massachusetts Institute of T e c h n o l o g y , The Pennsylvania State University a n d the Ege University in Turkey.
Prospects
T h e prospects f o r 1 9 7 5 w i l l be marked by t h e effect of t h e oil p o l i c y . B e i n g a w a r e t h a t 8 5 percent of t h e w o r l d sea transport consists of e n e r g y t r a n s p o r t , an i m p o r t a n t r e c o n s i d e r a t i o n of size, speed a n d s h i p t y p e as a c o n s e q u e n c e of t h e increased oil prices is under progress. Still larger c r u d e oil carriers at l o w e r speeds, p r o d u c t carriers, a further d e v e l o p m e n t of restricted draft tankers f o r i m p o r t a n t traffic areas, a r e c o n s t r u c t i o n of t h e Suez canal in c o m p e t i t i o n w i t h t h e S o u t h A f r i c a route, all raise q u e s t i o n s t h a t need t o be a n s w e r e d in t h e near f u t u r e .
A n o t h e r c o n s e q u e n c e of t h e higher oil prices is t h e increased a c t i v i t y o f f s h o r e a n d at larger w a t e r d e p t h s . T h e c o m p l e x i t y of these o c e a n e n g i n e e r i n g
enterprises d e m a n d s t h e h i g h e s t efforts of t h e scientific a n d t e c h n o l o g i c a l abilities.
T h e h a n d l i n g of sea g o i n g c o n s t r u c t i o n s , in particular in harbour areas w i t h dense t r a f f i c , asks f o r s t r o n g m u l t i - d i s c i p l i n a r y c o - o p e r a t i o n .
T h e N e t h e r l a n d s S h i p M o d e l Basin w i l l c o n t r i b u t e t o these d e v e l o p m e n t s w h e r e possible a n d n e e d e d . The m u t u a l benefit derived f r o m t h e f a v o u r a b l e i n t e r a c t i o n b e t w e e n industrial enterprise a n d s c i e n t i f i c industrial service is clearly
e x p e r i e n c i n g a p o s i t i v e increase in our c o m m u n i t y w i t h its g r o w i n g s o c i a l -t e c h n o l o g i c a l c o n c e r n w i -t h respec-t -t o safe-ty and energy c o n -t r o l .
S o m e i m p o r t a n t f i g u r e s
T u m o v e r of d i f f e r e n t facilities in 1 9 6 8 1 9 6 9 1 9 7 0 1971 1 9 7 2 1 9 7 3 1 9 7 4 per cent of total t u r n o v e r :
Deep w a t e r t o w i n g tank 3 4 3 0 2 7 3 2 3 0 31 2 6
Depressurized t o w i n g tank -
-
--
- - 1 3Propulsion h y d r o d y n a m i c s
-c a v i t a t i o n 1 3 6 9 10 8 7 5
T o t a l , S h i p p r o p u l s i o n 4 7 3 6 3 6 4 2 3 8 3 8 4 4
W a v e and current basin 2 2 3 2 2 9 13 21 19 17
Seakeeping basin 16 2 0 17 25 19 18 13 T o w i n g t a n k for u n c o n v e n t i o n a l m a r i t i m e c o n s t r u c t i o n s * * * # _ * * 5 S h a l l o w w a t e r basin 9 6 12 8 7 11 9 M a n o e u v r i n g simulator - - 1 5 11 9 7 T o t a l , S h i p h y d r o d y n a m i c s -O f f s h o r e t e c h n o l o g y 4 7 5 8 59 51 5 8 5 7 51 C o m p u t e r centre 6 6 5 7 4 5 5
Total t u r n o v e r N S M B , per cent 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 Orders f r o m f o r e i g n countries in per
cent of t o t a l t u r n o v e r 58 50 53 6 4 5 8 5 8 6 4 N S M B research in per cent of
total t u r n o v e r 12 16 10 24 19 11 11
Total i n c o m e ( t u r n o v e r and other i n c o m e ) in per cent related t o
1 9 6 8 ( D f l . 9 , 1 9 1 , 0 0 0 . - ) = 1 0 0 1 0 0 1 1 0 1 2 2 1 1 5 131 1 7 0 2 3 3 Index of cost of l i v i n g related
t o 1 9 6 8 = 1 0 0 1 0 0 1 0 7 . 5 1 1 2 . 2 1 2 0 . 7 1 3 0 . 2 1 4 0 . 6 1 5 4 . 1 Personnel 3 1 1 3 1 1 3 3 9 3 3 7 3 2 3 ' 3 5 5 ^ 4 1 2 ^ ' 4 0 of w h i c h are e m p l o y e d in Ede ^ 5 4 of w h i c h are e m p l o y e d in Ede ^ 6 8 of w h i c h are e m p l o y e d in Ede * In t h e years 1 9 6 8 t h r o u g h 1 9 7 3 i n c l u d e d in t u r n o v e r of s e a k e e p i n g basin. 2 9
Million Dutch guilders
251 \
Distribution of turnover
1970
1971
1972
1973
Total turnover
Other parts of the world
N. America
Europe
Netherlands
1974
Publications, lectures, meetings
T h e f o l l o w i n g p u b l i c a t i o n s w e r e i s s u e d (the n u m b e r s m a r k e d w i t h * w e r e p a p e r s )
No. Title
2 7 2 * De keuze van de voort¬ stuwer
3 5 9 * Het manoeuvreren met grote schepen
3 8 3 * Ducted propeller systems suitable for tugs and pushboats
393a Wetenschappelijke dienstverlening aan scheepsbouw en scheepvaart
4 0 4 * Vibratory hull forces induced by cavitating propellers
427a De invloed van de water-diepte op de manoeuvreer-eigenschappen van schepen 428 Hull resonance no
explanation of excessive vibrations
428 Hull resonance does not explain excessive vibration 428 Hull resonances are not
the sole reason for excessive vibration 4 3 0 * Feasibility and profit of
navigation information and navigational aids offshore 431 * Some design-criteria for
offshore structures carrying sensors and monitors for the information to large vessels 439 Extended diagrams for
determining the resistance and required power for single-screw ships
450 Onderzoek ten behoeve van de exploitatie van de zee 451 Symposium on 'Ship
Handling', Wageningen, November 2 8 - 3 0 , 1973 4 5 2 * Influences of the water
depth on the manoeuvring characteristics of ships Author J . D. van Manen J . P. Hooft and G. F. M. Remery M. W. C. Oosterveld J . D. van Manen P. van Oossanen and
J . van der Kooy J . P. Hooft S. Hylarides S. Hylarides S. Hylarides J . van Dixhoorn, L. A. Koelé and J . P. Hooft L. A. Koelé and J . P. Hooft Published in Catalogus voor de Scheepvaart, 5de editie 1973, p. 51 6de editie 1974, p. 55 Catalogus voor de Scheepvaart, 5de editie 1973, p. 133 6de editie 1974, p. 149 Schip en Werf, 1974, p. 416 and 438 Catalogus voor de Scheepvaart, 5de editie 1973, p. 90 6de editie 1974, p. 105 Trans. RINA, 1973, p. 111 Nautisch Technisch Tijdschrift De Zee, 1974, p. 247 ISP, 1974, p. 89
Shipp. World & Shipb., 1974, p. 760
Marine Engineering/Log, Nov. 1974, p. 36
Schip en Werf, 1974, p. 500
Schip en Werf, 1974, p. 461
W. H. a u f m Keiler Schip en Werf, 1974 p. 489
G. van Oortmerssen Schip en Werf, 1974, p. 16 M. W. C. N S M B , Wageningen, 1974 Oosterveld
(Editor)
G. van Oortmerssen Symp. on 'Ship Handling', Wageningen, 1973, Paper VI (1974)
No. Title Authior Published in 4 5 3 * 4 5 4 * 455* 457 4 5 8 * 458a 458b 459 460 461 462 4 6 4 * 465* 466*
Analysis and training of ship handling capabilities Statistical analysis of ship's manoeuvres . J . Paymans and . IVieurs Oldenkamp J . H. J . van der Meulen
Cavitatie-onderzoek bij bet Nederlands Scheeps-b o u w k u n d i g Proefstation
Calculation of performance P. van Oossanen and cavitation characteristics
of propellers including effects of non-uniform f l o w and viscosity Scheepsbouw en w e t e n -schap
Shipbuilding and science
Symp. on 'Ship Handling', Wageningen, 1973, Paper IX (1974)
Symp. on 'Ship Handling', Wageningen, 1973, Paper XII (1974) Cavitatiegeluid Bijeenkomst, Wageningen, 1973, p. 77 (1974) N S M B , Wageningen, 1974 (Doctor's thesis)
J . D. van Manen Schip en Werf, 1 974, p. 11 3
Schiffbau und Wissenschaft Schematische Darstellung der Theorie, der A n w e n -dungen und der Randgebiete der Finiten Element Methode
(F.E.M.) mit praktischen Beispielen schiffbaulicher Festigkeits und S c h w i n -gungsprobleme
The manoeuvring simulator and the depressurized t o w i n g tank. Two new facilities of the Netherlands Ship Model Basin
Scientific industrial service for the design of ships, navigation systems and offshore constructions Comparison of ship motion theories w i t h experiments for a container ship Will the 'regular wave concept' yield meaningful motion predictions for offshore structures? Mooring forces induced by passing ships The berthing of a large tanker to a jetty J . D. van Manen J . D. van Manen T. H. Oei J . P. Hooft and M. W. C. Oosterveld J . D. van Manen and J . P. Hooft C. Flokstra H. L. Minkenberg and Tan Seng Gie
G. F. M. Remery
G. van Oortmerssen
Schiff und Hafen, 1974, p. 389
Hansa, 1974, p. 773 Schiff und Hafen, 1974, p. 428 Hansa, 1974, p. 777 A l P C N - P I A N C Bull., 1974, No. 17, p. 48 ISP, 1974, p. 168 Sixth A n n . Offshore
Technology Conf., Houston, Texas, 1974, Vol. II, p. 61 Sixth A n n . Offshore
Technology Conf., Houston, Texas, 1974, Vol. II, p. 349 Sixth Ann. Offshore
Technology Conf., Houston, Texas, 1974, Vol. II, p. 665
No. Title Author Published in 467 The manoeuvrability of ships
as influenced by environment and human behaviour
468 Damping in propeller-generated ship vibrations 469 The behaviour of a ship in
head waves at restricted water depths
470 Friction reduction and degradation in turbulent f l o w of dilute polymer solutions
472 Relaxation effects, caused by relative motion, on shock waves in gas-bubble/liquid mixtures 4 7 3 * Research on human behaviour in steering large ships 474 Thrust measurements by means of straingauges, eliminating participation of torque
474 Taking torque out of shaft thrust measurement 474 Thrust measurement by
strain gauge w i t h o u t the influence of torque 4 7 5 * Ship manoeuvring simulator J . P. Hooft S. Hylarides J . P. Hooft J . H. J . van der Meulen J . of Nav., 1974, p. 367 N S M B , Wageningen, 1974 (Doctor's thesis) ISP, 1974, p. 367
Appl. Sci. Res., 1974, p. 161
L. Noordzij and L. van Wijngaarden J . P. Hooft and P. J . Paymans S. Hylarides S. Hylarides S. Hylarides
G. M. van der Bend and G. Mak 4 7 6 * Some hydrodynamic aspects M. F. van Sluijs,
of offshore exploration, production, storage and loading units
4 7 7 * Software package for shipyard production at N S M B
4 7 8 * Evaluation of performance model tests and the power prediction from model test statistics
4 7 9 * Further computer-analyzed data of the Wageningen B-screw series
Tan Seng Gie and H. L A. inkenberg Koops J . Holtrop M. W. C. Oosterveld and P. van Oossanen J . of Fluid Mech., 1974, Vol. 66, p. 115 J . of Nav., 1974, p. 4 6 4 Schip en Werf, 1974, p. 481 Holland Shipb., 1974, Vol. 23, p. 735
Marine Week, 1974, No. 28, p. 40
Shipp. World & Shipb., 1974, p. 1259
Proc. 1 974 Summer Computer Simulation Conf., Houston, Texas, 1974 lie Colloque Int. sur I'Exploitation des Océans, Bordeaux, 1974, Vol. 3, Bx 332
IV Int. Symp. on Ship Automation, Geneva, 1974, Vol. II, p. 159
IV Int. Symp. on Ship A u t o m a t i o n , Geneva, 1974, Vol. II, p. 323
IV Int. Symp. on Ship A u t o m a t i o n , Geneva, 1974, Vol. II, p. 423
B e s i d e s t h e p u b l i c a t i o n s m e n t i o n e d b e f o r e , t h e f o l l o w i n g l e c t u r e s w e r e given in 1974
Date Subject Author April 3 - 4 Motions of station- J . P. Hooft
ary structures
Ship relative mo- M. F. van Sluijs tions and related
phenomena
April 4 Numerieke bestu- A. W. Ruys ring in de
scheepsbouw
May 1 5 - 1 6 Handling of large J . P. Hooft ships
Some propeller M. W. C. cavitation and Oosterveld, excitation c o n - C. Verdonk,
siderations for J . van der Kooy and large tankers P. van Oossanen May 29 Low frequency J . A. Pinkster
phenomena associ-ated w i t h vessels moored at sea
June 25 The analysis of I. Oldenkamp and safety margins in P. J . Paymans the maneuvering
of large ships in confined waters
Hybrid computa- G. Mak and tion for the sim- G. M. van der Bend ulation of the
maneuvering of ships
July 11 Experimental J . D. van Manen studies of human and H. Rijken s w i m m i n g at the Netherlands Ship Model Basin Audience International Symposium on the Dynamics of Marine Vehicles and Structures in Waves in London, sponsored by Office of Naval Research and Royal Institution of Naval Architects Belgian yards at Boom near Antwerpen
West European Conference on Marine Technology at Delft, organized by the British, French, German and Dutch Institutions of Naval Architects and Marine Engineers, i.e.: RINA, I. Mar. E., A T M A , STG, KIVI/SST
SPE European Spring Meeting of the Society of Petroleum Engineers o f t h e American Institute of Mining, Metallurgical, and Petroleum Engineers in Amsterdam Tenth Symposium on Naval Hydrodynamics in Boston, Massachusetts, sponsored by Office of
Naval Research, U.S. Coast Guard and
Massachusetts Institute of Technology
Symposium on S w i m m i n g and Flying in Nature in Pasadena, California, sponsored by National Science Foundation, Office of Naval Research, Ford Foundation and California Institute of Technology
Date Subject Author August 27 Dynamic measure- J . D. van Manen and
ment techniques on H. Rijken s w i m m i n g bodies
at the Netherlands Ship Model Basin
August 28 September 3 - 4 Friction reduction and degradation of polymer additives and the influence on cavitation The influence of polymer injection on cavitation J . H. J . van der Meulen J . H. J . van der Meulen
Cavitation testing G. Kuiper of marine propellers
in the N S M B de-pressurized t o w i n g tank
September 12 Ship-model corre-lation allowances and new techniques in the depressurized t o w i n g tank September 26 Bijzondere
drijven-de constructies Afmeer-systemen Op staal gefun-deerde constructies Manoeuvreren op beperkt water J . J . Muntjewerf H. L. Minkenberg W. Wichers Boreel J . G. Rosink Audience Second International Symposium on Biome-chanics in S w i m m i n g in Brussels, sponsored by 'Laboratoire de l'Effort of the Université Libre de
Bruxelles, Instituut voor Morfologie of the Vrije Universiteit Brussel, Na-tional Fund for Scientific Research, Administration de l'Education Physique des Sports et de la Vie en Plein Air and Bestuur voor Lichamelijke Opvoeding, Sport en Openluchtleven' EUROMECH 5 2 : 'Drag Reduction in Turbulent Flow due to Additives' in Stockholm
Conference on Cavitation in Edinburgh, sponsored by Fluid Machinery Group of The Institution of
Mechanical Engineers
Local Section of the Society of Naval Architects at El Ferrol del Caudillo
Colloquium 'Ocean Engineering' at Delft, organized by Society of Students in Naval Ar-chitecture 'William Froude'
Date October 7 November 1 5 December 3 December 1 1 - 1 3 Subject Wave action on large off-shore structures SL-7 container-ships : design, construction, and operational experience Plan voor het o n -derwijsprogramma voor de maritieme ingenieur
Scheepsbouwkun- J . D. van Manen dige aspekten van
'Ocean Engineering' Author L. J . Boreel J . W. Boylston, D. J . deKoff and J . J . Muntjewerf J . D. van Manen Trade-offs in sub-cavitating propeller design Experience after one year of tests in the N S M B depressurized t o w i n g tank
Prediction of full scale wake charac-teristics based on model wake survey Propeller hydro-dynamics and shaft dynamics A method to cal-culate the pressure field induced by a cavitating propeller Propeller-induced hydrodynamic hull forces on a Great
Lakes bulk carrier. Results of model tests and full scale measurements Holographic study of cavitation i n -ception on a hemispherical nosed body P. van Oossanen
W. van den Berg and G. Kuiper
Hoekstra
S. Hylarides and W. van Gent L. Noordzij
J . van der Kooy and A. Jonk J . H. J . van der Meulen and N. B. Oosterveld Audience Conference on 'Off-shore Structures' in London, organized by Institution of Civil Engineers Eighty-second Annual Meeting of the Society of Naval Architects and Marine Engineers in New York
Presentatie-oriëntatiedag over 'De ontwikkelingen van en het onderwijs in de maritieme techniek' at Delft, organized by 'Onderafdeling der Scheepsbouwkunde van de Technische Hogeschool Delft' Symposium on 'High Powered Propulsion on Large Ships' at Wageningen, organized by Netherlands Ship Model Basin
T h e f o l l o w i n g m e e t i n g s w e r e a t t e n d e d in 1974 January 24 February 26—27 March 5 - 8 March 7 April 1-5 April 18 April 1 8 - 1 9 April 19 May 1 May 6 - 8 May 1 3 - 1 4 May 1 4 - 1 7
Conference on Ship Behaviour in Confined Waters in London, sponsored by Chamber of Shipping of the United Kingdom, National Ports Council and National Physical Laboratory ITTC Seakeeping Committee at Ede
ITTC Cavitation Committee at Grenoble
Meeting of S N A M E Panel H-10 (Controllability) in Washington International Symposium on the Dynamics of Marine Vehicles and Structures in Waves in London, sponsored by Office of Naval Research and Royal Institution of Naval Architects
Landelijke bijeenkomst over het onderwerp 'Thesauri: hun rol in informatie- en documentatiesyste-men' at Utrecht, organized by 'Genootschap voor Automatisering en Nederlands Orgaan voor de
Bevordering van de Informatie-verzorging'
ITTC Performance Committee in Berlin
North Sea T o w i n g Tank Conference in Paris
Meeting between Ergonomics Research Society and Royal Institute of Navigation in London Sixth Annual Offshore Technology Conference in Houston, Texas, sponsored by American Institute of M i n i n g , Metallurgical, and Petroleum Engineers et al. ITTC Propeller Committee at Ede West European Conference on Marine Technology in The Hague and Delft, organized by the British, French, German and Dutch Institutions of Naval Architects and Marine Engineers, i.e.: RINA, I. Mar. E., A T M A , STG, KIVI/SST
K. Meurs M. F. van Sluijs P. van Oossanen J . P. Hooft M. F. van Sluijs A. W. Ruys J . J . Muntjewerf J . D. van Manen P. J . Paymans J . D. van Manen, H. L. Minkenberg, G. van Oortmerssen and G. F. M. Remery M. W. C. Oosterveld J . D. van Manen, M. W. C. Oosterveld and J . van der Kooy
May 30 May 30 June 5 - 6 June 1 3 - 1 4 June 2 4 - 2 5 July 8 - 1 2 July 9 - 1 1 August 2 7 - 3 0 August 2 7 - 3 0
Symposium 'Future gas supplies for Europe' in Amsterdam, organized by 'Afdeling voor Petroieumtechniek en de Afdeling voor Werktuig- en Scheepsbouw van het Koninklijk Instituut van Ingenieurs'
NC-Symposium 1974 at Delft, organized by 'Nederlandse Contactgroep Numerical Control en het Metaalinstituut T N O ' Meeting of ISO/TC 8/SC 3 at Ede ITTC Performance Committee in London
Tenth Symposium on Naval Hydrodynamics in Boston, Massachusetts, sponsored by Office of Naval Research, U.S. Coast Guard and Massa-chusetts Institute of Technology Symposium on Swimming and Flying in Nature in Pasadena, California, sponsored by National Science Foundation, Office of Naval Research, Ford Foundation and California Institute of Technology Summer Computer Simulation Conference in Houston, Texas, sponsored by American Institute for Chemical Engineers, American Meteorology Society, Instrument Society of America, Society for Computer Simulation and Society to Help Avoid Redundant Effort Second International Symposium on Biomechanics in Swimming in Brussels, sponsored by 'Labora-toire de l'Effort of the Université Libre de Bruxelles, Instituut voor Morfologie of the Vrije Universiteit Brussel, National Fund for
Scientific Research, Administration de l'Education Physique des Sports et de la Vie en Plein Air and Bestuur voor Lichamelijke Opvoe-ding, Sport en Openluchtleven' EUROMECH 5 2 : 'Drag Reduction in Turbulent Flow due to
Additives' in Stockholm W. C. Oosterveld A. W. Ruys J . D. van Manen J . J . Muntjewerf J . P. Hooft, I. Oldenkamp and G. Mak
J . H. J . van der Meulen
van der Bend
H. Rijken
J. H. J . van der Meulen
September 3 - 5 September 2 3 - 2 6 October 1-4 October 1-4 October 7 - 8 October 23 October 25 November 1 2 - 1 3 November 1 2 - 1 4 November 1 3 - 1 5 November 1 4 - 1 6 December 3 Conference on Cavitation in Edinburgh, sponsored by Fluid Machinery Group of The Institution of Mechanical Engineers
Stone Manganese Marine Con-ference 'Ships for the mid-1980's' in London
2nd International Colloquium on the Exploitation of the Oceans in Bordeaux, organized by 'Associa-tion pour rOrganisa'Associa-tion des Col-loques Océanologiques a Bordeaux Shipbuilding Symposium
'Developments in Ship Design and Production A u t o m a t i o n ' in Trieste, organized by ' A / S Kongsberg Vapenfabrikk'
Conference on 'Off-shore Structures' in London, organized by Institution of Civil Engineers Annual General Meeting of the
Royal Institute of Navigation in London
Meeting of S N A M E Panel H-10 (Controllability) in New York ITTC Performance Committee in Washington
ITTC Seakeeping Committee in Leningrad
IV International Symposium on Ship Automation at Geneva, organized by 'Istituto Interna-zionale delle Comunicazioni'
Eighty-second Annual Meeting of the Society of Naval Architects and Marine Engineers in New York
Presentatie-oriëntatiedag over 'De ontwikkelingen van en bet onderwijs in de maritieme tech-niek' at Delft, organized by 'Onderafdeling der Scheepsbouw-kunde van de Technische Hoge-school Delft'
G. Kuiper and
J . H. J . van der Meulen
J . D. van Manen
M. F. van Sluijs and Tan Seng Gie
A. Koops and A. W. Ruys
L. J . Boreel and G. van Oortmerssen J . P. Hooft P. J . Paymans J . J . Muntjewerf M. F. van Sluijs
J . Holtrop and A. Koops
J . J . Muntjewerf
December 1 0 - 1 3
December 1 2 - 1 3
Symposium on 'Higin Powered Propulsion of Large Ships' at Wageningen, organized by Netherlands Ship Model Basin
Meeting of ISO/TC 8/WG 2 at Delft
J . D. van Manen, M. W. C. Oosterveld, W. van den Berg, W. van Gent, M. Hoekstra, S. Hylarides, A. Jonk,
J . van der Kooy, G. Kuiper,
J . H. J . van der Meulen, L. Noordzij and
P. van Oossanen A. W. Ruys
