15 May 2020
David Lasselle has joined the Hannay Reels team as a Design Engineer. David is a 2018 graduate of Clarkson University with a Mechanical Engineering degree and a concentration in manufacturing. Prior to joining Hannay Reels, he worked for an electric motor startup company in Potsdam, New York, where he gained valuable experience working on various electrical and mechanical design projects.
Due to the nature of their design and uses, tunnels have particularly unique fire risks, and any fire can spread quickly, risking damage to assets or injuries to teams. Mining, cable and communication tunnels are subject to significantly high risks, as they utilize heavy-duty machinery, flammable materials and cables, which are all subject to the production of excess heat. Here we discuss the prevalent fire risks in tunnels and explain how businesses operating within them can assess and mitigate these risks. What causes the heightened fire safety risks in tunnels? Lack of natural ventilation: The enclosed design of tunnels results in a lack of natural ventilation, making it incredibly difficult to regulate temperatures. As heavy-duty machinery operates for long period of time within tunnels, this causes a significant fire risk. Smoke spread across curved ceilings: Tunnels are generally built with a curved ceiling structure. This enhances the spread of smoke along the ceiling, resulting in the entire surface area of the ceiling being covered. When the temperature of smoke decreases – once fire has been extinguished – it can sink to human eye-level, increasing the risk of smoke inhalation. Limited access: Tunnels are often well-sealed and confined, with limited access. This means that if a fire breaks out in a particular area of the tunnel, access points can be restricted, proving evacuation to be challenging. As a result, evacuation may be limited to a singular route – the same route for people and smoke. Heightened risk of structural damage: The sealed and confined nature of tunnels means that temperatures, caused by uncontrolled fires, can reach up to 140°C. These severe temperatures can cause structural damage to tunnels if left unresolved. What are the fire risks in tunnels? Ignition sources: Ignition sources are commonplace in tunnel environments. Vehicles (powered by lithium-ion batteries), heaters and electrical sources, which power equipment and machinery, such as conveyor belts, all present significant fire risks if not correctly monitored. Overheating: Nearly half of all fires in industrial environments are caused by the overheating of electrical equipment. This can be as a result of overuse or even poor maintenance. In manufacturing tunnels, machinery, such as conveyor belts, is continuously used to support operations. If unmonitored, the friction in belts can begin to heat, potentially igniting the materials they carry. Additionally, if industrial machinery reaches high temperatures, it can speed up the propagation process of a fire, especially when in contact with flammable materials, such as coal, wood or dust. Maintenance of equipment: Tunnels of all kinds use machinery to support operations, such as mining, transportation of goods or maintenance work. Due to the lack of ventilation, dust is commonplace, and its build-up can cause clogging in this machinery, amplifying the risk of overheating. Depending on its material, dust can be highly flammable. Combustible materials: Combustible materials are frequently present in tunnels, particularly in mining tunnels. These materials create a prominent fire risk, due to their extremely flammable natural, making it crucial to ensure they are transported and stored safely. Electrical faults: Some tunnels, such as cable tunnels, store lengthy networks of cables, which have the potential to cause fires. A lack of maintenance or heat can increase this risk significantly. So, how can you reduce fire risks in tunnels? Regular risk assessments By conducting regular risk assessments, you can identify any potential fire risks and put the appropriate measures in place to control these. Once a risk assessment has been conducted, it is important to share the results with team members, so they are aware and can act safely to further reduce risk. Temperature checks As overheating is a considerable risk in tunnels, it’s crucial to ensure temperature is continually monitored. This allows you to act to reduce temperatures if they reach or exceed a certain limit, before a fire breaks out. Regular equipment maintenance Regular maintenance of all electrical equipment within a tunnel is key Equipment should be subject to regular maintenance and testing to HSE standards. This will ensure you identify any issues early, allowing you to rectify problems to reduce fire risk. Equipment should also be regularly cleaned to decrease the risk of dust build-up. Any electrical equipment used to support operations should be subject to regular PAT testing (portable appliance testing) and checked for any loose cables or damage. Temperature regulation within the tunnel can also limit the effects of exterior heating on cabling. In cable tunnels, where there is a lot of electrical equipment present, these regular checks are paramount to ensuring safety. Storage and transportation of materials When combustible materials are transported, they should be subject to appropriate controls and measures to ensure they do not present fire risks. For example, combustible materials should be safely stored during transport and subject to regular temperature monitoring to quickly identify the occurrence of any hot spots. Electrical faults Regular maintenance of all electrical equipment within a tunnel is key for mitigating fire risk, as if a fire is to begin within a ‘hidden area’, such as in cable ducts, it can be difficult to access or control the flames. To reduce the risk of cables overheating, the temperature should be consistently monitored to highlight any high temperatures which may result in a fire. Using fire detection and suppression equipment to enhance safety Putting appropriate measures in place can actively reduce fire risks within tunnels. However, unnoticed hotspots, overheating between regular maintenance or combustion of flammable materials are all still prevalent fire risks. As such, supporting your fire prevention measures with a rigorous fire detection and suppression system is key. Overheating is a considerable risk in tunnels If a fire were to break out, detection it early is crucial for allowing the safe evacuation of teams and decreasing the risk of structural and equipment damage. As every tunnel is unique, the fire detection and suppression system must be bespoke and tailored to the site’s individual uses and risks. There is no ‘one-size-fits-all’ approach.
There are many daily risks faced by buildings and their managers, with electrical fires being one of the most common and dangerous. Commercial fires impact occupant health, property and the business itself – with 25% of businesses who suffer a fire never reopening. Given the often-unpredictable nature of electrical fires, businesses must invest in the latest technologies to prevent irreparable damage. It is the responsibility of the consultant engineer to show leadership and initiative in improving safety to protect the business, its employees and its most valuable assets. Engineers must look beyond simply tackling overloads and short circuits and examine a range of connected solutions that can stop a fire before it even has a chance to begin. This drastically reduces the cost of damages and repairs, while giving building operators unrivalled visibility. Connected protection is crucial at every level of the circuit, from the switchboard to distribution. A centralized system for equipment monitoring and detection provides building managers with all the information they need to keep fire risk under control, and therefore protect staff, property and business. Electrical fire risk awareness During the design and implementation phase, the consultant engineer’s role is traditionally to respect and master the local standards. They should ensure all components and parts of the circuit comply with the latest wiring rules, electrical and building codes. Yet for enhanced safety they should also be willing to look beyond the standards of the day. Given the often-unpredictable nature of electrical fires, businesses must invest in the latest technologies to prevent irreparable damage Today’s regulations do a good job of protecting buildings from the dangers of short circuits and overloads, mostly by mandating the use of circuit breakers. However, consultant engineers should also be aware of the risks posed by circuit deterioration and mistakes made during the installation. Loose cabling and faulty insulation or connections – even something as small as an untightened screw – can significantly increase a circuit’s fire risk. It’s up to consultant engineers to know their market and provide solutions that go beyond the minimum to detect and prevent electrical fires. Why electrical engineers must go the extra mile A stitch in time saves nine. While tackling overloads and short circuits is crucial, engineers must go further, examining a range of connected solutions that can stop a fire before it even has a chance to begin. Acting pre-emptively can drastically reduce the cost of damages and repairs and provide building operators with unrivalled visibility of their facility. Connected protection is crucial at every level of the circuit, from the switchboard to distribution. A centralized system for equipment monitoring and detection will provide the building manager with all the information they need to keep fire risk under control. Connected protection is crucial at every level of the circuit For optimal protection, organisations should employ smart, connected solutions that detect fire and the risk of fire at every level. This means additional protection for the switchboard and the circuit at all levels of the electrical installation, underpinned by a centralised system for monitoring and pro-active action. Using Residual Current Devices (RCDs) against insulation faults triggered by earth leakage currents exceeding 300mA, is a familiar solution. Engineers now have access to more effective earth leakage protection solutions with the same footprint as a classical overload and short-circuit protection. Products can now also offer permanent earth leakage current measurement which, when connected to a monitoring system, allows pre-alarming and monitoring during the time of any drift in the insulation. Identify switchboard vulnerabilities Unprotected electrical switchboards are especially vulnerable to fire risk. The equipment is susceptible to rodent infestation and internal overheating, issues that can often go unnoticed until it is too late. The IEC 61439-2 Low-voltage switchgear and control gear assemblies – Part 2: Power switchgear and control gear assembly’s standard addresses these risks, making compliance a must. However, fulfilling these design and manufacturing rules for switchboards does not eliminate the risk of connection failure. A critical sequence of events can occur. First, increasing electrical contact resistance accelerates further deterioration. This increased resistance induces a rise in temperature – high temperatures deteriorate the connection surface even more. The more deteriorated surface leads to a further increase in contact resistance, and the resulting thermal runaway will cause complete connection failure. Fire, flash-over and explosions become a real risk. Enhanced electrical fire prevention Moreover, final circuits should be protected by an arc fault detection device (AFDD) for enhanced fire prevention. Final circuits should be protected by an arc fault detection device (AFDD) Circuits age unevenly and unpredictably, so persistent monitoring and predictive maintenance are key to limiting fire risk. Cloud analytics can help provide asset health analytics to interpret the status and history of your most critical assets, with preventive notifications and 24/7 support. Fire prevention must be a top priority when assessing all the safety and risk-management of a building. In the case of electrical fires, prevention is better than cure. Therefore, establishing the right approach before crisis strikes will be invaluable. Connected solutions across the entire circuit are an effective solution for consultant engineers to defend buildings from the often-underestimated dangers of faulty installation and ageing components. In short, smart electrical fire prevention provides peace of mind for engineers, facility owners and occupants alike.
Combining fire alarm and voice evacuation on a single, IP-based platform accelerates emergency response and unlocks a wide range of efficiency gains. This evolution continues with a new generation of fire alarm panels. One of the main tasks for every building and safety manager consists of preparing optimally for emergency scenarios. This includes having the right protocols in place for fires to make sure that a building can be evacuated as quickly as possible when every second counts. For an optimal response, operators need as much live situational intelligence as possible; as fast as possible. Critical information includes the exact location of the fire source and current temperature levels in the immediate vicinity. Also an overview of the most critical rooms and floors that need to be prioritized for evacuation. In an ideal world, this information is available in a central location, such as a control room, from which all emergency responses are directed and coordinated. And even more ideally, the building’s fire alarm and voice evacuation systems should not only be connected and integrated – they should also deliver alerts and status reports on the same platform in a coordinated manner.For an optimal response, operators need as much live situational intelligence as possible; as fast as possible In reality, most buildings lack this level of integration and synchronization in their disparate fire alarm and voice evacuation systems. Some buildings run on patchwork solution in which both systems may be controlled in a single location, but entirely without integration whatsoever. This not only creates challenges in terms of installation and maintenance of these systems. In the worst case, the lack of integration can cost valuable seconds in response time. But system integration between fire and voice alarm solutions has not only come a long way in recent years. As the latest evolution, a new generation of fire panels helps to connect and control both systems on a single interface, thereby opening the door to immediate efficiency improvements and future innovations. Connecting IP-Based Fire Alarm and Voice Evacuation Systems For the past few years, Bosch has been offering connections between IP-based fire alarm and voice evacuation systems as a standard, out-of-the-box feature. The “Smart Safety Link” is an interface that creates a connection between fire and voice alarm systems. As a direct, plug-and-play connection, it replaces workaround solutions or relay-based connections limited to single evacuation zones in the building. As the direct takeaways from a systems architecture perspective, the Smart Safety Link requires far less cables and significantly reduces installation costs and timelines. Bosch has been offering connections between IP-based fire alarm and voice evacuation systems as a standard, out-of-the-box featureAnd by creating the connection on an IP-based architecture, the system constantly monitors the health and status of all connected devices. For operators, this significantly increases the system’s overall reliability while lowering the risk for false alarms. It also allows for replacing or repairing components as needed, right when failures happen or become imminent. The resulting systems architecture is not only more stable and reliable, but also far less complex in terms of set-up. Depending on the size of the building, one or more voice alarm systems can also be connected to the fire alarm control panels. The direct connection via Smart Safety Link eliminates the need for including additional interface modules to accommodate a voice evacuation connection, thereby keeping investment costs low. Targeted Evacuation by Building Zones Beyond the ease and efficiency of setting up a building’s alarm systems, the connection between fire alarm and voice evacuation on a single platform significantly improves emergency responses: Firstly, in case of a fire alarm the Smart Safety Link allows for voice-guided evacuation of a building by separate zones. This allows for addressing rooms and building floors closest to the fire source first, starting with the evacuation of the most endangered building occupants. This not only supports an orderly evacuation response but also helps to avoid panic and additional complications.Studies state that using voice evacuation with clear instructions creates significant time gains Secondly, the integration makes evacuations much faster overall in situations when time is of the essence. Studies such as David Canter’s “Fire and Human Behavior” clearly state that using voice evacuation with clear instructions creates significant time gains of up to 30 percent for emergency response teams compared to a non-voice alarm signal. And thirdly, the Smart Safety Link also allows for a wide range of automated emergency responses, for instance pre-recorded voice evacuation messages directing occupants of different zones to their respective nearest exits. Supported by strobes, guide lights and clear signage, this automatic combination of fire alarm and voice instructions allows operators to focus on the big picture and monitor the situation in real-time. Evolving the Link Between Fire and Voice Alarm While the integration between fire alarm and voice evacuation via Smart Safety Link has been a widely adopted feature for several years now, with constant gains in efficiency and ease of use, the evolution continues. Bosch recently released a new generation of panels that provide the foundation for immediate new functionality as well as a platform for future technologies guided by Smart Building and Internet of Things (IoT) principles.Bosch recently released a new generation of panels that provide the foundation for immediate new functionality Continuing the proven, modular concept of its predecessors, the new “Avenar” panels provide an intuitive user interface, simplified planning and streamlined purchasing process for operators and system integrators. The panels work with existing fire alarm system components, but offer enhanced scalability, computing power and functionality for future applications. Most of all, the Avenar series creates a single point of access and control for personnel and operators while putting both the voice alarm and fire alarm system components at their fingertips. A Combined Graphic User Interface for Both Systems Previously, many systems still required two separate user interface environments to control fire alarm and voice evacuation components. Here’s where Avenar bridges the gap: Users can now fully control safety equipment such as fire alarm, voice alarm, door controls, and more, directly on the Avenar panel display via the “eMatrix” feature. With its 7-inch touch screen, eMatrix puts full control of all system components on a single interface. The results include faster response times from eliminating the need to switch between platforms, as well as a one-stop overview of the latest situation.With its 7-inch touch screen, eMatrix puts full control of all system components on a single interface eMatrix displays the status of all connected fire safety equipment and evacuation zones in a color-coded format, indicating states by red, yellow, and green labels. Operators also directly see the status of automated emergency responses currently in progress, with the option to intervene manually as needed. These manual commands are available in the form of icons on screen that control sirens, strobe lights and voice announcements. Constant feedback on the progress of evacuation measures allows for an unprecedented level of control in emergency situations. Networked Solutions for Tomorrow’s Smart Buildings In a world where connectivity and cloud computing are key drivers of innovation, both panels support fast ethernet system architecture with 100Mbit data transfer rates. What’s more, fire panels and voice alarm components connect to a network, allowing for the integration of building management systems such as HVAC. In a world challenged by pandemic restrictions, remote maintenance and control are day one features of the platform. Looking into the future, the next generation not only immediately puts faster response times and better situational oversight into system operator’s hands. When it comes to smart building technologies that support emergency responses with AI-based automation for even faster turnaround, the Avenar panels also provide the hardware and connectivity to pave the way.
