The most important aspect of a railway fire protection system is detection. The various fire detection systems with which we equip the area or asset to be protected indicate to the control module whether the situation is normal or, on the contrary, there are abnormal smoke levels or excessive temperatures. A series of actions are triggered by an alarm signal generated by the detection devices. These actions, governed by the control panels that Triple E designs and manufactures, are defined by technical requirements, regulations and certifications.
In this article, we are going to discuss the detection methods we use in the passenger lounge in railway rolling stock: optical detectors and suction detectors, as well as thermal detectors, most commonly used in technical areas.
Optical fire detection system
An optical fire detection system has a similar appearance to the devices used in hotels, hospitals or other high-occupancy places. It has a built-in system that emits an alarm signal in the event of a high concentration of smoke in the air.
This type of detector consists of an LED light emitter and a photosensitive receiver. In this case, smoke in the air is detected by the absorption or scattering of light. Thus, when the light beam is obstructed inside the device and the light emitted is scattered, the receiver picks up this change in the light signal and automatically triggers the alarm signal.
These devices are particularly suitable for use when the materials that may be burned are slow-burning (fabrics, wood, etc.) and generate large quantities of soot with large particles. These components are highly reliable and trouble-free during their service life. In addition, Triple E’s engineers thoroughly determine the number of elements required in all areas of the carriages.
Suction detectors
With this fire detection system, the device continuously samples the air through a duct with several installed nozzles. Simultaneously, a laser emitter inside the device detects the presence of smoke, which is more accurate than conventional detectors.
These are configurable devices that can detect the smallest amount of smoke in the vehicle’s air. However, their high sensitivity requires our engineers to check the viability of the system in certain environments where the presence of particles could lead to false alarms (e.g. in dusty areas). This detector is more complex and has electromechanical elements that require more intensive maintenance than just regular cleaning.
Accordingly, at Triple E we have developed an independent detector as an alternative to the system described above. This gives the detector artificial intelligence and the ability to work independently. It is therefore particularly suitable for certain watertight compartments, such as toilets and electrical switchboards. It can also be a solution for retrofitting very old rolling stock.
Thermal fire detection
Lastly, we will explain how thermal detectors work. By means of a heat-reactive sensor cable, they are used to protect sensitive technical areas such as engines, electrical switchboards, traction converters, HVAC equipment, etc… Thus, in the event of temperatures previously established as abnormally high, a series of electronic signals would be generated that would initiate the procedures to achieve detection and, if necessary, effective extinguishing. This would, as always, guarantee everyone’s safety.
