Dredging Operations SWMS
Cutter suction and trailing suction hopper dredge operations. Drowning risk, confined space in trunnion bearings, contaminated sediment handling, dredge cycle navigation.
SWMS variants reference your state’s WHS legislation. Instant download after payment.
Dredging operations using cutter suction dredges (CSD) and trailing suction hopper dredges (TSHD) involve simultaneous high-risk activities: powered mobile plant operation over water, confined space entry into trunnion bearings and spud wells, handling of potentially contaminated sediment, and continuous navigation in active port and waterway environments. Workers face drowning, entanglement in cutter heads and suction lines, exposure to hydrogen sulphide from anoxic sediments, and crush injuries from swinging spuds and anchor wires. Under WHS Regulation 2025 a Safe Work Method Statement is mandatory because the work triggers multiple Schedule 1 high-risk construction work categories — work on or near water with a drowning risk, diving work for inspections and clearances, and operation of powered mobile plant. The Marine Safety (Domestic Commercial Vessel) National Law Act 2012 and AMSA Marine Orders impose parallel duties on the vessel master that must be integrated with land-based PCBU obligations. This SWMS aligns dredge crew, dive teams, survey personnel, and shore-based supervisors to a single documented control framework.
Hazards identified
7 hazards covered, sorted by priority.
Fatal cold-water immersion or secondary drowning; coronial inquest and Category 1 PCBU prosecution under WHS Act s31
Oxygen depletion or H2S toxicity causing rapid unconsciousness and death; multiple-fatality rescuer entrapment events
Catastrophic limb amputation, dive umbilical severance, fatal drowning; permanent disability and lifetime workers compensation liability
Acute respiratory failure, chemical pneumonitis, loss of consciousness; chronic neurological injury from repeat sub-acute exposure
Vessel sinking, multiple fatalities, major marine pollution incident; AMSA prosecution and loss of operator certificate of competency
Dermal absorption, ingestion and chronic toxicity; long-latency cancer claims and contaminated land regulator enforcement
Blunt force trauma, traumatic amputation, fatal impact; AS 2759 wire rope failure investigation and plant prohibition notice
Control measures
Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.
- 1Elimination — Use remotely operated vehicle (ROV) survey and side-scan sonar instead of diver inspection wherever channel clearance can be verified without in-water personnel deployment.
- 2Elimination — Schedule cutter head clearance and pipeline reconnection during full plant isolation and lockout to remove rotating-machinery exposure entirely from the task.
- 3Substitution — Replace mechanical confined space entry into trunnion bearings with sealed grease-port monitoring and borescope inspection through engineered access ports.
- 4Engineering — Install permanent guardrails, toe boards and self-closing gates to AS 1657 around spud wells, gantries and overflow weirs; fit man-overboard recovery davits port and starboard.
- 5Engineering — Continuous fixed gas detection (O2, H2S, LEL, CO) in hopper, engine room and trunnion voids per AS/NZS 60079.29.2 with bridge-annunciated alarms at 10 ppm H2S.
- 6Engineering — Dredge cutter and pump interlock prevents start-up unless dive supervisor key-switch and bridge confirmation are both engaged, complying with AS/NZS 4024.1601 isolation principles.
- 7Administrative — Pre-start brief signs workers onto this SWMS, confirms AMSA-compliant passage plan, VHF Ch 16/13 watch, and tidal window per Marine Order 504.
- 8Administrative — Dive operations conducted under AS/NZS 2299.1 with dedicated standby diver, two-way comms, and surface-supplied breathing air; no SCUBA inside 30 m of operating cutter.
- 9Administrative — Sediment sampling SDS reviewed before each new dredge cell; contaminated spoil handled under EPL conditions with decontamination station rigged at deck access.
- 10PPE — Auto-inflating PFD Level 150 to AS 4758, cut-five gloves, steel-cap sea boots, hi-vis foul-weather gear, and half-face APR with ABEK1-P3 cartridges when H2S above 5 ppm.
Applicable Codes of Practice
Mandates dive supervisor competency, standby diver, emergency procedures and equipment for any in-water inspection or clearance work conducted from the dredge.
Requires entry permit, atmospheric testing, stand-by person and rescue plan for trunnion bearing, hopper and spud well entries during maintenance shifts.
Governs master and crew competency, safe manning, navigation watch and passage planning for the dredge as a Domestic Commercial Vessel under the National Law.
Specifies PFD performance levels for deck work over water and fall-arrest equipment for elevated gantry, ladder and A-frame inspection tasks.
High-Risk Construction Work triggered
All deck, spud, anchor handling and overflow weir tasks occur over open water with realistic fall-overboard and entrapment-drowning exposure throughout the dredge cycle.
Periodic cutter head clearance, suction inlet inspection and propeller fouling removal require occupational diving conducted under AS/NZS 2299.1 surface-supplied protocols.
Dredge swing patterns cross active commercial shipping lanes and port approaches, with continuous interaction between dredge plant and transiting vessels.
PCBU must consult workers, notify the regulator of HRCW, and retain the signed SWMS for two years (or until incident investigation closes); penalties are substantial and indexed annually under the prevailing WHS schedule.
Who this is for
- →Dredge masters and engineers on CSD and TSHD vessels
- →Marine contractors delivering port deepening and capital works
- →Commercial dive supervisors supporting dredge clearance operations
- →Port authority project managers and harbour master delegates
What you receive
- ✓Editable DOCX template — Microsoft Word compatible
- ✓State-specific WHS legislation schedule (NSW/VIC/QLD/SA/WA/TAS/NT/ACT)
- ✓Hazard register with risk ratings + hierarchy-of-control mapping
- ✓Worker sign-on register, pre-start checklist, and incident escalation flow
Worked example
On a capital deepening project at a regional bulk export berth, the dredge master convenes the 0600 pre-start brief on the CSD's bridge wing. The deck crew, two divers, the standby diver, the survey tech and the engineer sign onto this SWMS on a ruggedised tablet after the master walks through the day's task: relocating the spuds, clearing a steel cable reported fouled on the cutter head, then resuming production on cell B4. Working down the hazard register, the dive supervisor flags hazard 3 (cutter entanglement) and confirms the engineering control — bridge-and-dive-supervisor dual key isolation — will be tested before the diver enters the water. The engineer notes overnight H2S readings spiked to 8 ppm in the hopper from the previous cell's anoxic mud, so the administrative control on respiratory protection is escalated and ABEK1-P3 cartridges are issued. During the dive, comms degrade briefly; the standby diver dresses in immediately per the AS/NZS 2299.1 procedure referenced in the SWMS, and the supervisor pauses the task. The SWMS is annotated in the field with the deviation, re-signed by affected workers, and uploaded to the project's compliance register before work resumes — demonstrating the document functioning as a live control instrument, not a shelf artefact.
Related legislation
- WHS Act 2011 (model)
- WHS Regulation 2025
- AS 2550 — Cranes, hoists and winches; AS 1418 series