Fire

Fire detection is no longer just about triggering an alarm, it’s about interpreting heat data correctly in complex, high-risk environments. As critical infrastructure operates under greater thermal stress, traditional detection methods struggle to balance early warning with false alarm reduction.

Modern fiber optic fire detection systems take a different approach. By continuously measuring temperature along every metre of an asset and applying intelligent algorithms to that data, they can detect fire conditions earlier, more accurately, and with far greater reliability. Understanding how these algorithms work and how detection thresholds are set is now essential for achieving effective fire protection.

This blog post explores how smart algorithms improve fire detection accuracy, why legacy systems fall short, and how intelligent threshold design enables faster, more dependable responses in demanding environments.

Why fire detection accuracy depends on algorithms

Fire detection is effectively a data interpretation challenge, not just a sensing one. Modern environments generate constant background heat from machinery, power systems, vehicles and processes, so a simple ‘trigger point’ detection system can’t distinguish between normal operational heat and early-stage fire conditions. Accurate detection depends on understanding how quickly, where, and in what pattern temperature changes occur.

Poor algorithm design leads either to nuisance alarms or dangerously delayed detection, which means as assets become larger, hotter, and more complex, algorithm intelligence becomes critical.

The role of fiber optic distributed temperature sensing (DTS)

Distributed temperature sensing systems measure temperature continuously along the full length of a fiber optic cable, so unlike point detectors, DTS provides a complete thermal profile of the protected asset. Temperature is measured at high spatial resolution (typically every 1 metre), with frequent sampling allowing systems to observe temperature trends, not just isolated spikes. This continuous coverage ensures no blind spots in long or complex environments. Our distributed temperature sensing systems collect and provide all the raw data needed for advanced algorithmic analysis.

Key algorithmic approaches used in fiber optic fire detection

Absolute temperature thresholds

These trigger alarms when the temperature exceeds a predefined value and are simple and reliable for clearly defined fire scenarios. However, the algorithm can be slow to respond if thresholds are set too high and has an increased risk of false alarms if thresholds are set too low.

Adaptive Rate-of-rise detection

The Adaptive Rate-of-Rise Alarm detects abnormal rates of temperature increase by comparing current conditions to an adaptive thermal baseline. Unlike conventional fixed thresholds, it responds rapidly to emerging fire behaviour while remaining immune to gradual ambient and environmental temperature changes.

Hot Spot Detection

The Hotspot Detection Alarm identifies localised abnormal heating along the sensing fiber by comparing each point to surrounding conditions and calculating the deviation from the average within the zone. It is highly effective at detecting early-stage thermal events caused by friction, electrical loading, or mechanical issues, enabling intervention before escalation occurs.

Combined algorithm logic

Many modern systems have found the ultimate solution by applying multiple algorithms simultaneously. This enables cross-verification across algorithms to improve detection confidence and provides faster alarms without sacrificing reliability; if anything, it increases it.

Why tuning matters when choosing fire detection thresholds

Threshold selection has a direct effect on both detection speed and false alarm rates. Often, generic thresholds rarely suit complex or high-risk environments, so operational temperatures must be fully understood before thresholds can be set. Even just marginally different zones in one site can require different detection logic.

This is why using an intelligent, adaptable fire detection system is so vital, as intelligent systems allow thresholds to evolve as operating conditions change. It’s a system designed to work for each unique application – as opposed to poorly tuned systems which erode trust and reduce operational effectiveness.

Why legacy fire detection systems fall short

Many of the widely used legacy systems rely on single-point or single-condition triggers, where limited contextual awareness is their downfall, leading to delayed or missed alarms. The very popular smoke-based systems depend on air movement and fire development, meaning no possibility of early detection. Alternatively, heat cable systems often lack spatial resolution and algorithm flexibility because fixed logic cannot adapt to changing asset behaviour. This means, in high-interference environments in particular, legacy systems struggle to keep up with the changing surroundings.

How Bandweaver applies ‘Smart Algorithms’ in FireLaser and T-Laser

Our FireLaser and T-Laser systems use high-resolution DTS combined with intelligent alarm processing to support multiple alarm types, including absolute temperature, adaptative rate-of-rise, and hot spot detection. Detection logic can be configured per zone to reflect asset risk and behaviour, allowing for a more adaptable fire detection strategy suited to each environment. High sampling frequencies enable early recognition of abnormal thermal trends with a software-driven configuration to allow optimisation without physical systems changes. Both systems are designed for demanding environments such as tunnels, conveyors, power plants, and other industrial sites.

Intelligent algorithms can rapidly distinguish between real fire signatures and benign thermal events through localised analysis to prevent system-wide alarms from normal temperature shifts. Early detection occurs closer to the ignition source, allowing the fire to be stopped at the earliest moment before it can damage assets or infrastructure. Due to its smart detection abilities, the system results in significantly fewer false alarms, improving operator confidence and response quality whilst lowering operational disruption and maintenance costs.

As mentioned, faster detection limits damage and reduce recovery time, whilst precise location data enables targeted response and intervention. However, the passive fiber optic sensing cable also reduces maintenance requirements and exceeds the typical lifespan of a detection system to deliver a lower total cost of ownership. It’s this improved reliability all round that supports regulatory compliance and insurance confidence.

Smarter systems lead to safer outcomes

High-performance fire detection is no longer defined by sensitivity alone but by intelligence. In complex, high-risk environments, smart algorithms are essential to transform raw temperature data into clear, actionable insight. When detection thresholds are intelligently designed and tuned, operators gain earlier warnings, greater confidence, and the time needed to intervene before incidents escalate.

As infrastructure grows more demanding and risks continue to evolve, fire detection systems must keep pace. Protecting the assets that support people, communities, and essential services requires solutions built for modern conditions, not legacy limitations. Smart, software-driven fire detection is the future, and the organisations that prioritise it today will be the ones best prepared for tomorrow.

If you’re reviewing your fire detection strategy, now is the time to ask whether your system is truly working for you. Explore how intelligent, fiber-optic fire detection can deliver earlier insight, greater reliability, and long-term confidence: https://www.bandweaver.com/fiber_optic_sensing_technology/distributed-temperature-sensing/

Major, high-profile car park fires and tunnel incidents in the past have demonstrated the same basic failure: by the time anyone knew what was happening, it was already too late.

In the UK two cases tell this story and show the real cost of poor detection. The Liverpool Kings Dock fire of 2017 and the Luton Airport Terminal Car Park fire of 2023. A report from the Merseyside fire brigade showed the Liverpool fire destroyed 1,150 vehicles and caused severe structural damage, a clear indication of how fast modern vehicle fires can escalate. Meanwhile, the Luton Airport fire had a major operational impact, affecting 1,300 vehicles and causing disruption for months.

These incidents have exposed a consistent problem: legacy standards, systems designed for a bygone era, and a culture that treats detection as a checkbox rather than a life-saving tool.

The pattern we keep repeating

There is a substantial gap between laboratory or design assumptions and real-world conditions. This means detection systems that have been specified for decades aren’t fit for purpose when faced with modern cars, tighter spacing and plastic or fuels that burn hotter for longer. Research[1] from 1968 simply isn’t  enough to keep pace with current vehicles and environments.

This leads to significant problems such as late or manual detection. Interestingly, in both cases, the initial alert didn’t come from the fire detection systems but was raised by a member of the public who saw the flames and called from a mobile phone. Response teams also suffer from a lack of precise location data; in the Liverpool fire, the response team was sent out to fight the fire on the wrong level of the car park, completely missing the growing threat on other levels. A lack of targeted response increases danger to civilians and first responders as well as increasing the damage to vehicles, infrastructure and assets. To make matters worse, systems are often installed and forgotten about, which is a serious issue when dealing with systems that require adequate and continuous maintenance and realistic testing to operate successfully.

By contrast, some countries, including the Netherlands, Norway, and  Turkey, enforce stricter commissioning and are more accepting of distributed sensing solutions. When regional regulation changes are made, they drive adoption, and the market uptake increases. So, the route to improved fire detection is simpler than it seems.

The cost of complacency

The fire at the Liverpool Kings Dock in 2017 is the perfect example of how a small fire can rapidly escalate if not dealt with properly. Initially the fire was confined to a single car, but undetected, it was allowed to spread rapidly, causing structural damage and catastrophic asset loss. Observations from engineers after the fire noted that extreme heat caused spalling and structural failure, which shows that modern car fires behave more like petrochemical events in some cases.

The Luton Airport car park fire was a similar incident. From a small vehicle fire, the blaze spread, leading to a partial collapse of the car park, major flight disruption and multiple firefighters treated for smoke inhalation. The Bedfordshire Fire Brigade published a report concluding that the absence of sprinklers contributed to the extent of the blaze and recommended the consideration of mandatory suppression for car parks.

Both these events show that when detection and suppression lag behind modern fire dynamics, human life is put at risk, financial and operational costs soar, and the fire response is hindered.

What other countries are getting right

In the Netherlands they have strict commissioning standards, such as pan-fire testing, to set a high bar for what a detection system must detect in car parks. Our fiber optic linear heat detection systems are among the few solutions that can pass these tests.

Norway makes consistent regulatory updates for tunnels and infrastructure and are creating new demand for systems to meet these regulations. This goes to show that regulatory change is a powerful adoption driver.

In clusters across the globe, peer adoption drives improved fire detection systems. Successful installation and operation in one country or state often leads competitor sites to follow, creating clusters of development and regulatory improvement.

Where regulators or clients demand performance-based testing instead of checkbox compliance, the uptake of contemporary solutions like fiber optic linear heat detection increases.

How modern technology could have altered outcomes

Simply put, fiber optic LHD uses continuous distributed sensing along every metre of fiber, not single-point sensors. Rate of rise and deviation alarms detect thermal anomalies early, often before visible flame or significant smoke. The system allows pinpoint location targeting; to within 1 metre, enabling targeted response to reduce search time.

If we apply the LHD system capabilities to the two incidents, it leaves us with a very different result. In either scenario a distributed LHD system installed throughout the car park with sensors spaced appropriately to the volume of cars would be able to detect the initial blaze within seconds of it spiking in temperature. This would raise an alarm, alerting operators with the exact location and triggering automated responses. Early intervention would stop the blaze in its tracks, preventing hundreds of thousands of pounds of damage and disruption to business. Each system pays for itself over and over by averting each incident.

LHD is even stronger when integrated with suppression, ventilation control, SCADA and CCTV, the system becomes an active control loop from detection to isolation and suppression.

Why does change still lag?

A more conservative consulting culture has a huge impact on regulatory change. Many consultants and standards bodies err on the side of caution, adopting new technology slowly and requiring extensive proof before approving new sensor types for certain applications. Despite fiber optic LHD having been used since the 1980s, many still regard it as new because they haven’t revisited it in years.

Standards are often deliberately set more conservatively for safety and are then slow to move. Significant incidents often prompt regulatory change, but this is reactive rather than proactive. It’s time for those in the industry and standards bodies to take Bedfordshire Fire’s recommendations: mandating automatic suppression for open multi-storey car parks and stronger detection systems.

Cost can be a barrier to fiber optic LHD, as the systems are seen to have a higher upfront cost than other point sensors. But the cost per metre and long-term reliability make it cost-effective at scale, and the technology is more cost effective for operators over time. The lifecycle and complexity of these systems are also misunderstood, but the reality is completely opposite, with their long lifecycle and lack of complex maintenance being a key benefit.

From reaction to prevention

Repeated fire safety failures show a pattern: that modern risks demand modern distributed detection and integration, not legacy point sensors and box-ticking compliance.

It’s time for asset owners, consultants and regulators to reassess risk with the current operating realities of different environments and prioritise performance-based procurement with strict commissioning standards. Consider fiber optic detection as a core element of a layered fire strategy; it’s proven itself in numerous projects like the Turin Metro and parking applications to provide earlier alerts and precise location information.

Learning from these failures is no longer optional; it’s vital to prevent future catastrophes. Our partners are part of this change, bringing effective, safer fire detection solutions to industries across the globe. If you’re ready to make a difference, here’s how: Join our global network of partners.

[1] , The Ministry of Technology and Fire Offices’ Committee Joint Fire Research Organisation produced Fire Note No.10, “Fire and Car-Park Buildings”

Tunnels are among the most challenging environments for fire safety. Enclosed spaces, heavy traffic, complex airflow patterns, and critical evacuation procedures mean that even a small fire can escalate into a major incident within minutes. Traditional detection systems, while useful, often work in isolation: smoke detectors trigger alarms, flame cameras identify visible fire, and suppression systems deploy water or foam. The problem is that these standalone systems don’t always locate the source of the fire accurately or communicate effectively, and in environments where every second counts, that can make the difference between containment and catastrophe.

That’s why the industry is increasingly moving towards hybrid fire detection systems, integrated solutions that combine multiple technologies into a single, intelligent network. By merging the strengths of fiber optic linear heat detection (LHD), flame detection cameras, and AI-powered analytics, operators gain earlier warning, greater accuracy, and clearer situational awareness. The result is a faster, more coordinated response that saves both lives and infrastructure.

Why traditional systems are struggling

Point detectors and smoke sensors were designed for environments where air is relatively still and threats can be monitored from fixed positions. A tunnel is the exact opposite. Fans move air constantly, pushing smoke away from detectors. Curved designs break up lines of sight. Noise, dust, and temperature variations all create conditions where alarms can be either delayed or misleading.

This creates two critical problems. First, operators may not receive a warning until a fire has already spread beyond its point of origin, losing valuable seconds for evacuation and suppression. Second, when alarms are triggered too easily, operators lose confidence in the system. False activations can lead to tunnel closures, unnecessary water deployment, and a loss of public trust in safety procedures. A detection system that is too slow or too sensitive creates operational risk, which is why many operators are seeking alternatives that give them more reliable, real-time information.

Moving toward a hybrid solution

Hybrid fire detection systems address these challenges by combining different technologies, each one filling the gaps left by another. Fiber optic LHD provides continuous temperature monitoring along the full length of the tunnel. Instead of relying on sensors placed at intervals, a single fiber cable can detect abnormal rises in heat at any point, ensuring there are no blind spots.

Flame detection cameras add another layer, giving operators rapid visual confirmation of any incident. By integrating thermal imaging and analytics, these cameras can distinguish between genuine flames and harmless heat sources.

This creates a more intelligent platform that doesn’t just tell operators when a fire has already broken out but can identify precursors, such as electrical overheating, that signal risk in advance. In practice, this means fires are detected sooner, alarms are more accurate, and response strategies can be tailored to the exact location and severity of the incident.

Case in point, the Santa Lucia Tunnel

The Santa Lucia Tunnel presented a demanding brief. At 7.8 km long, one of the largest single-arch, three-lane tunnels in Europe, it required a fire detection solution that could provide complete, dependable coverage across its entire length while coping with heavy traffic, exhaust particulates and complex airflow. The owner, Autostrade per l’Italia, specified a high-performance system that would detect fires rapidly, tolerate tunnel contaminants, and integrate seamlessly with the tunnel’s automated fire-suppression logic.

To meet that brief, the project team chose a fiber-optic linear heat detection approach. The installation used Bandweaver’s FireLaser DTS paired with the FireFiber AT armoured sensing cable, installed at roof level (around 7.2 m) and fixed at regular intervals to give a continuous thermal profile with one-metre spatial resolution. Because the tunnel’s sprinkler system was already divided into many discrete zones, the detection design was mapped into 982 zones, so temperature readings and alarm logic aligned exactly with the suppression layout.

Redundancy and precision were central to the design. The scheme employed two detection cables along the tunnel roof and a multi-controller configuration that provided resilience against cable damage or controller faults. The FireLaser units are capable of EN54-22 compliant measurements every five seconds, a significant advantage over alternatives that take much longer per channel, and the FireLaser provided the accurate location data required to trigger only the specific sprinkler valve associated with the detected hotspot. The overall detection architecture was intentionally hybrid: fiber LHD provided the precise thermal location, while video flame detectors and optical beam smoke sensors formed part of the automated logic that controls suppression activation.

Commissioning and calibration were handled on site by RAET with oversight from the project engineers. The system took three weeks to commission; during installation the team encountered expected practicalities such as cable sag, which required zone recalibration. Because the FireLaser’s zones are software-configurable, RAET was able to re-reference the sensing cable to match the sprinkler zones using cold-spray reference points, and the final configuration was signed off by independent consultants. The project demonstrates how a distributed fiber solution can be engineered to meet exacting operational and integration requirements in the most challenging tunnel environments.

The outcome delivered what the operator asked for: faster, location-precise detection that is robust against dust, exhaust and moisture; continuous one-metre sampling along the tunnel; redundant architecture; and tight integration into the tunnel’s control and suppression systems. These attributes combine to reduce false activations, support targeted suppression, and provide operators with the confidence and clarity needed to act quickly when every second counts.

The future of tunnel fire safety

The Santa Lucia Tunnel is just one example of how hybrid detection is already proving its worth. As tunnels grow longer and traffic volumes increase, reliance on any single technology will no longer be sufficient. Future projects will continue to push for smarter, integrated systems that not only detect fires faster but also give operators the context they need to make the right decisions instantly.

At Bandweaver, we are helping operators move beyond traditional fire safety approaches with innovative hybrid solutions that combine fiber optic sensing, video analytics, and AI. These technologies are already transforming tunnel safety, and we’re ready to help you implement them.

If you’d like to learn more about how our solutions can support your next tunnel project, get in touch with our team today.

Traditional fire detection systems weren’t built for the realities of tunnels, substations, chemical plants, or heavy industrial environments. In these settings, smoke and heat behave unpredictably, and when detection fails, the consequences are catastrophic. What follows is a dangerous cycle: missed alarms, loss of confidence in the system, and slower emergency responses.

It’s time to stop asking, “Does it work in the lab?” and start asking, “Does it work where it matters?” Fiber optic linear heat detection is redefining what’s possible in fire safety, proving it’s not only suitable for harsh environments but optimised for them. In this article, we’ll explore the critical role this technology plays in protecting the world’s toughest and most high-risk environments.

Why “ordinary” fire detection doesn’t cut it

Conventional smoke and thermal sensors are designed with stable, clean environments in mind, environments with clear air, minimal interference, and consistent conditions. But for many high-risk facilities, this couldn’t be further from reality.

In substations and transformer enclosures, electromagnetic interference can scramble readings or trigger false alarms. In more complex settings like chemical plants, tunnels, and enclosed industrial spaces, factors like dust, humidity, or airborne particulates can obscure or degrade standard sensors altogether.

This creates a serious risk for organisations operating in extreme environments with high-value assets and infrastructure. When sensors fail, or when false alarms erode confidence, operators hesitate. Responses are slow. Fires escalate.

Fiber optic heat detection: a built-in advantage

In volatile, unpredictable conditions, fiber optic linear heat detection offers a distinct advantage.

Using a passive sensing cable, with no in-field electronics, power supplies, or communication modules, it eliminates the typical points of failure found in traditional systems. The cable is immune to electromagnetic disturbance, corrosion, temperature extremes, and airborne contaminants.

What’s more, every metre of fiber optic cable acts as a continuous, highly accurate heat sensor, delivering precise thermal mapping across large distances. These systems integrate easily with CCTV, suppression equipment, and intelligent software, creating a comprehensive fire detection and prevention solution that enables not only timely reaction but also smarter, data-driven response strategies.

Where fiber optics shine in tough environments

Tunnels, subways and rail networks
Fiber optic cables can be run along entire tunnels or infrastructure layouts, detecting subtle temperature changes or fast-rising heat from cable faults or fires. This allows suppression or ventilation systems to activate at the precise point of risk, before the situation escalates.

Heavy industry and mining operations
These are among the most demanding environments, where early detection is critical. Fiber optic systems can identify overheating bearings, blocked chutes, or overloaded motors, often before any smoke or flames appear. This enables rapid intervention and helps avoid serious damage.

Oil and gas facilities
With zero electronics in hazardous zones, fiber optic detection is perfectly suited to environments containing flammable gases or volatile compounds. It allows continuous monitoring without increasing risk, something traditional systems can’t offer.

Energy infrastructure
In high-voltage substations and transmission areas, where conventional systems degrade quickly, fiber optics remain stable and reliable. They provide early warnings of cable overheating or transformer faults that could otherwise lead to catastrophic fires.

High-moisture or washdown areas
Environments like food processing facilities, where constant cleaning and high humidity are standard, can quickly corrode or compromise standard detectors. Fiber optic systems, by contrast, remain unaffected, providing consistent and long-term fire safety coverage.

Performance you can measure

When a fire or abnormal heat source emerges, fiber optic sensing cables can detect the event to within 1°C and 1 metre, often before flames are even visible. In one real-world example, a customer using our linear heat detection system on a conveyor belt was alerted to a heat spike near a bearing. The maintenance team responded swiftly, replaced the affected part, and prevented what could have been a serious fire.

Preventing just one incident like this can justify the cost of the system, saving thousands in asset damage, downtime, and emergency response. Over time, the benefits multiply. Unlike traditional systems, which are often subject to breakdown and expensive maintenance due to environmental wear, fiber optic systems operate for years with minimal intervention.

Crucially, fiber optics drastically reduce false alarms. In harsh environments, false alarms are more than a nuisance, they erode trust and dull the urgency of real emergency response. With fiber optic fire detection, you get greater specificity and accuracy, ensuring teams are only deployed when it truly matters.

Overcoming the awareness gap

Despite these clear advantages, many fire safety professionals still associate fiber optic systems with older, copper-based technologies, which are outdated, fragile, and expensive. That couldn’t be further from the truth.

Modern fiber optic systems are lighter, faster, smarter, and more cost-effective per metre than ever before. Yet awareness hasn’t caught up. In many regions, standards and regulations still lag behind the capabilities of this technology, creating a bottleneck to broader adoption.

That said, change is happening. In the Netherlands, for example, rigorous new testing and commissioning standards have been introduced, standards that fiber optic systems meet effortlessly. This growing recognition is setting the tone for wider industry adoption and elevating expectations around fire detection performance.

Laying the blueprint for resilient fire safety

It begins with rethinking fire detection, starting with a clear-eyed audit of your environment. What are the conditions really like? Are your current systems fit for purpose, or just convenient?

Forward-thinking partners are already reshaping their fire safety strategies. They’re implementing fiber optic detection across new sectors and integrating with other smart technologies to create a layered, responsive defence strategy.

Fiber optic linear heat detection isn’t just adequate; it’s engineered for the job. It’s time to stop settling for outdated systems and start investing in solutions designed for the environments you operate in.

Join the global movement transforming fire safety, one cable at a time: https://www.bandweaver.com/about-bandweaver/partners/