Dredging 101 Why, Who, How and So What! 2015 WAMSI Research Conference 30 March 2015
Presentation Contents Quick Oversight on Why we need to Dredge and Who Carries it out Global Context of some of our Projects How Dredges work and their Turbidity Generating Sources
Things Have Changed (improved?) Drilling Rock by hand ready for blasting, Swan River Mouth, now Fremantle Inner Harbour
Why? ~30% GDP for Australia generated via seaborne trade 1 Shipping Channels, like roads, need to be maintained and improved Dredging of shipping channels, for maintenance and capital deepening is necessary Dredging also required for other maritime development activities References: 1 Ports Australia, April 2014 Dredging and Australian Ports
Global Shipping Fleet is Growing in Size Sourced from Ports Australia
Who? A number of domestic players, generally with smaller sized equipment suited to minor capital and maintenance dredging projects Only five key International Companies who have recent track record to directly execute projects in Australia under our contracting, HSE and IR conditions o A couple of companies have completed works as part of a JV or sub contract For large projects proponents are competing globally for a limited fleet of equipment we generally can t pick and choose
International Trailer Suction Hopper Dredge Fleet 300 250 Global Fleet Potentially Available to Australian Market 200 150 100 50 0 0-4999 5000-9999 10000-14999 15000-19999 20000-24999 25000-29999 30000-34999 35000-39999 45000-49999 Hopper Capacity (m 3 )
International Cutter Suction Dredge Fleet 140 120 100 Global CSD Fleet Potentially Available to Australia 80 60 40 20 0 Total Installed kw
So What? Recent Large Capital Dredging Projects-Australia Location Volume Dredged Duration Ichthys (NT) 16Mm3 ~14months Ichthys (NT) 16 Mm 3 14 months Gladstone (Qld) 25Mm3 Gladstone (Qld) 36 Mm 3 28 months Gorgon (WA) 8Mm3 Gorgon (WA) 8 Mm 3 6 months Wheatstone 25Mm3 Wheatstone (WA) 25 Mm 3 25 months Port Hedland (south west creek) (WA) 14 Mm 3 12 months Totals ~100Mm 3 ~85 months (100 Subiaco Football Stadiums)
Recent Capital Projects and Scale - Global Suez Canal Channel Duplication: 230Mm 3 of Dredging over 50km of Channel 17 Cutter Suction Dredges and 2 Trailer Suction Hopper Dredges Contract Signed October 2014, started soon after and to be completed by August 2015 (i.e. <10 months)! Panama Canal Expansion 1 ~ 60Mm 3 of Dredging and excavation on the Atlantic, Pacific Entrances and Gatun Lake References: 1 http://micanaldepanama.com/expansion/faq/
How - Types of dredgers Hydraulic (slurry formed to transport material) Mechanical (near insitu density removal) Cutter Suction Dredge Trailer Suction Hopper Dredge Water Injection Dredge Backhoe Dredge Grab/Clamshell Dredge Dipper Dredge Bucket Ladder Dredge Suction Dredge
CSD Typical Features Deck Crane Bridge Side Anchors Working/ Travelling Spud Fixed Spud Slurry Pumps + Pipework Suction Mouth Ladder Cutter Head Source: IADC Dredging for Development, 2010 https://www.iadc-dredging.com/
Cutter Suction Dredges Small and Large
Ground anchors Delta flippers (sand) Bruce Danforth Stevin Stevsharks (rock)
Gravity anchors Box anchors Concrete block Tripod platform?
Placement anchor booms
Cutting Teeth Before, and After
Blade Tooth Adaptor
Reclamation Areas In Theory
Reclamation Area In Practice Dredge Material Discharge Point Dredge and Pipeline Internal Bund Tailwater Discharge Point External Bund
Weir Boxes
Reclamation Area Lined
Trailer Suction Hopper Dredge
Bridge and Accommodation Draghead Suction Pipe Hopper Pump Ashore Connection
TSHD Dredging Cycle Hopper Overflow Losses Propellor Wash Draghead DREDGING SAILING LOADED TO DISPOSAL SITE Propellor Wash Propellor Wash SAILING EMPTY TO RECOMMENCE DREDGING DUMPING MATERIAL/ PUMPING ASHORE Fines Stripping from Dumped Material Fines within Tailwater Discharge Propellor Wash
Bridge Operations
Turbidity Hopper Overflow during dredging
TSHD - Draghead
Turtle Exclusion Chains
Loaded and Travelling to Disposal Site
TSHD Bottom Dumping via Split Hopper
TSHD Bottom Dumping via Doors
Plume Generation Bottom Dumping
Beach Renourishment Pumping Out
Backhoe and Grab Dredges
Backhoe Dredge
Backhoe Dredge
Online Resources PIANC - http://pianc.org.au/, www.pianc.org CEDA (Central Dredging Association) - www.dredging.org/ IADC (International Association of Dredging Companies) www.iadc-dredging.com/en/74/dredging/ US Army Corp of Engineers - http://el.erdc.usace.army.mil/dots/ IHC Dredging - www.ihcmerwede.com/dredging/