Underkeel Clearance Management Systems. Captain Jonathon Pearce Senior Pilotage Advisor

Transcription

1 Underkeel Clearance Management Systems Captain Jonathon Pearce Senior Pilotage Advisor

2 Underkeel Clearance Risk Management (UKCM) The management of the touch bottom or grounding hazard Risk = Frequency * Consequence Frequency is low/rare and in region of 3x10-5 (one in movements) Consequence can be Catastrophic Effective Management required

3 Sea Empress 1996 Sea Empress resulted in a total financial cost of 52m - 109m and similar environmental costs.

4 Iron King Port Hedland 1 August 2008 Port Hedland, was facing a loss of US$ 40 million for each tide that the channel remained closed when the Iron King grounded. Pictures by Mike Cummings

5 mv Rena 5 October 2011 NZ

6 Navigation in the Vertical Dimension

7 Static Underkeel Allowances measured waves PREDICTED TIDE DRAFT DATUM X % OF DRAFT X MUST ACCOUNT FOR measured tide and currents - WAVE RESPONSE - CHANGES IN TIDAL RESIDUAL - SQUAT DEPTH - SAFETY ALLOWANCES measured wind and pressure latest sounded depths 8 astronomical tides ship in given load state ship speed envelopes

8 Static Rule History

9 Static Rule A Top Down Approach VARIABLE RISK Nett Clearance changes for every transit Is it Safe, Marginal or Unsafe? Static Allowance Tidal Residual Squat Heel Wave Response/Setdown Nett Clearance?

10 Static Rule Compromise Optimism v Conservatism Too Too optimistic conservative - Safety - Less jeopardised cargo Static Rules are: Blunt compromise between economics and safety; Nett clearances change from day to day, ship to ship and even transit to transit!

11 Safety Case Study Marsden Point, NZ Capella Voyager 16 April 2003 Eastern Honor 27 July 2003

12 Marsden Vessel Analysis Under most conditions a static rule will be conservative However, groundings can occur when a ship is sensitive to the prevailing conditions (this is actual data!) Don t be complacent about your existing rules!

13 Static Rule Questions 1.Are existing rules adequate and justifiable? 2.Are all the factors that contribute to the static rule understood? 3.Does no incidents mean the rule is reliable? 4.Are there times when the rule may have been unsafe/marginal? 5. Are primary factors calculated and conveyed to the Master?

14 Dynamic UKC Methodology measured waves measured tide & currents measured wind & pressure latest sounded depths 8 astronomical tides ship in given load state ship speed envelopes

15 Underkeel Clearance Limits DUKCM limits in accordance with PIANC Guidelines Bottom Clearance Bottom touch due to vessel motions Manoeuvrability Margin Inability to manoeuvre

16 MM & BC BC Limit 25cms Manoeuvrability Safety Limit 90cms BC Limit 25cms BC Limit 25cms

17 DUKC - System Inputs/Outputs

18 High-resolution bathymetry grid

19 Bathy Nodes DUKC Bathymetry Nodes

20 Channel Segment Channel Boundary Channel Section 300m to channel boundary 100m segment 15.7m Max 14.8m BC Declared Depth MM 15.0m for 300m x 100m section Scale exaggerated by 25x for emphasis

21 Hydrodynamic model Water level and currents within Prince of Wales Channel predictable Predictions use water levels at Goods Island and Ince Point

22 Complex tidal regimes Recorded water level across Prince of Wales Channel 15/16 May 2007 booby goods hammond nardana ince Water level relative to AHD [m] :00 18:00 00:00 06:00 12:00

23 Tidal Residuals Positive Residual Negative Residual Predictions Measurements

24 Residual Analysis - Lagged tides

25 Vancouver Example - 2 nd Narrows Tide; Current; Air Draft

26 Squat

27 Squat Low pressure caused by return flow creates a local depression in the water surface Vessel must sink with depression and may change trim to balance its weight

28 Which formulae? tmax CB B F Co t lpp 1 F S 2.4 l 2 nh F 2 nh 2 nh 2 2 pp 1 F nh K 0.27 T nh 1.08 / 2.75 SbE B F h T h s S C C K T br v F T S C K T sr v T S b Ho t 3 S ( Frh ) where F L F rh 2 nh 2 2 pp 1 F nh V s gh nh Sb 0.01L M 2 pp Cb L pp / T 1 F S b H L F F 2 nh 2 2 pp 1 F nh 2 2 nh K s 1 T S V C D 95 h 2 b k b S T Cb Vs. 45 h 3 2 V As S 2.20 S2 Cb where S2 g A A 1 C 1 C V SbJ h T Lpp B h T Lpp B g Note : L B R and h T R pp LB ht 3 2 b b s c s

29 Squat Channel Blockage

30 Squat Case Study Port of Lisbon

31 Actual Squat Example - Maximum Modelled Speed - Measured Speed - Measured Squat - Maximum Modelled Squat

32 Heel

33 Wave Response

34 Vessel Sensitivity Wave Energy (m 2 /Hz) Differing Wave Response 4 Formosa Fifteen 26 March 2009 Lbp 165m Beam 32.2m Draft 11.5m (Torm Gudrun Lbp 234m Beam 42m Draft 12.5m, Corona Majesty Lbp 220m Beam 38m Draft 13.8m) DUKC Predicted SA Roll: Formosa Trader [6.1] degs, WRA [2.2]m [8.7] degs, WRA [3.1]m Corona Maj [3.6] degs, WRA [1.7]m [5.2] degs, WRA - 1.8m [2.3]m Torm Gudrun [1.8] degs, WRA [0.9]m [2.9] degs, WRA [1.8]m % Exc Tom Gudrun Corona Maj Formosa Fifteen Sea Swell Period (s) 0

35 Wave Response Calculation Offshore Swell height = 2m, period = 14 seconds 2.4m EBB 1.2m PostPanamax Swell (2.8m Hm0) Handymax Tidal Current (5.0kn) 0.9m FLOOD 2.8m Swell (1.7m Hm0) Tidal Current (3.0kn)

36 DUKC A Bottom Up Methodology CONSTANT RISK Minimum Clearance maintained for every transit Always Safe! Required Water Depth Wave Response/Setdown Heel Squat Tidal Residual Minimum Clearance (Predetermined Limit)

37 UKC Safety Case Study Port Taranaki

38 Benefit Case Study - Port Taranaki

39 Benefit Case Study - Port Taranaki Orange Area DUKC Tidal Window Blue Area Static Tidal Window Static Rules not Sufficient in High Swell Conditions

40 Case Study Torres Strait AMSA Under Keel Clearance Management System

41 Operational Area Torres Strait

42 Stakeholders Involvement

43 Met Ocean Display

44 Met Ocean Display

45 Voyage Planning

46 Transit Planning

47 Transit Planning Report

48 Transit Overview

49 Detailed Graphs

50 Operating Envelopes/Gates

51 Outputs and Reports

52 Transit Monitoring

53 Benefits : Pilots - Port Enhanced decision making Improved Master/Pilot Information Exchange Contingency planning Increased transit plan accuracy Optimised safe speed profiling Removes commercial pressure from the Pilot - the hardest decision for a pilot to make is to say NO! Port: Improves Safety Increases Economic Benefits Greater Operating Flexibility

54 Full Scale Vessel Motion Analyses (FSVMA) Purpose: Determine accuracy of DUKC modelling. Calibrate DUKC models. Outcome: Has ensured the safety of over 80,000 DUKC transits Worldwide (in operational use every 1.5 hrs)

55 Full Scale Measurements Measurements at 30 different ports Over 280 vessels: Containers, Bulk Carriers, Tankers Swell ports, Rivers, Bars, Channels, Open Water Vancouver Columbia River

56 Measuring Dynamic Motions

57 Squat Validation

58 Predicted Significant Roll

59 Predicted Significant Pitch

60 iheave Severe conditions can make FSVMA hazardous or impractical

61 iheave Solid-state accelerometers & gyroscopes IMU Specification Pitch & roll to 0.03 degrees Heave to 0.05 meters (or 5%)

62 UKC developments POADSS Port Operational Approach and Decision Support System European Research Project MarNIS

63 What is POADSS? (Port Operational Approach and Decision Support System) POADSS Next generation Portable Pilot Unit (PPU) Real-time position via laptop, charting software and GPS. DGPS, (also RTK corrections) AIS feeds Includes: 3D position information IMU integration measured heave, roll and pitch motions Broadband connection real-time data, such as tide, weather, traffic, WMS Up-to-date HD bathymetric data Dynamic Underkeel Clearance (DUKC) Prototype developed and tested (2008) ADX XR 1 st POADSS type PPU 2011

64 POADSS Architecture

65 Real-time Transit Planning

66 Real-time Dynamic Motions

67 Dynamic Tide Contours

68 14.7m Vessel 12k Area 1

69 14.7m Vessel 14k Area 1

70 14.7m Vessel 16k Area 1

71 14.7m Vessel 12k Area 2 High waves / Low waves

72 14.7m Vessel 14k Area 2 High waves / Low waves

73 14.7m Vessel 16k Area 2 High waves / Low waves

74 What If High Waves... High waves / Low waves

75 What If Low Waves... High waves / Low waves

76 Additional Applications with DUKC Dredge Optimisation Optimised bed depth based on DUKC simulation Thousands of simulations provide thousands of optimised bed depths

77 VOLUME OF DREDGING SAVED Different requirements result in different optimised depths. 1. Access for 14.5 metre draft tankers on 95% of high waters. 2. Access for all inbound vessels on 90% of occasions regardless of tide. 3. Minimum requirement of 4 hour operating windows for container vessels in winter.

78 Who is OMC International? Inventor and sole supplier of DUKC 17 years in operation with over 80,000 safe transits Installed at 21 Australian, NZ and EU ports OMC is the approved supplier to AMSA for the Torres Strait UKCM system

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