arctic dredging - past, present and future r1€¦ · monitoring: satellite, heli recce, ......
TRANSCRIPT
Arctic Dredging ‐ Past, Challenges and Future
Agenda
• Introduction• Past
Challenges Developments
2Aquarius Oranje
Past – Historic projects
• Beaufort Sea, Cutters, Hoppers, Trenching• Pipe laying studies• Newfoundland, Glory holes• Russia, river maintenance• Sakhalin shore approaches, sea bed preparation
• Caspian, island – port construction
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Gogland, L1 summer broken ice
Beaufort Hoppers
• Vessels by Boka, Volker, Zanen,
• Issues• Season• Performance
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Sailing and Dredging in ice6
Dragram and wires in ice
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Bun building
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Ice Management
Issues• Class and season (extension)
– July / end Oct– Preparations start Mar, min 40C– Break up: floe ice incl MY ice – Continue: to abt 10cm ice– No open water 1 in 10 yrs
• Uptime, safe speed in ice (Numeral)
• Icebreaker Support; Alerting• Technical; equipment; • Winterization• Crew; other
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Class Notation
Season, Beaufort Experience
• Effective operating days 85%– Limited due to limited icebreaking power– Limited due to safety constraints by hull loads
• Effective sailing speed, worst yr 70%– Circumnavigate dangerous ice– Lack of power in new ice– Reduced speed in transit
• No downtime due to arms‐wires in ice• Ice thickness limit 10/20 cm new ice
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Operating Season HoppersBeaufort Sea
• Class CASPPR Proposed• Class D, E 112 120• Class A 148 130• Class 2 173 140• Class 4 245 175• Class 6 All year 240
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Beaufort Conditions, NRC CHC TR 57
• Wave height Kopanoar
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Beaufort % of ice coverAug 13, 1980‐2012
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Sea ice chart, Aug 24, 2009
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FMI Thickness and Drift Chart
PerformanceOperational limits
Thickness in m
Speed in kt.More IM, Higher Class, Lower concentration
Hopper Dredge Design• No ice class• Stationary craft with subm fairleads
• Sufficient freeboard• Bow reinforced
• Ice class• Shell strengthened• Increased Midship Section
• Dragarm and wire protection
• More power• Shelter• Ductile materials
Superdredge
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Class 6, 25000 m3
Arctic hopper dredgers, OMAE 1994
Performance ratings
Unit Cost, 20% lower for Class 6
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Pipelaying and trenchingDesign requirements
Vessels Stationary Mobile
Summer Large Hull Bow strengtheningLarge freeboard Hoist wire protectionEnviro protection Good maneuverability
Winter Strong winches, wires Wire protectionUnderwater fairleads Wire reinforcementLocal strength Propulsion powerShelter Local strength
Shelter
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Trenching season limitations
• Summer storms effect surface trenchers25% downtime
• Hopper dredge production loss < 10%• Ice floes in summer• Thickness of first year ice• Drift and speed of ice • Season length
– Summer start <2/10th ice– Summer end < 15 cm ice
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Healy Rock dredging, Alaska Aug 2009
Surface trenchers progress rates
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Ice effects operations through:
• Station keeping / mooring in ice• Wire exposure• Pipeline stinger exposure• Trenching may become critical in comparison to a possible layrate
• Ice management• Ice alerts, ice monitoring
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Caspian Sea, Kashagan Field ‐ D Island
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8 cofferdams
Ice ride up Ice in port
Monitoring: Satellite, Heli recce, IT06
Alerting, AKAC Inc IT’06
Ice Monitoring Developments1. New/more Satellites: more, quicker, cheaper?2. Enhance
a. ice drift monitoring toolsb. ice forecasting toolc. identification of different ice types
3. Provide high resolution localized ice charts 4. Enhance understanding of types & kinds of ice conditions
Ice Parameters of InterestTimco 2007
Dutch “ice”developments
• Arctic Operating Handbook, MIP– Determine Operations gaps– Icing, season, environmental severity, rules, uptime, safety, risks, human capital
– Prepare suggestions for new Operating Guidelines for submission to ISO
• MIIP projects (Maritieme Innovatie Impuls Projecten)
– Remote Sensing in arctic waters– Dredging and trenching in arctic waters– Others
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Future developments
• Baffin Bay• Barents Sea• Bay of Baydaradskaya• Beaufort & Chukchi Sea• Kara Sea• Sea of Okhotsk
• Concepts• Cost• Feasibility • Knowledge and tools• Seasons and durations• Systems• Support and logistics• Uptime
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Challenges
Beaufort: 2012/27 for DIAND, LTLC April’12
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• Conoco Phillips 3 yr study– Evaluate commercial development of Amauligak– Develop concepts, GBS, Floater, Transport, Soils, scouring, environment, construction
Questions ?
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