Industry Solutions / Transportation

Critical power and cooling for rail, airports, tunnels, roads and ports in Australia

Transport assets fail differently to office buildings. When power drops in a commercial tower, people go home early. When power drops at a signalling location, a rail network moves to degraded-mode working, train movements slow to walking pace under written authority, and the recovery is measured in hours of disrupted timetable rather than minutes of outage. When power drops at an aerodrome, the aircraft on final approach does not have the luxury of waiting for a generator to come up to speed. When power drops in a road tunnel during a fire event, the jet fans that hold the smoke layer off the escape path stop turning.

That difference should drive every decision in the electrical and mechanical design, and in practice it often does not. A great deal of transport backup power in Australia was specified by people applying data centre habits to a safety context, or by people applying safety thinking without understanding what a UPS actually does during a transfer. The result is equipment rooms with correctly sized UPS and no cooling, roadside cabinets rated for a European ambient sitting in full Queensland sun, and battery strings that were compliant on the day of handover and have never been load tested since.

Indigi Power and Cooling is an Indigenous and Veteran owned critical power and cooling specialist, registered with Supply Nation and ICN Gateway. We hold active work in the rail sector, including battery replacement programmes and substation projects, and we work on both the electrical and the mechanical side because in transport the two are the same problem. A UPS that overheats is not a UPS. A ventilation system without protected power is not a safety system.

What actually fails, and what governs it

The single most useful thing a transport asset owner can do before going to market is to write down, per asset class, what stops when the supply stops and which document sets the requirement. The answer is rarely AS/NZS 3000 alone. Most transport asset classes in Australia sit under a sector-specific technical specification that is more prescriptive than the wiring rules, and in rail it sits under a network-specific one on top of that.

Read that table as a warning about scope. Almost every transport tender we see asks for the UPS and forgets the cooling that keeps it alive, or asks for the cooling and treats the battery as a consumable that somebody else will worry about. Both halves belong in the same scope of works, and both belong in the same maintenance regime.

Rail signalling power: a safety system, not an availability target

Signalling power supplies are safety-critical in the literal engineering sense. Signalling is designed to fail safe, so a loss of supply does not cause a collision, it causes signals to revert to their most restrictive aspect. That is the correct behaviour and it is also enormously disruptive. Trains are then worked under degraded-mode procedures, which are slower, more labour intensive and carry their own human-factors risk. The commercial consequence of a signalling power failure is a network-wide delay, and the safety consequence is that a system designed to remove human error from train separation has temporarily handed that job back to people.

In Australia the sector-level reference is AS 7703, the Railway Signalling Power Supply Systems standard published through the Rail Industry Safety and Standards Board. Sitting on top of it, each network owner runs its own technical standards and its own approvals regime. ARTC publishes signalling power system standards for the interstate network. Transport for NSW publishes signalling equipment power supply specifications, including a dedicated specification for uninterruptible power supplies serving railway signalling loads at 240 V single phase and 415 V three phase. Queensland Rail and Metro Trains Melbourne likewise maintain their own engineering standards. The practical consequence is important and often missed by suppliers coming from an IT background: meeting AS/NZS 3000 and holding a manufacturer datasheet is not sufficient. Equipment frequently needs authority-specific approval, product acceptance or type registration before it can be installed on that network at all. Confirm the applicable approval pathway with the network owner before committing to a product.

Trackside equipment rooms and relay rooms

Relay rooms, equipment huts and location cases hold interlockings, object controllers, axle counter evaluators, power supplies and battery banks in a very small volume, often with no mains cooling and a solar-loaded steel or concrete shell. Internal temperature is the quiet killer here. Valve-regulated lead acid battery life roughly halves for each sustained 10 degrees Celsius above 20 to 25 degrees, so a hut that runs at 40 degrees through a Queensland summer is not delivering the design life the asset register assumes. We treat trackside rooms as a cooling problem as much as a power problem, and where mechanical cooling is warranted we install and service it under ARCtick licensing as required by the Ozone Protection and Synthetic Greenhouse Gas Management Regulations.

Level crossings, axle counters and interlocking supplies

Level crossing protection, axle counter heads and interlocking supplies are distributed, remote and rarely visited. That distribution is exactly why battery discipline matters more here than in a manned facility. A weak string at a crossing does not announce itself until the day the feeder trips, and by then the failure is public and consequential. Our approach is scheduled impedance and capacity testing on a documented cycle, string-level records rather than site-level records, and replacement planned against measured degradation rather than an arbitrary calendar date.

The trackside environment is genuinely hostile

Trackside equipment lives with continuous vibration from passing traffic, brake dust and ballast dust, wide daily temperature swing, and electromagnetic interference from traction supply and return currents. Each of those attacks a different part of the system. Vibration loosens terminations and fatigues battery inter-cell connectors. Dust blocks filters and heat exchangers and shortens the effective service interval. Temperature swing drives condensation inside enclosures. EMI corrupts monitoring and communications long before it affects the power path. A specification that only addresses the electrical parameters and ignores these four will produce equipment that passes factory acceptance testing and then underperforms in service.

Airports: aeronautical ground lighting sets the pace

An airport is several different critical facilities wearing one name. The one with the tightest power requirement is aeronautical ground lighting. CASA regulates aerodrome facilities and equipment through the Part 139 Manual of Standards, with lighting and secondary power supply requirements set out in Chapter 9. The important technical subtlety is how switch-over time is defined. CASA guidance defines it as the time required for the measured intensity of a light in a given direction to fall from 50 per cent and recover to 50 per cent during a power supply changeover, when the light is being operated at 25 per cent intensity or above. It is a photometric measurement, not a switchboard measurement, which means the constant current regulator's own restart behaviour counts against the allowance.

CASA guidance on all-weather operations indicates a maximum switch-over time for runway edge lights of one second where the lowest approach minima apply, relaxing to 15 seconds for other lights and less demanding operations. Confirm the figure applicable to your aerodrome and approach category against the current Part 139 MOS, because these values are category dependent and the standards are periodically amended. The engineering point stands regardless: a one second allowance cannot be met by generator start alone, so the constant current regulators and the associated control must sit behind a UPS, and that UPS has to hold a regulator load which is not a friendly, flat, IT-style load.

Beyond the airfield, the same site carries terminal systems, baggage handling, security screening, apron and ground support power, and increasingly the airport's own data centre supporting the operational database, common-use terminal equipment and airport operational control. Those are conventional critical power and precision cooling problems, and we treat them accordingly: three-phase online double-conversion UPS on essential switchboards, precision cooling in comms and equipment rooms held within the ASHRAE TC 9.9 recommended envelope of 18 to 27 degrees Celsius at equipment inlet, and ventilation hygiene managed under AS/NZS 3666 where air handling serves occupied terminal space.

Tunnels, roads and intelligent transport systems

Tunnel ventilation and why fire mode drives the design

Road and rail tunnels run ventilation for two entirely different duties. Normal-mode ventilation manages vehicle emissions and air quality, and it is a comfort and health function with a fairly relaxed availability requirement. Fire-mode ventilation controls smoke, holds a tenable layer above the escape route and gives occupants a survivable path out, and it is a life-safety function with an availability requirement close to absolute. The electrical design is set by the second duty, not the first, and it flows through everything: supply segregation so a single fault cannot take both feeds, fire-rated cabling on the paths that must survive the event, UPS on the control, detection and communications layer so the system can still decide what to do while the mechanical plant transfers to standby supply, and lighting, PA, CCTV and emergency phones held up through the transfer.

Tunnel plant rooms and control rooms also generate serious heat in confined space, and the equipment in them is often the least accessible on the whole asset. Cooling redundancy is worth more here than it is in an office comms room, because a failed unit cannot simply be swapped out at lunchtime on a Tuesday.

Traffic signals, tolling gantries and roadside cabinets

Intersection control is where power continuity translates most directly into public risk. A dark intersection reverts to an uncontrolled intersection, and in Australia that means give way to the right at exactly the moment drivers are least expecting to. State road authorities have responded with prescriptive specifications for roadside uninterruptible power supplies. Queensland's Department of Transport and Main Roads publishes MRTS213 for UPS for roadside devices, requiring the UPS to power roadside devices, and traffic signal controllers in particular, under the full range of environmental conditions. Main Roads Western Australia publishes Specification 713 for uninterruptible power supply for electrical and ITS equipment. South Australia's Department for Infrastructure and Transport addresses ITS equipment requiring uninterruptible supply in its ITS design documents. Typical Australian roadside UPS offerings target around four hours of backup for a controller of roughly 1,400 W, commonly using 48 V lithium iron phosphate batteries selected for high-temperature tolerance rather than lead acid.

Cabinet cooling at high ambient is the under-served problem

This is the part of roadside infrastructure that most suppliers skip, and it is where we see the most avoidable failures. A roadside cabinet sits in full sun with no shading, no meaningful thermal mass, and a solar gain that can lift internal temperature well above ambient in a sealed enclosure. Add a controller, a communications shelf, a detector interface, a UPS inverter and a battery, and the internal heat load is no longer trivial. Passive ventilation with filtered louvres works up to a point, but louvres admit dust, insects and moisture and they lose effectiveness on exactly the days you need them most. Once the internal target cannot be met passively, the answer is an enclosure air conditioner or a thermoelectric cooler sized to the solar gain plus the internal dissipation, with the set point chosen around battery life rather than around equipment survival.

The distinction matters commercially. Electronics will usually survive 60 degrees Celsius. Batteries will not survive it for long, and the battery is the reason the cabinet has a UPS in the first place. Designing cabinet cooling to the electronics rating and then replacing batteries every 18 months is a false economy that shows up in the maintenance budget rather than the capital budget, which is often why it goes unnoticed for years. Where cabinets genuinely cannot be cooled, the correct response is a high-temperature battery chemistry and a monitoring regime that reports state of health remotely, not optimism.

Ports, freight terminals and marine environments

Ports combine three power problems that rarely appear together elsewhere. The terminal operating system and its supporting communications network is a conventional data availability problem, and losing it stops container movements even though every crane is still mechanically capable of working. Crane control systems, interlocks and anti-collision protection are a safety problem, and they demand ride-through so that a supply disturbance does not drop a load or lose position feedback. Reefer monitoring is a cargo integrity problem: the refrigerated containers themselves draw substantial power, and while a short interruption is survivable for the cargo, losing the monitoring layer means nobody knows which boxes went out of range and for how long, which is a claims and food-safety exposure rather than a plant exposure.

On top of all three sits salt-laden air. Marine atmospheric corrosion attacks heat exchanger coils, enclosure hardware, terminations and printed circuit boards, and it will do so at a rate that makes standard inland service intervals inadequate. Coil coatings, appropriate enclosure ratings, more frequent inspection of terminations and a maintenance interval set for the environment rather than the catalogue are all reasonable responses. Ignoring the environment and then blaming the equipment is the common alternative.

Compliance that actually applies

Electrical installation and alteration work is carried out to AS/NZS 3000, the wiring rules, by licensed electrical workers in the relevant state or territory. Any work involving refrigerant, which includes commissioning, decommissioning, recovery and most service on a cooling unit, requires ARCtick licensing under the Ozone Protection and Synthetic Greenhouse Gas Management Regulations. Where mechanical ventilation and air handling serves occupied terminal, station or concourse space, AS/NZS 3666 governs hygiene and maintenance of that system. Where lifts serve stations, terminals and interchanges, the AS 1735 lift series applies, and lift backup power has its own behavioural quirks that a general-purpose UPS specification will not cover. Precision cooling for equipment rooms is designed against the ASHRAE TC 9.9 recommended envelope of 18 to 27 degrees Celsius at equipment inlet.

Above all of that sit the rail network and road authority regimes described earlier, plus in some cases critical infrastructure obligations for assets declared under Commonwealth critical infrastructure legislation. Those obligations tend to focus on risk management programmes and incident reporting rather than on prescribing equipment, but they change how you evidence what you have done, which in turn changes what your maintenance records need to look like.

What Indigi does on a transport project

Indicative pricing: single-phase UPS installation from $850 up to 3 kVA, from $1,250 for 3 to 10 kVA and from $1,800 for 10 to 20 kVA. Three-phase installation starts from $3,200 for small systems and from $6,500 for medium systems. Cooling design and installation runs from $8,000 to $15,000 for small rooms, $25,000 to $45,000 for medium installations and $45,000 to $60,000 plus for large projects. UPS maintenance is $720 ex GST for a one-off visit or $1,940 per year ex GST on a standard annual plan. Distributed roadside and trackside programmes are quoted per site count and access requirement, because travel, possession windows and permit conditions usually dominate the labour cost rather than the work itself.

Frequently asked questions

What is the UPS system in the airport?

An airport UPS is an uninterruptible power supply that carries critical aviation loads through the gap between a mains failure and the standby generator reaching full load. It typically protects aeronautical ground lighting constant current regulators, air traffic and airside communications, terminal and flight information systems, baggage handling controls, security screening and the airport's operational data centre. The reason it cannot be replaced by a generator alone is timing: CASA defines a maximum switch-over time for aerodrome lighting measured photometrically, and at the most demanding approach minima that allowance is around one second, far shorter than any generator start sequence.

How does rail signalling work?

Rail signalling divides the track into sections and ensures that only one train occupies a section at a time. Train detection, historically by track circuit and increasingly by axle counter, tells the interlocking which sections are occupied. The interlocking then only permits signal aspects and point movements that are safe given that occupancy, and it enforces this in logic rather than relying on the signaller. Everything in the chain, from detection to interlocking to signal lamps and point machines, needs continuous power, which is why signalling power supply is treated as a safety system in Australia and is covered by AS 7703 as well as by each network owner's own engineering standards.

Are train tracks electrified in Australia?

Only partly. Australia's suburban passenger networks in Sydney, Melbourne, Brisbane, Perth and Adelaide are substantially electrified, while most interstate and regional freight and passenger lines run on diesel traction. That mix matters for power design in two ways. On electrified sections, traction return currents and the associated electromagnetic environment influence earthing, bonding and equipment immunity for signalling and communications gear. On non-electrified sections, trackside equipment often depends on a single distribution supply with no local alternative, which makes UPS backup and battery condition the only thing standing between a feeder fault and a signalling outage.

What is the traffic signal battery backup?

A traffic signal battery backup is a UPS and battery set installed in or beside the traffic controller cabinet that keeps the intersection running normally through a mains outage instead of letting it go dark. In Australia these are procured against state road authority specifications, such as Queensland's TMR MRTS213 for UPS for roadside devices and Main Roads WA Specification 713 for ITS equipment. Australian systems commonly target around four hours of backup for a controller drawing about 1,400 W, and increasingly use 48 V lithium iron phosphate batteries because they tolerate cabinet temperatures that shorten sealed lead acid life dramatically.

How long will an UPS battery backup last?

Two different questions hide inside that one. Runtime on a single outage is a function of load against battery capacity: a typical equipment room UPS at full load gives minutes, while a purpose-designed transport installation is usually specified for hours, with roadside traffic signal systems commonly targeting around four hours. Service life is the more important number for asset owners. Valve-regulated lead acid strings are generally rated for a design life of several years at 20 to 25 degrees Celsius, and that life falls sharply with sustained heat, which is why an uncooled trackside hut or a sun-loaded roadside cabinet erodes battery life faster than any duty cycle does. Runtime should be proven by discharge test, not assumed from a datasheet.

What is the purpose of tunnel ventilation?

Tunnel ventilation serves two purposes with very different criticality. In normal operation it dilutes and removes vehicle emissions and manages air quality, temperature and humidity for people passing through. In fire mode it controls smoke movement, holds a tenable layer above the escape route and keeps a survivable path available for evacuating occupants and for responding emergency services. The second duty is what drives the electrical design, because a life-safety ventilation function has to work during the event that is most likely to disturb the power supply. That is why fans, control systems, detection and emergency lighting are put on segregated essential supplies with UPS on the control and detection layer.

What are the 4 types of power supplies?

In a transport context the four layers usually meant are the normal utility supply, the standby generator, the uninterruptible power supply with its battery, and local distributed supplies such as cabinet batteries or solar and battery systems at remote sites. They are complementary rather than alternatives. The utility supply carries the load in normal operation, the generator provides long duration backup but takes seconds to start and accept load, the UPS bridges that gap with zero break and conditions the supply while it does so, and local supplies serve assets too remote or too small to justify a generator. When people describe UPS topologies instead, the common types are standby, line interactive, and online double conversion, and transport safety loads should be on the last of these.

Where we work

Related services and industries

• High temperature and outdoor UPS systems for roadside cabinets, gantries and trackside enclosures
• Battery maintenance and replacement, including signalling and substation battery programmes
• Three phase UPS installation and commissioning for terminals, control rooms and substations
• Single phase UPS installation and commissioning for equipment huts and roadside cabinets
• Switchroom cooling for substations, plant rooms and trackside equipment rooms
• Elevator and lift UPS systems for stations, interchanges and terminals under AS 1735
• Power integrity inspection to establish the real condition of an inherited asset base
• UPS maintenance plans covering dispersed multi-site transport estates
• Telco and communications infrastructure, which shares the remote cabinet and battery problem
• Industrial power and cooling for freight terminals, workshops and process environments
• Secure and critical facility UPS and cooling for control centres and operations rooms
• UPS battery replacement cost calculator for budgeting a distributed replacement programme

Planning transport power or cooling work? Send us the asset type, site count, the network or road authority standard that applies, the existing UPS and battery details, and your access or possession constraints. We will come back with a condition position, a compliance path and an installed price. Indigi Power and Cooling is Indigenous and Veteran owned, and registered with Supply Nation and ICN Gateway. Contact Indigi Power and Cooling Battery Replacement