Transcript
Wave Buoy Mooring Design Evaluation
Prepared by: Randolph Kashino AXYS Technologies Head Office 2045 Mills Road Sidney, British Columbia Canada PWGSC Contract Number: W7701-4501464898 Technical Authority: Eric Thornhill, Defence Scientist Contractor’s Publication Date: September 2016
The scientific or technical validity of this Contract Report is entirely the responsibility of the Contractor and the contents do not necessarily have the approval or endorsement of the Department of National Defence of Canada.
Contract Report
DRDC-RDDC-2017-C064
May 2017
Template in use: (2010) SR Advanced Template_EN (051115).dotm
© Her Majesty the Queen in Right of Canada, as represented by the Minister of National Defence, 2016
© Sa Majesté la Reine (en droit du Canada), telle que représentée par le ministre de la Défense nationale,
2016
Wave Buoy Mooring Design Evaluation For Defense Research and Development Canada – Atlantic Research Centre (DRDC-ARC)
Final Report September 27, 2016
Prepared by
Randolph Kashino
AXYS Technologies
Head Office European Office 2045 Mills Road Esplanadestraat 1 Sidney, British Columbia 8400 Oostende Canada Belgium
www.axystechnologies.com
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Contact Author Reviewed Randolph Kashino First name Last name +1 250 655 5862 Telephone number rkashino@axys.com Email address
Revision History Rev Date Change By 00 2016/09/27 Draft RKK
01 2017/04/18 Final – Confidentiality Statements Removed
RKK
02 2017/05/11 Final – revised Appendix RKK
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Table of Contents
1. Mooring Simulation Tasks ..................................................................................................................... 8 Sea State Conditions to Simulate: ............................................................................................................. 8
2. WHOI CABLE Program ......................................................................................................................... 13
3. Simulations .......................................................................................................................................... 14 3.1. Simulation 5.1.1 .......................................................................................................................... 14 3.2. Simulation 5.1.2 .......................................................................................................................... 18 3.3. Simulation 5.1.3 .......................................................................................................................... 22 3.4. Simulation 5.1.4 .......................................................................................................................... 26 3.5. Simulation 5.1.5 .......................................................................................................................... 30 3.6. Simulation 5.1.6 .......................................................................................................................... 34 3.7. Simulation 5.1.7 .......................................................................................................................... 38 3.8. Simulation 5.1.8 .......................................................................................................................... 42 3.9. Simulation 5.1.9 .......................................................................................................................... 46 3.10. Simulation 5.1.10 ........................................................................................................................ 50 3.11. Simualtion 5.1.11 ........................................................................................................................ 54 Simulation 5.4. Figure 3 Configuration ................................................................................................. 58
4. Bungee Compliance Assessment ........................................................................................................ 63
5. Summary and Evaluation .................................................................................................................... 64
6. References .......................................................................................................................................... 71
7. Appendix I. Splicing 12 Strand Single Braid for Moorings ................................................................... 72
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Table of Figures
Figure 1. DRDC Original SHOL 2C Mooring ................................................................................................. 10 Figure 2. DRDC SHOL 2D New Mooring Design........................................................................................... 11 Figure 3. DRCD SHOL 2D Modified Proposed New Design ......................................................................... 12 Figure 4. Simulation 5.1.1 wave height time series .................................................................................... 14 Figure 5. Simulation 5.1.1 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor ....... 16 Figure 6. Simulation 5.1.1 Mooring Profile with Static Currents Conditions .............................................. 17 Figure 7. Simulation 5.1.1 near Surface Mooring Profile with Static Currents Conditions ......................... 17 Figure 8. Simulation 5.1.2 wave height time series .................................................................................... 18 Figure 9. Simulation 5.1.2 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor ....... 20 Figure 10. Simulation 5.1.2 Mooring Profile with Static Currents Conditions ............................................ 21 Figure 11. Simulation 5.1.2 near Surface Mooring Profile with Static Currents Conditions ....................... 21 Figure 12. Simulation 5.1.3 wave height time series .................................................................................. 22 Figure 13. Simulation 5.1.3 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor ..... 24 Figure 14. Simulation 5.1.3 Mooring Profile with Static Currents Conditions ............................................ 25 Figure 15. Simulation 5.1.3 near Surface Mooring Profile with Static Currents Conditions ....................... 25 Figure 16. Simulation 5.1.4 wave height time series .................................................................................. 26 Figure 17. Simulation 5.1.4 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor ..... 28 Figure 18. Simulation 5.1.4 Mooring Profile with Static Currents Conditions ............................................ 29 Figure 19. Simulation 5.1.4 near Surface Mooring Profile with Static Currents Conditions ....................... 29 Figure 20. Simulation 5.1.5 wave height time series .................................................................................. 30 Figure 21. Simulation 5.1.5 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor ..... 31 Figure 22. Simulation 5.1.5 Mooring Profile with Static Currents Conditions ............................................ 32 Figure 23. Simulation 5.1.5 near Surface Mooring Profile with Static Currents Conditions ....................... 33 Figure 24. Simulation 5.1.6 wave height time series .................................................................................. 34 Figure 25. Simulation 5.1.6 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor ..... 36 Figure 26. Simulation 5.1.6 Mooring Profile with Static Currents Conditions ............................................ 37 Figure 27. Simulation 5.1.6 near Surface Mooring Profile with Static Currents Conditions ....................... 37 Figure 28. Simulation 5.1.7 wave height time series .................................................................................. 38 Figure 29. Simulation 5.1.7 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor ..... 40 Figure 30. Simulation 5.1.7 Mooring Profile with Static Currents Conditions ............................................ 40 Figure 31. Simulation 5.1.7 near Surface Mooring Profile with Static Currents Conditions ....................... 41 Figure 32. Simulation 5.1.8 wave height time series .................................................................................. 42 Figure 33. Simulation 5.1.8 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor ..... 44 Figure 34. Simulation 5.1.8 Mooring Profile with Static Currents Conditions ............................................ 44 Figure 35. Simulation 5.1.8 near Surface Mooring Profile with Static Currents Conditions ....................... 45 Figure 36. Simulation 5.1.9 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor ..... 48 Figure 37. Simulation 5.1.9 Mooring Profile with Static Currents Conditions ............................................ 48 Figure 38. Simulation 5.1.9 near Surface Mooring Profile with Static Currents Conditions ....................... 49 Figure 39. Simulation 5.1.10 wave height time series ................................................................................ 50
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Figure 40. Simulation 5.1.10 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor ... 52 Figure 41. Simulation 5.1.10 Mooring Profile with Static Currents Conditions .......................................... 52 Figure 42. Simulation 5.1.10 near Surface Mooring Profile with Static Currents Conditions..................... 53 Figure 43. Simulation 5.1.11 wave height time series ................................................................................ 54 Figure 44. Simulation 5.1.11 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor ... 56 Figure 45. Simulation 5.1.11 Mooring Profile with Static Currents Conditions .......................................... 56 Figure 46. Simulation 5.1.11 near Surface Mooring Profile with Static Currents Conditions..................... 57 Figure 47. Simulation 5.4 wave height time series ..................................................................................... 58 Figure 48. Simulation 5.4 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor ........ 60 Figure 49. Simulation 5.4 Mooring Profile with Static Currents Conditions ............................................... 61 Figure 50. Simulation 5.4 near Surface Mooring Profile with Static Currents Conditions .......................... 61 Figure 51. Comparison of Maximum Dynamic Tensions ............................................................................ 67 Figure 52. Comparison of Triaxys Buoy Reserve Buoyancy after Maximum Dynamic Tension .................. 67 Figure 53. Comparison of Average Dynamic Tension ................................................................................. 68 Figure 54. Comparison of Reserve Buoyance after Average Dynamic Tension .......................................... 68 Figure 55. Comparison of Static Tensions. Currents only. .......................................................................... 69 Figure 56. Comparison of Triaxys Buoy Reserve Buoyancy after Static Tension. Currents only. ............... 69 Figure 57. Comparison Dynamic Tension at Anchor ................................................................................... 70 Figure 58. Comparison of Average Dynamic Tension at Anchor ................................................................ 70
Table of Tables
Table 1. Ocean Current Profile used in Simulations ..................................................................................... 8 Table 2. List of Planned Simulations ............................................................................................................. 9 Table 3. Simulation 5.1.1 Environmental conditions .................................................................................. 14 Table 4. Simulation 5.1.1 Buoy and Anchor Tension Results ...................................................................... 15 Table 5. Simulation 5.1.2 Environmental conditions .................................................................................. 18 Table 6. Simulation 5.1.2 Buoy and Anchor Tension Results ...................................................................... 19 Table 7. Simulation 5.1.2 Environmental conditions .................................................................................. 22 Table 8. Simulation 5.1.3 Buoy and Anchor Tension Results ...................................................................... 23 Table 9.Simulation 5.1.4 Environmental conditions ................................................................................... 26 Table 10. Simulation 5.1.4 Buoy and Anchor Tension Results .................................................................... 27 Table 11. Simulation 5.1.5 Environmental conditions ................................................................................ 30 Table 12. Simulation 5.1.5 Buoy and Anchor Tension Results .................................................................... 31 Table 13. Simulation 5.1.6 Environmental conditions ................................................................................ 34 Table 14. Simulation 5.1.6 Buoy and Anchor Tension Results .................................................................... 35 Table 15. Simulation 5.1.7 Environmental conditions ................................................................................ 38 Table 16. Simulation 5.1.7 Buoy and Anchor Tension Results .................................................................... 39 Table 17. Simulation 5.1.8 Environmental conditions ................................................................................ 42 Table 18. Simulation 5.1.8 Buoy and Anchor Tension Results .................................................................... 43 Table 19. Simulation 5.1.9 Environmental conditions ................................................................................ 46 Table 20. Simulation 5.1.9 wave height time series ................................................................................... 46
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Table 21. Simulation 5.1.9 Buoy and Anchor Tension Results .................................................................... 47 Table 22. Simulation 5.1.10 Environmental conditions .............................................................................. 50 Table 23. Simulation 5.1.10 Buoy and Anchor Tension Results .................................................................. 51 Table 24. Simulation 5.1.11 Environmental condtions ............................................................................... 54 Table 25. Simulation 5.1.11 Buoy and Anchor Tension Results .................................................................. 55 Table 26. Simulation 5.4 Environmental conditions ................................................................................... 58 Table 27. Simulation 5.4 Buoy and Anchor Tension Results ....................................................................... 59
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1. Mooring Simulation Tasks
Sea State Conditions to Simulate: Ocean Depth: 122 metres Significant Wave Height (Hs): 12 metres Peak Wave Period (Tp): 15 seconds Ocean Currents: 0.58 metres per second at surface to 0.29 metres per second at ocean bottom. Derived from given currents in Statement of Work (Reference 1): with a Depth Averaged current [U(m)] of 0.5 m/s using Power Law for profile: U(z) = U(m) (Z/0.32*d)^(1/7) Where: Z is the height above seabed d is the water depth U(z) is the current velocity at height(z) U(m) is the depth averaged current velocity Table 1. Ocean Current Profile used in Simulations
Simulation Velocity Profile Depth(m) Velocity(m/s)
0 0.58 7 0.58
12 0.58 22 0.57 42 0.55
121 0.29
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Table 2. List of Planned Simulations
5.1.1 Original as per figure 1 (December 2015 deployment) 5.1.2 Substitute all ¾” diameter 3-strand poly rope with 7/16” diameter Amsteel-blue
Rope in figure 1. 5.1.3 Change 135 m of 3/4” poly to 450 m of 1” poly (4:1 ratio) figure 1. 5.1.4 Change 135 m of ¾” poly to 450 m of 7/16” Amsteel-Blue (4:1 ratio) figure 1. 5.1.5 Figure 2 configuration (2:1 ratio + chain). 220m (205+15) Amsteel blue with 2 Vinycon
buoys 5.1.6 Figure 2 configuration; substitute 7/16” Amsteel-Blue with 1” 3-strand poly (2:1
Ratio + chain). 5.1.7 Figure 2 configuration; change 205 m 7/16” Amsteel-Blue to 327 m of 7/16”
Amsteel- Blue (3:1 ratio + chain). 5.1.8 Figure 2 configuration; change 205 m 7/16” Amsteel-Blue to 327 m of 1” 3-
Strand poly (3:1 ratio + chain). 5.1.9 Figure 3 configuration; 220 m 3/8” (9mm) Amsteel Blue + 6m Vectran rope with 3
Vinycon buoys 5.1.10 Figure 3 configuration; 220m 3/8” (10mm) XTrema Line + 6m Vectran rope with 3
Vinycon Buoys. 5.1.11 Figure 3 configuration; 220m 7/16” (11mm) Amsteel Blue Line + 6m Vectran rope with 3
Vinycon Buoys. 5.4 Extreme Simulation of optimum mooring with HS: 18m and Tp: 20s.
Figure 2 configuration (2:1 ratio + chain).
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Figure 1. DRDC Original SHOL 2C Mooring
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Figure 2. DRDC SHOL 2D New Mooring Design
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Figure 3. DRCD SHOL 2D Modified Proposed New Design
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2. WHOI CABLE Program The WHOI Cable version 2.0 program was used for the mooring simulations. (Reference 2 ). Axys Technologies, Inc. has been using the WHOI Cable program since 2006 to design and test many oceanographic moorings and has not found any problems with deployments that range worldwide. The WHOI Cable program, itself, was designed specifically for Oceanographic mooring systems and tested by the Woods Hole Oceanographic Institution. The solutions were a 2 Dimensional dynamic simulation with input currents and waves propagation in the same direction. A static simulation is resolved at the same time based on input currents. The mean and maximum dynamic, including static tensions at the Buoy and Anchor are presented. Environment input conditions are presented as well as an analysis of output wave heights. The output wave height statistics are determined from the buoy heave in the simulation. For the simulation the following wave statistics are presented: Significant Wave Height (Hs) is estimated from 4 times the Standard Deviation of the wave height time series. Tz is the zero crossing period which is determined from the number of zero crossings divide the time length in seconds of the wave height time series analysed. Ts is the significant period as calculated from the 1.33 times Tz. Hmax is the maximum wave height as determined from manually picking the largest trough to peak waves in the simulation wave height time series graph.
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3. Simulations 3.1. Simulation 5.1.1
Table 3. Simulation 5.1.1 Environmental conditions
Figure 4. Simulation 5.1.1 wave height time series
Parameter Input
Hs: 12
Tp : 15
Cv -surface : 0.58
Cv- mid : 0.53
Cv -bottom : 0.29
Simulation
Hs : 12.1
Hmax : 16.3
Ts : 13.8
Tz : 10.3
Simulation 5.1.1 Environmental Conditions
-10-8-6-4-202468
10
200 250 300 350 400 450 500
Heig
ht (m
)
Time (s)
Simulation 5.1.1: Wave Height Time Series
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Table 4. Simulation 5.1.1 Buoy and Anchor Tension Results
lbs Kg
Maximum DynamicTension at Buoy 539 244
Average Dynamic Tension at Buoy 172 78
Reserve Buoyancy after Maximum Dynamic Tension -27 -12
Reserve Buoyancy after Average Dynamic Tension 339 154
Maximimum Dynamic Tension at Anchor 520 236
Average Dynamic Tension at Anchor 167 76
Static Tension at Buoy 89 40
Reserve Buoyancy after Static Tension at Buoy 422 192
Reserve Buoyancy of TRIAXYS Buoy 511 232
Dynamic Analysis
Static Analysis
Simulation 5.1.1
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Figure 5. Simulation 5.1.1 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor
0
50
100
150
200
250
300
350
400
450
500
550
600
200 250 300 350 400 450 500
Tens
ion
(lbs)
Time (s)
Dynamic Simulation 5.1.1for Depth: 122m
Waves: Hs=12.0 m Tp=15s Currents: 0.58 m/s Surface to 0.29 m/s BottomTriaxys NW Total Reserve Buoyancy: 511 lbs
Reserve after Maximum Dynamic Tension: -27 lbsReserve after Mean Dynamic Tension: 339 lbs
Tension at Anchor (lbs) Tension at Buoy (lbs) Reserve Buoyancy
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Figure 6. Simulation 5.1.1 Mooring Profile with Static Currents Conditions
Figure 7. Simulation 5.1.1 near Surface Mooring Profile with Static Currents Conditions
0
10
20
30
40
50
60
70
80
90
100
110
120
130
0 10 20 30 40 50 60 70 80 90 100 110 120
Simulation 5.1.1Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 89 lbsTension at Anchor: 82 lbs
110
115
120
125
105 110 115 120 125
Simulation 5.1.1Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 89 lbsTension at Anchor: 82 lbs
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3.2. Simulation 5.1.2
Table 5. Simulation 5.1.2 Environmental conditions
Figure 8. Simulation 5.1.2 wave height time series
Parameter Input
Hs: 12
Tp : 15
Cv -surface : 0.58
Cv- mid : 0.53
Cv -bottom : 0.29
Simulation
Hs : 13.3
Hmax : 16.3
Ts : 17.3
Tz : 13.0
Simulation 5.1.2 Environmental Conditions
-15
-10
-5
0
5
10
15
200 250 300 350 400 450 500
Heig
ht (m
)
Time (s)
Simulation 5.1.2: Wave Height Time Series
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Table 6. Simulation 5.1.2 Buoy and Anchor Tension Results
lbs Kg
Maximum DynamicTension at Buoy 614 279
Average Dynamic Tension at Buoy 158 72
Reserve Buoyancy after Maximum Dynamic Tension -103 -47
Reserve Buoyancy after Average Dynamic Tension 353 160
Maximimum Dynamic Tension at Anchor 593 269
Average Dynamic Tension at Anchor 150 68
Static Tension at Buoy 73 33
Reserve Buoyancy after Static Tension at Buoy 438 199
Reserve Buoyancy of TRIAXYS Buoy 511 232
Dynamic Analysis
Static Analysis
Simulation 5.1.2
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Figure 9. Simulation 5.1.2 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor
0
50
100
150
200
250
300
350
400
450
500
550
600
200 250 300 350 400 450 500
Tens
ion
(lbs)
Time (s)
Dynamic Simulation 5.1.2for Depth: 122m
Waves: Hs=12.0 m Tp=15s Currents: 0.58 m/s Surface to 0.29 m/s BottomTriaxys NW Total Reserve Buoyancy: 511 lbs
Reserve after Maximum Dynamic Tension: -103 lbsReserve after Mean Dynamic Tension: 353 lbs
Tension at Anchor (lbs) Tension at Buoy (lbs) Reserve Buoyancy
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Figure 10. Simulation 5.1.2 Mooring Profile with Static Currents Conditions
Figure 11. Simulation 5.1.2 near Surface Mooring Profile with Static Currents Conditions
0
10
20
30
40
50
60
70
80
90
100
110
120
130
0 10 20 30 40 50 60 70 80 90 100 110 120
Simulaton 5.1.2Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 73 lbsTension at Anchor: 64 lbs
110
115
120
125
105 110 115 120 125
Simulation 5.1.2Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 89 lbsTension at Anchor: 82 lbs
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3.3. Simulation 5.1.3 Table 7. Simulation 5.1.2 Environmental conditions
Figure 12. Simulation 5.1.3 wave height time series
Parameter Input
Hs: 12
Tp : 15
Cv -surface : 0.58
Cv- mid : 0.53
Cv -bottom : 0.29
Simulation
Hs : 9.7
Hmax : 12.7
Ts : 16.6
Tz : 12.5
Simulation 5.1.3 Environmental Conditions
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10
300 350 400 450 500 550 600
Heig
ht (m
)
Time (s)
Simulation 5.1.3: Wave Height Time Series
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Table 8. Simulation 5.1.3 Buoy and Anchor Tension Results
lbs Kg
Maximum DynamicTension at Buoy 278 126
Average Dynamic Tension at Buoy 49 22
Reserve Buoyancy after Maximum Dynamic Tension 233 106
Reserve Buoyancy after Average Dynamic Tension 462 210
Maximimum Dynamic Tension at Anchor 276 125
Average Dynamic Tension at Anchor 64 29
Static Tension at Buoy 24 11
Reserve Buoyancy after Static Tension at Buoy 487 221
Reserve Buoyancy of TRIAXYS Buoy 511 232
Dynamic Analysis
Static Analysis
Simulation 5.1.3
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Figure 13. Simulation 5.1.3 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor
0
50
100
150
200
250
300
350
400
450
500
550
600
300 350 400 450 500 550 600
Tens
ion
(lbs)
Time (s)
Dynamic Simulation 5.1.3for Depth: 122m
Waves: Hs=12.0 m Tp=15s Currents: 0.58 m/s Surface to 0.29 m/s BottomTriaxys NW Total Reserve Buoyancy: 511 lbs
Reserve after Maximum Dynamic Tension: 233 lbsReserve after Mean Dynamic Tension: 462 lbs
Tension at Anchor (lbs) Tension at Buoy (lbs) Reserve Buoyancy
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Figure 14. Simulation 5.1.3 Mooring Profile with Static Currents Conditions
Figure 15. Simulation 5.1.3 near Surface Mooring Profile with Static Currents Conditions
0
10
20
30
40
50
60
70
80
90
100
110
120
130
0 100 200 300 400 500
Simulaton 5.1.3Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 24 lbsTension at Anchor: 34 lbs
110
115
120
125
455 460 465 470
Simulation 5.1.3Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 24 lbsTension at Anchor: 34 lbs
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3.4. Simulation 5.1.4 Table 9.Simulation 5.1.4 Environmental conditions
Figure 16. Simulation 5.1.4 wave height time series
Parameter Input
Hs: 12
Tp : 15
Cv -surface : 0.58
Cv- mid : 0.53
Cv -bottom : 0.29
Simulation
Hs : 9.7
Hmax : 12.3
Ts : 15.3
Tz : 11.5
Simulation 5.1.4 Environmental Conditions
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10
300 350 400 450 500 550 600
Heig
ht (m
)
Time (s)
Simulation 5.1.2: Wave Height Time Series
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Table 10. Simulation 5.1.4 Buoy and Anchor Tension Results
lbs Kg
Maximum DynamicTension at Buoy 311 141
Average Dynamic Tension at Buoy 54 25
Reserve Buoyancy after Maximum Dynamic Tension 200 91
Reserve Buoyancy after Average Dynamic Tension 457 207
Maximimum Dynamic Tension at Anchor 297 135
Average Dynamic Tension at Anchor 57 26
Static Tension at Buoy 32 14
Reserve Buoyancy after Static Tension at Buoy 479 217
Reserve Buoyancy of TRIAXYS Buoy 511 232
Dynamic Analysis
Static Analysis
Simulation 5.1.4
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Figure 17. Simulation 5.1.4 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor
0
50
100
150
200
250
300
350
400
450
500
550
600
200 250 300 350 400 450 500
Tens
ion
(lbs)
Time (s)
Dynamic Simulation 5.1.4for Depth: 122m
Waves: Hs=12.0 m Tp=15s Currents: 0.58 m/s Surface to 0.29 m/s BottomTriaxys NW Total Reserve Buoyancy: 511 lbs
Reserve after Maximum Dynamic Tension: 200 lbsReserve after Mean Dynamic Tension: 457 lbs
Tension at Anchor (lbs) Tension at Buoy (lbs) Reserve Buoyancy
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Figure 18. Simulation 5.1.4 Mooring Profile with Static Currents Conditions
Figure 19. Simulation 5.1.4 near Surface Mooring Profile with Static Currents Conditions
0
10
20
30
40
50
60
70
80
90
100
110
120
130
0 100 200 300 400 500
Simulaton 5.1.4Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 31 lbsTension at Anchor: 32 lbs
110
115
120
125
455 460 465 470
Simulation 5.1.4Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 31 lbsTension at Anchor: 32 lbs
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3.5. Simulation 5.1.5
Table 11. Simulation 5.1.5 Environmental conditions
Figure 20. Simulation 5.1.5 wave height time series
Parameter Input
Hs: 12
Tp : 15
Cv -surface : 0.58
Cv- mid : 0.53
Cv -bottom : 0.29
Simulation
Hs : 12.2
Hmax : 16.8
Ts : 14.3
Tz : 10.7
Simulation Environmental Conditions
Simulation 5.1.5
-15
-10
-5
0
5
10
15
200 250 300 350 400 450 500
Heig
ht (m
)
Time (s)
Simulation 5.1.5: Wave Height Time Series
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Table 12. Simulation 5.1.5 Buoy and Anchor Tension Results
Figure 21. Simulation 5.1.5 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor
lbs Kg
Maximum DynamicTension at Buoy 336 152
Average Dynamic Tension at Buoy 95 43
Reserve Buoyancy after Maximum Dynamic Tension 175 80
Reserve Buoyancy after Average Dynamic Tension 417 189
Maximimum Dynamic Tension at Anchor 278 126
Average Dynamic Tension at Anchor 84 38
Static Tension at Buoy 53 24
Reserve Buoyancy after Static Tension at Buoy 458 208
Reserve Buoyancy of TRIAXYS Buoy 511 232
Dynamic Analysis
Static Analysis
Simulation 5.1.5
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Figure 22. Simulation 5.1.5 Mooring Profile with Static Currents Conditions
0
50
100
150
200
250
300
350
400
450
500
550
600
200 250 300 350 400 450 500
Tens
ion
(lbs)
Time (s)
Dynamic Simulation 5.1.5for Depth: 122m
Waves: Hs=12.0 m Tp=15s Currents: 0.58 m/s Surface to 0.29 m/s BottomTriaxys NW Total Reserve Buoyancy: 511 lbs
Reserve after Maximum Dynamic Tension: 175 lbsReserve after Mean Dynamic Tension: 417 lbs
Tension at Anchor (lbs) Tension at Buoy (lbs) Reserve Buoyancy
0
10
20
30
40
50
60
70
80
90
100
110
120
130
0 20 40 60 80 100 120 140 160 180 200 220 240 260
Simulaton 5.1.5Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 53 lbsTension at Anchor: 42 lbs
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Figure 23. Simulation 5.1.5 near Surface Mooring Profile with Static Currents Conditions
110
115
120
125
240 245 250 255
Simulation 5.1.5Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 53 lbsTension at Anchor: 42 lbs
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3.6. Simulation 5.1.6 Table 13. Simulation 5.1.6 Environmental conditions
Figure 24. Simulation 5.1.6 wave height time series
Parameter Input
Hs: 12
Tp : 15
Cv -surface : 0.58
Cv- mid : 0.53
Cv -bottom : 0.29
Simulation
Hs : 13.1
Hmax : 12.9
Ts : 16.6
Tz : 12.5
Simulation Environmental Conditions
Simulation 5.1.6
-15
-10
-5
0
5
10
15
200 250 300 350 400 450 500
Heig
ht (m
)
Time (s)
Simulation 5.1.6: Wave Height Time Series
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Table 14. Simulation 5.1.6 Buoy and Anchor Tension Results
lbs Kg
Maximum DynamicTension at Buoy 368 167
Average Dynamic Tension at Buoy 106 48
Reserve Buoyancy after Maximum Dynamic Tension 144 65
Reserve Buoyancy after Average Dynamic Tension 405 184
Maximimum Dynamic Tension at Anchor 351 159
Average Dynamic Tension at Anchor 103 47
Static Tension at Buoy 80 36
Reserve Buoyancy after Static Tension at Buoy 431 196
Reserve Buoyancy of TRIAXYS Buoy 511 232
Dynamic Analysis
Static Analysis
Simulation 5.1.6
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Figure 25. Simulation 5.1.6 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor
0
50
100
150
200
250
300
350
400
450
500
550
600
200 250 300 350 400 450 500
Tens
ion
(lbs)
Time (s)
Dynamic Simulation 5.1.6for Depth: 122m
Waves: Hs=12.0 m Tp=15s Currents: 0.58 m/s Surface to 0.29 m/s BottomTriaxys NW Total Reserve Buoyancy: 511 lbs
Reserve after Maximum Dynamic Tension: 144 lbsReserve after Mean Dynamic Tension: 405 lbs
Tension at Anchor (lbs) Tension at Buoy (lbs) Reserve Buoyancy
37
Figure 26. Simulation 5.1.6 Mooring Profile with Static Currents Conditions
Figure 27. Simulation 5.1.6 near Surface Mooring Profile with Static Currents Conditions
0
10
20
30
40
50
60
70
80
90
100
110
120
130
0 20 40 60 80 100 120 140 160 180 200 220 240 260
Simulation 5.1.6Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 80 lbsTension at Anchor: 73 lbs
110
115
120
125
240 245 250 255
Simulation 5.1.6Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 80 lbsTension at Anchor: 73 lbs
38
3.7. Simulation 5.1.7 Table 15. Simulation 5.1.7 Environmental conditions
Figure 28. Simulation 5.1.7 wave height time series
Parameter Input
Hs: 12
Tp : 15
Cv -surface : 0.58
Cv- mid : 0.53
Cv -bottom : 0.29
Simulation
Hs : 14.2
Hmax : 14.1
Ts : 19.0
Tz : 14.3
Simulation Environmental Conditions
Simulation 5.1.7
-15
-10
-5
0
5
10
15
200 250 300 350 400 450 500
Heig
ht (m
)
Time (s)
Simulation 5.1.7: Wave Height Time Series
39
Table 16. Simulation 5.1.7 Buoy and Anchor Tension Results
lbs Kg
Maximum DynamicTension at Buoy 294 133
Average Dynamic Tension at Buoy 65 29
Reserve Buoyancy after Maximum Dynamic Tension 217 98
Reserve Buoyancy after Average Dynamic Tension 447 203
Maximimum Dynamic Tension at Anchor 290 132
Average Dynamic Tension at Anchor 64 29
Static Tension at Buoy 42 19
Reserve Buoyancy after Static Tension at Buoy 469 213
Reserve Buoyancy of TRIAXYS Buoy 511 232
Dynamic Analysis
Static Analysis
Simulation 5.1.7
40
Figure 29. Simulation 5.1.7 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor
Figure 30. Simulation 5.1.7 Mooring Profile with Static Currents Conditions
0
50
100
150
200
250
300
350
400
450
500
550
600
200 250 300 350 400 450 500
Tens
ion
(lbs)
Time (s)
Dynamic Simulation 5.1.7for Depth: 122m
Waves: Hs=12.0 m Tp=15s Currents: 0.58 m/s Surface to 0.29 m/s BottomTriaxys NW Total Reserve Buoyancy: 511 lbs
Reserve after Maximum Dynamic Tension: 217 lbsReserve after Mean Dynamic Tension: 447 lbs
Tension at Anchor (lbs) Tension at Buoy (lbs) Reserve Buoyancy
0
10
20
30
40
50
60
70
80
90
100
110
120
130
0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400
Simulation 5.1.7Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 42 lbsTension at Anchor: 36 lbs
41
Figure 31. Simulation 5.1.7 near Surface Mooring Profile with Static Currents Conditions
110
115
120
125
370 375 380 385
Simulaton 5.1.7Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 42 lbsTension at Anchor: 36 lbs
42
3.8. Simulation 5.1.8 Table 17. Simulation 5.1.8 Environmental conditions
Figure 32. Simulation 5.1.8 wave height time series
Parameter Input
Hs: 12
Tp : 15
Cv -surface : 0.58
Cv- mid : 0.53
Cv -bottom : 0.29
Simulation
Hs : 15.7
Hmax : 13.3
Ts : 20.0
Tz : 15.0
Simulation Environmental Conditions
Simulation 5.1.8
-15
-10
-5
0
5
10
15
200 250 300 350 400 450 500
Heig
ht (m
)
Time (s)
Simulation 5.1.8: Wave Height Time Series
43
Table 18. Simulation 5.1.8 Buoy and Anchor Tension Results
lbs Kg
Maximum DynamicTension at Buoy 304 138
Average Dynamic Tension at Buoy 68 31
Reserve Buoyancy after Maximum Dynamic Tension 207 94
Reserve Buoyancy after Average Dynamic Tension 443 201
Maximimum Dynamic Tension at Anchor 324 147
Average Dynamic Tension at Anchor 76 35
Static Tension at Buoy 60 27
Reserve Buoyancy after Static Tension at Buoy 451 205
Reserve Buoyancy of TRIAXYS Buoy 511 232
Dynamic Analysis
Static Analysis
Simulation 5.1.8
44
Figure 33. Simulation 5.1.8 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor
Figure 34. Simulation 5.1.8 Mooring Profile with Static Currents Conditions
0
50
100
150
200
250
300
350
400
450
500
550
600
200 250 300 350 400 450 500
Tens
ion
(lbs)
Time (s)
Dynamic Simulation 5.1.8for Depth: 122m
Waves: Hs=12.0 m Tp=15s Currents: 0.58 m/s Surface to 0.29 m/s BottomTriaxys NW Total Reserve Buoyancy: 511 lbs
Reserve after Maximum Dynamic Tension: 207 lbsReserve after Mean Dynamic Tension: 443 lbs
Tension at Anchor (lbs) Tension at Buoy (lbs) Reserve Buoyancy
0102030405060708090
100110120130
0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400
Simualtion 5.1.8Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 60 lbsTension at Anchor: 60 lbs
45
Figure 35. Simulation 5.1.8 near Surface Mooring Profile with Static Currents Conditions
110
115
120
125
370 375 380 385
Simulation 5.1.8Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 60 lbsTension at Anchor: 60 lbs
46
3.9. Simulation 5.1.9 Table 19. Simulation 5.1.9 Environmental conditions
Table 20. Simulation 5.1.9 wave height time series
Parameter Input
Hs: 12
Tp : 15
Cv -surface : 0.58
Cv- mid : 0.53
Cv -bottom : 0.29
Simulation
Hs : 11.7
Hmax : 16.0
Ts : 12.5
Tz : 9.4
Simulation Environmental Conditions
Simulation 5.1.9
-15
-10
-5
0
5
10
15
200 250 300 350 400 450 500
Heig
ht (m
)
Time (s)
Simulation 5.1.9: Wave Height Time Series
47
Table 21. Simulation 5.1.9 Buoy and Anchor Tension Results
lbs Kg
Maximum DynamicTension at Buoy 203 92
Average Dynamic Tension at Buoy 39 18
Reserve Buoyancy after Maximum Dynamic Tension 308 140
Reserve Buoyancy after Average Dynamic Tension 472 214
Maximimum Dynamic Tension at Anchor 125 57
Average Dynamic Tension at Anchor 69 31
Static Tension at Buoy 22 10
Reserve Buoyancy after Static Tension at Buoy 489 222
Reserve Buoyancy of TRIAXYS Buoy 511 232
Dynamic Analysis
Static Analysis
Simulation 5.1.9
48
Figure 36. Simulation 5.1.9 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor
Figure 37. Simulation 5.1.9 Mooring Profile with Static Currents Conditions
0
50
100
150
200
250
300
350
400
450
500
550
600
200 250 300 350 400 450 500
Tens
ion
(lbs)
Time (s)
Dynamic Simulation 5.1.9for Depth: 122m
Waves: Hs=12.0 m Tp=15s Currents: 0.58 m/s Surface to 0.29 m/s BottomTriaxys NW Total Reserve Buoyancy: 511 lbs
Reserve after Maximum Dynamic Tension: 308 lbsReserve after Mean Dynamic Tension: 472 lbs
Tension at Anchor (lbs) Tension at Buoy (lbs) Reserve Buoyancy
0
10
20
30
40
50
60
70
80
90
100
110
120
130
0 20 40 60 80 100 120 140 160 180 200 220 240 260
Simulaton 5.1.9Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 22 lbsTension at Anchor: 45 lbs
49
Figure 38. Simulation 5.1.9 near Surface Mooring Profile with Static Currents Conditions
110
115
120
125
220 225 230 235 240
Simulation 5.1.9Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 22 lbsTension at Anchor: 45 lbs
50
3.10. Simulation 5.1.10
Table 22. Simulation 5.1.10 Environmental conditions
Figure 39. Simulation 5.1.10 wave height time series
Parameter Input
Hs: 12
Tp : 15
Cv -surface : 0.58
Cv- mid : 0.53
Cv -bottom : 0.29
Simulation
Hs : 11.8
Hmax : 15.9
Ts : 13.8
Tz : 10.3
Simulation Environmental Conditions
Simulation 5.1.10
-15
-10
-5
0
5
10
15
200 250 300 350 400 450 500
Heig
ht (m
)
Time (s)
Simulation 5.1.10: Wave Height Time Series
51
Table 23. Simulation 5.1.10 Buoy and Anchor Tension Results
lbs Kg
Maximum DynamicTension at Buoy 208 94
Average Dynamic Tension at Buoy 41 19
Reserve Buoyancy after Maximum Dynamic Tension 304 138
Reserve Buoyancy after Average Dynamic Tension 470 213
Maximimum Dynamic Tension at Anchor 128 58
Average Dynamic Tension at Anchor 72 33
Static Tension at Buoy 23 10
Reserve Buoyancy after Static Tension at Buoy 488 221
Reserve Buoyancy of TRIAXYS Buoy 511 232
Dynamic Analysis
Static Analysis
Simulation 5.1.10
52
Figure 40. Simulation 5.1.10 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor
Figure 41. Simulation 5.1.10 Mooring Profile with Static Currents Conditions
0
50
100
150
200
250
300
350
400
450
500
550
600
200 250 300 350 400 450 500
Tens
ion
(lbs)
Time (s)
Dynamic Simulation 5.1.10for Depth: 122m
Waves: Hs=12.0 m Tp=15s Currents: 0.58 m/s Surface to 0.29 m/s BottomTriaxys NW Total Reserve Buoyancy: 511 lbs
Reserve after Maximum Dynamic Tension: 308 lbsReserve after Mean Dynamic Tension: 472 lbs
Tension at Anchor (lbs) Tension at Buoy (lbs) Reserve Buoyancy
0
10
20
30
40
50
60
70
80
90
100
110
120
130
0 20 40 60 80 100 120 140 160 180 200 220 240 260
Simulaton 5.1.10Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 23 lbsTension at Anchor: 46 lbs
53
Figure 42. Simulation 5.1.10 near Surface Mooring Profile with Static Currents Conditions
110
115
120
125
220 225 230 235 240
Simulation 5.1.10Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 23 lbsTension at Anchor: 46 lbs
54
3.11. Simualtion 5.1.11
Table 24. Simulation 5.1.11 Environmental condtions
Figure 43. Simulation 5.1.11 wave height time series
Parameter Input
Hs: 12
Tp : 15
Cv -surface : 0.58
Cv- mid : 0.53
Cv -bottom : 0.29
Simulation
Hs : 11.7
Hmax : 15.8
Ts : 12.5
Tz : 9.4
Simulation Environmental Conditions
Simulation 5.1.11
-15
-10
-5
0
5
10
15
200 250 300 350 400 450 500
Heig
ht (m
)
Time (s)
Simulation 5.1.11: Wave Height Time Series
55
Table 25. Simulation 5.1.11 Buoy and Anchor Tension Results
lbs Kg
Maximum DynamicTension at Buoy 216 98
Average Dynamic Tension at Buoy 42 19
Reserve Buoyancy after Maximum Dynamic Tension 296 134
Reserve Buoyancy after Average Dynamic Tension 469 213
Maximimum Dynamic Tension at Anchor 132 60
Average Dynamic Tension at Anchor 74 34
Static Tension at Buoy 24 11
Reserve Buoyancy after Static Tension at Buoy 487 221
Reserve Buoyancy of TRIAXYS Buoy 511 232
Dynamic Analysis
Static Analysis
Simulation 5.1.11
56
Figure 44. Simulation 5.1.11 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor
Figure 45. Simulation 5.1.11 Mooring Profile with Static Currents Conditions
0
50
100
150
200
250
300
350
400
450
500
550
600
200 250 300 350 400 450 500
Tens
ion
(lbs)
Time (s)
Dynamic Simulation 5.1.11for Depth: 122m
Waves: Hs=12.0 m Tp=15s Currents: 0.58 m/s Surface to 0.29 m/s BottomTriaxys NW Total Reserve Buoyancy: 511 lbs
Reserve after Maximum Dynamic Tension: 296 lbsReserve after Mean Dynamic Tension: 469 lbs
Tension at Anchor (lbs) Tension at Buoy (lbs) Reserve Buoyancy
0
10
20
30
40
50
60
70
80
90
100
110
120
130
0 20 40 60 80 100 120 140 160 180 200 220 240 260
Simulaton 5.1.11Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 24 lbsTension at Anchor: 48 lbs
57
Figure 46. Simulation 5.1.11 near Surface Mooring Profile with Static Currents Conditions
110
115
120
125
220 225 230 235 240
Simulation 5.1.11Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 24 lbsTension at Anchor: 48 lbs
58
Simulation 5.4. Figure 3 Configuration Table 26. Simulation 5.4 Environmental conditions
Figure 47. Simulation 5.4 wave height time series
Parameter Input
Hs: 18
Tp : 20
Cv -surface : 0.58
Cv- mid : 0.53
Cv -bottom : 0.29
Simulation
Hs : 18.4
Hmax : 20.9
Ts : 20.0
Tz : 15.0
Simulation Environmental Conditions
Simulation 5.4
-15
-10
-5
0
5
10
15
200 250 300 350 400 450 500
Heig
ht (m
)
Time (s)
Simulation 5.4: Wave Height Time Series
59
Table 27. Simulation 5.4 Buoy and Anchor Tension Results
lbs Kg
Maximum DynamicTension at Buoy 467 212
Average Dynamic Tension at Buoy 70 32
Reserve Buoyancy after Maximum Dynamic Tension 44 20
Reserve Buoyancy after Average Dynamic Tension 441 200
Maximimum Dynamic Tension at Anchor 442 201
Average Dynamic Tension at Anchor 67 31
Static Tension at Buoy 53 24
Reserve Buoyancy after Static Tension at Buoy 458 208
Reserve Buoyancy of TRIAXYS Buoy 511 232
Dynamic Analysis
Static Analysis
Simulation 5.4
60
Figure 48. Simulation 5.4 Dynamic Mooring Analysis Time Series of Tensions on Buoy and Anchor
0
50
100
150
200
250
300
350
400
450
500
550
600
200 250 300 350 400 450 500
Tens
ion
(lbs)
Time (s)
Dynamic Simulation 5.4for Depth: 122m
Waves: Hs=18.0 m Tp=20s Currents: 0.58 m/s Surface to 0.29 m/s BottomTriaxys NW Total Reserve Buoyancy: 511 lbs
Reserve after Maximum Dynamic Tension: 44 lbsReserve after Mean Dynamic Tension: 441 lbs
Tension at Anchor (lbs) Tension at Buoy (lbs) Reserve Buoyancy
61
Figure 49. Simulation 5.4 Mooring Profile with Static Currents Conditions
Figure 50. Simulation 5.4 near Surface Mooring Profile with Static Currents Conditions
0
10
20
30
40
50
60
70
80
90
100
110
120
130
0 20 40 60 80 100 120 140 160 180 200 220 240 260
Simulation 5.4Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 53 lbsTension at Anchor: 42 lbs
110
115
120
125
240 245 250 255
Simulation 5.4Static Mooring Analysis for Depth: 122m
Currents: 0.58m/s Surface to 0.29m/s BottomTriaxysNW Total Reserve Buoyancy: 511 lbs
Tension at Buoy: 53 lbsTension at Anchor: 42 lbs
62
63
4. Bungee Compliance Assessment The Standard Compliant Sections provided by AXYS Technologies Inc. for the TRIAXYS™ Directional Wave Buoy have a Termination Pull out between 1000 and 1200 pounds. In order to facilitate operational mooring tensions of 2500 lbs a Special Build of the Axys Compliant section which limits the extent such that tensions on the compliant sections terminations are no more than 250 lbs were constructed. The Samson Ropes Amsteel™ Safety Line is a shortened length to enable this. Excess tension will be taken up by the Safety Line which has a Minimum Breaking Strength of 16,200 lbs. This is a Safety Factor of 6.6 on the maximum expected operational tension of 2500 lbs.
64
5. Summary and Evaluation With the given environmental conditions the 2 variations of the original SHOL 2C, the dynamic tensions were the highest of the simulations tested. Both the SHOL 2C with Polypropylene and Amsteel™ (Dyneema™) rope resulted in the dynamic tensions being higher than the reserve buoyancy. This simulations indicates that the Triaxys Buoy would have been submerged momentarily with these moorings and environmental conditions. The SHOL 2C with Amsteel™ variation showed higher maximum dynamic tension, but lower average dynamic and static tension. This due to the characteric of the Polypropylene line being more elastic under tension than the Amsteel™ Dyneema™ therefore under dynamic tension the elasticity allows the Polypropylene to stretch more and momentarily relieve some of the tension. However, under static and average dynamic tension the larger diameter of the Polypropylene rope creates more drag on the mooring with the given result being higher average dynamic and static tensions. The results of a longer mooring and therefore larger scope result in lowering dynamic tensions, however the long scope on positively buoyant rope will likely become operationally problematic in lighter environmental conditions because of the hazard of the rope floating to the surface or near surface. The use of 3 strand polypropylene is not recommended for large scope moorings in the deep sea. This is because under cyclic tensions the 3 strand rope after a large tension will start to hockle then twist on itself. This results in an overall shortening of the mooring and creates tangled points which are points of buoyancy which in turn results in more tangling and shortening of the mooring. (Reference 3). If polypropylene rope is to be used it should be a torque balanced braid such as 8 strand plaited or a 12 strand single braid. For slack line and inverse catenary style moorings, Double Braid rope should also be avoid because under cyclic tension with high loading the outer cover will creep into bunches and create high tensions on the inner core between these bunches. The high tensions on the core will eventual fatigue the fiber and lead to breakage. The new proposed SHOL 2D mooring simulations with 220 meters (205m+15m) of Amsteel™ rope performed much better than the original SHOL 2C moorings with 150m of Polypropylene and Double braid rope. The reason being partly that the SHOL 2D mooring with a smaller diameter Amsteel™ does result in less drag force, but to a large part the longer mooring helps to relieve the overall tension of the mooring. The simulations with the 327m longer rope resulted in higher maximum dynamic tensions but lower average dynamic tension and static tension. This likely due to the longer rope having an overall better elasticity and also possibly due to dynamic motion drag due to the longer rope damping the maximum tensions. Under average and static conditions the longer rope has more drag and which will therefore result in higher average dynamic and static tensions.
65
The newest SHOL 2D (Figure 3) mooring design using 3 Vinycon subsurface floats, 220 m of 10 mm XTrema ™ (Dyneema™) rope with 6 m of 12mm Vectran™ rope performs the best. Variations on this design were also done using 9mm and 11mm Amsteel™ rope which resulted in showing small variances on the tenstions. It can be conclude the main factors in the better performance were likely due to the addition of the additional subsurface buoyancy and the use of the negatively buoyant Vectran rope near the surface.
Recommendations:
The newest mooring design (Figure 3) appears to have very good performance in comparison to the other moorings simulated. Some minor changes that we would recommend are:
1. Splicing of rope eyes should be done with the Herzog style eye splice. This eye splice locks the splice and prevents pullout that can occur in cycling tensions. See Appendix I. Splicing 12 Strand Single Braid for Moorings. For Supplementary Instructions see the following online videos:
12-Strand Single Braid Eye Splice for Moorings: https://vimeo.com/43442821 12-Strand Single Braid End for End Splice for Moorings: https://vimeo.com/97493078
Another suitable 12 strand eye splice is the Brummel-Lock Eye Splice.
See: http://www.phillystran.com/Resource_/PageResource/Phillystran%20Brummel-Lock%20Splice%20Procedure.pdf
2. For the Vectran to XTrema Line connection we would recommend either the Herzog End for End
Splice or that the 2 ropes be joined with a Strop Bend (Cow Hitch) instead of having an Hard Eye and Shackle. The End for End splice will have 90% efficiency in strength and the Strop Bend will have 85 to 90% efficiency of Splice. (Reference 4 and 5). The Strop Bend (Cow Hitch) has the advantage of being easily replacing rope sections during service. It also, removes the possibility of metallic corrosion and wear at these connections. See Figure 51
66
Figure 51. Making a Strop Bend (Cow Hitch) on 2 ropes with Eye Splices
67
Following are graphs comparing the Simulations:
Figure 52. Comparison of Maximum Dynamic Tensions
Figure 53. Comparison of Triaxys Buoy Reserve Buoyancy after Maximum Dynamic Tension
0
100
200
300
400
500
600
700
Tens
ion
(lbs)
Maximum Dynamic Tension at Buoy
-200
-100
0
100
200
300
400
500
600
Tens
ion
(lbs)
Reserve Buoyancy after Maximum Dynamic Tension
68
Figure 54. Comparison of Average Dynamic Tension
Figure 55. Comparison of Reserve Buoyance after Average Dynamic Tension
0
100
200
300
400
500
600
700Te
nsio
n (lb
s)Average Dynamic Tension at Buoy
-200
-100
0
100
200
300
400
500
600
Tens
ion
(lbs)
Reserve Buoyancy after Average Dynamic Tension
69
Figure 56. Comparison of Static Tensions. Currents only.
Figure 57. Comparison of Triaxys Buoy Reserve Buoyancy after Static Tension. Currents only.
0
100
200
300
400
500
600
700Te
nsio
n (lb
s)Static Tension at Buoy
-200
-100
0
100
200
300
400
500
600
Tens
ion
(lbs)
Reserve Buoyancy after Static Tension at Buoy
70
Figure 58. Comparison Dynamic Tension at Anchor
Figure 59. Comparison of Average Dynamic Tension at Anchor
0
100
200
300
400
500
600
700Te
nsio
n (lb
s)Maximimum Dynamic Tension at Anchor
0
100
200
300
400
500
600
700
Tens
ion
(lbs)
Average Dynamic Tension at Anchor
71
6. References
1. DRDC-ARC Statement of Work. 2016. PReq 2016-07644 2. Gobat, Jason, M. Grosenbaugh, and M.S. Triantafyllou, 1997. WHOI Cable:
Time Domain Numerical Simulation of Moored and Towed Oceanographic Systems. Technical Report WHO-97-15. Woods Hole Oceanographic Institution. Woods Hole, MA 02543
3. Paul Gates, Peter Cusack and Peter Watt. 1996. SOUTH PACIFIC COMMISSION
FISH AGGREGATING DEVICE (FAD) MANUAL. VOLUME II RIGGING DEEP-WATER FAD MOORINGS. South Pacific Commission Noumea, New Caledonia
4. Samson Rope Inc. 2014. ROPE USER'S MANUAL. Guide to Rope Selection,
Handling, Inspection and Retirement. SamsonRope.com 5. Pederson, Mark, Greg Mozgai and Danielle Stenvers. 2011. The Effect of
Bending on the Tensile Strength of Statically Loaded Synthetic Ropes. 2011 MTS/OIPEEC 9th International Rope Technology Workshop.
72
7. Appendix I. Splicing 12 Strand Single Braid for Moorings
For Supplementary Instructions see the following online videos: 12-Strand Single Braid Eye Splice for Moorings: https://vimeo.com/43442821 12-Strand Single Braid End for End Splice for Moorings: https://vimeo.com/97493078
12 Strand Single Braid Splicing Instructions for Oceanographic Moorings
1 Eye Splice
Figure 60. 12 Strand Single Braid locked Eye Splice
73
Eye Splice Procedure
1. Measurement: Tape end of line to be spliced and measure one (1) “tubular” fid length (2 wire fid lengths because wire fid is ½ size) from the end of the line and make Mark #1. One tubular fid length is about 22 times the diameter of the rope. From Mark #1 measure another tubular fid length (2 wire fid lengths) then make Mark #2. Now for the size of eye desired and make Mark #3.
Figure 61. Measurement with Fids for splicing
74
2. Taper: From Mark #1, in the direction of the taped end of the line, mark every 2nd right and left strands (paralleled pairs of strands) for 3 pairs. ( See insert figures #3 and #4).
Figure 62. From Mark #1, toward taped end. Mark every 2nd Right & Left pair of Strands
Figure 63. Cut each pair of marked strands. Pull out rope from end.
Cut every 2nd pair of marked strands and pull out of line (note: tape may have to be removed in order to pull out strands). Tapered end will now have only 5 pairs of strands remaining. Tape tapered tail tightly to keep from unbraiding during rest of splicing procedure.
Figure 64. The Tapered end.
75
3. Locking: Attach fid to tapered end of line. At Mark #3 pass fid completely through line and go between strands. Pull on fid and tapered tail until Mark #2 just disappears inside stranding part of line. Be sure not to twist line.
Figure 65. Pull fid through Mark 1 and pull rope through to align Mark 2 and 3 to form the eye.
Note: With line 1/4” to 5/8” diameter only one lock tuck has to be done, however 3 is recommended for increased security. Lines of 5/8” diameter to 1-5/16” diameter ( 4” circumference, 3 lock tucks should be done. See Step 4 for proper procedure on addtionnal locks. If your particular application will not allow locking proceed with Step 5, burying the tapered tail about 1-1/4 fid lengths starting at Mark 3.
76
4. Additional Locking:
Count down four (4) pairs of strands from point where tail comes out standing pair. This is about 1 diameter of the rope. Insert fid through the rope, centered between fourth and fifth pairs of strands (See figure) then pull tail through. Repeat Steps 3 and 4 two more times. Four passes of tail section will have been made through the standing part of the line. Be sure the line has no twists.
Figure 66. Additional Locking
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5. Bury Taper:
Measure about 1-1/4 tubular fid length ( 2-1/2 wire fid lengths), then create a Mark #4. Then count down four (4) pairs of strands from the standing part of the line from the last insertion. Insert the fid and tapered tail at this point, through the hollow of the rope, and bring the fid out at Mark #4. Pull fid and tapered tail out. Don’t let the line twist. Note: if no “locks” are to be used, Insert fid at Mark 3, then work a distance of 1-1/4 fid lengths through hollow of the rope, to bury tapered tail.
Figure 67. Bury Taper. Push fid through to Mark 4 and pull tapered tail through.
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6. Complete Taper: Remove fid. Remove tape from taper. Pull hard on tapered tail with one hand. (See insert 1 and 2). With other hand smooth bunched line away from eye splice. Be sure all tucks are tight and that there is no slack. Now, cut off tail at an angle close to the end of the standing part of line. Smooth cover once more, away from the eye to bury tail. With larger ropes it is easier to bury by tying a small line to eye and securing firmly to fixed object. Then, with both hands and weight of body, smooth cover slack to tighten locks and bury tail in standing part.
Figure 68. Complete Taper. Finished 3 Lock and 1 Lock Splice
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2 Fid Specifications
Table 28. Tubular Fid Specifications
Rope Circumference Rope Diameter Fid Short Section Length
Total Fid Length
3/4" 1/4 “ 2-1/16” 5-1/2” 1” 5/16 ” 2-1/2” 6-3/4”
1-1/8” 3/8 “ 2-7/8” 7-3/4” 1-1/4” 7/16 “ 3-9/16” 9-1/2” 1-1/2” 1/2 “ 4-1/8” 11” 1-3/4” 9/16 “ 3-5/8” 12-1/4”
2” 5/8 “ 4/1/8” 14” 2-1/4” 3/4 “ 4-3/4” 16” 2-3/4” 7/8 “ 4-3/4” 19”
3” 1 “ 5-1/4” 21”
Table 29. Wire Fid Specifications
Rope Circumference Rope Diameter Fid Short Section Length
Total Fid Length (L)
3/4" 1/4 “ 1” 2-3/4” 1” 5/16 ” 1-1/4” 3-3/8”
1-1/8” 3/8 “ 1-1/2” 3-7/8” 1-1/4” 7/16 “ 1-3/4” 4-3/4” 1-1/2” 1/2 “ 2” 5-1/2” 1-3/4” 9/16 “ 1-7/8” 6-1/8”
2” 5/8 “ 2” 7” 2-1/4” 3/4 “ 2” 8” 2-3/4” 7/8 “ 2-3/8” 9-1/2”
3” 1 “ 2-5/8” 10-1/2” 3-3/4” 1-1/4” 3-1/4” 13-1/4” 4-1/2” 1-1/2” 4” 16” 5-1/2” 1-3/4” 4-3/4” 19”
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3 End for End Splice
Figure 69. End for End Splice
TOOLS NEEDED: Electrical Tape, Marking Pen, Scissors, Fid and Tape Measure. Step 1: Lay two ends side by side and Mark #1 at one tubular Fid length (~22 times diameter of rope) from end of ropes. Mark #2 at two tubular fid lengths from end of ropes.
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Step 2: From Mark #1, working toward the end of the rope, mark every 4th pair of strands right and left lay 4 times.
Step 3: Start your taper by pulling out the marked strands. For the last 3 marked pairs, cut and remove every 4th left and right lay back to the end of the rope. If necessary, such as in larger diameter ropes, cut off excess on tail at an angle to give final tapered effect.
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Step 4: Take one end of the tapered rope, with fid attached, and then pass it through Mark 2 of the second rope. Count 3 pairs of strands and pass through again. Repeat a total of 3 times. Insert the tapered section directly through the hollow of the rope and pull until the full section that is tapered is buried in the body of the rope.
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Step 5: Take the end of the other rope and repeat Step 4 above.
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Step 6: Bury the ends and milk back on both ends to remove excess slack on crossover.
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