Naval Base, Submarine Maintenance, Shipyard & Dry Dock HVAC Duct Guide — RAN, HMAS Stirling, Osborne, Henderson, AUKUS Pillar 1

Why naval-base, submarine and shipyard HVAC is the most demanding environment in Australian defence

Australian Defence Force facilities span an extraordinary engineering range — high-altitude command bunkers, monsoonal forward operating bases, hardened intelligence vaults, classified data centres and tropical patrol-boat berths — but the most demanding HVAC envelope in the whole portfolio sits on the working waterfront. A Royal Australian Navy base combines five aggressive load classes simultaneously: a C5-M chloride-aerosol atmosphere that strips zinc coatings in years rather than decades, a Zone 1 hazardous classification around fuel jetties and paint halls, a hex-chrome welding-fume exposure tighter than almost any peer industry, an isocyanate spray-paint exposure that operator respirators alone cannot manage, and a security-classification overlay that drives country-of-manufacture audit on every fan, damper and controller. There is no civilian peer that runs all five envelopes at once.

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 Royal Australian Navy site. Marine aluminium 5052 or 5251 is the alternative where weight reduction or galvanic compatibility with aluminium structure is the dominant constraint — typical at Henderson Western Australia where Austal's purpose-built aluminium catamaran shed sits adjacent to surface-steel construction halls. Hot-dip galvanised G275 carbon steel is permitted only inside a fully conditioned envelope held at positive pressure that demonstrably excludes salt aerosol. We have seen too many failures where a value-engineered galvanised duct ran to outdoor air at a coastal jetty and was perforated along the seam in seven years to make any other recommendation.

The second dimension is the breadth of facility types inside a single site. A typical Royal Australian Navy fleet base contains, in close proximity: a working waterfront with finger jetties and fuel offloading, an enclosed submarine drydock pen or surface-vessel graving dock, a covered ship hangar or vessel maintenance shed, a paint hall, a blast bay, multiple welding bays for stick, MIG, MAG, TIG and submerged-arc work, an engine-room overhaul facility, a battery shop, a magazine, naval stores, a torpedo or missile assembly building, a sonar electronics shop, an underwater equipment test pool, a submarine escape training tank, a diving school with compression chamber, the operational headquarters with classified communications, the sailor accommodation precinct and the officers' mess. Every one of those buildings runs against a different ventilation rate, a different hazardous-area class, a different acoustic target and a different commissioning deliverable.

The third dimension is the AUKUS Pillar 1 industrial context. Since the September 2021 announcement of the trilateral security partnership between Australia, the United Kingdom and the United States, the Defence Maritime Affairs precincts at Osborne South Australia and Henderson Western Australia have become the principal infrastructure expansion sites in the country. HMAS Stirling at Garden Island Western Australia — the home of every Collins-class submarine in Royal Australian Navy service — is the operating base for the future SSN-AUKUS fleet and is in continuous facility expansion through 2040. The Australian Submarine Agency, the Office of the Director-General Defence Materiel, the Defence Strategic Review programs and the Submarine Institute of Australia are the principal industrial-base coordinators, with the Henderson Alliance shipbuilders forum representing the Western Australian shipbuilding cluster. The HVAC duct demand from this single industrial expansion is the largest peacetime defence facility scope in Australian history.

SBKJ Group operates from Box Hill North Victoria as the Australian arm of the SBKJ international duct machinery business. Our engineering team supports naval, submarine and shipyard 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. The heavy-gauge welded plenum sections inside the submarine drydock pen, the blast-resistant penetrations on command-facility envelopes and the EMP-shielded honeycomb assemblies on Top Secret zones are typically performed by specialist welded-fabrication subcontractors. We co-ordinate with those subcontractors at the project boundary so the lighter-gauge sheet metal and the heavier-gauge welded scope integrate cleanly.

The standards stack — what naval and shipyard HVAC duct is engineered against

Australian Defence Maritime Affairs HVAC is designed against an overlapping stack of civilian standards, defence-specific standards and international references. The stack is hierarchical: the most demanding overlay governs in any given location, and a single welding bay inside a submarine drydock pen will sit under five or six overlays at once.

Civilian Australian baseline

AS 1668.2 governs mechanical ventilation rates and is the starting point for every occupied space on the site, from sailor accommodation through to the operations headquarters. AS 1668.1 governs fire and smoke control, including smoke spill ductwork, stair pressurisation and zone smoke control on multi-storey command and accommodation 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 the fire-rated penetration where a duct crosses a fire compartment boundary; the duct itself, the fire damper and the penetration sealing system are tested as a system and the certification is 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 Royal Australian Navy footprint sits in category C5-M (marine high corrosivity) with chloride deposition routinely above 300 mg per square metre per day and in extreme exposure positions — Garden Island Sydney's seaward elevation, the Pacific-facing aspect of HMAS Cairns Queensland — 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 an epoxy primer plus polyurethane topcoat to a durability class matched to the exposure (C5-M Long is the standard for Royal Australian Navy site duct). The coating system is referenced as a commissioning deliverable on every project.

Hazardous-area overlays

AS/NZS 60079 series governs equipment in explosive atmospheres — the entire international ATEX/IECEx framework adopted into Australian standards. AS/NZS 60079.10.1 establishes hazardous-area zoning for gas atmospheres around fuel jetties, fuel offloading manifolds, paint hall spray envelopes, paint solvent storage, magazine vapour vents and any space where flammable vapour is present during normal or abnormal operation. AS/NZS 60079.10.2 covers combustible dust zoning around abrasive blast halls, grain stores (not generally applicable to naval bases but referenced) and any combustible-dust producing process. AS 1940 governs the storage and handling of flammable and combustible liquids in bulk, with detailed rules on tank-room ventilation, vapour recovery, leak detection and emergency shutdown. AS 3000 (the Australian wiring rules) overlays electrical installation in marine zones, with strict separation between hazardous and non-hazardous wiring paths.

Confined-space and shipbuilding OHS overlays

AS 2865 governs confined-space entry — directly relevant to vessel interior work, tank service inside the boat, and any duct or plenum entry on a covered shipyard floor. The permit-to-work system, gas testing, rescue equipment and exit time are all governed by AS 2865 and referenced in the contractor's site-specific safety plan. AS 4801 governs occupational health and safety management in shipbuilding. AS 4754 and AS 4753 govern hot work permit systems in marine and industrial environments — every welding, cutting, grinding or hot-air operation inside a vessel or covered shipyard requires a hot work permit. AS 3957 governs dust control. The Safe Work Australia workplace exposure standards (WES) carry the binding numerical limits — welding fume general 1 mg/m³ eight-hour TWA, hex chrome Cr(VI) 0.005 mg/m³ eight-hour TWA, nickel 1 mg/m³, asbestos legacy in older ships 0.1 fibre per millilitre, respirable silica 0.05 mg/m³, lead 0.05 mg/m³ (relevant to paint stripping operations), benzene 1 ppm STEL (fuel handling), hydrogen sulphide 10 ppm eight-hour TWA / 15 ppm STEL (sewer and bilge), carbon monoxide 30 ppm, isocyanate 0.005 ppm STEL (polyurethane paint), zinc oxide fume 5 mg/m³ (galvanising). The hex chrome and isocyanate limits are the two binding constraints on almost every welding bay and paint hall design.

Pressure vessel and cleanroom overlays

AS 2030 and AS 1210 govern pressure vessels — directly relevant to the diving school compression chamber, the recompression chamber for diver decompression sickness treatment, and any high-pressure service inside the engine room overhaul facility. ISO 14644 governs cleanroom classification — applicable to semiconductor sonar assembly facilities (typically Class 7 or Class 8) and to the precision-instrument calibration laboratory adjacent to the electronics shop.

Defence-specific overlays

The Defence Manual of Fire Safety (DMFS) is the binding fire safety reference on every Department of Defence site in Australia, overlaying the National Construction Code with defence-specific requirements on magazine separation, weapons store ventilation, paint hall fire detection and naval store sprinkler systems. The DEF (AUST) 5000 series defence standards cover a wide range of equipment and material specifications, with HVAC-relevant subset on coatings, materials, electrical and seismic requirements. NATA accreditation is required for every commissioning test deliverable — air flow measurement, smoke testing, leakage testing, fire damper actuation, ATEX/IECEx certification verification. The Defence Trade Controls Act 2012 and ITAR (International Traffic in Arms Regulations) govern the technology-export status of certain components, with the Defence and Strategic Goods List defining the controlled equipment. AS 5577 governs industrial automation control-system security and is referenced on building management systems serving defence facilities. AS 4068 governs sound absorption coefficients in confined spaces and is referenced on submarine drydock pen acoustic design.

Submarine-specific overlay

Australian Submarine Force Capability standards are the classified internal specifications for submarine-support facilities and are released only to cleared contractors. The published standards stack above is the public minimum — the actual contract performance specification on any submarine-related project carries additional requirements that are not disclosed outside the cleared supply chain. SBKJ engineering services on AUKUS-aligned submarine support facilities are supplied through prime contractors who hold the head Defence Industry Security Programme (DISP) accreditation and the contractual relationship with the Australian Submarine Agency or the Commonwealth.

ISO 9223 C5-M coastal corrosivity — the material decision

The single most consequential design decision on any Royal Australian Navy site HVAC 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 naval projects fail in seven years against a 30-year design life. The remediation cost — strip-out, abatement, refabrication, reinstallation, downtime — typically exceeds the original duct cost by an order of magnitude. There is no economic case for the cheaper material.

ISO 9223 categories at Australian naval sites

HMAS Stirling at Garden Island Western Australia sits inside Cockburn Sound on the seaward side of the Perth metropolitan area. Chloride deposition on the seaward elevation is consistently above 300 mg/m²/day with peak events above 700 mg/m²/day during Indian Ocean swells. The site is C5-M Long durability across the entire footprint with the seaward jetty face approaching CX (extreme) conditions. Garden Island Sydney sits on Sydney Harbour at the eastern end of the inner harbour with somewhat moderated chloride exposure (200 to 400 mg/m²/day) but with an aggressive sulphur dioxide co-exposure from the surrounding urban industrial base — the combined C5-M plus C5-I (industrial) overlay drives even more aggressive corrosion than either alone. HMAS Coonawarra Darwin sits on Darwin Harbour with tropical chloride deposition and elevated ambient temperature — the highest combined chloride-temperature exposure of any Royal Australian Navy site. HMAS Cairns Queensland sits on Trinity Inlet with similar tropical exposure. HMAS Cerberus Western Port Victoria sits on a sheltered embayment with lower chloride deposition (100 to 200 mg/m²/day) but still firmly in C5-M class. HMAS Albatross Nowra New South Wales is inland by 10 kilometres but the prevailing easterly winds carry chloride sufficient to keep the site in C4 (high) rather than dropping to C3 (medium). HMAS Creswell Jervis Bay sits on the coast at Jervis Bay with C5-M exposure. HMAS Watson at South Head Sydney sits on a Pacific-facing headland with C5-M severe exposure on the seaward elevation. HMAS Penguin and HMAS Waterhen on Sydney Harbour sit in C5-M moderate. HMAS Moreton Brisbane sits on Brisbane River with C4 to C5-M depending on aspect. HMAS Encounter Adelaide sits in C4 exposure. HMAS Huon Hobart sits in C3 to C4 with the lowest chloride exposure of any Royal Australian Navy site but still requires stainless duct in seaward elevation due to occasional Southern Ocean salt-spray events.

316L stainless steel — the workhorse

316L stainless steel (UNS S31603) is the default duct material across every Royal Australian Navy site we service. The grade is the low-carbon variant of 316 with carbon content under 0.030 per cent, which prevents sensitisation in the weld heat-affected zone and preserves pitting resistance across the weld. The pitting resistance equivalent number (PREN) for 316L is approximately 24 to 26 depending on the actual chemistry, which gives a reliable service life in C5-M exposure of 30 to 50 years on duct service with appropriate handling and installation.

Surface finish 2B is the standard mill finish for general construction duct — cold rolled, annealed, pickled, lightly skin-passed for surface uniformity. For visible architectural duct in officer accommodation and reception areas the finish is upgraded to 2B-DD or BA (bright annealed). For duct exposed to particularly aggressive service (paint hall extract handling isocyanate condensate, fuel jetty handling diesel vapour with sulphur co-exposure) we specify pickled and passivated finish after fabrication to remove any iron contamination from forming tools that could initiate pitting in service.

Gauge selection runs from 0.7 mm for accommodation duct under low static pressure 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 halls and blast bays. The 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.

Marine aluminium 5052 and 5251

Marine-grade aluminium sheet — typically alloy 5052-H32 or 5251-H22 — is the approved alternative to 316L in three specific scenarios. The first scenario is weight-critical service, including elevated plant rooms inside the submarine drydock pen building, ceiling-mounted duct over the submarine itself, and rooftop plenum sections where structural support is constrained. The second scenario is galvanic compatibility where the duct runs in proximity to aluminium structure — Austal's aluminium catamaran shed at Henderson Western Australia is the most prominent example, where mixing zinc-coated steel duct with aluminium structure creates a galvanic cell that accelerates aluminium corrosion at the structural fasteners. The third scenario is non-magnetic service, where 316L's residual permeability is too high for the EMI-sensitive equipment in proximity — sonar electronics laboratories and degaussing range support facilities are the typical applications.

Aluminium alloy 5052 has good resistance to marine atmosphere and is commonly available in 0.8 mm to 2.0 mm sheet gauge for duct fabrication. Forming behaviour is slightly different from steel and the SBAL-V tooling is configured with aluminium-specific rollers and modified lubrication, which is a tooling change rather than a machine change. Aluminium duct is welded with TIG (GTAW) rather than the resistance seam welding used on stainless — the SBSF-1525 stitchwelder is not generally suitable for aluminium although it handles stainless plenum welds across the same project.

Hot-dip galvanised G275 — the limited application

Hot-dip galvanised G275 carbon steel duct is acceptable on a Royal Australian Navy site only inside a fully conditioned envelope held at positive pressure that demonstrably excludes salt aerosol. The accommodation precinct, the officers' mess, the gymnasium, the medical centre, the operations headquarters administration block and the training establishment classroom buildings all qualify. The duct must be inboard of the make-up air filter, must not be exposed to outside air at any service position, and must be coated to AS/NZS 2312 protective coating system class C5-M Long where the duct sits in a plant room or service area with intermittent outside-air exposure. The G275 specification — 275 g/m² zinc coating mass to AS 1397 — gives a service life of 30+ years in inland Australian climates but is not adequate for coastal exposure without supplementary coating.

Anti-magnetic stainless and copper sheet

Anti-magnetic 316L stainless is specified in EMI-sensitive electronics rooms — sonar electronics shop, degaussing range support, missile and torpedo electronics assembly, classified communications rooms — where the residual permeability of conventional 316L can perturb precision instrumentation. The anti-magnetic specification requires solution-annealing after forming and a documented permeability test on each batch. Copper sheet is reserved for EMP waveguide-below-cutoff penetrations and a small number of TEMPEST-shielded enclosures where copper attenuation properties exceed steel. Copper duct is rare and appears as a small fraction of the total project scope concentrated at boundary penetrations.

Australian naval-base portfolio — site-by-site HVAC scope

The Royal Australian Navy operates a network of fleet bases, support bases, training establishments and communications stations across the Australian coastline. Each site has a distinct HVAC duct profile driven by its mission, its facility mix and its environmental envelope. The summary below covers the major sites in the order they appear most prominently in the AUKUS Pillar 1 and broader Defence Maritime Affairs infrastructure expansion.

HMAS Stirling — Garden Island Western Australia

HMAS Stirling at Garden Island Western Australia is the largest naval base in Australia and the home port of every Collins-class submarine in service. The base sits inside Cockburn Sound at Rockingham, approximately 50 kilometres south of Perth, on a man-made causeway connecting Garden Island to the mainland. The submarine squadron headquarters is co-located on the base. As the operating port for the future SSN-AUKUS fleet — the nuclear-powered conventionally-armed submarines being acquired and built under AUKUS Pillar 1 — HMAS Stirling is in continuous facility expansion through 2040 and beyond.

The HVAC duct scope on the base spans the full Defence Maritime Affairs range: a submarine drydock pen of approximately 120,000 cubic metres conditioned volume, multiple covered submarine maintenance bays, surface combatant berths with associated workshop and engine room overhaul facilities, paint halls and blast bays, naval stores including bulk fuel storage, magazine and torpedo storage, accommodation for over 3000 personnel, the operational headquarters with classified communications, the submarine squadron headquarters, training and simulator facilities, gymnasium, medical centre, mess and recreational areas. The duct material is 316L stainless throughout the operational waterfront, the workshops, the paint hall, the blast bay and the magazine; hot-dip galvanised G275 with AS/NZS 2312 protective coating in the accommodation and admin precinct; and marine aluminium where weight reduction or anti-magnetic service is required. The total fabricated duct scope across the base infrastructure through 2040 is in the order of 25,000 to 35,000 square metres.

Garden Island — Sydney New South Wales

Garden Island Sydney is the East Coast fleet base operating the surface combatant fleet — Hobart-class destroyers, Anzac-class frigates and the future Hunter-class frigates as they are commissioned. HMAS Kuttabul is the support base co-located with Garden Island. The site contains the Captain Cook Graving Dock (the largest graving dock in Australia, capable of docking the largest surface combatants), multiple working berths, the Fleet Base East operations centre, accommodation, and the workshops that support sustainment of the surface fleet. Thales Australia operates the sonar facility on the precinct. BAE Systems Australia has historically operated work at Garden Island NSW although the Williamstown Victoria shipyard is the principal BAE construction site.

The HVAC duct scope on the Sydney precinct includes the Captain Cook Graving Dock with associated workshops, the paint hall, the blast bay, the welding bays, the engine room overhaul facility, the naval stores, the magazine, the operations headquarters, accommodation precincts at HMAS Kuttabul and the dependent commercial precinct buildings. Marine corrosivity is C5-M with industrial co-exposure (C5-M plus C5-I), which actually accelerates corrosion beyond C5-M alone — 316L stainless duct is mandatory throughout. The sulphur dioxide co-exposure in inner Sydney air drives some additional consideration for stainless duct passivation, although the dominant corrosivity driver is still chloride.

HMAS Coonawarra — Darwin Northern Territory

HMAS Coonawarra is the Royal Australian Navy base in Darwin and the home port of the Pacific patrol boat fleet operated under the Pacific Patrol Boat Programme. The base sits on Darwin Harbour with tropical chloride exposure and elevated ambient temperature year-round. The forward-operating role of the base means that the HVAC scope is more concentrated on operational support — patrol boat berthing, fuel and lube oil handling, small-vessel maintenance workshops, accommodation, mess, operations centre — and less on the heavy industrial shipyard scope present at Stirling or Garden Island Sydney.

The duct material is 316L stainless across the entire operational waterfront because the combined tropical chloride and temperature exposure is the most aggressive marine envelope in the country. The accommodation precinct uses galvanised G275 inside the conditioned envelope. The base is in continuous expansion to support US Marine Rotational Force-Darwin and the Force Posture Initiative, which drives additional accommodation and support facility scope.

HMAS Cairns — Cairns Queensland

HMAS Cairns is the Royal Australian Navy base in Cairns supporting the Pacific patrol boat fleet and forward-operating naval activities in the Coral Sea and Pacific. The base sits on Trinity Inlet with tropical chloride exposure similar to HMAS Coonawarra Darwin. The HVAC scope mirrors the Coonawarra profile with patrol boat berthing, small-vessel workshops, accommodation and operations.

HMAS Cerberus — Western Port Victoria

HMAS Cerberus on Western Port Victoria is the principal Royal Australian Navy training establishment for sailors and junior officers. The base contains accommodation for trainees, classrooms, simulators, drill halls, the mess and recreational areas, the medical centre and the training-specific workshop facilities (engineering, electrical, weapons, navigation). The duct scope is closer to a tertiary education campus than to an operational fleet base, with the addition of marine-specific training facilities (boat handling, damage control trainer, firefighting trainer) that introduce process-specific HVAC requirements. The duct material is hot-dip galvanised G275 with AS/NZS 2312 protective coating in the accommodation and admin scope, and 316L stainless in the workshop, mess kitchen and process-specific training areas. The damage control trainer and firefighting trainer use 316L stainless throughout because the simulated fire and flood environment is highly corrosive.

HMAS Albatross — Nowra New South Wales

HMAS Albatross at Nowra New South Wales is the Royal Australian Navy Fleet Air Arm base operating the MH-60R Seahawk Romeo helicopter fleet and the MRH-90 Taipan (until retirement) and replacement helicopter platforms. The base contains aircraft hangars, fuel and weapons facilities, operations centre, accommodation, mess and the Australian Defence Force basic flying training school. The hangar HVAC scope is closer to the airbase profile covered in our aviation MRO hangar paint shop HVAC duct guide than to the maritime waterfront profile. Marine corrosivity is C4 to C5-M because the base is inland by 10 kilometres but exposed to coastal wind.

HMAS Creswell — Jervis Bay New South Wales

HMAS Creswell at Jervis Bay is the Royal Australian Navy College, the principal training establishment for officers entering the Navy. The HVAC scope follows the training establishment profile with accommodation, classroom and simulator buildings, mess and ceremonial spaces, and process-specific training facilities. The site sits in C5-M exposure on the Pacific coast and uses 316L stainless duct for exposed service.

HMAS Harman, HMAS Watson, HMAS Penguin, HMAS Waterhen, HMAS Moreton, HMAS Encounter, HMAS Huon

HMAS Harman in Canberra is the communications and signal-intelligence support base, with the HVAC duct scope concentrated in classified ICT and communications facility design rather than waterfront infrastructure. HMAS Watson at South Head Sydney is the combat training establishment with the maritime warfare training centre and the school of maritime warfare. HMAS Penguin and HMAS Waterhen on Sydney Harbour are smaller support bases. HMAS Moreton in Brisbane, HMAS Encounter in Adelaide and HMAS Huon in Hobart are the regional support bases providing reserve and support functions to the broader Defence Maritime Affairs network. Each site carries a smaller-scale version of the standard naval-base HVAC scope with material selection following the local ISO 9223 corrosivity class.

Defence shipbuilding precincts — Henderson WA and Osborne SA

The two principal Defence shipbuilding precincts in Australia are Henderson Western Australia and Osborne South Australia. Both are in active expansion under AUKUS Pillar 1 and broader Defence acquisition programmes. The HVAC duct demand across these two precincts through 2040 is the single largest infrastructure scope in Australian peacetime defence history.

Henderson WA shipbuilding precinct

Henderson Western Australia is approximately 40 kilometres south of Perth on Cockburn Sound, adjacent to HMAS Stirling. The precinct is being expanded into the largest naval shipbuilding precinct in Australia under the Defence Strategic Review and the AUKUS Pillar 1 industrial base programme. The principal tenants are Civmec (ASX:CVL, commercial shipbuilding and the Arafura-class offshore patrol vessel programme), Austal Limited (ASX:ASB, the aluminium Cape-class patrol boat, Pacific patrol boat, and Landing Craft Air Cushion programmes), Damen Shipyards Gorinchem Australia (an Arafura partner), Luerssen Australia (offshore patrol vessel partner), and BAE Systems Australia (Hunter-class frigate construction is principally at Osborne but Henderson holds a major share of the broader BAE Australia work). The Henderson Alliance shipbuilders forum coordinates the precinct.

The HVAC duct scope across the Henderson precinct includes the multi-bay assembly halls (each in the order of 80,000 to 200,000 cubic metres conditioned volume), the paint halls and blast bays, the welding bays, the engine room overhaul facilities, the parts production workshops, the maintenance facility shops, the accommodation precincts for shift workers, the office and admin precincts, the training facilities, the parts and material stores. Civmec's principal assembly hall is approximately 110 metres long by 50 metres wide by 40 metres high — a conditioned volume in the order of 220,000 cubic metres. The Austal aluminium catamaran shed uses Aluzinc AZ150 aluminium-zinc coated duct or marine aluminium 5052 throughout the production bay for galvanic compatibility with the aluminium hull structure. The Luerssen offshore patrol vessel hall is a multi-bay assembly building in the 80,000 to 100,000 cubic metre range.

Osborne SA submarine and frigate construction precinct

Osborne South Australia is approximately 25 kilometres north-west of Adelaide on the Port Adelaide River. The precinct is the principal east-coast counterpart to Henderson and is the build location for the Hunter-class frigate (BAE Systems Australia) and the SSN-AUKUS submarine (ASC Pty Ltd). The Osborne site is in active expansion through 2030 and beyond, with new assembly halls, training facilities, accommodation precincts and ICT infrastructure being delivered against the AUKUS Pillar 1 schedule. The Australian Submarine Agency is the principal Commonwealth project office.

ASC Pty Ltd at Osborne operates the Collins-class submarine sustainment programme — every Collins-class boat passes through a full-cycle docking maintenance at Osborne — and is being expanded for SSN-AUKUS hull module fabrication and final assembly. The HVAC duct scope on the ASC submarine portion is the most demanding in the precinct, combining the submarine drydock pen profile (316L stainless throughout, atmospheric monitoring, air revitalisation interfaces, isocyanate and hex chrome capture), the paint hall, the blast bay, the welding bays, the classified electronics assembly, the secure command and integration spaces, the accommodation, and the training facilities. The total fabricated duct scope for ASC at Osborne through 2040 is conservatively in the order of 40,000 to 60,000 square metres.

BAE Systems Australia at Osborne is constructing the Hunter-class frigate — the largest surface combatant ever built in Australia. The construction hall is a clean, climate-controlled assembly building approximately 110 metres long by 50 metres wide by 35 metres high. The HVAC duct scope covers internal climate control, fume extraction, paint shop ventilation, blast bay extract, process cooling and the supporting accommodation, training and admin facilities. The duct material is hot-dip galvanised G275 for the general supply inside the conditioned envelope, 316L stainless for the paint and welding extract, marine aluminium where galvanic compatibility is required, and AS/NZS 2312 protective coating on every ferrous exposed surface.

Williamstown VIC and historical shipyards

BAE Systems Australia operates the Williamstown Victoria shipyard, which is the historical home of Royal Australian Navy surface shipbuilding. The site is on Hobson's Bay at the western edge of Melbourne with C5-M marine corrosivity. The site supports surface combatant work and sustainment activity. Forgacs was absorbed into Civmec in earlier industry consolidation. Submarine Corporation was the predecessor of ASC Pty Ltd. Naval Group Australia (formerly DCNS) was the prime contractor on the terminated Attack-class submarine programme — the contract was terminated in September 2021 with the AUKUS announcement and Naval Group Australia is no longer a principal participant in the Australian submarine industrial base.

Combat systems and electronic warfare

Saab Australia at Mawson Lakes South Australia is the principal combat management system integrator for the Royal Australian Navy surface combatant fleet. Thales Australia at Garden Island New South Wales is the principal sonar integrator. BAE Combat Systems is the principal weapons-systems integrator. Each of these facilities is a classified ICT and electronics assembly environment with anti-magnetic 316L stainless duct, TEMPEST emanation control, and country-of-manufacture audit on every component. The HVAC duct scope is small in floor area but high in specification.

The submarine drydock pen — the most demanding HVAC envelope on any Australian defence site

The submarine drydock pen is the single most demanding HVAC envelope in the entire Australian Defence Maritime Affairs portfolio. The combination of an enclosed large-volume space, a chloride-laden marine atmosphere, hydrocarbon and battery service inside the boat, hex chrome welding fume from stainless work, isocyanate from polyurethane paint, hydrogen from battery service, ozone from MIG welding, hydrogen sulphide from bilge water, and a continuous atmospheric monitoring overlay creates an engineering envelope that no civilian peer matches.

Volume and air-change rate

A modern enclosed submarine drydock pen for a Collins-class boat or a future SSN-AUKUS boat is typically a covered hardstand or shed over a graving dock or a syncrolift, with the boat sitting on keel blocks inside the conditioned envelope. The conditioned volume for a single boat is in the order of 80,000 to 180,000 cubic metres depending on the building geometry and the height clearance over the boat. The engineered mechanical ventilation rate runs at 6 to 10 air changes per hour during active maintenance operations, scaling down to 1 to 2 air changes per hour for quiescent periods when the boat is out of the building or no hot work is occurring. The supply air rate at the peak of 10 ACH on a 180,000 cubic metre volume is 1,800,000 cubic metres per hour or 500 cubic metres per second — a mechanical plant scale equivalent to a major hospital or a small data centre.

Atmospheric monitoring

The submarine drydock pen carries continuous atmospheric monitoring tied to the building management system and to the boat's internal air revitalisation interfaces when the boat is alongside. The monitored parameters include oxygen partial pressure (target 20.9 per cent ambient with alarm on deviation), carbon dioxide concentration (alarm at 5000 ppm eight-hour TWA, 30,000 ppm STEL), carbon monoxide (Safe Work Australia WES 30 ppm eight-hour TWA, alarm at 25 ppm), total hydrocarbons (alarm at 25 per cent of the relevant lower explosive limit), hydrogen sulphide (10 ppm eight-hour TWA, 15 ppm STEL — alarm at 8 ppm), hydrogen (alarm at 25 per cent LEL = 1 per cent volume), volatile organic compounds (selected species depending on the active operations), and aerosol particulate including welding fume, hex chrome and isocyanate at the operator breathing zone. The monitoring grid covers the boat hatch positions, the floor of the pen, the high points where buoyant gases accumulate, and the operator stations. The monitoring system is itself zone-classified equipment certified to AS/NZS 60079 with intrinsically-safe cabling.

Air revitalisation interfaces

Submarine air revitalisation is the closed-cycle atmosphere management plant that maintains breathable atmosphere inside the boat during submerged operations. The plant includes the CO2 scrubber (typically amine-based on Collins-class, anticipated to be different on SSN-AUKUS), the oxygen generation plant (electrolytic), the carbon-monoxide and hydrocarbon catalytic burners, the particulate filtration and the humidity control. During alongside maintenance the boat's air revitalisation plant may be shut down for service and the boat's internal atmosphere is supplied from the shore plant through controlled-volume interfaces at the boat hatch positions. The shore-side HVAC system has dedicated supply ducts that interface with the boat at the access hatch, with controlled-volume dampers and the air condition matched to the boat's internal atmosphere management plant expectation — temperature 18 to 22 degrees Celsius, humidity 40 to 60 per cent, oxygen 20.9 per cent ambient.

Confined-space ventilation in the boat

Work inside the submarine pressure hull during alongside maintenance is confined-space entry under AS 2865. Each tank, void, compartment and cabling space inside the boat has a defined entry procedure, gas testing requirement, ventilation rate, rescue equipment, exit time and permit-to-work record. The shore-side HVAC system provides supplementary forced-ventilation supply via flexible ducting through the hatch into the active work compartment, sized to the maximum credible activity (typically welding or cutting inside the boat — the WES limit on hex chrome from stainless welding is the binding criterion at 0.005 mg/m³ at the operator breathing zone). The flexible ducting is 316L stainless wire-reinforced PVC or all-stainless flexible duct with bonded earthing continuity to the shore HVAC.

Duct construction and leakage class

The duct construction inside the submarine drydock pen is 316L stainless throughout, with welded plenum sections in the main supply and extract trunks, TDF flanged construction on branch runs and accommodation ducts, and SMACNA Class 3 leakage class minimum on all extract paths. The plenum welding is performed on the SBSF-1525 stitchwelder at the contractor's fabrication shop because the leakage class achievable on welded plenum sections is one to two orders of magnitude tighter than TDF-only construction. The TDF flange is produced on the SBAL-V auto duct line in the same fabrication shop on the same coil. The combined SBAL-V plus SBSF-1525 cell handles the full duct scope for a submarine drydock pen project on a single shift, single-machine basis.

Acoustic and vibration control

The submarine drydock pen has a tight acoustic target driven by the working communications requirement and the structural vibration constraint on the boat itself. AS 4068 sound absorption coefficients are applied to the wall and ceiling lining selection, and the duct system is designed to NC-50 industrial baseline with NC-40 at operator stations and NC-35 at the supervisor positions. Sound power data is required on every fan submittal and inertia bases are used on all rotating equipment to control structure-borne vibration through the building floor into the boat. Flexible connections are fitted at every fan inlet and outlet.

Dry dock, graving dock and covered welding bay HVAC

A dry dock or graving dock for a surface combatant is fundamentally different in HVAC scope from a submarine drydock pen. The surface dock is generally an open or partially covered concrete dock with the vessel sitting on keel blocks exposed to ambient weather. The HVAC scope is concentrated in adjacent covered welding bays, paint halls, blast bays and workshops rather than in a conditioned envelope over the dock itself.

Captain Cook Graving Dock — Sydney

The Captain Cook Graving Dock at Garden Island Sydney is the largest graving dock in Australia, with internal length approximately 351 metres and width 45 metres. The dock supports the largest surface combatants in the Royal Australian Navy fleet — the Hobart-class destroyers, the future Hunter-class frigates, and supplementary US Navy and allied vessels under joint operations. The dock itself is open to ambient weather and is not HVAC-conditioned. The adjacent workshop and support buildings — paint hall, blast bay, welding bays, engine room overhaul, parts production, accommodation — carry the HVAC duct scope.

Covered welding bay

The covered welding bay adjacent to the dock is a partially enclosed building where blocks, plates and structural sections are welded under controlled atmospheric conditions before installation on the vessel in the dock. The welding bay HVAC scope is dominated by source-capture extraction at every welding station — MIG, MAG, TIG, SAW and stick welding all carry distinct fume profiles. The most demanding criterion is hex chrome Cr(VI) from stainless welding, with Safe Work Australia WES at 0.005 mg/m³ eight-hour TWA. The engineering control is a movable source-capture arm at each welding station with face velocity 0.5 metres per second minimum at 300 mm from the arc, feeding a HEPA-filtered cartridge collector with chrome-rated media. The exhaust hood and the flexible arm are 316L stainless construction. The collector cartridges are change-out under controlled conditions with respiratory protection.

General dilution ventilation supplements the source capture for non-welding heat load and for low-level fugitive fume. The dilution rate is set by AS 1668.2 plus AS/NZS 1715 occupational atmospheric overlay, typically 6 to 10 air changes per hour at the working zone height. The supply air is tempered to 20 to 22 degrees Celsius year-round to maintain worker productivity in a sustained operation. The make-up air is filtered through MERV 14 minimum filtration to exclude outdoor particulates that would otherwise interfere with the welding atmosphere.

Acoustic control in the welding bay targets NC-55 industrial baseline. Sound attenuators are not generally cost-effective in a heavy industrial environment because the operational noise (the welding arc itself, grinding, hammering) dominates the duct-related noise. The duct sizing is conservative to keep face velocities below 8 metres per second at branch take-offs and below 12 metres per second in the main trunk.

Combined cutting and grinding station HVAC

Plasma and oxy-fuel cutting stations are integrated into the welding bay or located in a dedicated cutting bay with downdraft table ventilation. The downdraft table pulls capture velocity of 0.5 to 1.0 m/s across the cutting surface, drawing particulate and fume through a grated table top into a filtered collector below the floor. The duct material is 316L stainless because the cutting fume profile contains zinc oxide (from galvanised plate cutting), aluminium oxide (from aluminium cutting), and chromium oxide (from stainless cutting). The collector cartridges are change-out under controlled conditions. The SBPC1500 plasma cutter — when SBKJ supplies it to the shipyard fabrication workshop — is integrated with the downdraft table on the same fabrication-shop cell.

NFPA 660 combustible-dust overlay

NFPA 660 combustible dust governs aluminium and magnesium grinding and cutting operations where fine metallic particulate can accumulate to deflagration concentration. The duct material is conductive 316L stainless with continuous earthing across every flange (under 10 ohms end-to-end), the collector has deflagration venting or chemical suppression, and explosion isolation valves prevent flame propagation back from the collector to the upstream duct. The aluminium catamaran shed at Henderson Western Australia is the most prominent application — Austal's production bay handles substantial aluminium plate and the fume extraction is engineered against NFPA 660.

Paint hall HVAC — AS/NZS 2312 marine coatings and isocyanate capture

The marine paint hall is a high-engineering envelope because of the combination of NFPA 33 fire-safety overlay, AS/NZS 2312 protective coating system selection, isocyanate Safe Work Australia WES (0.005 ppm STEL on the isocyanate monomer), Zone 2 hazardous-area classification inside the spray envelope, and the strict quality control on the coating finish that drives a controlled air-flow regime and temperature stability.

NFPA 33 booth design

The spray application of flammable or combustible material is governed by NFPA 33 (US standard adopted into Australian Defence Manual of Fire Safety) with the booth interior classified as a hazardous area during spray operations. The booth construction is continuous-welded 316L stainless interior with no rivets, fasteners or sealants that could spark or fail under solvent exposure. The exhaust path is also continuous-welded 316L stainless. The exhaust fan is spark-resistant non-ferrous wheel construction. The fan motor sits outside the airstream in an externally mounted housing. Every electrical fitting inside the booth is certified Ex equipment to AS/NZS 60079.

Downdraft and semi-downdraft air-flow

The booth air-flow is downdraft or semi-downdraft with face velocity 0.5 m/s downward through filter floors. The downdraft profile draws contaminated air away from the operator breathing zone and pushes it through floor-level cartridge filtration before the exhaust path. Cross-draft is acceptable for smaller booths but is not preferred for marine coating because the cross-flow can disturb the wet film and create surface defects. The make-up air is tempered to within 2 degrees Celsius of booth ambient — typically 20 to 22 degrees Celsius — to prevent thermal-shock micro-cratering of the wet topcoat at the spray fan. The make-up air is filtered to MERV 14 minimum to exclude outdoor particulates that would otherwise contaminate the finish.

AS/NZS 2312 protective coating system

Marine protective coatings for Royal Australian Navy vessels follow AS/NZS 2312 with the specific coating system matched to the service durability class. The standard for the vessel exterior is C5-M Long durability with an epoxy primer (high-build, micaceous iron oxide or zinc-rich), an intermediate epoxy or epoxy mastic, and a polyurethane topcoat (gloss or semi-gloss depending on the service). The polyurethane topcoat contains isocyanate monomers — typically HDI or IPDI — with the Safe Work Australia WES at 0.005 ppm STEL and 0.02 mg/m³ eight-hour TWA. Operator respiratory protection alone is not sufficient and the engineered booth ventilation is the primary control.

Stack discharge and AS 3580 boundary air

The booth exhaust stack discharges at a minimum 3 metres above roof line and 15 metres horizontally from any building air intake, with stack-tip velocity of 15 metres per second minimum to ensure effective plume dispersion. The discharge is monitored for total volatile organic compounds and for isocyanate to demonstrate compliance with AS 3580 boundary air quality at the site fence. Where the site fence is close to the paint hall — typical on Sydney Garden Island where the site is densely developed — additional carbon adsorption or thermal oxidation is fitted on the exhaust to further reduce the boundary VOC.

Heated curing zone

Marine polyurethane topcoats cure at ambient temperature but the cure time is accelerated by elevated temperature. A separate heated curing zone adjacent to the spray booth holds the freshly coated component at 40 to 60 degrees Celsius for 4 to 8 hours, with continuous extraction at 6 air changes per hour to clear the residual solvent that continues to outgas during cure. The duct material in the cure zone is 304L or 316L stainless because the elevated temperature combined with isocyanate vapour is aggressive on coatings. The cure zone is separated from the spray booth so that solvent vapour from the cure zone does not feed back into the spray atmosphere.

Blast hall HVAC — abrasive blast, silica and NFPA 660

The blast hall is the second most demanding HVAC envelope in the shipyard after the paint hall. The combination of abrasive blast dust (typically copper slag, garnet, glass bead or steel grit), silica content in the blast media (AS 3957 silica dust control), and the deflagration risk from accumulated dust (NFPA 660 combustible dust) drives a specific HVAC duct envelope.

Capture velocity and air-flow

The blast hall captures dust at the blast face at velocities of 1000 feet per minute or higher — approximately 5 metres per second — to prevent fugitive dust escape into the surrounding building. The air-flow regime is generally a uni-directional flow from the operator end of the hall through the blast face and into the extraction wall. The blast face air velocity is set by the maximum credible operator activity (typically open blast nozzle work with large surface area exposure). The make-up air is filtered to MERV 8 minimum and tempered for operator comfort.

AS 3957 silica dust

Silica content in blast media is regulated under AS 3957 with the Safe Work Australia WES on respirable silica at 0.05 mg/m³ eight-hour TWA. The engineering control is the source-capture air-flow described above plus operator-side respiratory protection (forced supplied-air helmet typically) plus dust collector with high-efficiency filtration. The collector cartridges are change-out under controlled conditions with the operator in respiratory protection.

NFPA 660 combustible dust

Blast dust can contain combustible metallic content — aluminium dust from aluminium hull blasting, steel dust from steel hull blasting, copper slag dust from the blast media itself. The deflagration risk requires conductive 316L stainless ductwork with electrically continuous flanges, explosion isolation valves between the blast hall and the collector, deflagration venting or chemical suppression on the collector, and continuity testing to under 10 ohms across the full duct run. The fan is spark-resistant non-ferrous construction with the motor outside the airstream.

Slag dust accumulation

Copper slag blast media is denser than steel or garnet and accumulates more aggressively at low-velocity points in the duct. The duct design avoids horizontal long runs at velocities below 12 metres per second, uses gentle bends and access doors at every change of direction, and provides for periodic cleaning at the contractor's maintenance schedule. The access doors are 316L stainless with captive gasketed clamps that maintain duct integrity through the deflagration test pressure.

Engine room overhaul and machinery sustainment HVAC

The engine room overhaul facility supports the disassembly, repair, machining and reassembly of marine diesel engines, gas turbines, electrical generators, pumps, valves and other rotating machinery from the surface and submarine fleets. The HVAC scope combines machining oil mist and hydraulic fluid mist extract, fuel handling vapour extract, refrigerant handling under AS/NZS 5149, and the general dilution ventilation for a sustained heavy industrial environment.

Oil mist and hydraulic fluid mist extract

Machining stations — lathes, mills, grinders, honing machines — generate oil mist and metalworking fluid aerosol that requires source-capture extract at each station. The capture face velocity is 0.5 metres per second at the work zone, with the extract feeding a mist collector with high-efficiency coalescing filtration. The recovered fluid is recycled through the central metalworking fluid system. The duct material is 316L stainless for the extract path because the combined chloride marine atmosphere and the oil mist condensate is aggressive on galvanised steel.

Diesel engine commissioning bay

The diesel engine commissioning bay tests overhauled engines under load before re-installation on the vessel. The exhaust capture is a high-temperature 316L stainless engine exhaust hood with the duct run discharging through a roof stack. The exhaust gas temperature peaks at 400 to 500 degrees Celsius during full-power testing, requiring high-temperature duct construction with expansion joints and high-temperature insulation. The hood is positioned over the engine exhaust outlet with a flexible bellows that accommodates engine movement on the test stand.

Refrigerant handling

Naval vessels carry substantial refrigeration plant for compartment cooling, food storage and weapons cooling. The engine room overhaul facility supports refrigerant charging and recovery operations on the overhauled plant. Refrigerant handling is governed by AS/NZS 5149 with leak detection on the refrigerant types in use (R-134a, R-410A, R-407C and selected military-specific refrigerants). The ventilation rate is set by the maximum credible release scenario and the ductwork is 316L stainless with bonded earthing continuity.

Battery shop HVAC — lead-acid legacy and lithium-ion future

The battery shop supports the maintenance, testing, charging and replacement of submarine main batteries and surface combatant battery systems. The HVAC duct envelope is shaped by the battery chemistry — historically lead-acid for Collins-class submarines, transitioning to lithium-ion for future fleet under AS/NZS 5139 and NFPA 855.

Lead-acid battery shop

Lead-acid batteries during charging release hydrogen and oxygen through electrolysis of the electrolyte. The hydrogen accumulation is the primary hazard. The shop is classified Zone 2 under AS/NZS 60079.10.1 with hydrogen dispersion ventilation maintaining the hydrogen concentration below 25 per cent of the lower explosive limit (4 per cent volume in air = 25 per cent LEL at 1 per cent volume). The ventilation rate is set by the maximum credible charging activity, typically 6 to 12 air changes per hour at the ceiling level where hydrogen accumulates. The duct material is 316L stainless with bonded earthing continuity, the fan is spark-resistant non-ferrous, and the motor is outside the airstream.

The acid mist from battery service is aggressive on aluminium and on galvanised steel, which reinforces the 316L stainless duct material selection. Lead-exposure control is separate from the ventilation envelope — operators handling battery plates wear respiratory protection and the work zone is wet-cleaned to control dust dispersal. The Safe Work Australia WES on lead is 0.05 mg/m³ eight-hour TWA.

Lithium-ion battery shop

Lithium-ion batteries do not release hydrogen during normal charging but carry a thermal-runaway hazard if abused, overcharged or damaged. The shop is engineered against AS/NZS 5139 and NFPA 855 with the design basis including a single-cell thermal-runaway scenario expanding to module-scale failure. The ventilation rate is sized for the worst-case scenario, with rapid-extract capability initiated by smoke or temperature detection. The duct material is 316L stainless. The ventilation discharge is via a dedicated stack at a safe distance from any air intake. Fire suppression on the storage racks is engineered to AS/NZS 5139 with water mist or aerosol-suppression systems.

Naval stores, fuel jetty and magazine HVAC

Naval stores cover the bulk storage of fuel, lube oil, ammunition and stores for the fleet sustainment programme. The HVAC envelope is dominated by hazardous-area classification, vapour management, leak detection and explosion-relief venting. Each store type has a distinct HVAC profile.

Bulk fuel storage

Naval bulk fuel stores hold F-44 marine diesel, F-76 naval distillate, F-34 jet fuel for Fleet Air Arm operations, and small quantities of specialty fuels. The storage tanks are above-ground or under-ground depending on the site, with the tank-room ventilation governed by AS 1940 and AS/NZS 60079. The tank vents discharge through dedicated stacks with vapour recovery. The pump-room is classified Zone 1 hazardous area with 316L stainless duct, bonded earthing continuity, spark-resistant non-ferrous fans, externally-mounted motors and continuous hydrocarbon monitoring tied to automatic shutdown at 25 per cent LEL.

Fuel offloading jetty

The fuel offloading jetty is the working interface between bulk-fuel tankers and the shore storage. The Zone 1 hazardous area extends through a defined envelope around the manifold, pumps and vapour vents during transfer operations, with Zone 2 extending outward. The ventilation envelope on the jetty pump house is 316L stainless duct with bonded earthing continuity (commissioned at under 10 ohms end-to-end), spark-resistant fan and external motor. Vapour recovery is mandatory under AS 1940. The tanker connection is a closed-circuit operation with vapour returned to the tanker — the on-shore storage tank vapour space is held at controlled pressure to receive the displaced vapour during offloading.

Ammunition and weapons magazine

Naval ammunition and weapons stores hold conventional munitions, missiles, torpedoes and the supporting pyrotechnic devices. The magazine HVAC is governed by Department of Defence Explosives Safety Board (DDESB) safety distances, the Defence Manual of Fire Safety (DMFS), AS 1940 (for any flammable propellant component) and AS/NZS 60079 where vapour exposure applies. The ventilation rate is set by the maximum credible event analysis and may include passive ventilation rather than mechanical fans to eliminate electrical equipment from the magazine zone. Where mechanical ventilation is required, the duct is heavier-gauge welded construction (typically 3 mm wall minimum) with explosion-relief venting at controlled points. The duct material is 316L stainless throughout.

Torpedo and missile assembly

The torpedo and missile assembly facility supports the maintenance, testing and assembly of the Royal Australian Navy weapons inventory. The facility carries a TEMPEST RF-shielded envelope on the classified electronics zones, with waveguide-below-cutoff penetrations on every HVAC duct crossing the boundary. The duct material is 316L stainless throughout. The component country-of-manufacture audit applies to every fan, damper, sensor and controller in the controlled zone — Five Eyes-aligned country of manufacture only (Australia, United States, United Kingdom, Canada, New Zealand). The audit trail is logged at component serial number level and retained for the life of the facility.

Sonar electronics shop and underwater equipment test pool

The sonar electronics shop is a classified electronics assembly facility supporting the maintenance and integration of Royal Australian Navy sonar systems. Thales Australia at Garden Island Sydney is the principal sonar integrator and operates the largest such facility in the country. The HVAC envelope combines ISO 14644 cleanroom classification, ESD-controlled work area, anti-magnetic 316L stainless duct, TEMPEST emanation control on selected zones, and country-of-manufacture audit on every component.

ISO 14644 cleanroom for semiconductor sonar

Sonar transducer and semiconductor assembly requires ISO 14644 Class 7 or Class 8 cleanroom envelope. The HVAC supply is HEPA-filtered through ceiling-mounted fan-filter units or through a centralised AHU with terminal HEPA filtration at the diffuser. The return path is through low-wall returns at the working zone level. The ductwork inside the cleanroom envelope is bonded conductive 316L stainless with internal smooth-surface finish and continuously welded longitudinal seams. The air-flow regime is typically uni-directional vertical flow with face velocity 0.3 to 0.5 metres per second across the work surface.

ESD control

Electrostatic discharge control is mandatory in semiconductor assembly. The duct is bonded to the building earth with continuity tested at under 10 ohms across the full duct run. The flooring is bonded conductive (ESD-safe vinyl or epoxy with embedded ground grid). Operators wear ESD-safe garments with wrist-strap grounding at the work station.

Anti-magnetic specification

Sonar electronics are sensitive to magnetic field perturbation from ferromagnetic ductwork. The duct is anti-magnetic 316L stainless with solution-annealing after forming and documented permeability test on each batch — relative permeability under 1.05 is the typical specification. The fan and damper assemblies inside the controlled zone are also low-magnetic construction.

Underwater equipment test pool

The underwater equipment test pool is an indoor pool used for sonar transducer, sensor and undersea-equipment certification under controlled water conditions. The pool water is chlorinated for hygiene and the headspace above the pool is humid (typically 60 to 75 per cent relative humidity). The HVAC envelope combines high-rate extract above the pool surface (4 to 6 air changes per hour at the pool space) to clear the chloramine evaporation, combined sensible and latent cooling sized for the worst-case evaporation load, and 316L stainless duct throughout because chloramine attacks aluminium and galvanised steel. The pool deck and the equipment work area are conditioned to operator comfort at 22 to 24 degrees Celsius dry bulb and 50 to 60 per cent relative humidity.

Submarine escape training tank and diving school HVAC

The submarine escape training tank — the Deep Escape Submarine Simulator (DESS) — is a specialised facility used to train submariners in the escape procedures from a disabled submarine. The facility consists of a deep (typically 30 to 40 metre) water tank with associated chamber, lock-out and lock-in compartments, and the support spaces (operator station, change rooms, medical observation). The diving school provides instruction and qualification for clearance divers, ships divers and submarine escape rescue divers, with associated compression chamber for diver training and decompression sickness treatment.

DESS tank HVAC

The DESS tank hall is a high-humidity, chlorinated-atmosphere envelope similar to the underwater equipment test pool but at substantially larger scale. The conditioned volume around the tank is in the order of 5000 to 10,000 cubic metres. The HVAC scope includes continuous extract above the tank surface at 4 to 6 air changes per hour, combined sensible and latent cooling sized for the worst-case training-day evaporation load (multiple trainees in the water with active surface disturbance creates higher evaporation than a quiescent pool), and 316L stainless duct throughout. The locker and change rooms are vented separately to avoid pulling humid air into adjacent training spaces. The plant room access is through airlock construction.

The chamber, lock-out and lock-in compartments are pressure vessels under AS 2030 and AS 1210, with HVAC interfaces to the chamber bulkhead that are themselves zone-classified equipment.

Diving school compression chamber HVAC

The compression chamber for diver training and decompression sickness treatment is a pressure vessel rated to the operational diving depth (typically 50 to 100 metres equivalent for clearance diver training). The chamber HVAC is internal to the chamber and is part of the chamber manufacturer's scope — the shore HVAC interface is at the chamber bulkhead. The shore-side support spaces (operator station, medical observation, decompression chamber hall) are conditioned to operator comfort at 22 to 24 degrees Celsius and 50 to 60 per cent relative humidity. The atmospheric monitoring inside the chamber is continuous with O2, CO2, hydrocarbon and humidity sensors tied to the chamber control system.

Worker accommodation and officers' mess HVAC

The worker accommodation and officers' mess HVAC scope on a Royal Australian Navy base is the largest single duct-quantity scope by linear metre, mirroring the wider defence facility pattern documented in our defence and military HVAC duct guide. The construction is conventional commercial-grade lockformed galvanised sheet duct under SMACNA Class 6 leakage, with AS/NZS 2312 protective coating applied where the duct is exposed to outside air in plant rooms.

Sailor accommodation

Royal Australian Navy sailor accommodation is built to National Construction Code Class 3 with AS 1668.2 ventilation rates (typically 10 L/s per person plus 25 L/s per WC for amenities) and AS 1668.1 fire and smoke control. The duct construction is conventional commercial-grade lockformed galvanised G275 sheet duct under SMACNA Class 6 leakage. The duct is fabricated on the SBAL-V auto duct production line in galvanised configuration — the same machine that handles the 316L stainless scope on a separate coil. A single-shift, single-machine SBAL-V cell with the throughput of 16 m/min at 87 kW handles the accommodation duct demand for a brigade-scale precinct over a 24-month construction window.

Officers' mess and recreational

The officers' mess and recreational areas follow commercial recreational and food service standards with slightly higher outside-air rates than office spaces (AS 1668.2 Table 3.3). Kitchen exhaust duct on canteens follows the same rules as commercial kitchen exhaust — typically 1.2 mm minimum gauge, fully welded construction in the cooking zone, with cleanout access at every change of direction. The fabrication is on the SBAL-V coil line with the welded sections produced on the SBSF-1525 stitchwelder. The fan and grease filter selection follows the AS 1668.2 commercial kitchen specification.

Medical centre

Defence medical centre HVAC follows AS 1668.2 with overlays from the Australasian Health Facility Guidelines. Negative-pressure isolation rooms require SMACNA Seal Class A and dedicated extract paths. Operating theatres and procedure rooms require ultra-clean air supply at controlled temperature and humidity. Pharmacy and laboratory exhaust requires 316L stainless construction.

Gymnasium and indoor sports

Gymnasium HVAC follows commercial recreational standards. The high humidity from sustained exercise creates condensation risk on cold-water pipes and chilled-water duct — the duct is hot-dip galvanised G275 with AS/NZS 2312 protective coating where the duct is exposed to the gym ambient.

Classified communications, ASIO-cleared secure rooms and TEMPEST scope

The classified communications scope on a Royal Australian Navy base spans the operational headquarters communications centre, the submarine squadron communications, the secure intelligence preparation rooms (some of which are ASIO-cleared), and the supporting cyber and electronic warfare facilities. The HVAC envelope follows the same TEMPEST emanation control and country-of-manufacture audit pattern as the defence-military classified facility profile.

TEMPEST emanation control

TEMPEST prevents electronic emanations from leaking outside a classified facility. From the HVAC perspective, every conductive penetration through a TEMPEST-shielded enclosure is treated as a potential RF antenna. The duct design responses are: route classified-zone HVAC ducts only inside the shielded envelope, separate AHU return paths from any unclassified zone, use waveguide-below-cutoff penetrations at the boundary, and audit country of manufacture for fans, dampers and controllers — Top Secret and ASIO-cleared zones require Five Eyes-aligned manufacture only.

ASIO-cleared secure rooms

The classified intelligence preparation rooms at the Royal Australian Navy operational headquarters and at HMAS Stirling submarine squadron are ASIO-cleared spaces with the highest classification overlays in the defence portfolio. The duct material is anti-magnetic 316L stainless throughout the controlled zone. Country-of-manufacture audit is the most rigorous of any defence application. The audit trail is retained for the life of the facility plus a defined records-retention period.

Submarine command and control facility

The submarine command and control facility — the shore-based operational coordination centre for the submarine fleet — sits at HMAS Stirling Western Australia. The HVAC envelope combines classified communications, TEMPEST emanation control, redundant cooling for the operations centre electronics, and the supporting accommodation for shift workers. The duct material is anti-magnetic 316L stainless in the operations zone and standard 316L in the supporting areas.

SBKJ machinery recommendation for naval, submarine and shipyard duct fabrication

SBKJ Group's machine portfolio supports the lighter-gauge sheet-metal portion of naval, submarine and shipyard HVAC ductwork — the accommodation, admin, plant room, paint hall, blast bay, welding bay and engine room workshop scope. Heavier-gauge welded plenum sections, blast-resistant penetrations and EMP-shielded honeycomb assemblies are typically performed by specialist welded-fabrication subcontractors. We co-ordinate with those subcontractors at the project boundary so the lighter-gauge sheet metal and the heavier-gauge welded scope integrate cleanly.

SBAL-V auto duct production line — stainless configuration

The SBAL-V auto duct production line in 316L stainless configuration is the principal machine for naval, submarine and shipyard duct fabrication. The machine handles 316L stainless coil at 0.5 to 1.5 mm thickness and 1500 mm coil width on a 16 m/min throughput with 87 kW total installed power. The roller and tool assemblies are configured for stainless coil with adjusted lubrication and run-out speeds. The TDF flange is produced inline on the same coil. Surface finish is 2B as standard with a 2B-DD upgrade available for visible architectural ducts. The SBAL-V in stainless configuration covers the full naval site supply duct scope — paint hall extract, blast bay extract, welding bay extract, engine room overhaul ducts, submarine drydock pen accommodation ducts, and the entire outdoor exposed duct portion of the project.

SBAL-V auto duct production line — galvanised configuration

The SBAL-V in galvanised G275 configuration is the workhorse for accommodation, admin, training and general worker-comfort duct. The same machine handles the galvanised scope on a separate coil from the stainless scope, with tooling change-over time in the order of 30 minutes between coils. Throughput on a single shift exceeds the requirement for a brigade-scale accommodation precinct.

SBAL-III auto duct production line

The SBAL-III auto duct production line is a smaller-capacity alternative to the SBAL-V, with throughput 14 m/min and total installed power 15.7 kW. The SBAL-III suits smaller fabrication workshops on standalone naval projects where the SBAL-V capacity is not required.

SBAL-II auto duct production line

The SBAL-II is the highest-throughput SBAL variant at 18 m/min on 5.5 kW installed power. The SBAL-II suits accommodation-dominant projects where the duct demand is concentrated in galvanised G275 sheet and the throughput per shift is the binding constraint.

SBTF spiral tubeformer (1500C, 1602, 2020)

The SBTF spiral tubeformer in the 1500C, 1602 or 2020 configurations supports round duct fabrication from 80 mm to 2000 mm diameter, covering the full naval base round-duct scope. Coil thickness is configurable for galvanised G275, 304L stainless or 316L stainless. The four-roller drive section maintains the helical seam quality required for SMACNA Class 6 or Class 3 leakage. The SBTF cell is integrated with the SBAL-V cell at the contractor's fabrication shop, sharing the coil stock and the supervisor.

SBEM-1250 elbow machine

The SBEM-1250 elbow machine produces gored elbow fittings in galvanised G275 and 316L stainless from 200 mm to 1250 mm diameter. The elbow machine sits alongside the SBAL-V coil line and supplies the fitting demand that the coil line itself does not generate.

SBSF-1525 stitchwelder

The SBSF-1525 stitchwelder is critical for thick-gauge stainless plenum construction in the submarine drydock pen and paint hall extract path where TDF flanges alone cannot achieve the required leakage class. The stitchwelder produces a resistance seam weld on the longitudinal joint of the plenum section at 2.5 kW power input. The weld is continuous, leak-free at SMACNA Seal Class A pressure, and corrosion-equivalent to the parent metal — no additional pickling or passivation is required on the seam. The SBSF-1525 sits alongside the SBAL-V cell at the contractor's fabrication shop and handles the welded plenum portion of the scope on the same coil stock that the SBAL-V uses for the lighter sections.

SBFB-1500 flange machine

The SBFB-1500 flange machine produces angle-iron flanges at 7.5 kW power input and 1.20 m/min throughput, supporting the flanged-joint construction that supplements TDF on submarine drydock pen and paint hall plenum sections.

SBHF hydraulic press

The SBHF hydraulic press handles the heavier-gauge forming operations on access doors, transition fittings and bulkhead penetrations.

SBPC1500 plasma cutter

The SBPC1500 plasma cutter handles 316L stainless duct fittings, transitions, access doors and bulkhead penetrations on the shipyard maintenance shop floor. The cutter is integrated with the downdraft cutting table for combined cutting and grinding fume extraction. The SBPC1500 is the principal cutting machine for the stainless fitting and transition scope across the entire project.

SBLR-600 and SBLR-600A roll forming line

The SBLR-600 and SBLR-600A roll forming line at 7.6 m/min handles the specialty profile work — rectangular trim, transition reinforcing and structural support brackets — that supplements the main coil line.

Spark-resistant fan selection — not SBKJ scope

The spark-resistant non-ferrous fan selection for shipyard blast bay, paint hall and fuel jetty service is left to the contractor's ATEX/IECEx fan supplier. SBKJ Group supplies the duct fabrication machinery and the duct itself; we do not supply the rotating equipment. We co-ordinate at the project boundary so the fan inlet and outlet connections match the duct dimensions and the flange type.

Australian Industry Capability content and AUKUS Pillar 1 procurement

AUKUS Pillar 1 and major Defence Maritime Affairs projects target a contracted Australian Industry Capability (AIC) content percentage on the mechanical building services scope. The AIC content is calculated across the supply chain — Australian fabrication labour, Australian-supplied raw materials, Australian-installed insulation and Australian-supplied components all count towards the AIC percentage. AUKUS-aligned facility construction projects routinely target AIC content of 60 per cent or higher on the mechanical building services.

For HVAC ductwork the AIC content is dominated by Australian fabricated duct (the labour-intensive portion of the scope), Australian-installed insulation, and Australian-supplied galvanised G275 and 316L stainless coil where available. Stainless coil is partially produced in Australia at the BlueScope and the Liberty Primary Steel operations, with imports filling the balance from Five Eyes-aligned countries. Specialised filtration components, ATEX/IECEx-certified fans and the EMP-rated honeycomb penetrations are frequently imported from Five Eyes-aligned countries (United States, United Kingdom, Canada, New Zealand) with foreign-ownership disclosure in the supply chain.

SBKJ Group operates from Box Hill North Victoria as the Australian arm of the SBKJ international machine-supply business. We support naval, submarine and shipyard HVAC contractors through the AIC framework with Australian-based engineering, commissioning and field service. The duct fabrication machinery is supplied and installed at the contractor's Australian workshop, with the duct itself fabricated in Australia from coil sourced from Australian and Five Eyes partner mills. The contractor's AIC content is calculated across the resulting scope and presented to the Australian Submarine Agency or the relevant Commonwealth project office as a contracted deliverable.

How SBKJ supports naval, submarine and shipyard HVAC contractors

SBKJ Group's engagement model with Defence Maritime Affairs HVAC contractors runs in four modes that mirror the wider defence portfolio. Each engagement is structured around the specific contractor's role in the project and the regulatory envelope they are working under.

The first mode is auto duct line and ancillary machinery supply. We sell, install, commission and field-service the duct fabrication machinery in the contractor's Australian workshop. The SBAL-V, SBAL-III, SBAL-II, SBTF, SBEM-1250, SBSF-1525, SBFB-1500, SBHF, SBPC1500 and SBLR-600/600A machines cover the full lighter-gauge sheet-metal scope on naval, submarine and shipyard projects. The commercial relationship is direct between SBKJ Group and the duct contractor.

The second mode is engineering consultation on duct material selection, AS 4254 construction class, leakage class and AS/NZS 60079 hazardous-area envelope. SBKJ engineers have combined experience across hardened, marine, hazardous-area and classified facility work. Where a defence specification requires resolution between the SMACNA, AS/NZS 4254, EN 1505 and DW/144 standards, our engineers provide the cross-walk reference.

The third mode is sub-supply through prime contractors on AUKUS-aligned projects. SBKJ machinery and engineering services are routinely supplied through prime contractors who hold the head DISP accreditation and the contractual relationship with the Australian Submarine Agency or the Commonwealth project office. This is the dominant mode for AUKUS Pillar 1 shipbuilding precinct and major-base infrastructure work.

The fourth mode is co-ordination with welded-fabrication subcontractors on heavy-gauge scope. For the blast-hardened, EMP-shielded and heavy-gauge submarine drydock pen plenum sections that fall outside SBKJ's machinery scope, we co-ordinate with the contractor's chosen welded-fabrication subcontractor to ensure that the lighter-gauge sheet-metal scope and the heavier-gauge welded scope integrate cleanly at the project boundary. The SBSF-1525 stitchwelder handles the intermediate-gauge welded plenum scope — 1.2 mm to 1.5 mm 316L stainless on resistance seam welds — that bridges between the SBAL-V coil line output and the specialist welded-fabrication subcontractor's heavy-gauge scope. Industry bodies including the Australian Industry & Defence Network (AIDN), the Defence Teaming Centre (DTC), the Submarine Institute of Australia (SIA) and the Henderson Alliance shipbuilders forum are useful coordination points for cross-supplier scope.

Commissioning, NATA-accredited testing and the audit-of-record

The final stage of a naval, submarine or shipyard HVAC project is commissioning and the NATA-accredited test deliverables that close out the contract. The commissioning report is the audit-of-record document that triggers warranty start, supports any subsequent dispute resolution and is referenced through the operational life of the facility.

Air-flow measurement

Air-flow measurement at every diffuser, every grille and every plant connection is NATA-accredited and presented as a balance report. The measurement equipment is calibrated and the technician is certified. The report includes the design air flow, the measured air flow, the deviation and the corrective action where the deviation exceeds the specified tolerance (typically plus or minus 10 per cent).

Smoke-pencil capture verification

Smoke-pencil verification at every welding hood, every spray booth face and every blast bay face confirms the capture velocity meets the specification. The test is recorded with photographic evidence and the smoke trajectory is documented. Capture failures trigger corrective action — typically additional source-capture hood positioning, increased fan duty or additional baffle work.

Leakage testing

Leakage testing per the SMACNA HVAC Air Duct Leakage Test Manual is performed on every plant connection and every plenum section. The test pressure is set by the operational static pressure class. The measured leakage is compared to the specified leakage class (Class 6 for accommodation, Class 3 for hazardous-area extract, Seal Class A for paint hall and submarine drydock pen plenum). Failures trigger remediation — typically additional sealant on TDF joints or rectification of the welded seam.

AS 1530.4 fire-rated penetration verification

Every fire-rated penetration is verified against the tested-system certification. The fire damper actuation is tested under power and under fire-mode signal. The penetration sealing system is verified for the rated time class (typically -/120/120 for naval base accommodation, -/180/180 for command facility and magazine).

AS/NZS 60079 zone certification

Every hazardous-area component carries an ATEX/IECEx certificate that is verified at commissioning. The fan motor, the damper actuator, the cabling, the light fittings and the instrumentation are individually verified. The duct bonding and earthing continuity is measured at under 10 ohms across the full duct run from the extract point to the discharge stack.

Continuous monitoring system functional acceptance

The atmospheric monitoring system in the submarine drydock pen, the welding bay and the paint hall is functionally tested at commissioning with calibrated reference gas. The alarm levels are verified, the data logging is verified, the building management system integration is verified and the operator response procedure is rehearsed. The functional acceptance test is the gate to facility hand-over.

Project programme — design, fabrication, install and hand-over

A naval, submarine or shipyard HVAC project typically runs on an 18 to 36 month programme from design start to commissioning, depending on the facility scale and the security classification overlay. The largest projects — a new submarine drydock pen at HMAS Stirling, a new SSN-AUKUS construction hall at ASC Osborne — run 36 to 60 months.

The design phase runs 6 to 12 months on the major projects, with the schematic design, detail design and construction-documentation phases each gated by the prime contractor and the Commonwealth project office review. The DISP accreditation and the Australian Industry Capability content are locked at schematic design and refined through detail design.

The fabrication phase runs 6 to 18 months in parallel with the building shell and structural-services trades. The duct fabrication is performed at the contractor's Australian workshop on the SBAL-V coil line and the ancillary machines. The fabrication-shop output is shipped to site on flat-pack pallets or in pre-assembled modules. 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 6 to 18 months on site with the duct rigging, support installation, sealing and pressure-testing performed by the contractor's installation crew. The hazardous-area certification and the security clearance management are managed in parallel with the installation activity. The DISP-accredited installers complete the work inside the controlled zones with the audit trail maintained throughout.

The commissioning phase runs 2 to 6 months at the back end of the programme, with the NATA-accredited testing, the functional acceptance and the contractor's quality close-out. The signed first-article acceptance report is the audit-of-record and triggers warranty start.

Closing — the engineering discipline that defence demands

Naval-base, submarine and shipyard HVAC is the most demanding engineering envelope in the Australian Defence Maritime Affairs portfolio. The combination of ISO 9223 C5-M chloride atmosphere, AS/NZS 60079 hazardous-area zoning, hex chrome and isocyanate Safe Work Australia exposure standards, AS 2865 confined-space entry, the Defence Manual of Fire Safety overlay and the AUKUS Pillar 1 industrial context 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, spiral tubeformers, plasma cutters, stitchwelders, flange formers, elbow machines, hydraulic presses and roll forming lines — the SBAL-V, SBAL-III, SBAL-II, SBTF-1500C/1602/2020, SBEM-1250, SBSF-1525, SBFB-1500, SBHF, SBPC1500 and SBLR-600/600A machines. The heavier-gauge welded plenum, blast-resistant penetration and EMP-shielded honeycomb scope is co-ordinated with specialist welded-fabrication subcontractors at the project boundary.

The AUKUS Pillar 1 industrial expansion at HMAS Stirling Western Australia, ASC Osborne South Australia, Henderson Western Australia, Garden Island Sydney and the wider Royal Australian Navy footprint is the largest peacetime defence infrastructure undertaking in Australian history. The HVAC duct scope across that expansion through 2040 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.

FAQ

Why must HVAC duct in Australian naval bases be 316L stainless or marine aluminium?

Royal Australian Navy bases sit 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 through electrochemical zinc consumption, after which pitting attacks the underlying carbon steel. 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.

What HVAC standards apply to Australian naval base and shipyard ductwork?

Civilian baseline AS 1668.2, AS 1668.1, AS 4254, AS 1530.4, AS 3580 and AS/NZS 1715. Marine overlays ISO 9223 C5-M corrosivity and AS/NZS 2312 protective coatings. Hazardous-area AS/NZS 60079, AS 1940 and AS 3000. Confined-space AS 2865. OHS AS 4801, AS 4754 and AS 4753 hot work permits. Pressure-vessel AS 2030 and AS 1210. Cleanroom ISO 14644 on sonar electronics. Defence overlays Defence Manual of Fire Safety, DEF (AUST) 5000 series and AS 5577 industrial automation control-system security. NATA accreditation on every commissioning test deliverable.

How does a submarine drydock pen differ from a surface combatant graving dock in HVAC scope?

A surface combatant graving dock is open or partially covered and the HVAC scope is concentrated in adjacent welding bays, paint halls and workshops. A submarine drydock pen is an enclosed, large-volume covered hardstand with 80,000 to 180,000 cubic metres conditioned volume around a single boat, engineered ventilation at 6 to 10 ACH, continuous atmospheric monitoring tied to the boat air revitalisation interfaces, and 316L stainless duct mandatory throughout. Hex chrome from stainless welding (WES 0.005 mg/m³) and isocyanate from polyurethane paint (STEL 0.005 ppm) are the binding ventilation criteria.

What is the AUKUS Pillar 1 industrial significance for Australian shipyard HVAC?

AUKUS Pillar 1 commits Australia to nuclear-powered conventionally-armed submarines through Virginia-class transfers, SSN-AUKUS construction at ASC Osborne, and operation from HMAS Stirling. The supporting industrial base is the largest defence undertaking in Australian peacetime history with infrastructure investment in the tens of billions of Australian dollars through 2055. The HVAC duct scope across new submarine construction halls, sustainment workshops, classified ICT facilities, training establishments and accommodation precincts is conservatively measured in hundreds of thousands of square metres of fabricated sheet duct, with substantial Australian Industry Capability content targets.

What ventilation rate captures hexavalent chromium from stainless welding fume?

Hex chrome Cr(VI) generated when austenitic stainless steel is welded carries Safe Work Australia WES at 0.005 mg/m³ eight-hour TWA — a hundred-fold tighter than the general welding fume limit. The engineering control is source-capture extract at the arc with 0.5 m/s face velocity at 300 mm from the arc, 316L stainless flexible exhaust hoods feeding a HEPA-filtered cartridge collector with chrome-rated media. Hex-chrome capture is the binding ventilation criterion in almost every submarine and shipyard welding bay design.

How is a marine paint hall ducted to control isocyanate from polyurethane primer and topcoat?

NFPA 33 downdraft or semi-downdraft booth, 0.5 m/s face velocity downward through filter floors, 316L stainless continuously welded ductwork, spark-resistant non-ferrous fan, externally-mounted motor outside the airstream, cartridge particulate filtration on the extract, tempered make-up air to within 2°C of booth ambient. Isocyanate Safe Work Australia STEL is 0.005 ppm. AS/NZS 2312 marine primer and topcoat referenced on coating selection. Stack discharge 3 m minimum above roof and 15 m from any air intake under AS 3580 boundary-air rules.

What hazardous-area zoning applies to a naval fuel jetty?

AS/NZS 60079.10.1 Zone 1 within a defined envelope around the manifold, pumps and vapour vents during transfer operations, Zone 2 extending outward. AS 1940 governs decanting. Every fan, light fitting, instrumentation cable and damper actuator is Ex equipment to AS/NZS 60079 or IECEx. 316L stainless duct with bonded earthing continuity under 10 ohms end-to-end. Spark-resistant non-ferrous fan wheel, externally-mounted motor. Vapour recovery mandatory, hydrocarbon monitoring with automatic shutdown at 25 per cent LEL.

What SBKJ machines does an Australian naval-base duct fabrication shop need?

SBAL-V auto duct production line configured for 316L stainless coil at 0.5 to 1.5 mm gauge, 1500 mm width, 16 m/min throughput, 87 kW total installed power — the principal machine. SBSF-1525 stitchwelder for thick-gauge stainless plenum construction. SBPC1500 plasma cutter for stainless duct fittings, transitions and access doors. SBTF spiral tubeformer (1500C, 1602 or 2020) for round duct. SBEM-1250 elbow machine for gored fittings. SBFB-1500 flange machine for angle-iron flanges. SBHF hydraulic press for heavier forming. SBLR-600/600A roll forming line for specialty profiles. Spark-resistant fan selection is the contractor's ATEX/IECEx supplier, not SBKJ scope.