Development of an Automatic Load Moment Control System for a Floating Dock

Transcription

1 Development of an Automatic Load Moment Control System for a Floating Dock Manuel Melo Sanchez University of Rostock Naval Architecture and Ocean Engineering 1

2 Project Description Transfer - Shore Floating Dock Static analysis Trolley Transfer System 9 or 4.5 m span Trolley max. Load tons Algorithm Development Trolley placement Concept for ballast tank planning University of Rostock Naval Architecture and Ocean Engineering 2

3 Project Description Important considerations 2 shore beams 500 tons X shore beam Pre-ballasting with tons Load cell reading < 500! Load cell reading > 0! Heeling not permitted Simplify model University of Rostock Naval Architecture and Ocean Engineering 3

4 Project Description (Creo que nie wazne) Dock dimensions University of Rostock Naval Architecture and Ocean Engineering 4

5 Technical Changes & Specifications Reversible pump against gravity based filling Torricelli for stream speed No fixed flow Pump-Tank configuration Facilitate ballast planning 2 pumps on a section 2 Pump 4 6 Pump Pump 3 5 Pump 7 2 Pump 4 6 Pump Pump 3 5 Pump 7 University of Rostock Naval Architecture and Ocean Engineering 5

6 Information for analysis Ship information (Block vessel) 5000 tons Maximum transfer capacity Lightweight distribution constant Vessel LOA 85 m Trolley transfer system 9 trolleys 9 meters between trolleys University of Rostock Naval Architecture and Ocean Engineering 6

7 Meter per Meter moment calculation Observations 18 peaks Small peaks First trolley wheel Big peaks Trolley on dock Interpolation between big peaks University of Rostock Naval Architecture and Ocean Engineering 7

8 Loading Cases University of Rostock Naval Architecture and Ocean Engineering 8

9 Loading Cases University of Rostock Naval Architecture and Ocean Engineering 9

10 Loading Cases University of Rostock Naval Architecture and Ocean Engineering 10

11 Righting Moment vs. Transfer Moment Observations Ballast system Difficulty to follow transfer system Transfer system Low speed at first meters. Key variables to control Trolley speed Pump Capacity University of Rostock Naval Architecture and Ocean Engineering 11

12 Moment with draft and Trim Control Procedure Determine water volume in/out Calculate righting moment Difference between transfer and righting moments Difference between weight applied and removed. University of Rostock Naval Architecture and Ocean Engineering 12

13 Moment with draft and Trim Control Observations Preloading can be standardized. Average water level in in tanks similar to the designer Limit of 5000 tons confirmed. Transfer speed profile input/output variable University of Rostock Naval Architecture and Ocean Engineering 13

14 MEXICO - Guanajuato University of Rostock Naval Architecture and Ocean Engineering 14

15 MEXICO - Teotihuacan University of Rostock Naval Architecture and Ocean Engineering 15

16 MEXICO Jardín Surrealista University of Rostock Naval Architecture and Ocean Engineering 16

17 Algorithm Flow Chart University of Rostock Naval Architecture and Ocean Engineering 17

18 Trolley Placement Algorithm Maximum # trestles Define restrictions Read File LW distribution f.tab Trapezoidal Rule Length Minimum # trestles Weight Center of gravity 9 m Calculate displacement m x m Determine trestle reactions of each combination Combination of trolleys Max<Min 4,5 m considered University of Rostock Naval Architecture and Ocean Engineering 18

19 Concept for Ballast Tank Planning Algorithm Procedure description User is asked for parameters Read from initial_tank.tab tank information Tanks Initial volume and water level, LCG, water plane area. Read from initial_tank.tab tank information Dock length, breadth, displacement, GM, MTC. University of Rostock Naval Architecture and Ocean Engineering 19

20 Concept for Ballast Tank Planning Algorithm Input data Determine space between trestles Determine CG Determine Loading sequences Determine distance to advance Transfer Moment per Loading Seq. Just for the 1st sequence Read no heel combiantions from file combi.tab Calculate Final Average Water level Big Loop -Speed Pump Combination Determine Volume Limits University of Rostock Naval Architecture and Ocean Engineering 20

21 Conclusions Reversible pump implementation The ballast system cannot keep up with the TTS speed for approx. the first 40 meters - Preloading Coordination of Transfer and Ballast System TTS system speed, pump capacity and trestle location as key variable for the whole process. Future Work Combine both programs into one. Complete code for ballast planning. University of Rostock Naval Architecture and Ocean Engineering 21

22 Acknowledgements Thank You! - Vielen Dank! Gracias! Dziękuje! Questions? University of Rostock Naval Architecture and Ocean Engineering 22