Marine Engine / Vessel Servicing SWMS

Marine engine and vessel servicing covers maintenance, fault diagnosis, repair and recommissioning of inboard and outboard propulsion systems, fuel lines, cooling circuits, starter batteries and associated electrical wiring on commercial and recreational vessels berthed at wharves, slipways or hardstands. The work routinely combines confined engine bay entry, hot work near residual fuel vapour, energised 12/24 V DC and 240 V AC shore power systems, and physical risks from suspended drive components. Under WHS Regulation 2011 r291 (and corresponding 2025 amendments), this scope satisfies multiple High Risk Construction Work triggers — confined space entry, work involving energised electrical installations, and work where there is a risk of drowning from falls into water more than 300 mm deep. A documented SWMS is therefore mandatory before work commences, must be developed in consultation with workers under s47, retained for the duration of the task, and produced on request to the regulator or principal contractor.

Hazards identified

7 hazards covered, sorted by priority.

Control measures

Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.

1. 1Elimination — Remove outboard from transom and transfer engine to dedicated workshop bench where confined bay entry, fall-to-water and shore-power exposure are eliminated entirely.
2. 2Elimination — Drain and purge fuel system to atmosphere using grounded transfer pump before any hot work, eliminating residual vapour ignition risk in the engine bay.
3. 3Substitution — Substitute solvent-based degreasers with low-VOC aqueous cleaners (per AS/NZS 60079.10.1 zoning) to reduce flammable atmosphere generation during servicing.
4. 4Substitution — Use battery-powered cordless diagnostic tooling in place of 240 V AC corded equipment to remove shore-power lead and trip hazards across the wharf interface.
5. 5Engineering — Install forced mechanical ventilation (minimum 20 air changes/hour) and continuous LEL/O2/CO monitoring in the engine bay per AS 2865 confined space requirements before entry.
6. 6Engineering — Lock out and tag out battery isolator, fuel shutoff valve and shore power inlet using individual padlocks per AS/NZS 4836 prior to any intrusive work.
7. 7Administrative — Issue confined space entry permit, hot work permit and pre-start atmospheric test record signed by competent person; brief all workers via this SWMS at pre-start.
8. 8Administrative — Maintain dedicated standby attendant in radio contact with entrant, rescue plan rehearsed, and emergency services notified of vessel berth location and access route.
9. 9PPE — Inherently flame-resistant coveralls (AS/NZS 4824), Type 1 self-inflating PFD (AS 4758.1), Class 0 electrical gloves, safety glasses with side shields, and steel-cap marine boots.
10. 10PPE — Half-face respirator with A1P2 cartridges (AS/NZS 1716) when handling fuel, solvents or coolant aerosols, replaced per manufacturer schedule and stored sealed between uses.

Applicable Codes of Practice

High-Risk Construction Work triggered

Worked example

At a regional commercial wharf, a two-person marine mechanic crew is tasked with replacing a leaking high-pressure fuel rail on a 6.7 L inboard diesel aboard a 12 m workboat berthed alongside. At the 0700 pre-start, the lead mechanic walks the apprentice through this SWMS on the wharf, page by page. They identify three controlling hazards for the shift: confined engine bay entry, residual diesel vapour during the rail removal, and the 1.8 m fall to water between hull and pile. Controls selected are mechanical ventilation set up before entry, continuous LEL/O2 monitoring clipped at the entrant's collar, a standby attendant positioned at the engine hatch with radio, padlocked isolation of battery and fuel shutoff, and Type 1 PFDs worn throughout boarding. Both workers sign the SWMS sign-on sheet and the confined space permit. Mid-task the LEL monitor alarms at 8% LEL when the rail is cracked open — work stops immediately per the SWMS stop-work trigger, ventilation is increased, and a vapour catch tray is added. The SWMS is annotated with this change, both workers re-sign acknowledging the revised control, and work resumes only once readings return below 5% LEL for ten continuous minutes. The completed SWMS is filed with the principal contractor that afternoon.

Related legislation

• WHS Act 2011 (model)
• WHS Regulation 2025
• AS/NZS 3000 — Electrical installations

Frequently asked questions