NUMERICAL MODELING FOR MARINE MOBILE
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Port development work involves laborious activities and sub sequential use of large amount of ...

Port development work involves laborious activities and sub sequential use of large amount of
energy. Modular construction has facilitate labour require, energy usage, hence carbon footage has
gain approval of efficient product development in recent year. The use of such mobile equipments
equally gives advantage to port to reduce port traffic, safety preservation of environment reduction in
maintenance and berth allocation. Heavy seaborne traffic in port leads to the requirement of port
terminal development or improvement. Port terminal involved problem related to traffic and high cost.
The use of mobile floating protection facilities can offset this problem. The study involved design and
modeling of a safe loading and unloading facilities to ensure the smooth flow of the work and
reduction in the work delay. The berthing facility is moveable, floating structure that act as a protection
for ships berthing in port. The modeling involve design of that determine the safe berthing velocity and
, the berthing energy, environmental load (wind and current) and material which are the important
parameters for fender selection and to ensure that it is safe to carry out its function as loading and
unloading facilities. By using light weight less energy can be employ to build berth, and to conduct
berthing operation, and by providing safety the system can be provided discount for environmental
conservation. The result of this study hoped to improve safety and efficiency of the port operation in
handling of the ships entering and leaving the port. The model is designed for prototyping physical
system that can be use for experiments and commercialization.
Keywords: Mobile, Floating, Berthing Facilities, Berthing Energy, Port, Modular, Mobile, Port,
Safety, Light Weight

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NUMERICAL MODELING FOR MARINE MOBILE Document Transcript

  • 1. International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol: 11 No: 06 23 NUMERICAL MODELING FOR MARINE MOBILE FLOATING BERTHING PROTECTION FACILITIES O.Sulaman, N. W. Sani, Ab. Saman, A. Azlan Department of Maritime Technology, Faculty of Maritime Studies & Marine Science, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, MalaysiaAbstract Port development work involves laborious activities and sub sequential use of large amount ofenergy. Modular construction has facilitate labour require, energy usage, hence carbon footage hasgain approval of efficient product development in recent year. The use of such mobile equipmentsequally gives advantage to port to reduce port traffic, safety preservation of environment reduction inmaintenance and berth allocation. Heavy seaborne traffic in port leads to the requirement of portterminal development or improvement. Port terminal involved problem related to traffic and high cost.The use of mobile floating protection facilities can offset this problem. The study involved design andmodeling of a safe loading and unloading facilities to ensure the smooth flow of the work andreduction in the work delay. The berthing facility is moveable, floating structure that act as a protectionfor ships berthing in port. The modeling involve design of that determine the safe berthing velocity and, the berthing energy, environmental load (wind and current) and material which are the importantparameters for fender selection and to ensure that it is safe to carry out its function as loading andunloading facilities. By using light weight less energy can be employ to build berth, and to conductberthing operation, and by providing safety the system can be provided discount for environmentalconservation. The result of this study hoped to improve safety and efficiency of the port operation inhandling of the ships entering and leaving the port. The model is designed for prototyping physicalsystem that can be use for experiments and commercialization.Keywords: Mobile, Floating, Berthing Facilities, Berthing Energy, Port, Modular, Mobile, Port,Safety, Light Weight1. INTRODUCTIONWorldwide seaborne traffic at major ports is continually growing. This bring alonghigh demand for ships from shipbuilding companies and also jetty constructions. Portoperators need to enhance the facilities in the ports so that they can compete with theother competitors. Due to the restriction of the capital to build the facilities that needa lot of money for example jetty, berth required in order reducing the heavy seabornetraffic which is a burden to the port owner. A cost effective way alleviate such burdenfor port owner is to acquire floating pier which act as loading and unloading floatingpier. Floating piers are much less costly compare to building a jetty or berth. Marinefenders are crucial to a ship berth. A proper fender design should effectively absorbor dissipate the kinetic energy carried by a docking ship and thus mitigate the impactforce to a sustainable level [1]. Fender design normally involves extensive trade-offsdepending on the type, purpose, site, function, and operation concept of a berthingfacility. Standard fender design practice to date uses a nominal berthing energyspecified in terms of the displacement, approach speed, and attitude of docking ship.This paper describes the result of numerical model for a mobile berthing and mooringsystem. The study determines the safe berthing velocity, berthing energy andenvironmental loading for ships at various displacements [2]. 110301-06-8989 IJMME-IJENS © December 2011 IJENS IJENS
  • 2. International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol: 11 No: 06 24 2. Mehodology2.1 Berthing facility structure and barge particularsPlatform which is originated as a barge is design because it is a moveable and floatingstructure which can be use anywhere and can be installed in anytime when needed. D-type fender and Tee bollard are selected to use as the protection equipments for thebarge. General arrangement of the berthing facilities is drawn out by AutoCAD 2007together with its relevant protection equipments.Table 1: Barge particulars Particular Unit LOA 62.5 m Breadth 14.5 m Moulded depth 3.5 m Depth 2.68 m Lightship 383 tons Maximum Displacement 2380 tons Minimum Draft 0.52 m Maximum Draft 2.68 m Capacity 2500 tons2.2 Berthing energy and berthing velocityThe berthing energy is used to determine the most suitable fender for the berthingfacilities. The ships ranging from 1000-10000 tons in water displacement arechoosing as models of ships that berth at the facilities. As the ship is stopped by thefender, the momentum of the entrained water continues to push against the ship andthis effectively increases its overall mass. The mass of specified water is calledAdded Seawater Mass; the added seawater influence coefficient is called Cm [3].The berthing velocity is obtained from actual measurements or relevant existingstatistic information. When the actual measured speed velocity is not available, theBSI and PIANC etc. standard is adopted to determine the required velocity value [3].The berthing energy was calculated by: (1) ߨ‫ߩ ܮ 2ܦ‬ ‫+ 1 = ݉ܥ‬ (2) 4‫݀ܯ‬ 110301-06-8989 IJMME-IJENS © December 2011 IJENS IJENS
  • 3. International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol: 11 No: 06 25 (3) 1 ‫= ݁ܥ‬ ‫ܫ‬ 1 + ( 2) ‫ݎ‬2.3 Environmental loads on berthing facilitiesWinds, currents, and waves produce dynamic loads on moored vessels due to wavesfollows. Static loads due to wind and current are separated into longitudinal load,lateral load, and yaw moment. The following formulas are used to determine the windand waves loads [3].Table 2: Environmetal parameters Source: Tanjung Langsat Port, Pasir GudangEnvironmental ConsiderationWind Normal wind speed = 8m/sec Extreme wind speed = 12m/secWaves Max wave height = 0.4m(for 12m/sec)Current Slight change <0.1m/secAverage water depth 12mAverage soil depth 9m2.3.1 Lateral wind load and longitudinal wind loadLoads on moored vessels due to wind result primarily from drag. The generalequation used to determine lateral and longitudinal wind load are: (4) (5)2.3.2 Lateral current load and longitudinal current loadCurrent loads developed on moored vessels result from form drag, friction drag, andpropeller drag. Lateral forces are dominated by form drag. Form drag is dependentupon the ratio of vessel draft to water depth: as the water depth decreases, current 110301-06-8989 IJMME-IJENS © December 2011 IJENS IJENS
  • 4. International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol: 11 No: 06 26flows around rather than underneath the vessel. Longitudinal forces due to current arecaused by form drag, friction drag, and propeller drag[4]. The general equation usedto determine lateral and longitudinal current load are: (6) (7)3. RESULTS AND DISCUSSION3.1 Structure selectionGeneral arrangement of the berthing facilities is drawn by AutoCAD 2007 and it hasthe length of overall of 62.5m, breadth 14.5m, draft 3.5m. The wetted area of theberthing facilities is 1212.98m2. The underwater volume is 2198.24m3.Figure 1 shows General arrangement of the berthing facilities Figure 1: General arrangement of berthing facilities 110301-06-8989 IJMME-IJENS © December 2011 IJENS IJENS
  • 5. International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol: 11 No: 06 273.2 Berthing EnergyResults from the numerical model for the berthing velocity and berthing energy wereis shown in Table 3 and Table 4.Value of the berthing velocity for the ships berthingat the berthing facilities varies from 1000 tons to 10000 tons of water displacementwere listed in Table 3. Table 3: Berthing Velocity Water Displacement (tons) Berthing velocity (m/sec) 1000 0.6667 2000 0.5533 3000 0.4940 4000 0.4551 5000 0.4267 6000 0.4047 7000 0.3868 8000 0.3719 9000 0.3592 10000 0.3481From Table 4, the ship berthing at the berthing facilities is ranging from 1000 to10000 tons in water displacement. The highest speed value of the berthing velocityoccur when the 1000 tons displacement ship berthing at the berthing facilities whichis 0.6667 m/sec. The higher the value of water displacement of the ship, the lower thevalue of berthing velocity. Figure 2 shows water displacement versus berthingvelocity. Figure 3 shows PIANC recommendation for berthing velocity. 0.8 V 0.7 e 0.6 m l 0.5 / o 0.4 s c 0.3 e Berthing Velocity i c 0.2 t 0.1 y 0 0 2000 4000 6000 8000 10000 12000 Water Displacement (tons) Figure 2: Graph water displacement versus berthing velocity 110301-06-8989 IJMME-IJENS © December 2011 IJENS IJENS
  • 6. International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol: 11 No: 06 28Figure 3: PIANC Standard for berthing velocitya. Easy berthing (sheltered) b.dificult berthing (berthing) c. easy berthing (exposed, d. Good berthing(exposed,) , Difficult berthing (exposed)From Table 2, the ship berthing at the berthing facilities is ranging from 1000 to10000 tons in water displacement. The highest value of the berthing energy occurwhen the 2000 tons displacement ship berthing at the berthing facilities which is 94.1ton.m (See Figure 4 ). Table 2: Berthing Energy Berthing Energy Displacement (ton.m) (Md) Maximum Load Lightship 1000 32.2873 89.3095 2000 25.8694 94.0985 3000 21.8085 91.0958 4000 19.0577 86.6001 5000 17.0567 82.0414 6000 15.5306 77.8292 7000 14.3121 73.9820 8000 13.3186 70.5391 9000 12.4891 67.4507 10000 11.7781 64.6406 110301-06-8989 IJMME-IJENS © December 2011 IJENS IJENS
  • 7. International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol: 11 No: 06 29 Ship Displacem ent versus Berthing Energy 1 00 90 B e 80 r 70 t h ( 60 i t n o 50 g n L ightship 40 . Max L oad E m ) 30 n e 20 r 10 g y 0 0 2000 40 0 0 6 00 0 8 0 00 1 00 0 0 1 2 00 0 Displacem ent (Md) Figure 4: Graph water displacement versus berthing energy3.3 Environmental loadings on berthing facilities From Table 3, the wind angle is taken from 30o to 175o with the average 30o asinterval. The maximum lateral wind load occurs when the wind is extreme at 90owhich has the value of 3109.75 pounds. The maximum longitudinal wind load occurswhen the wind is extreme at 175o which has the value of 1500.52 pounds ( See Figure5). Table 3. Wind loadAngle Wind Load (θ°) (pounds) Lateral Longitudinal Yaw- moment Normal Wind Extreme Wind Normal Wind Extreme Wind (foot- (26.25ft/sec) (39.37ft/sec) (26.25ft/sec) (39.37ft/sec) pounds) 30 691.05 1554.87 -579.75 -1304.46 16330.99 60 1196.94 2693.12 -334.72 -753.12 17977.93 90 1382.10 3109.75 0 0 8856.29 115 1252.61 2818.39 282.92 636.57 -963.183 145 792.74 1783.67 548.37 1233.85 -7436.76 175 120.45 271.03 666.89 1500.52 -2167.43 110301-06-8989 IJMME-IJENS © December 2011 IJENS IJENS
  • 8. International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol: 11 No: 06 30 Angle versus Wind Load 3500 L 3000 o 2500 a 2000 d 1500 W Lat-N ( i p 1000 Lat-E n o 500 d u Long-N 0 n -500 0 50 100 150 200 Long-E d -1000 s -1500 ) -2000 Wind Angle(°) Figure 5. Graph wind angle versus wind load Table 4. Current loadAngle Current Load (θ°) (pounds) Lateral Longitudinal Min Yaw moment Max Yaw moment Min draft Max draft draft (foot-pounds) draft (foot- pounds) 30 9.30 97.47 56.17 689.4589 -0.76 -3.90 60 16.11 0 97.29 0 -0.44 -2.25 90 18.60 -162.44 112.34 -1149.10 0 0 115 16.85 -294.28 101.82 -2082.98 0.37 1.90 145 10.67 -279.52 64.44 -1977.42 12.21 3.67 175 1.60 -5.59 9.79 -40.06 0.87 4.45From Table 4, the current angle is taken from 30o to 175o with the average 30o asinterval. The maximum lateral current load occurs when the berthing facilities is inmaximum draft and have the current angle of 90o which has the value of 112.34pounds. The maximum longitudinal current load occurs when the berthing facilities isin minimum draft and have the current angle of 145o which has the value of 12.21pounds (See figure 6). 110301-06-8989 IJMME-IJENS © December 2011 IJENS IJENS
  • 9. International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol: 11 No: 06 31 Angle versus Current Load 120 L 100 o C a 80 u d Lat-Min T ( r 60 p r Lat-MaxT o e 40 Long-MinT u n n 20 Long-MaxT t d s 0 ). 0 50 100 150 200 -20 Current Angle(°) Figure 6. Graph current angle versus current load4. EQUIPMENTS SELECTIONTotal Lateral load on berthing facilities is 3222.09 pounds, the total longitudinal loadon berthing facilities is 1512.73 pounds and the horizontal hawser load, H is 3559.52pounds.Fender selectionAccording to the British standard, the ultimate fender capacity is 2 X berthingEnergy. The maximum berthing energy occurs when the berthing facilities are in themaximum load and the berthing ship is at 1000 tons displacement which has the valueof 89 ton.m. The fender capacity must be at least 2 x 89ton.m = 178 ton.mChain SelectionApproximate chain tension, T = 1.12 H (Horizontal Hawser Load) = = 3986.66 poundsMaximum allowable working load,Tbreak Tdesign = 0.35 Tbreak 3986.66 pounds = 0.35 Tbreak Tbreak = 11390.46 pounds * 1-inch chain with a breaking strength of 14,500 poundsAnchor SelectionRequired holding capacity = 3559.52 poundsSeafloor type is sand Depth of sand = 30 feetAnchor type is Stockless safe efficiency =4 110301-06-8989 IJMME-IJENS © December 2011 IJENS IJENS
  • 10. International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol: 11 No: 06 32Holding capacity = efficiency x weight 3559.52 = (4)(weight) Weight = 3559.52/4 =889.88pounds = 0.9 kipsUse 1,000-pound (1-kip) Stockless anchor5. CONCLUSIONThis paper presents numerical model for safe berthing and protection of mobilefloating berthing protection facilities. The berthing facilities can help to decrease theheavy seaborne traffic and the cost of building an extra Jetty which may become aburden to ports operator. Mobile berthing facilities can be installed anytime andanywhere to help the port operator to save money and time. The model can beimproved as a working platform by simulation and prototyping for experiment thatcan be used for further investigation.REFERENCES[1] You-Sheng Wu. (2001). Practical Design of Ships and Other Floating Structures. ELSEVIERAmsterdam.[2] John H.Hansen (1978). Mobile Ship Loading and Unloading Facility. http://www.patentstorm.us/patents/4075860.pdf [Accessed 27 August 2009].[3] J. P. Jones (2006).Fleet Moorings. Design of fleet mooring 110-135. Naval facilities Engineering Command.[4] Bert J. Warner. (1989). Stable Floating pier. United State Patent Publication 110301-06-8989 IJMME-IJENS © December 2011 IJENS IJENS