Why Australian marine manufacturing HVAC is the most multi-disciplinary brief in the country
Australian shipbuilding, yacht manufacturing and cruise-refit work sits in a stretched supply chain across five geographic clusters and at least eight distinct facility types. From the Australian Marine Complex (AMC) at Henderson Western Australia — where Civmec ASX:CVL builds Arafura-class Offshore Patrol Vessels in partnership with Luerssen Australia, BAE Systems Australia builds Hunter-class Type 26 frigate hull modules, and the wider Henderson Alliance shipbuilders forum coordinates the Indian Ocean shipbuilding industrial base — through to the Osborne Naval Shipyard in South Australia, where ASC Pty Ltd sustains the Collins-class submarine fleet and is the build-yard for the future SSN-AUKUS submarine program; from the Williamstown VIC historic shipyard at BAE Systems Australia Maritime, through to the Coomera QLD luxury motor yacht cluster where Riviera Australia builds 60-to-80-foot pleasure cruisers as the biggest luxury motor yacht builder in the Southern Hemisphere and Maritimo (the Bill Barry-Cotter yard) builds 50-to-100-foot luxury motor yachts; from the Newcastle NSW catamaran kit yards at Schionning Designs, through to the cruise-refit ports of Sydney White Bay, the Australian Marine Complex Henderson WA, Wallaroo SA and Hobart Tasmania.
No two facilities run the same HVAC brief. A composite layup hall at Riviera Coomera handles styrene-monomer-bearing polyester resin with MEKP catalyst and is bound by the 50 ppm styrene Safe Work Australia exposure standard. A welding hall at Civmec Henderson on Arafura-class OPV hull modules handles MIG, MAG, TIG, submerged-arc, stick and flux-cored arc welding on stainless and duplex grades and is bound by the 0.005 mg/m³ hex chrome Cr(VI) exposure standard — a hundred-fold tighter than the general welding fume limit. A marine paint booth at the AMC Henderson applies Awlgrip and International Paint polyurethane topcoats over Hempel and Sigmacoat epoxy primer systems and is bound by the 0.005 ppm STEL isocyanate exposure standard. A diesel engine test cell at the Yanmar Australia Brisbane facility commissioning Yanmar marine diesels handles 450 to 600 degree Celsius exhaust on sea-level static runs. A galley fit-out shed for the cruise sector pre-assembles commercial kitchens to NFPA 96 grease-extract standard before installation on the vessel. Each is a separate engineering problem and they cannot share extract paths or filtration trains.
The duct material decision is settled before the first calculation is finished. SBKJ engineers default to 316L stainless steel (UNS S31603) at 0.7 to 1.5 mm gauge for all outdoor, semi-outdoor and make-up air exposed duct on every Australian shipyard, marine cluster and cruise-refit port we service. Marine aluminium 5052 or 5251 is the alternative where weight reduction or galvanic compatibility with aluminium hull structure is the dominant constraint — typical at the production yacht yards where the aluminium-hulled catamaran sheds run on a different material than the steel-hulled motor yacht halls next door. Hot-dip galvanised G275 carbon steel is permitted only inside a fully conditioned envelope held at positive pressure that demonstrably excludes salt aerosol.
The second dimension is the standards stack overlay: a naval shipbuilding facility runs AS 1668.2, AS 4254 and AS 1530.4 as civilian baseline; AS 1554.1, AS 1554.6 and AS 1554.7 for steel, stainless and aluminium welding QA; AS 1796 and AS 2980 for welder qualification; AS 4458, AS 4037 and AS 1210 for pressure equipment including autoclaves and hydrostatic test compartments; AS/NZS 60079 for hazardous-area zoning around LPG, welding gas, paint solvent, composite styrene and fuel handling; AS 1940 for flammable liquid storage; AS 4114 with NFPA 33 for spray booths; AS 3957 with NFPA 660 for dust including aluminium and composite carbon-fibre; AS 9100 and ISO 3834-2 for welding QMS on naval prime contracting; AMSA, IMO MARPOL Annex VI and SOLAS Chapter II-2 for the maritime authority overlay; and the IACS classification societies (Lloyd's Register, DNV, Bureau Veritas, ABS, NK, RINA) for type approval where the duct is fabricated as shipboard equipment. Every standard in that stack has an HVAC duct implication and the engineering documentation has to map cleanly onto all of them at once.
The third dimension is the AUKUS pivot and the broader naval shipbuilding industrial expansion. The Hunter Class Type 26 frigate program covers 9 vessels through BAE Systems Australia Maritime; the Arafura-class OPV program covers 12 vessels through the Luerssen Australia and Civmec joint venture at Henderson WA; the Collins-class submarine sustainment at ASC Osborne continues through 2040; the AUKUS Pillar 1 SSN-AUKUS submarine build at ASC Osborne is the largest defence undertaking in Australian peacetime history. Add the Joint Logistics Ship program at Navantia Australia and the broader Defence Industry Capability Plan and the supporting facility expansion runs into the tens of billions of Australian dollars through 2050, with HVAC duct demand conservatively in the hundreds of thousands of square metres of fabricated sheet and strong Australian Industry Capability content targets driving locally-fabricated content.
SBKJ Group operates from Box Hill North Victoria as the Australian arm of the SBKJ international duct machinery business. Our engineering team supports Australian marine-sector HVAC contractors with auto duct line and ancillary machinery for the lighter-gauge sheet portion of the project — accommodation, admin, plant rooms, paint hall ductwork, blast bay extract, welding bay extract, engine room workshops and the wider non-classified scope. Heavy-gauge welded plenum, marine-aluminium specialised welding and EMP-shielded zones on the naval ITAR side are typically performed by specialist welded-fabrication subcontractors operating under the same project umbrella, with the boundary defined at the welding procedure qualification level.
The standards stack — what marine HVAC duct is engineered against
Australian marine manufacturing HVAC is designed against an overlapping stack of civilian standards, welding standards, hazardous-area standards, maritime authority standards and IACS classification society standards. The stack is hierarchical and a single composite layup hall will sit under five or six overlays at once.
Civilian Australian baseline
AS 1668.2 governs mechanical ventilation rates as the starting point for every occupied space, from the drafting office through to the welding hall. AS 1668.1 governs fire and smoke control including smoke spill ductwork, stair pressurisation and zone smoke control on multi-storey administration buildings. AS 4254 — in its current edition AS 4254.1 (flexible duct) and AS 4254.2 (rigid duct) — sets the construction class, leakage class, support spacing and seam construction for fabricated sheet duct. AS 1530.4 governs fire-rated penetrations where a duct crosses a fire compartment boundary (the duct, fire damper and penetration sealing system tested as a system, certification referenced on the as-built drawings). AS 3580 governs boundary air quality at the site fence and dictates extract stack discharge height and separation from intakes. AS 1170.4 governs seismic restraint of mechanical services. AS/NZS 1715 governs occupational atmospheric contaminant control in workshops, paint shops and welding bays.
Marine corrosion overlays
ISO 9223 classifies atmospheric corrosivity into six categories from C1 (very low) through CX (extreme). Coastal Australia along the entire shipbuilding and marine manufacturing footprint sits in C5-M (marine high corrosivity) with chloride deposition routinely above 300 mg/m²/day, and in extreme positions — the seaward elevation at the Australian Marine Complex Henderson, the Cockburn Sound aspect of the Hunter Class Type 26 hull-module shed, the Indian Ocean facing aspect of the Civmec OPV hall — above 1000 mg/m²/day. C5-M strips G275 hot-dip galvanised duct in three to seven years through electrochemical zinc consumption, after which pitting attacks the underlying carbon steel along every longitudinal seam. AS/NZS 2312 governs the protective paint coating system applied to ferrous structures and ductwork in marine service — typically epoxy primer plus polyurethane topcoat at C5-M Long durability for shipyard duct, referenced as a commissioning deliverable.
Welding, pressure equipment, hazardous-area, paint booth and dust overlays
AS 1554.1 governs welding of steel structures, AS 1554.6 of austenitic and duplex stainless steel (heat-input limit, back-purge requirement, post-weld passivation), AS 1554.7 of aluminium (TIG/GTAW and MIG/GMAW qualifications across 5xxx, 6xxx and 7xxx marine alloy families). AS 1796 governs welder qualification for general manufacturing; AS 2980 governs welder qualification for pressure equipment with stricter test piece geometry. ISO 3834-2 (comprehensive welding QMS) is required for Tier 1 IACS suppliers; AS 9100 (aerospace QMS) is referenced on naval prime contracting. AS 4458, AS 4037 and AS 1210 govern pressure equipment fabrication, in-service inspection and unfired pressure vessels respectively — applicable to autoclaves (composite curing at 7 bar) and hydrostatic test compartments. AS/NZS 60079.10.1 establishes hazardous-area zoning for gas atmospheres around LPG cutting torch supply, welding shielding gas, paint solvent, paint spray envelopes, composite styrene catalyst dispensing, autoclave nitrogen inerting and fuel offloading manifolds; AS/NZS 60079.10.2 covers combustible dust zoning around abrasive blast halls, aluminium-dust zones and carbon-fibre trim bays; AS 1940 governs flammable liquid storage; AS 3000 governs electrical wiring in marine zones. AS 4114 governs spray-painting booths with NFPA 33 cross-reference for downdraft and semi-downdraft configurations. AS 3957 governs dust control with NFPA 660 cross-reference for combustible dust in aluminium and carbon-fibre zones. Face velocity at the spray booth (0.5 m/s) and at the blast face (5+ m/s) are binding criteria, as is the explosion-protection design on the dust collector for combustible-dust zones.
Maritime authority and IACS class society overlays
The Australian Maritime Safety Authority (AMSA) is the federal regulator for maritime safety in Australian waters and overlays the broader IMO framework. IMO MARPOL Annex VI governs air pollution from ships (SOx, NOx emissions) referenced indirectly on shipboard HVAC discharge. IMO SOLAS Chapter II-2 governs fire protection on ships and references shipboard HVAC fire damper, smoke extraction and accommodation ventilation arrangements. The International Association of Classification Societies (IACS) covers Lloyd's Register, DNV (formerly DNV GL), Bureau Veritas, American Bureau of Shipping, Nippon Kaiji Kyokai (NK/ClassNK) and Registro Italiano Navale (RINA). Every commercial and naval vessel carries an IACS class assignment; shipboard HVAC duct is type-approved under the relevant class society rules including material specification, welding procedure, fire-rated penetration, insulation and air-tightness. Type approval is binding — a non-approved duct cannot be installed on a class-registered vessel. The land-side fabrication shop holds the IACS welding procedure qualification record (WPQR) and welder qualification certificate as a prerequisite to taking on shipboard work. The combined AS 9100 and ISO 3834-2 certification is a standard prerequisite for inclusion in the Australian Industry + Defence Network (AIDN) supply chain on Hunter Class, Arafura OPV and SSN-AUKUS programs.
ISO 9223 C5-M coastal corrosivity — the material decision
The single most consequential design decision on any Australian shipyard, marine cluster or cruise-refit project is the duct material selection. The decision is settled before the first ventilation calculation is finished because the material drives the procurement lead time, the fabrication shop tooling, the installation cost and — most importantly — the lifecycle. We have seen value-engineered galvanised duct on coastal yacht projects fail in seven years against a 30-year design life; the remediation cost (strip-out, abatement, refabrication, reinstallation, production downtime) typically exceeds the original duct cost by an order of magnitude.
The Australian Marine Complex at Henderson WA sits directly on Cockburn Sound with chloride deposition consistently above 300 mg/m²/day on the seaward elevation and peaks above 700 mg/m²/day during Indian Ocean swells — C5-M Long durability across the footprint with the seaward jetty face approaching CX (extreme) conditions. The Osborne Naval Shipyard SA sits on the Port Adelaide industrial waterfront with C5-M exposure moderated by the partially sheltered upper Gulf St Vincent at 200 to 350 mg/m²/day. The Williamstown historic shipyard sits on Hobsons Bay Victoria with C4 to C5-M depending on aspect — the seaward elevation toward Port Phillip Heads carries higher exposure than the protected inner-bay aspect. The Coomera marine cluster on the Gold Coast canal system sits in C5-M tropical-subtropical exposure with elevated humidity and temperature compounding the chloride attack. The Newcastle catamaran kit yards at Schionning Designs sit in C5-M on the Hunter River estuary. Sydney White Bay cruise terminal sits in C5-M moderate inside the inner harbour. Wallaroo SA cruise berth sits on the Yorke Peninsula in C5-M severe exposure on the open Spencer Gulf. Hobart Port cruise and Antarctic vessel terminal sits in C3 to C4 with periodic C5-M events on Southern Ocean storm passage.
316L stainless steel (UNS S31603) is the default duct material across every Australian shipbuilding and marine manufacturing site we service. The low-carbon variant of 316 (carbon under 0.030 per cent) prevents sensitisation in the weld heat-affected zone and preserves pitting resistance across the weld. The pitting resistance equivalent number (PREN) is approximately 24 to 26, giving a reliable service life in C5-M of 30 to 50 years on duct service. Surface finish 2B is the standard mill finish for general construction duct; for visible architectural duct in office and reception areas the finish is upgraded to 2B-DD or BA. For duct exposed to particularly aggressive service — paint booth extract handling isocyanate condensate, composite layup extract handling styrene with MEKP peroxide, engine test cell exhaust handling combustion products with sulphur co-exposure — we specify pickled and passivated finish after fabrication; welded plenum sections on the SBKJ SBSF-1525 stitchwelder receive a post-fabrication passivation treatment. Gauge selection runs from 0.7 mm for accommodation and admin duct through 1.0 mm and 1.2 mm for plant room and main supply duct, to 1.5 mm and occasionally 2.0 mm for heavy-service extract in paint booths, blast bays and engine test cell exhaust capture. The SBKJ SBAL-V auto duct production line in 316L stainless configuration handles the full 0.5 mm to 1.5 mm range on a single coil-fed pass with 16 m/min throughput and 87 kW total installed power — the principal machine for the marine sector duct fabrication shop.
Marine-grade aluminium sheet (alloy 5052-H32 or 5251-H22) is the approved alternative to 316L in three specific scenarios: weight-critical service (elevated plant rooms inside the OPV and frigate construction halls, ceiling-mounted duct over the vessel itself, rooftop plenum sections where structural support is constrained); galvanic compatibility where the duct runs in proximity to aluminium hull structure (Lightwave Yachts aluminium catamaran shed at Coomera, smaller aluminium production sheds along the Gold Coast and Mooloolaba, where zinc-coated steel duct mixed with aluminium structure creates a galvanic cell that accelerates aluminium corrosion at structural fasteners); and non-magnetic service where 316L's residual permeability is too high for EMI-sensitive equipment in proximity (sonar electronics shops at the Hunter Class hull-module integration buildings). Aluminium duct is welded with TIG (GTAW) under AS 1554.7 procedure qualification; the SBKJ SBLR-600 welder handles the longer-run aluminium plenum welds. Hot-dip galvanised G275 carbon steel duct is acceptable only inside a fully conditioned envelope held at positive pressure that demonstrably excludes salt aerosol — the administration block, drafting office, canteen, worker amenity block, security gatehouse and training establishment classroom buildings all qualify. Every section of marine duct carries an electrically continuous bond from end to end at under 10 ohms, mandatory in every hazardous-area zone for static dissipation and good practice everywhere else for lightning protection.
Hull plate cutting and forming bay HVAC
The hull plate cutting and forming bay is typically the loudest and dustiest space in the shipyard. Plasma cutting on hull plate at 10 to 40 mm gauge generates an intense plume of metal vapour, slag and dust; laser cutting at the precision-fittings end generates a smaller but still substantial fume plume; waterjet cutting generates a saturated water-borne contamination that has to be captured at source before it spreads across the shop floor.
Plasma cutting extract
Plasma cutting on steel hull plate is the standard cutting method at Civmec Henderson on the Arafura OPV hull modules, at BAE Systems Henderson on the Hunter Class hull modules and at ASC Osborne on the Collins-class submarine maintenance work. Plasma cutting on aluminium hull plate is the standard at Lightwave Yachts Coomera and at the smaller aluminium catamaran sheds. The extract scope is a down-draft cutting table where the bed itself is the local extract — the plasma plume is drawn downward through perforations in the cutting table into a plenum below, then transported by ductwork to a HEPA-filtered cartridge collector. Face velocity at the cutting table surface is 0.7 m/s minimum for fume capture. 316L stainless ductwork in the extract path because the plasma fume carries iron oxide, manganese oxide, hex chrome (where stainless or duplex is cut) and chloride salts; HEPA H13 final filtration on the collector discharge. The SBKJ SBPC1500 plasma cutter at the duct fabrication shop is itself used to cut the stainless duct fittings serving the extract paths in the customer's hull plate cutting bay — a recursive use of the technology where the duct machine serves the wider shipyard.
Where aluminium plate is plasma-cut at the catamaran sheds, NFPA 660 combustible-dust overlay applies. Aluminium dust is a Class IIIA combustible metal dust and the duct path requires explosion isolation valves at the duct entry to the collector and a deflagration vent on the collector itself. Spark detection on the extract duct is mandatory. The dust collector is sited outdoors where possible to limit the deflagration consequence inside the building shell.
Laser cutting extract
Laser cutting at the precision-fittings end of the shipyard runs at fume rates substantially below plasma but still requires source-capture. A typical fibre laser at 4 to 12 kW cutting 6 to 25 mm steel handles 8 to 12 kW of fume-equivalent energy with a fume plume rising vertically from the cut zone at 0.3 to 0.5 m/s. The extract is via an overhead capture hood at 0.5 m/s face velocity into a stainless duct path to a HEPA-filtered collector. The same NFPA 660 overlay applies on aluminium laser cutting.
Waterjet cutting extract
Waterjet cutting generates water-borne contamination including abrasive garnet and entrained metal particulate. The extract is via overhead capture hood plus a sediment trap on the catchment tank. Stainless duct on the air extract path because of the chlorinated water environment.
Welding hall HVAC — the hex-chrome problem
The welding hall is the binding ventilation challenge on every naval and commercial shipbuilding project. The Hunter Class Type 26 frigate hull modules at BAE Systems Henderson, the Arafura-class OPV hull modules at Civmec/Luerssen Henderson, the Collins-class submarine maintenance welding at ASC Osborne and the surface-vessel hull welding at BAE Systems Williamstown all involve MIG, MAG, TIG, submerged-arc (SAW), stick (SMAW) and flux-cored arc (FCAW) welding on a mix of steel, stainless, duplex and high-strength low-alloy hull plate at gauges from 4 mm to 80 mm. The contaminant chemistry includes iron oxide fume (WES 5 mg/m³ as Fe2O3), manganese fume (WES 1 mg/m³), nickel fume (WES 1 mg/m³), ozone (WES 0.1 ppm — generated principally by MIG and TIG arcs), NOx (WES 3 ppm STEL — generated principally by SAW and stick), zinc oxide fume on galvanised plate weld-through (WES 5 mg/m³), and the killer — hexavalent chromium Cr(VI) at WES 0.005 mg/m³ eight-hour TWA whenever stainless, duplex or chromium-containing weld consumables are deposited.
Hex chrome generation in stainless welding is well-characterised: a typical MIG welding station on 316L stainless at 250 A and 25 V emits in the range of 200 micrograms per minute. With ventilation alone — without source capture — the local concentration around the arc reaches 0.1 to 0.5 mg/m³ within seconds, two orders of magnitude above the WES. Source capture at the arc is the only practicable engineering control that meets the WES; general dilution ventilation, even at 12 to 15 ACH, will not bring the welder breathing zone below 0.005 mg/m³.
The engineering control is source-capture extract at the arc with face velocity 0.5 m/s minimum at 300 mm from the arc, drawn through a 316L stainless flexible exhaust hood, transported through 316L stainless rigid duct to a HEPA-filtered cartridge collector with chrome-rated filter media. The collector is sited outdoors or in a dedicated plant room; HEPA H13 final filtration removes the residual particulate before discharge to atmosphere. Hex-chrome capture sets the supply-air rate, the fan total static, the filter pressure drop and the exhaust stack location. Supplementary overhead capture is installed on the gantry-crane work area where the welder cannot easily reach a local arm — the overhead plenum runs the full crane span at 4 to 6 metres above the floor, fabricated on the SBKJ SBSF-1525 stitchwelder to the AS 4254 Class A leakage criterion.
Robot welding cells at the OPV and Hunter Class hull module shops integrate source-capture extract into the cell envelope — the robot cell is enclosed in a light steel cabin with 0.7 m/s face velocity capture in a hood at the standard tool offset, cell ventilation at 12 to 15 ACH internal to the cabin through a HEPA-filtered cartridge collector with tempered make-up air. Submerged-arc welding on the heavy hull plate (OPV main longitudinal weld and frigate hull-section girth weld) generates NOx and ozone but very little visible fume because the flux blanket captures most of the metal vapour — the extract scope is flux recovery (vacuum into a hopper for re-use) plus a local NOx extract at the weld zone in 316L stainless duct without HEPA. FCAW generates a heavier fume load than MIG/MAG and uses the same source-capture configuration at 0.6 m/s face velocity to handle the higher fume rate.
Block assembly hangar and module integration HVAC
Block assembly hangars at Civmec Henderson, BAE Systems Henderson and Williamstown, and ASC Osborne take the hull modules from the construction halls and join them into larger blocks for transport to the dock or slipway. The hangars typically run with overhead crane access at 30 to 50 metre clear span and conditioned volumes from 150,000 to 400,000 cubic metres for the largest naval-grade buildings.
The HVAC scope is general dilution ventilation at 3 to 5 ACH (sized to dissipate residual welding fume from final welds and grinding work), plus localised source-capture at any welding or grinding station inside the hangar. The general dilution criterion is driven by ambient WES margins on residual contaminants — the hex chrome and welding fume captured at the construction hall source should not migrate into the hangar but a margin is held for the welding work performed inside the hangar itself. 316L stainless duct in the extract path; hot-dip galvanised G275 acceptable in the supply path inside the conditioned envelope provided the make-up air filter excludes salt aerosol.
Module integration sheds — where the engine room, the bridge, the accommodation block and the weapons systems are integrated into the assembled hull blocks — run at a similar general-dilution rate with additional localised extract on engine-room commissioning work and electrical-cable termination work. The fit-out work generates light-duty contamination (solvent vapour from cable termination, particulate from insulation work) that is handled by local extract at 0.3 to 0.5 m/s face velocity into a HEPA-filtered exhaust path.
Sandblast booth HVAC — silica and combustible dust
The sandblast booth handles surface preparation on hull plate, steel structures and incidental marine components. The blast media is typically copper slag, garnet abrasive or aluminium oxide; legacy use of silica sand has been phased out at the major Australian shipyards because the respirable crystalline silica generation cannot be reliably brought below the 0.05 mg/m³ WES. Even with non-silica blast media, the airborne dust load at the blast face exceeds 100 mg/m³ during operation and the booth atmosphere is opaque.
The engineering control is a vacuum-blast booth or a recirculating-media blast booth with 1000+ FPM (5+ m/s) capture velocity at the blast face, conductive 316L stainless ductwork with electrically continuous flanges, explosion isolation valves where slag and aluminium oxide can accumulate, deflagration vent on the dust collector. Continuity tested to under 10 ohms across the full duct run from blast cabinet to collector inlet. Respirable crystalline silica monitoring continuous if any silica is present in the residual feedstock. NFPA 660 combustible dust overlay where aluminium hull plate work generates aluminium oxide dust in the extract path.
The blast booth is typically a sealed cabinet with the operator outside or in a positive-pressure suit; the booth ventilation is balanced to maintain negative pressure to prevent dust escape into the surrounding workspace. The make-up air to the booth is HEPA-filtered to remove any external contamination that could enter the recirculating media and contaminate the blasted surface.
Marine paint booth HVAC — isocyanate, biocide, solvent
The marine paint booth is the engineering centrepiece of the shipyard HVAC scope. Marine paint systems combine isocyanate-bearing polyurethane topcoats (Awlgrip, International Paint, Hempel, Sigmacoat), epoxy primer systems (the same suppliers), copper-thiocyanate and copper-oxide anti-fouling coatings, and high VOC loads in xylene, toluene, MEK and aliphatic naphtha solvent carriers. The contaminant load is multi-component and the engineering control has to address each component.
AS 4114 governs spray-painting booth construction with NFPA 33 as the secondary reference. The downdraft configuration is preferred for large vessel components — overhead supply, drawn downward across the spray zone to a filter floor, captured into a sub-floor plenum and routed to the discharge stack. The semi-downdraft configuration handles medium-size components with sloped ceiling supply and sloped floor extract. Face velocity at the spray zone is 0.5 m/s minimum to capture both overspray particulate and entrained solvent vapour.
316L stainless ductwork with continuously welded seams runs throughout the extract path — the continuous weld is mandatory because TDF flange sealants degrade under solvent exposure and rivets create a spark risk and a leak path. The SBKJ SBSF-1525 stitchwelder fabricates the welded plenum sections to the AS 4254 Class A leakage criterion at 1.2 mm minimum gauge for the negative-pressure cycle load. The exhaust fan is spark-resistant non-ferrous wheel (AMCA Class B or Class C depending on the LEL margin at the fan inlet) with externally-mounted IECEx Ex-d motor outside the airstream on belt drive or magnetic coupling to the wheel shaft. This is contractor scope, not SBKJ scope, but the duct geometry at the fan flange is fabricated to the fan supplier's specification.
The filtration train includes a paint arrestor on the booth floor (multi-stage paper or filament filter), a cartridge particulate filter on the extract duct, a wet packed-bed isocyanate scrubber with chemical neutraliser dosing on the polyurethane discharge, and a HEPA H13 final filter on the stack discharge. The fan is sized for the dirty-filter operating point because the pressure drop rises through the campaign. Make-up air is tempered to within 2 degrees Celsius of booth ambient to prevent topcoat micro-cratering, HEPA-filtered to remove ambient particulate, humidity-controlled to 40 to 70 per cent RH, heated via direct gas-fired or indirect steam coil. The extract stack discharges at minimum 3 metres above roof line and 15 metres from any intake under AS 3580. Discharge is monitored continuously for VOC and isocyanate breakthrough, logged to the BMS and reported quarterly to the state EPA. The stack is sited downwind of the prevailing wind relative to the site office and neighbouring sensitive receivers.
Paint mix room HVAC — Zone 2 hazardous area
The paint mix room is where the multi-pack polyurethane and epoxy systems are mixed before delivery to the booth. The room is small (typically 30 to 80 square metres) but the contaminant intensity is high because the open mixing vessels release solvent vapour at the rate of grams per minute during mixing operations.
The room is zoned AS/NZS 60079.10.1 Zone 2 under AS 1940 flammable liquid storage rules. Continuous extract at 12 to 15 ACH, IECEx Ex-d motors on every fan, 316L stainless duct, bonded continuity throughout, continuous LEL monitoring with automatic shutdown at 25 per cent LEL, explosion-relief venting in the room shell. The make-up air is drawn from outside through a clean-air intake to displace the contaminated air toward the extract. Operator PPE is mandatory and the room operates with a single-occupancy permit during mixing.
Composite layup hall HVAC — the styrene problem
The composite layup hall is the engineering centrepiece of the yacht and catamaran manufacturing HVAC scope. GRP (glass-reinforced polyester) hull lamination is the standard construction method at Riviera Coomera, Maritimo Coomera, Lightwave Yachts Coomera, Schionning Designs Newcastle and the wider production-yacht cluster. The polyester resin carries styrene monomer at 30 to 45 per cent by mass; the styrene evaporates from the open lamination surface at room temperature; the styrene Safe Work Australia WES is 50 ppm eight-hour TWA and is the binding ventilation criterion for the entire hall.
The engineering control is dedicated styrene extract at 0.5 m/s face velocity across the layup table — push-pull configuration on small layup tables (perimeter slot extract supplemented by tempered make-up air across the table) or downdraft configuration on large hull moulds (overhead supply drawn downward through perforated floor or perimeter grilles). The face velocity is set by the styrene evaporation rate and the dilution required to bring the breathing zone below 50 ppm. The ductwork is 316L stainless continuously welded throughout the extract path because the styrene-solvent atmosphere degrades TDF flange sealants; minimum gauge is 1.2 mm for the negative-pressure load and the corrosion margin against entrained MEKP catalyst residue.
Methyl ethyl ketone peroxide is the polyester cure catalyst added at 1 to 2 per cent by mass just before lamination. MEKP is a self-igniting oxidiser if contaminated with organic dust or with metal catalysts. The extract duct path carries spark detection at the inlet to the collector with automatic isolation on detection; the duct is fabricated without any organic gasket material or oily film. MEKP storage is a separate AS 1940 Zone 1 cabinet outside the layup hall, with the catalyst dispensed via metering pump directly into the resin stream at the layup workstation. The styrene extract envelope is zoned AS/NZS 60079.10.1 Zone 2 — every fan, light fitting, instrumentation cable and damper actuator inside the zone is Ex equipment certified to AS/NZS 60079 or IECEx, IECEx Ex-d motors externally mounted, spark-resistant non-ferrous fan wheel, bonded continuity under 10 ohms across the run.
Where the yard runs carbon-fibre construction (typical at the higher-end Maritimo models, at Schionning's higher-spec catamaran kits, and at the superyacht-component side) the dry-fabric trimming and the cured-part trimming generate respirable carbon fibre. The trim stations carry source-capture extract at 0.7 m/s face velocity into a HEPA H13 collector. Carbon fibre is conductive and shorts electrical components if it migrates into adjacent workspaces — duct routing keeps the dust extract physically separated from any adjacent electrical or electronics work area. The amine-cured epoxy resin systems generate amine vapour at the catalyst dispensing point; the extract on amine handling is a dedicated stainless duct path separated from the styrene extract because the two atmospheres are chemically incompatible. The composite layup extract terminates in a HEPA H13 final filter on the stack discharge, sized for resin-particulate carry-over and replaced on a campaign schedule; the HEPA filter housing is bonded to building earth for static dissipation.
Autoclave curing HVAC
Autoclave curing of composite parts at 130 to 180 degrees Celsius and 7 bar pressure is standard for the higher-end carbon-fibre superyacht components, for the precision-aerospace-grade radomes and antenna mounts on the naval combat platforms, and for the high-performance racing-yacht hull components. The autoclave is a pressure vessel under AS 4458, AS 4037 and AS 1210 with separate engineering design verification.
The HVAC scope includes nitrogen inerting line on the autoclave atmosphere (the autoclave is purged with N2 before pressurisation to remove oxygen and prevent uncontrolled cure exotherm), heat-rejection ductwork in the autoclave plant room sized for the worst-case soak-and-cool cycle, and ventilation in the autoclave loading bay to handle the autoclave atmosphere venting at the end of the cycle. 316L stainless duct on the heat-rejection path because the discharge temperature exceeds the service rating of galvanised duct. The SBKJ SB-ZF1500 stitchwelder is used to fabricate the welded stainless heat-rejection plenum on this scope.
Post-cure trim and drill bay HVAC
Post-cure trim and drill operations on cured GRP and carbon-fibre parts generate respirable carbon-fibre dust and epoxy dust. Source-capture extract at every trim station at 0.7 m/s face velocity at the cutting plane, 316L stainless duct, HEPA H13 final filtration. The dust collector is sited outdoors or in a separate plant room because the carbon-fibre dust short-circuits electrical equipment if it migrates.
Fit-out shed HVAC
The fit-out shed handles the interior carpentry, electrical, plumbing and joinery work on the finished vessel before sea trials. The contamination load is light to moderate — wood dust at the cabinetry stations, solvent vapour at the adhesive stations, particulate at the insulation work. General dilution ventilation at 4 to 6 ACH, point-source extract at any composite-wood routing or cutting station for wood dust, localised solvent extract at any cabinetry adhesive station. Hot-dip galvanised G275 duct acceptable inside the conditioned envelope because the fit-out shed is typically inside the conditioned envelope with controlled make-up air; 316L stainless on any extract path discharging to outside air.
Diesel and gas turbine engine test cell HVAC
The diesel engine test cell handles sea-level static commissioning runs on the marine diesel propulsion engines — Caterpillar 3500-series, MTU 8000 and 4000-series, Wartsila W34 and W46, MAN B&W medium-speed engines, Cummins QSK-series, Volvo Penta IPS and inboard propulsion, and Yanmar marine diesel (the Yanmar Australia Brisbane facility being the regional service centre). The cell is a separate building or a separate cell within a larger commissioning hall with structural and acoustic isolation from the surrounding workspace.
High-temperature exhaust capture at the turbocharger discharge — typical 450 to 600 degrees Celsius exhaust temperature on a fully loaded medium-speed marine diesel — is routed through 316L stainless exhaust duct at 2.0 to 3.0 mm gauge into a heat-recovery silencer and acoustic stack sized for 65 dBA boundary and 85 dBA at the cell perimeter. Dilution ventilation runs at 8 to 12 ACH during operation with crankcase-breather and lube-oil vapour capture above the engine into a HEPA-filtered collector at 0.3 to 0.5 m/s face velocity; emergency purge at 30+ ACH is triggered by the LEL monitoring at 25 per cent LEL. The fuel supply manifold from the cell day tank to the engine is zoned AS/NZS 60079.10.1 Zone 1 during transfer and Zone 2 during operation, AS 1940 governs the day tank with leak detection and overfill protection, IECEx Ex-d motors throughout, 316L stainless duct mandatory in the fuel zone with bonded continuity under 10 ohms. Continuous CO monitoring at WES 30 ppm drives automatic emergency purge; the operator does not enter the cell during operation, observation is from a control room with viewing window or via CCTV.
The gas turbine test cell handles the LM2500 and related naval gas-turbine propulsion units in support of Hunter Class Type 26 and other gas-turbine driven naval platforms. The cell runs at 2 to 4 times the diesel airflow because the gas-turbine intake air itself is a major flow (LM2500 ingests 70 kg/s at full power, equivalent to 50,000 to 60,000 cubic metres per hour, before any cell dilution). Acoustic treatment is substantially heavier than on a diesel cell because intake and exhaust noise levels exceed 135 dBA at one metre — hollow acoustic shell with two layers of sound-absorbing media, multi-stage intake and exhaust silencers, cross-flow silencers on cell ventilation. The 316L stainless duct in the exhaust capture path is fabricated to 3.0 mm gauge because of the thermal cycling at gas-turbine exhaust temperature of 500 to 600 degrees Celsius. IECEx Ex-d motors throughout, continuous CO monitoring and emergency purge as for the diesel cell.
Hydrostatic test bay and compartment pressure test HVAC
The hydrostatic test bay handles the compartment pressure test on hull modules and vessel compartments. The bay floods the compartment with water and pressurises to the design proof pressure for the time specified by the IACS class society. The HVAC scope is general dilution ventilation at 4 to 6 ACH, water-mist capture on the pressure-relief discharge, and emergency ventilation in case of compartment failure (water release scenario). 316L stainless duct because the test bay handles seawater or chlorinated potable water under elevated pressure and the local atmosphere is humid with chloride aerosol.
Fuel system test and flush HVAC
The fuel system test and flush bay handles the post-build fuel system commissioning on the vessel — the fuel piping is pressure-tested, the day tank is filled, the engine fuel supply is purged and the fuel filtration is verified. The bay is zoned AS/NZS 60079.10.1 Zone 1 around the fuel handling, AS 1940 governs decanting. 316L stainless duct with bonded earthing continuity under 10 ohms end-to-end, IECEx Ex-d non-ferrous fan wheel, externally-mounted motor, vapour recovery mandatory, continuous hydrocarbon monitoring with automatic shutdown at 25 per cent LEL. Benzene WES 1 ppm STEL is the binding criterion on diesel fuel containing benzene as a minor constituent.
Galley fit-out shed HVAC
The galley fit-out shed pre-assembles commercial and cruise-ship kitchen modules before installation on the vessel. The modules are fully equipped with cooking equipment, refrigeration, sinks and worktops, then loaded onto the vessel as a complete unit during the fit-out phase. The HVAC scope is governed by NFPA 96 commercial kitchen exhaust standards plus AS 1668.2 outside-air rates.
316L stainless extract duct on every galley hood discharge — the standard galley extract material under NFPA 96 — with continuously welded grease-rated seams. The seam construction is welded because gaskets and sealants degrade under high-temperature grease exposure. The duct cleaning access is provided per NFPA 96 (every 3 to 6 metres along the run, at every change of direction, and at every fire damper). Fire damper at every fire-rated compartment boundary, tested under AS 1530.4.
Ship HVAC fit-out — IACS class type approval
The ship HVAC ductwork installed on the vessel itself is type-approved under the IACS classification society — Lloyd's Register, DNV, Bureau Veritas, ABS, NK or RINA depending on the flag and the prime contractor's class. The HVAC duct material is typically marine-grade aluminium 5052/5251 (for the lightweight machinery space and accommodation duct on yacht and small naval vessel construction) or 316L stainless (for the engine room exhaust, the galley extract and the technical-space ventilation on the larger commercial and naval vessel construction).
Land-side fabrication of the shipboard duct follows the class-approved welding procedure under AS 1554.1 (steel), AS 1554.6 (stainless) or AS 1554.7 (aluminium), with welder qualification under AS 1796 and AS 2980. The welding QMS is ISO 3834-2 comprehensive level with AS 9100 overlay on the naval prime contracting side. The class society conducts plan approval, witness inspection of the welding qualification, and survey of the production runs.
SBKJ machines fabricate the lighter-gauge sheet portion of the shipboard duct on the SBAL-V auto duct production line; the heavier-gauge welded plenum sections (typical at the engine room intake plenum, the galley hood duct and the cargo-space ventilation duct on commercial vessel construction) are fabricated by specialist welded-fabrication subcontractors operating under the same project umbrella. The boundary between the SBKJ-machine scope and the welded-subcontractor scope is defined at the welding procedure qualification level.
Dry dock and floating dock HVAC — cruise ship refit
Cruise ship refit dry-dock and floating-dock scope is mostly outdoor — the vessel sits in a graving dock or floating dock with the topside exposed to ambient — but a working refit campaign generates a substantial temporary HVAC scope. The principal Australian cruise-refit ports are Sydney White Bay (the Captain Cook Graving Dock and Sutherland Dock at Garden Island defer to Royal Australian Navy work but White Bay handles commercial cruise calls), the Australian Marine Complex Henderson WA (the common-user facility handles cruise calls on the Indian Ocean leg of the global cruise circuit), Wallaroo SA (the Wallaroo deep-water berth handles Antarctic-bound vessel refits and supply-vessel work) and Hobart Tasmania (the Hobart Port handles Antarctic research vessel refits and seasonal cruise calls).
The containerised welding station is a 20-foot shipping container converted to a welding workshop with HEPA-filtered extract, IECEx Ex-d motors, 316L stainless duct interior and dockside power supply — parked alongside the dock to provide source-capture fume extract on stainless and carbon-steel hull repair work for 2 to 6 welders per station with discharge monitored to the port boundary air quality limit. The temporary paint-booth tent is a fabric-shell enclosure erected on shore for accommodation-deck refurbishment carrying a full AS 4114 ventilation train scaled for the tent geometry — 0.5 m/s face velocity, 316L stainless flexible duct extract, IECEx Ex-d non-ferrous fan, cartridge particulate filter, HEPA H13 final filter on stack discharge, operated under the same hazardous-area permit and WES regime as a permanent booth. Mobile sandblast hoardings around localised hull plate replacement run AS 3957 dust extract at 1000+ FPM with conductive 316L stainless flex duct and deflagration vent on the collector. Cabin module mockup buildings for new fit-out work run HEPA H13 supply on the make-up air with balanced extract and 316L stainless duct throughout.
Cabin module fabrication and furniture/joinery HVAC
Cabin module fabrication for cruise-ship and naval accommodation runs in a clean-assembly environment with HEPA-filtered supply and balanced extract. The Norman Disney + Young (NDY) marine team is one of the principal Australian specialists in this scope; the cabin modules are pre-fabricated as fully outfitted units (bed, sanitary fittings, lighting, HVAC terminal, entertainment system) and lifted into the vessel as a single unit during the fit-out phase.
Furniture and joinery workshop for bespoke cabinetry (specialist suppliers including the Pelorus Naval Architects supply chain on the higher-end superyacht segment) runs wood-dust extract on every routing and cutting station. The dust extract is HEPA-filtered to handle the fine particulate from MDF, plywood and exotic-timber routing; 316L stainless on any extract path discharging outdoors.
Mechanical and electrical workshop HVAC
The mechanical workshop handles rotating equipment, welding and machining work on shipyard maintenance scope. Fume capture at the welding bays as previously specified for the main welding hall; oil mist capture at the machining stations; general dilution ventilation at 4 to 6 ACH. 316L stainless on the extract path, galvanised acceptable for general supply inside the conditioned envelope.
The electrical workshop handles cable termination, switchboard build and electrical instrument calibration. The contamination load is light (solvent vapour from cable termination, particulate from cable jacket trimming) and the HVAC scope is general dilution ventilation at 4 to 6 ACH with localised solvent extract at any cable-jacket trimming station. The conditioned environment is held at the lower humidity range (40 to 55 per cent RH) to limit corrosion on copper conductors and electronic components.
NDT inspection bay and fume hood laboratory HVAC
The NDT (non-destructive testing) inspection bay handles X-ray, ultrasonic, dye penetrant and eddy-current testing on welded hull sections. The X-ray scope requires a shielded enclosure with concrete or lead-bearing wall construction; the HVAC scope is general dilution ventilation at the occupancy criterion plus an ozone extract on the radiation source (X-ray generates ozone at the air-impingement zone). 316L stainless duct on the extract because of the marine corrosivity envelope.
The fume hood laboratory handles paint analysis, welding consumable verification and incoming-material chemistry checks. The fume hood is the standard laboratory unit with 0.5 m/s face velocity, HEPA-filtered exhaust, dedicated 316L stainless duct to the stack discharge. The hood manifold may be shared across multiple hoods with VAV control to manage the diversity factor.
Office, drafting and engineering HVAC
The office, drafting and engineering precinct is the cleanest space on the shipyard with the simplest HVAC scope. AS 1668.2 outside-air at 10 L/s/person, AS 1668.1 fire and smoke control, SMACNA Class 6 leakage. Hot-dip galvanised G275 duct acceptable throughout because the precinct is fully inside the conditioned envelope with positive pressure against the surrounding workshops. Computer-aided design rooms with multiple workstations are sized for the heat-load criterion (typically 200 to 300 W/m² internal load).
ITAR-secured server room HVAC for naval defence variants
The naval defence variants — the Hunter Class Type 26 frigate program, the Arafura-class OPV program, the Collins-class replacement program and the AUKUS Pillar 1 SSN-AUKUS submarine program — all involve ITAR-controlled technology in the design and integration phase. The supporting server rooms inside the naval prime contractor's engineering offices are classified facilities with ITAR-controlled access, DISP-accredited personnel and country-of-manufacture audit on every component.
The HVAC scope is a precision data centre environment with N+1 or 2N redundancy on the cooling, tight temperature and humidity tolerances (typically 22 ± 1 degrees Celsius, 45 ± 5 per cent RH), VESDA aspirating smoke detection, gaseous fire suppression (typical inert gas or fluorocarbon agent) and continuous remote monitoring. The duct material in the server room is hot-dip galvanised G275 inside the conditioned envelope (the ITAR overlay does not change the material selection on duct serving the controlled space — it changes the country-of-manufacture audit on the fans, dampers and controllers). The country-of-manufacture audit is Five Eyes-aligned only (Australia, US, UK, Canada, NZ) on every active component.
Worker amenity, canteen and security gatehouse HVAC
The worker amenity block, the canteen and the security gatehouse run on the same simple HVAC scope as the office precinct. AS 1668.2 outside-air, AS 1668.1 fire and smoke control, hot-dip galvanised G275 duct inside the conditioned envelope. The canteen kitchen exhaust runs under NFPA 96 with 316L stainless grease-rated extract duct on the cooking hood. The security gatehouse runs a standard small-office HVAC scope.
SBKJ machine selection for the marine sector fabrication shop
An Australian shipyard, marine cluster or cruise-refit duct fabrication shop is sized to the project portfolio. The SBKJ recommendation is a multi-machine cell that handles the full duct gauge and material range across the project lifecycle.
The SBAL-V auto duct production line is the principal coil line and the workhorse of the shipyard fabrication shop. Configured for 316L stainless coil at 0.7 to 1.5 mm gauge, the SBAL-V handles 1500 mm coil width, 16 m/min throughput and 87 kW total installed power. The same machine handles galvanised G275 for the conditioned-envelope portion of the project on a separate coil with a quick tooling change. The uplift over the SBAL-III is the higher throughput, integrated TDF flange forming and upgraded controls — relevant where the project tonnage justifies the capital outlay.
The SBSF-1525 stitchwelder is critical for thick-gauge stainless plenum construction across the marine paint booth extract duct, the composite layup hall styrene extract, the autoclave inerting line, the marine HVAC fit-out scope where Lloyd's Register or DNV type approval is required, and the welded plenum on the submarine and frigate construction halls where TDF flanges alone cannot achieve the required leakage class. The stitchwelder fabricates the AS 4254 Class A leakage seam — continuous fillet weld on the longitudinal seam — that gasketed TDF flanges cannot match. The SB-ZF1500 is the alternative configuration of the same machine class used on the autoclave heat-rejection plenum scope and the composite extract scope.
The SBPC1500 plasma cutter handles 316L stainless duct fittings, transitions and access doors — including the recursive use of cutting the fittings serving the customer's own hull plate cutting bay extract. The SBFB-1500 spiral tubeformer covers the 80 mm to 1500 mm round-duct range for the engine room, plant room and accommodation-block portions, producing spiral tube in continuous lengths cut to the installer's specified length. The SBLR-600 welder supplements the stitchwelder on long-seam plenum welds and on aluminium plenum construction where the welding process is TIG (GTAW) rather than resistance seam.
Every fan in the marine paint booth Zone 2 envelope, the composite layup styrene Zone 2 envelope, the aluminium dust NFPA 660 zone, the welding fume hood, the diesel and gas-turbine engine test cell, and the fuel handling Zone 1 envelope is spark-resistant non-ferrous wheel with IECEx Ex-d ATEX motor sitting outside the airstream. This is contractor scope, not SBKJ scope, but the duct geometry and bonding continuity at the fan flange is fabricated to ensure compatibility with the contractor's spark-resistant fan supplier. The SBKJ fabrication scope ends at the fan flange and resumes on the discharge side; the boundary is defined at the welding procedure qualification level on the fan flange welded interface.
Commissioning and IACS class compliance documentation
Final HVAC commissioning on a shipyard, marine cluster or cruise-refit project follows a structured documentation chain that closes both the land-side facility scope and the shipboard fit-out scope. The land-side facility scope is commissioned under NATA accreditation — air-flow measurement at every diffuser, grille and plant connection; smoke-pencil verification of capture velocity at every welding hood, spray booth face and blast bay face; leakage testing per the SMACNA HVAC Air Duct Leakage Test Manual at every plant connection and plenum section; AS/NZS 60079 zone certification on every hazardous-area component; AS 1530.4 fire-rated penetration verification on every fire compartment boundary crossing; ATEX/IECEx certificate verification on every Ex fan motor; continuous monitoring system functional acceptance with calibrated reference gas on every WES-driven extract path.
For the shipboard HVAC fit-out scope under IACS class — Lloyd's Register, DNV, Bureau Veritas, ABS, NK or RINA depending on the prime contractor's class — the documentation chain includes the class-society type approval certificate for the duct material, the welding procedure qualification record (WPQR) for every welding procedure used in fabrication, the welder qualification record for every welder employed on the work, the material test certificate for every batch of stainless and aluminium sheet, and the witness inspection records from the class surveyor's site visits. The signed first-article acceptance is endorsed by the class surveyor and triggers the warranty start. The Australian Industry + Defence Network (AIDN) maintains a supply-chain audit for the naval prime contractors — Australian-fabricated content, Australian-installed insulation, Australian-supplied galvanised and stainless coil where available, and Australian fabrication labour documented against the Australian Industry Capability schedule and submitted to the prime contractor's quality team as a contracted deliverable.
Project programme — design, fabrication, install and hand-over
A shipbuilding, marine manufacturing or cruise-refit HVAC project typically runs 12 to 36 months from design start to commissioning depending on facility scale and security classification overlay. The largest projects — a new Hunter Class hull module construction hall at BAE Systems Henderson, a new SSN-AUKUS construction hall at ASC Osborne, a new Riviera production hall expansion at Coomera — run 24 to 60 months. The design phase runs 4 to 12 months with schematic, detail and construction-documentation phases each gated by the prime contractor and Commonwealth project office review; DISP accreditation and Australian Industry Capability content are locked at schematic design.
The fabrication phase runs 6 to 18 months in parallel with the building shell and structural-services trades, performed at the contractor's Australian workshop on the SBAL-V coil line and ancillary machines. The SBAL-V capacity at 16 m/min throughput supports a fabrication-shop output of approximately 800 to 1200 square metres of duct per shift on a single-machine basis, with the SBSF-1525 stitchwelder adding the welded plenum scope on the same shift. The installation phase runs 4 to 18 months on site with duct rigging, support installation, sealing and pressure-testing by the contractor's installation crew; hazardous-area certification and security clearance management run in parallel. The commissioning phase runs 2 to 6 months at the back end with NATA-accredited testing, IACS class society endorsement (where applicable to the shipboard fit-out scope), functional acceptance and quality close-out — the signed first-article acceptance report is the audit-of-record and triggers warranty start.
Closing — the engineering discipline that marine demands
Australian commercial shipbuilding, naval shipbuilding, yacht and catamaran manufacturing, cruise ship refit and superyacht maintenance HVAC is the most multi-disciplinary engineering brief in Australian heavy industry. The combination of ISO 9223 C5-M chloride atmosphere across every shipyard, marine cluster and cruise-refit port; AS/NZS 60079 hazardous-area zoning around LPG cutting torch supply, welding shielding gas, paint solvent, composite styrene, autoclave nitrogen inerting and fuel handling; the hex chrome and isocyanate Safe Work Australia exposure standards; AS 1554 welding QA across steel, stainless and aluminium hull plate; AS 4114 spray booth construction with NFPA 33 cross-reference; AS 3957 dust control with NFPA 660 combustible dust overlay for aluminium and composite dust; AMSA, IMO MARPOL and SOLAS maritime authority overlays; the IACS classification society type approval where the duct is fabricated as shipboard equipment; AS 9100 and ISO 3834-2 welding QMS where naval prime contracting applies — creates a design problem that no civilian peer matches.
SBKJ Group supports the lighter-gauge sheet-metal portion of that scope through a portfolio of auto duct lines, stitchwelders, plasma cutters, spiral tubeformers, and roll-forming welders — the SBAL-V auto duct production line, the SBSF-1525 stitchwelder, the SB-ZF1500 stitchwelder, the SBPC1500 plasma cutter, the SBFB-1500 spiral tubeformer and the SBLR-600 welder. The heavier-gauge welded plenum, the specialist marine-aluminium scope and the EMP-shielded ITAR zones are co-ordinated with specialist welded-fabrication subcontractors at the project boundary.
The Australian shipbuilding industrial expansion through the Hunter Class Type 26 frigate program, the Arafura-class Offshore Patrol Vessel program, the Collins-class submarine sustainment and the AUKUS Pillar 1 SSN-AUKUS submarine build at Osborne; the continued growth of the Coomera luxury motor yacht cluster at Riviera and Maritimo; the catamaran kit-build sector at Schionning, Lightwave and Tasmanian Yacht Manufacturing; and the cruise-refit ports at Sydney White Bay, Henderson WA, Wallaroo SA and Hobart — collectively represent the largest peacetime marine infrastructure undertaking in Australian history. The HVAC duct scope across that expansion through 2050 is conservatively in the hundreds of thousands of square metres of fabricated sheet, with strong Australian Industry Capability content targets driving Australian-fabricated content. SBKJ Group is positioned to support Australian-based contractors through that scope from Box Hill North Victoria, with ARBS 2026 as our principal trade-show engagement for the marine sector and the broader HVAC industrial supply chain.
FAQ
Why does Australian shipbuilding, yacht and cruise-refit HVAC require 316L stainless or marine aluminium duct?
Every Australian shipyard, marine manufacturing cluster and cruise-refit port sits in ISO 9223 atmospheric corrosivity category C5-M with chloride deposition routinely above 300 mg/m²/day. C5-M strips G275 hot-dip galvanised duct in three to seven years. SBKJ specifies 316L stainless steel (UNS S31603) at 0.7 to 1.5 mm gauge as the default for outdoor, semi-outdoor and make-up air exposed duct, with marine aluminium 5052 or 5251 as the approved alternative for weight-critical or galvanic-compatibility scenarios. Galvanised G275 is acceptable only inside a fully conditioned envelope at positive pressure that demonstrably excludes salt aerosol.
Which standards govern shipbuilding and yacht-manufacturing HVAC duct?
AS 1668.2, AS 1668.1, AS 4254, AS 1530.4, AS 3580, AS 1170.4 civilian baseline. ISO 9223 C5-M and AS/NZS 2312 marine corrosion. AS 1554.1, AS 1554.6, AS 1554.7 welding. AS 1796 and AS 2980 welder qualification. AS 4458, AS 4037, AS 1210 pressure equipment. AS/NZS 60079 hazardous area. AS 1940 flammable liquids. AS 4114 spray booth with NFPA 33. AS 3957 dust with NFPA 660 combustible dust. AS 9100 and ISO 3834-2 welding QMS. AMSA, IMO MARPOL and SOLAS, plus IACS class society stack (Lloyd's Register, DNV, Bureau Veritas, ABS, NK, RINA) where the duct is type-approved as shipboard equipment.
How does a composite layup hall differ from a steel welding hall?
The composite layup hall handles GRP hull lamination with styrene (WES 50 ppm) as the binding criterion — dedicated styrene extract at 0.5 m/s face velocity, 316L stainless continuously welded duct, MEKP-rated spark detection, HEPA H13 final filtration, AS/NZS 60079 Zone 2 zoning. The steel welding hall handles MIG/MAG/TIG/SAW/stick/FCAW with hex chrome Cr(VI) (WES 0.005 mg/m³) as the binding criterion — source-capture at 0.5 m/s at 300 mm from the arc, 316L stainless flexible hoods, HEPA cartridge collector with chrome-rated media. The two halls share only the C5-M corrosivity envelope; the contaminant chemistry, ventilation rate, hazardous-area zoning and fire-protection overlay are entirely different.
What ventilation captures hex chrome from stainless welding in a frigate or OPV hall?
Source-capture at the arc with 0.5 m/s face velocity at 300 mm from the arc, 316L stainless flexible exhaust hoods, HEPA-filtered cartridge collector with chrome-rated media, supplementary overhead capture plenum for gantry-crane work. The WES is 0.005 mg/m³ eight-hour TWA — a hundred-fold tighter than the general welding fume limit. Hex chrome is the binding ventilation criterion on Civmec Henderson Arafura OPV work, BAE Systems Henderson Hunter Class work, and every shipyard handling stainless or duplex grades.
How is a marine paint booth ducted under AS 4114?
Downdraft or semi-downdraft AS 4114 booth with NFPA 33 cross-reference, 0.5 m/s face velocity through filter floors, 316L stainless continuously welded duct, IECEx Ex-d spark-resistant non-ferrous fan, externally-mounted motor, cartridge particulate filter on extract, isocyanate scrubber on polyurethane discharge, HEPA H13 final filter, tempered make-up air within 2°C of booth ambient. Isocyanate STEL 0.005 ppm is the binding criterion. Stack discharge 3 m above roof and 15 m from any intake under AS 3580.
What hazardous-area zoning applies to a diesel and gas-turbine engine test cell?
AS/NZS 60079.10.1 Zone 1 around fuel manifold during transfer, Zone 2 during operation. AS 1940 governs bulk diesel and MGO storage. IECEx Ex-d motors throughout, 316L stainless duct in fuel zone, bonded continuity under 10 ohms, continuous CO monitoring (WES 30 ppm) with automatic emergency purge. Gas turbine test cell runs 2-4x the diesel airflow and adds substantial acoustic treatment because intake and exhaust exceed 135 dBA.
What is the cruise-ship refit dry-dock HVAC scope at Sydney White Bay, Henderson, Wallaroo and Hobart?
Mostly outdoor — the vessel sits in a graving dock or floating dock with topside exposed to ambient — but the working refit campaign generates substantial temporary HVAC scope. Containerised welding stations alongside the dock with source-capture fume extract, temporary paint-booth tents on shore for accommodation-deck repaint carrying full AS 4114 ventilation, mobile sandblast hoardings with AS 3957 dust extract, cabin module mockup buildings with HEPA-filtered supply. The principal Australian cruise-refit ports are Sydney White Bay, the Australian Marine Complex Henderson WA, Wallaroo SA and Hobart Tasmania.
What SBKJ machines does a marine sector duct fabrication shop need?
SBAL-V auto duct production line configured for 316L stainless at 0.5 to 1.5 mm gauge, 1500 mm coil width, 16 m/min throughput, 87 kW installed power — the principal machine. SBSF-1525 stitchwelder for thick-gauge stainless plenum on marine paint booth, composite layup, autoclave inerting and IACS-class shipboard fit-out. SBPC1500 plasma cutter for stainless duct fittings. SBFB-1500 spiral tubeformer for 80 mm to 1500 mm round duct. SBLR-600 welder supplementing the stitchwelder on long-seam and aluminium plenum welds. Spark-resistant non-ferrous fan with IECEx Ex-d motor is contractor scope, not SBKJ scope — SBKJ fabricates the duct to integrate with the contractor's spark-resistant fan at the flange.
