Simulating Method of Ship s Turning-basins Designing

Transcription

1 International Journal on Marine Navigation and Safety of Sea Transportation Volue 5 Nuber 2 June 2011 Siulating Method of Ship s Turning-basins Designing J. Kornacki Szczecin Maritie University, Szczecin, Poland ABSTRACT: The paper presents one of the ethods of ship s turning-basins designing. The siulating ethod is ore and ore often used to the defining paraeters projected turning-basins, testing of existing turning-basins and the iproving of the anoeuvring practice on the particular anoeuvring basin. 1 INTRODUCTION The anoeuvre of ships turning is executed every tie during the ships presence in the port and it is one of the often port anoeuvres. The influences on the size of turning basin during the anoeuvre have the large quantity of factors. The turning basin has two eanings. First eaning is the anoeuvring basin deliited by the anoeuvring ships, second is the hydro-technical building artificial or natural with suitable horizontal and vertical diensions, where the considerable alterations of the course of the ship are executed. Obviously, the turnings over are practices in the place. This should be understand as the change of the course of the ship whose linear speeds, during the anoeuvre, are close to zero. Turning the ship over is done on the turning basin as a result of the planned tactics of anoeuvring and can be done on itself or in co-operation with tugs or use of anchors or spring lines. All diensions of turning basin as the hydro technical building has to be larger than the turning basin understood as the anoeuvre basin to avoid the collision with botto or bank (Kornacki 2007). The siulating ethod of designing the paraeters of turning basins are based on series of tests in coparable conditions on prepared odel of reservoir and the odel of the ship planned to use the turning basin. The results of tests are subjected the statistical processing. Effect of that kind of research is deliitation of the area of anoeuvring on the turning basin according to the various foundations of hydro eteorological conditions, various paraeters of ships and various levels of the trust. Characteristic feature of the siulating ethod is that siulating odels of the ship anoeuvring are especially designed to the solved proble. Figure 1. The exaple of tests of siulating of turning anoeuvres. The aterial in the result of siulating investigations coes into very large sizes, which is subjected 241

2 far processing. The application of the ethods which will let process got results to the for enabling aking far analysis necessary is. The area of anoeuvring of the ship is the basic criterion of the analysis of the results of siulating testing s, and the diensions of this area are it nuerical coefficient. The variety of the eleents of the syste of the port and narrow waters causes that various ethods are applied. These ethods are characterized liitations and conditions. The ethod of parallel sections, sector ethod and polar ethod are coplies with arking the diensions of the basins of anoeuvring of the ship in siulating investigations (Guziewicz & Ślączka, 1997). β - acute angle contained aong the longitudinal axis of the syetry of the ship and the secant of definite sector [⁰], i - the nuber of extree points on one board describing the waterline of floatation [-], R - the ray of the projected turning basin [], 2 DELIMITING THE BASIN OF MANOEUVRING OF THE SHIP ON THE TURNING BASIN The ethods of deliitation of the area of anoeuvring of the ship are based on the suitable division of the water areas of anoeuvring and the engageent of suitable point or the axis of the reference. For the needs of deliitation of the anoeuvring area on the turning basin and during the anoeuvres of the turning of the ship the polar ethod is engaged. This ethod differs fro the ethod of parallel sections that the sections are replaced by sectors and the axis of the reference is replaced by the point of reference. The difference in the relation to the sector ethod depends in the engageent of the point of reference not outside but inside the area of anoeuvring and the division of the anoeuvring basin on sectors hugging the round angle. The polar ethod in the principle is the change of the sector ethod. Co-ordinates of points ark the area of anoeuvring ship are qualified in the polar co-ordinates. Then, knowing the exact position of the point of the reference, they are easy to proceeding in the far analysis. Wanting deliit the anoeuvring basin in the polar ethod, the studied anoeuvring area should split on the sectors of the deliited width Δ α. The selection of the proper width of the sector essential is. The width of the sector siplifying should fulfil dependence (Guziewicz & Ślączka, 1997): L β α OA sin where: ( i ) R π α - width of the sector [⁰], L OA - length over all [], [⁰] (1) Figure 2. The split of the anoeuvring area in the polar ethod. The selection of the width of the sector is dependent fro the received suitable nuber of the extree points of the ship. This influences on the size the error steps out aong the deliited area of the anoeuvre and real anoeuvring area left by the ship. One can express this error in the approxiation (Guziewicz & Ślączka, 1997): π δ = α i cos β 360 Si R [] (2) where: δ Si - error of deliiting anoeuvring basin [], α - width of the sector [⁰], R i - the ray of the projected turning basin [], 242

3 β - acute angle contained aong the longitudinal axis of the syetry of the ship and the secant of definite sector [⁰], Distances d i of the extree points of ship fro the point of the reference are calculated, where i is the nuber of the extree points of the ship describing the waterline of flotation. The table of the distance D S [k, s, d i ] in which counted distances d i are assigned to sectors s for individual siulating tests k is created. Based on the table of the distance D S [k, s, d i ] the tables of axiu distances D S ax [k, s, d i ax ] and iniu distances D S in [k, s, d i in ] of extree points of ship waterline fro the point of reference in every sector of basin for every siulating test are created. This akes possible the assignent the line of oveent of the ship in the single test. Figure 3. The error of deliiting anoeuvring basin. During the test data with the course of the ship, shape of the waterline of floatation and the coordinates of geoetrical centre of the waterline of floatation are recorded. The co-ordinates of extree points of the ship are calculated in the polar coordinates. Figure 5. The line of oveent of the ship in the single test. Based on the table of axiu distances D S ax [k, s, d i ax ] and iniu distances D S in [k, s, d i in] and the suitable statistical odel of the expansion of axiu and iniu distances, the coordinates of points of the area of anoeuvring with the assuption of level of the trust are appointed in separate sectors. Figure 4. The extree points of the ship on one particular waterline. 243

4 anoeuvring area line of oveent The analysis of the results of siulating tests leads to easuring the paraeters of anoeuvring area, which eans the qualification of the paraeters of the horizontal safe anoeuvring area. Figures 7 and 8 present the vertical and the horizontal section view of turning basin. Figure 6. The line of oveent and anoeuvring area of the ship. Figure 7. The turning basin the vertical view. 3 THE PRACTICAL USE OF THE SIMULATING INVESTIGATIONS 3.1 The practical use of the polar ethod The polar ethod can be applied to the preparation of the easuring data to the statistical processing during real investigations. Error resulting fro the applied ethod of deliitation the line of oveent in this case is enlarged by error resulting fro the easureent and error resulting fro the preparation of the easuring data to the use of the polar ethod becoes. In the case of use of the polar ethod, while deliiting the anoeuvring basin of ship in siulating investigations, the results are burdened the only error the applied ethod. In the practice, the siulating ethod coplies in two ais. First, it coplies in the qualification of sizes of the planned turning basin. Second, it coplies in the qualification of axiu perissible sizes of ships can safely use the turning basin. The turning basin is safe for the ships anoeuvring, if every her sizes in the horizontal plane and perpendicular plane are larger than the sizes of the anoeuvring area traced by the anoeuvring ship. It is ean that on the whole area the safe under keel clearance and the safe distance fro banks and slopes has to be kept. Figure 8. The turning basin the horizontal view. During siulating investigation relevant to the turning basin, it is iportant to take into consideration also the expansion of the speed of propeller streas, the expansion of directions of propeller streas, and influence of the every kind of hydrotechnical buildings, slopes and banks on the ship (Galor, W. 2002). 244

5 3.2 The exaples of use of the siulating investigations Figures 9, 10 and 11 present the exaples of results of siulating investigation of typical turning anoeuvre. ships turning basin ax in 95% Figure 12. The north turning basin investigation in port of Świnoujście (The unpublished report 2000). Figure 9. The anoeuvring areas with different trust levels during turning anoeuvres. ships turning basin Figure 13. The south (BPP) turning basin investigation in port of Świnoujście (The unpublished report 1995a) ax in 95% Figure 10. The anoeuvring areas with different trust levels during turning anoeuvres. ships turning basin ax in 95% Figure 14. The turning basin investigation in port of Kołobrzeg (The unpublished report 1995b) Figure 11. The anoeuvring areas with different trust levels during turning anoeuvres. Figures 12, 13, 14 and 15 present the exaples of results of siulating investigation on real port water areas (Kornacki, J.& Galor, W. 2007). Figure 15. The turning basin investigation in port of Police (The unpublished report 1998). 245

6 These exaples are showing scale of use of the siulating investigations. Base on the northern turning basin in Świnoujście, the proble of the analysis of the turning basin can be present. The northern turning basin in Świnoujście was investigated several ties, usually in the context of considerations on the subject of the possibility of anoeuvring in the harbour of the axiu ships. Proble this cae back because of the developent of the harbour in Świnoujście and the abitions of the service larger ships. In the years was ade one of first analyses in the aspect of the possible odernization of the northern turning basin. The investigation was ade then to qualify possibilities of the entry the ships about the total length 255 into the harbour. The qualification of the possibility of the safe turn of ships on the northern turning basin was one of the eleents of these investigations. The eventuality of the increase of the sizes of the turning basin was taken into the consideration then so that ships do not violate the infrastructure of the western bank of Świna. In the year 2001, the proble was returned when the possibility of entering into the harbour of the ships of total length 260 were study again. The investigations were led with the assuption that the existing bathyetry of the port s reservoir will not be changed. In the year 2003, the possibility of the entry the ships of total length to 280 with new tugboat Uran was analysed. 4 CONCLUSIONS The ethods of deliiting the area of anoeuvring basin of the ship depend on the suitable split of the anoeuvring area. Polar ethod should be applied to arking anoeuvring area on turning basin. The polar ethod is based on the suitable split of the anoeuvring area, the engageent of the point of reference and proper rando variable to assignent of this basin. The distance of points describing the waterline of the ship fro the point of the reference is the applied universally rando variable. The taken value of the width of the sector in the polar ethod has the direct influence on the value of the error aong the real line of the oveent of the ship and the line of oveent of the ship deliited the polar ethod. Main advantage of the siulating ethod is the possibility of the exact qualification of the anoeuvring area. Through the far statistical analysis of any tests, the ready inforation of the sizes of the basin which the ship needs to the realization of the anoeuvre of the turning is available. Very iportant advantage of the siulating ethod is relatively low cost of investigation. Often, navigational obstructions ark the accessible anoeuvring basin. It has the influence on the way of anoeuvring. The use of the siulation allows optiizing sizes of such basin or the way of anoeuvring. REFERENCES Briggs M.J. &Borgan L.E. & Bratteland E Probability assessent for deep-draft navigation channel design. International Journal for Coastal Harbour and Offshore Engineering, Coastal Engineering 48, Elsevier. Galor W Bezpieczeństwo żeglugi na akwenach ograniczonych budowlai hydrotechnicznyi. Fundacja Rozwoju Wyższej Szkoły Morskiej w Szczecinie. Guca, S. & Jagniszczak, I Nawigacja dla kapitanów. Gdańsk: Fundacja Proocji Przeysłu Okrętowego I Gospodarki Morskiej. Guziewicz, J. & Ślączka, W Szczecin: The ethods of assigning ship's anoeuvring area applied in siulation research, International Scientific and Technical Conference on Sea Traffic Engineering, Maritie University of Szczecin. Kornacki, J. & Galor, W Gdynia: Analysis of ships turns anoeuvres in port water area. TransNav 07. Kornacki, J The analysis of the ethods of ship s turning-basins designing. Szczecin: XII International Scientific and Technical Conference on Marin Traffic Engineering, Maritie University of Szczecin. The unpublished report 1995a. Badania syulacyjne ruchu statków w bazie paliw płynnych w Świnoujściu. Maritie University of Szczecin. The unpublished report 1995b, Określenie optyalnego wariantu przebudowy wejścia do portu Kołobrzeg w oparciu o badania syulacyjnego ruchu statków, Maritie University of Szczecin. The unpublished report 1998, Badanie ożliwości optyalnej lokalizacji przeładowni kwasu fosforowego w Porcie Police. Maritie University of Szczecin. The unpublished report Analiza nawigacyjna dla przebudowanego Nabrzeża Górników w porcie handlowy Świnoujście. Naval University of Szczecin. 246