Thermite / Aluminothermic Welding SWMS
SWMS template for thermite / aluminothermic welding. Covers Cad-weld bonding for earthing, rail crossover.. 8-state AU coverage, CIH-reviewed editable DOCX, available as an instant download.
SWMS variants reference your state’s WHS legislation. Instant download after payment.
Thermite (aluminothermic) welding uses an exothermic reaction between aluminium powder and metal oxide to produce molten steel exceeding 2,500°C, used for rail joint welding, cathodic protection bonding, and earthing connections (Cad-weld). The reaction is violent, fast, and irreversible once ignited, generating molten metal ejection, intense radiant heat, metal fume, and ignition sources for surrounding combustibles. Under WHS Regulation 2011 r291, hot work involving risk of fire or explosion is classified as High Risk Construction Work, mandating a Safe Work Method Statement before work commences. The SWMS must address crucible preparation, mould alignment, ignition procedures, exclusion zones, fume capture, and emergency response for runaway reactions or mould failure. PCBUs failing to prepare, communicate, and enforce this SWMS expose workers to severe burns, respiratory injury, and ignition of surrounding assets including rail corridor vegetation or live substation equipment.
Hazards identified
7 hazards covered, sorted by priority.
Full-thickness burns to face, neck, and hands; permanent scarring; possible loss of sight from splash
Metal fume fever, chemical pneumonitis, and long-term respiratory sensitisation exceeding workplace exposure standards
Uncontrolled bushfire or asset fire; corridor closure, prosecution under Rural Fires Act and WHS legislation
Steam explosion ejecting molten metal up to 10 metres; catastrophic burns and projectile injury to crew
Thermal burns through standard cotton PPE, heat stress, and corneal flash burns without proper shade filter
Electric shock, arc flash, or damage to signalling and traction return systems requiring rail authority isolation
Musculoskeletal strain, slip injuries, and delayed evacuation in event of mould failure or fire
Control measures
Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.
- 1Elimination — Where feasible, specify exothermic cable connectors or mechanical compression joints in design to eliminate molten metal process entirely from earthing scopes.
- 2Elimination — Schedule thermite work outside Total Fire Ban days and high wind periods to eliminate uncontrolled ignition pathways in rail and bushland corridors.
- 3Substitution — Substitute traditional magnesium starter powder with electronic spark igniters where manufacturer permits, reducing premature ignition and flare-up risk to the operator.
- 4Substitution — Use single-shot pre-packaged cartridges in sealed moisture-proof sachets rather than bulk powder decanting to substitute lower-risk handling format.
- 5Engineering — Pre-heat graphite moulds with oxy-LPG torch to 150°C minimum to drive off moisture before charging, eliminating steam explosion mechanism per manufacturer IFU.
- 6Engineering — Establish 6-metre combustible-free exclusion zone with fire blankets, wet-down of vegetation, and dedicated 9kg dry powder extinguisher plus charged hose within arm's reach.
- 7Administrative — Issue rail authority Track Possession or Electrical Access Permit and isolate traction return before welding to bonded conductors; verify dead with approved tester.
- 8Administrative — Pre-start brief crew on this SWMS, confirm crucible condition, mould part-number match, and nominate spotter for fire watch 60 minutes post-tap.
- 9PPE — Aluminised reaction jacket and leggings to AS/NZS 4501.2, leather gauntlets, shade 5 goggles under face shield, and P2 respirator with metal fume cartridge.
- 10PPE — Steel-cap boots with metatarsal guard and natural-fibre underlayer; no synthetics that melt onto skin during molten metal splash event.
Applicable Codes of Practice
Sets specific duties for hot work fire prevention, fume control, and PPE selection directly applicable to aluminothermic processes.
Mandates hot work permit, combustible removal within 11m, and fire watch duration of 60 minutes post-completion for thermite tasks.
Governs P2/P3 respirator selection for metal oxide fume exposure during reaction and mould break-out generating airborne particulates.
Triggers heat stress assessment and provision of shaded rest, hydration, and rotation when working in PPE during summer rail corridor work.
High-Risk Construction Work triggered
The 2,500°C exothermic reaction and pre-heat torch create localised artificial heat extremes around the welder requiring documented thermal control measures.
Cad-weld bonding to substation earth grids, cathodic protection, and traction return rails involves working on or adjacent to energised conductors requiring isolation verification.
PCBUs must prepare, consult workers on, and retain this SWMS for 2 years (or duration of incident investigation). Penalties for non-compliance are substantial and indexed; current maximum follows the prevailing WHS schedule.
Who this is for
- →Rail welding contractors on heavy and light rail networks
- →Electrical contractors installing earthing and cathodic protection systems
- →Substation construction crews bonding earth grids and risers
- →Telecommunications tower riggers installing exothermic earth bonds
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 regional rail upgrade, a two-person welding crew is scheduled to install eight Cad-weld bonds connecting impedance bond cables to running rail during a four-hour Sunday possession. At the pre-start brief in the rail compound, the leading hand opens this SWMS on a tablet and walks the offsider through each hazard line by line. They identify that the day's forecast is 32°C with gusty westerly winds — the SWMS exclusion-zone control prompts them to wet down ballast and surrounding grass for six metres around each weld location and to confirm the Total Fire Ban status with the rail protection officer. The offsider sights the aluminised jackets, shade 5 goggles, and P2 fume respirators against the PPE checklist and signs on. During the third weld, the leading hand notices the graphite mould has a hairline crack from the previous shot; the SWMS mould-integrity control requires immediate rejection, so they swap to a spare mould before charging. After tap, the offsider commences the 60-minute fire watch documented on the back of the SWMS, with the dry powder extinguisher staged within arm's reach. The signed SWMS is returned to the site office and retained on the project HSE register.
Related legislation
- WHS Act 2011 (model)
- WHS Regulation 2025
- Code of Practice — Hazardous Manual Tasks