Hot box detection in European railway networks

Transcription

1 Hot box detection in European railway networks If an ineligible heating of a box or a brake is not discovered early enough,lubricating grease in the box will lose its function and a break-down of the box would follow. Thereby,inhomogeneous loads per axle are possible which can lead to a derailment of the boogie. Economic efficiency of a wayside hot box detection system can be demonstrated in comparison with the costs of prevented derailments. This article provides an overview on systems used in Europe for hot box detection. 1 Motivation for the use of hot box detectors Although railways rank worldwide among the safest means of transport, nevertheless every year there are some serious accidents. Some of these accidents, especially in the area of freight traffic are attributable to defective wheel bearings and brakes of a wagon in the train consist. If such effects can develop unrecognised, they lead to the overheating of the defective bearing or of the brake and to a breakage of the axle or of the steel tyre. A derailment of the wagon affected is the consequence. In order to identify such damage at an early stage, at appropriate distances along the track temperature measuring points (which are known as Hot Axle Box and Hot Wheel detection units HABD/HWD) are mounted on the track. These systems measure contactless the temperatures of the axle bearing boxes, wheels and brake discs passing over them. They are used on conventional lines as well as on high-speed lines. In that way, derailments due to overheated wheels and bearings can be prevented and trouble-free rail operations can be achieved. Dr.-Ing. Erich Eisenbrand CEO SST Signal & System Technik GmbH, Siershahn eeisenbrand@sst.ag 2 Basics of hot box detection on the basis of infrared technology 2.1 Physical basis of contactless temperature measurement Basis of contactless temperature measurement is the fact that each object the temperature of which is above the absolute zero point of 0 Kelvin ( C) emits electromagnetic radiation according to its state of warmth. The intensity of the radiation and the wavelength ( ) where the intensity of this radiation has a maximum depends upon the respective temperature of the object (Planck s radiation law, Wien s displacement law). [1] Also the nature and characteristics of the emitter s surface have an influence on the emitted energy. Only at higher temperatures (> 500 C) part of the radiation is released as visible light. Temperature detection by hot box detectors takes place predominantly in the medium infrared range (wavelength of 3 μ to 6 μm). Measuring instruments able to measure the radiation emitted by a surface on a contactless basis and the output signals of which are directly allocated to temperature values Fig. 1.1: Temperature of Axle Bearings, Steel Tyres, and Brake Discs are referred to as radiation thermometers (pyrometers). The infrared scanners of hot box detectors are very fast radiation thermometers developed specially for extreme use in the railway area. The allocation of the output signal of the radiation thermometer to the temperature radiation of the surface is done by means of calibration of the system. Therefor an electronically stored table of values for surface temperatures and corresponding output signals is created by means of factory calibration and auto-calibration during operation. Via this the output signal can be converted into temperature values. In order to be able to contactless and very quickly measure temperatures in the range from 0 C to 650 C special infrared detectors are used (quantum detectors), which convert the thermal radiation of the target into electric signals especially in the infrared range [2]. Like a photo-camera the measuring systems consist of lenses, mirrors and infrared detectors (Fig. 2.1). (1) Heat target such as axle bearing, wheel, brake disk (2) thermal radiation (3) shutter 2

2 Hot box detection in European railway networks unit (4) deflection mirror (5) optical system (6) infrared sensor (7) electronics. The infrared sensor may have one or more pixels. The infrared radiation of an axle-box passing by is detected by the system, converted into electric voltages and displayed as absolute temperatures. These electric voltages are converted into temperature values based on a previous calibration (comparison scale). (In the case of some older systems, the temperature is not detected absolutely but in relation to the ambient temperature, to be more precise, the cold bottom side of the vehicle.) The measurement and calculation of the temperature only takes fractions of a second. The temperature of the thermal target can be detected several times even at high speeds. Fig. 2.1: Principle of an Infrared Radiation Thermometer The temperature ranges generally demanded are: for the HABD* 0 C 150 C (temperature of the bearing box) for the HWD** 80 C 650 C (temperature of the wheel/brake disc) All of the systems used are insensitive in relation to: fouling, ambient temperature of the particular region of use, snow, ice, humidity etc. The main problems involved in the detection of temperatures in railway operations are: solar radiation (sun = disturbing heat source with a surface temperature of 6000 C) by reflection on parts of the train, braking sparks, disturbing heat sources in or near the area of the measured surfaces (axle bearings, wheels, brake discs). All of the systems in use incorporate mechanisms in the hardware and the software in order to reduce these disturbances to an absolute minimum. For future rail vehicles, certain measures have been prescribed in order to ensure trouble-free temperature detection on axle bearings by means of stationary hot box detectors (on this see DIN EN :2009). * HABD = Hot (Axle-)Box Detector ** HWD = Hot Wheel Detector 2.2 Functionality of hot box detectors The essential structure of a hot box detector is shown schematically in Fig. 2.2 and it consists of the following function blocks: (1) Infrared measuring systems (pyrometers) in the track (in a sleeper or on the rail) (2) Rail contact on the track (axle counter) (3) Evaluation electronics near the track (4) Data transmission and network Fig. 2.2: Principle of a Hot Axle Box Detection System (5) Display unit at the dispatcher s workplace. General functional routine: If a train approaches the measuring system, a rail contact (2) passed over activates the system and it becomes ready for measuring (in some cases the measuring system is also activated by the track occupied signal, e. g. in France). When the wheel passes the infrared measuring system (1) and the axle counters located there, the temperature values of the left-hand and the right-hand axle box cases, the temperatures of the wheel and of the brake disc (depending on the system configuration) are recorded and allocated to the axle number in the train consist. In the case of a dangerously high temperature, an alarm is triggered and the dispatcher (5) receives the following information at least: type of alarm (e. g. hot alarm, warm alarm) value of the temperature measured place of the measuring point type of temperature measured (bearing box, wheel, brake disc) number of the axle on which the alarm was detected side of the train on which the temperature was measured direction of travel of the train Depending on the type of construction of the system, additional information can be collected and reported. The individual evaluation of temperature values to generate further different customer-specific alarms is possible. Based on the type of alarm, the dispatcher activates routines laid down in advance. The thresholds for various types of alarms and the ensuing instructions for courses of action can differ in different countries. (In France the train is stopped automatically whenever a hot alarm is signalled.) The items of information of the distributed 3

3 Hot box detection in European railway networks hot box detection sites can be networked. In this way, in conjunction with the train number or by means of tags on the wagons (electronic identification marking of the wagons) trending of the temperature development of a particular axle box as well as information exchange with other hazard warning equipment is possible. Example: Product name: HOA50 Manufacturer: Ansaldo STS Example: Servo Systems: Manufacturer: formerly Harmon Industries now Progress Rail sibilities for suitably evaluating the bearing temperatures. With a further widening of the scanned area the risk of detecting hot parts which are not allocatable to a bearing is rising. Examples of multi-beam systems (line scanning): By the way of distributing hot box detectors along the rail network a high level of redundancy is achieved. If one unit along the track fails, the next unit in the network is able to detect the temperatures of all axle bearings and wheels of the train not measured by the last unit. (Some trains have a so called onboard system, where every axle bearing on the vehicle is fitted with temperature sensors. If the temperature detection fails on one axle bearing, this unit will no longer be monitored until the sensor system has been repaired.) 3 Examples of various measuring geometries and systems currently used in Europe Considering the hot box detectors currently in operational use in Europe, five systems of a more recent type of construction are found which in certain points hardly differ, but in other points differ considerably. Infrared measuring systems in operational use in Europe Remark: besides the systems named here, older systems both of other companies and of the companies listed are still in operation. (in alphabetical order) Company Product name Scanning equipment of the box case Ansaldo STS HBD50 IR detector with 1 pixel ÖBB TK99 IR detectors with 2 pixels each Progress Rail* FUES IR line detector with 4 pixels SST Signal & System PHOENIX MB IR line detector with 8 pixels Technik GmbH VAE voestalpine Eisenbahnsysteme GmbH HOA400 IR detector with 1 pixel and oscillating mirror (*Remark: Progress Rail formerly GETS, General Electric Transportation Systems) Remark on Servo systems: In some European countries Servo scanners are still used in considerable numbers. These rank among the single beam solutions with differential temperature evaluation. The cold bottom side of the vehicle is compared with the higher bearing temperature and from that a temperature (temperature difference) is deduced. With a clamp the detector unit is attached to the foot of the rail. This equipment meanwhile no longer meets the high demands of interoperability and harmonisation in Europe and is step by step replaced by more modern systems. For that reason this system will no more considered here. Dual-beam systems: This system type incorporates infrared scanners with two independent scanning points for axle bearing measurement. The infrared scanners measuring the wheel and brake disc temperatures each have one scanning point. Product name FUES PHOENIX MB HOA 400 Manufacturer Progress Rail (formerly GETS ) SST Signal & System Technik GmbH VAE Remark on the HOA 400: The HOA400 system does not have a line sensor; in this case line scanning (detection) is achieved by a mechanically oscillating mirror. Presentation of the individual systems in alphabetical order of the manufacturers 3.1 Single-beam system HBD50 (Ansaldo STS) The standard system consists of 3 scanners. Two scanners for axle bearings on the left-hand side and the right-hand side and one HWD scanner for the wheels and brake disk. The IR scanners are mounted on the rail. With the measuring geometry of the HWD scanner inclined obliquely upwards and against the track both wheels and the brake disc of one side can be detected. Each scanner has an infrared detector with one pixel. The maximum value of the temperature recorded is displayed. The measuring geometry of the scanners on the track is adjustable and can be varied at the customer s request. Operating Principle Supervision is defined by zones along the line. [3] When a train enters a measurement zone, it is first recognized by an electronic treadle located ahead the detectors, which determines the running direction (strike-in). This treadle counts the number of axles to be measured and sends the activation command to the detection system (READY mode). (Fig ) Classification of Different Infrared Hot Box Detection Systems At present time, the infrared measuring systems on the market can be divided into the following three categories. Single-beam systems: All infrared scanners of this system type have one scanning point. The whole system can consist of several infrared scanners with one scanning point each. Example: Product name: TK99 Manufacturer: ÖBB Multi-beam systems: Every infrared scanner in the system has several scanning points (line sensor with several pixels, rectangular to the travelling direction of the train). The complete system may consist of several infrared scanners each with several scanning points. Systems with line sensors provide in conjunction with modern software extensive pos- A second treadle triggers the axle box temperature measurement.another treadle then validates the position of one of the two wheels of a particular axle or of the brake disc to measure the temperature using the hot wheel sensor. This measurement is synchronised with the hot box measurement treadle for measuring the other wheel. Once the axle counting and the temperature measurement is completed, self-calibration takes place and the system is put into stand-by. The acquired data is then sent to the control room via its processing module 4

4 Hot box detection in European railway networks Fig : Operating Principle HOA50 Fig : Track Installation HBD50 (measurement point) located at the trackside. Hot axle and hot wheel detectors increase passenger and freight safety of trains through increased reliability and great accuracy in all networks using this equipment which include high-speed lines, as well as conventional lines in Europe, Egypt, Iran, China, Korea and Australia. Fig : Alarm Message Monitoring Station 3.2 Dual-beam system TK99 (ÖBB) This system type consists of two infrared sensors per axle bearing scanner on the left/right side thus 2 measuring points each. There are two HWD scanners, one for the wheel and one for the axle-mounted disc brakes, which are measured from below. The relative frequency of derailments, as a consequence of defective (overheated) bearings, in the network of the ÖBB in the early 1990s on one hand, as well as the Fig : Track Installation TK99 absence at that time of appropriate solutions on the other hand, inspired the ÖBB to develop their own hot box detector of the 5

5 Hot box detection in European railway networks Fig : Measuring Geometry TK99 Fig : Train Data Viewer at TK 99 Fig : FUES II EPOS Track Installation and HABD Detector type TK 99. [4] The main feature is the patented measuring geometry (Patent AT B), which is particularly adapted to Austrian requirements (RoLa intermodal -Transport, Schlieren type bogies, Y25 bogies). Beside the bearings, the brakes are also checked with regard to inadmissible warming-up and/or overheating. Since, from an operating point of view, only a minimal false alarm rate (alarming although there has not been any damage) is permitted, special attention had to be given to this requirement. A stipulation required no manual post processing of alarms had to be carried out by personnel. Therefore the equipment had to achieve the two objectives of high availability with a simultaneously low false alarm rate. After a trial phase a rollout into the complete network and across the whole area was able to be started which was essentially completed by the end of At present 240 equipments are in operation at 147 locations throughout the network. This results in an average distance of 30 km on main lines and about 50 km on supplementary lines. In order to be able to meet the requirement of high availability also in daily operations, the status of each individual unit is monitored by a maintenance control centre. In the process appropriate messages are sent by the unit to the maintenance personnel in the event of a malfunction. As a matter of fact, a very large time is shown between two malfunctions. The validation of the alarms is generally carried out by the engine driver of the train affected, in cooperation with the train dispatcher responsible. The way of proceeding and the responsibilities are in this case clearly and unambiguously regulated in what is known as process instructions. Over the last few years a validation rate of 99.5 % has been observed, i.e. the alarm signalled was actually verified on the wagon. A specifically Austrian detail is the way of proceeding in the event of an alarm message HBD hot being given. Here stopping takes place at the defined main signal (no routes are taken back by means of an emergency cancellation, but simply no new ones are made available any more) as well as unconditional taking out of service of the defective wagon even if verification by the engine driver should once turn out to be negative. This measure shows very clearly the high level of confidence of the operational management bodies in the equipments of the type TK Multi-Beam System FUES (Progress Rail) Fig : FUES II EPOS Measuring Geometry with FBOA TAS The FUES II EPOS [5] is a further development of the system FUES I/FUES II. Every IR scanner of the system FUES II EPOS (Easy Pull-Out System) has one infrared line detector with 4 pixels. With this a line 6

6 Hot box detection in European railway networks (rectangular to the direction of travel) can be scanned at travelling speeds of up to 500 km/h. In the standard configuration, the overall system consists of three to four such modular scanners which cover the axle bearings, the wheels and the brake discs. The trackside components are installed in a hollow metal sleeper (Fig ) and the detectors locate warming-up in a defined target area by means of infrared technology. The system presents the absolute and relative temperatures as well as temperature differences between the elements (pixel) in real time. The components installed at the trackside are all operated at a voltage of +/ 24 V DC. In addition, the FUES II EPOS also has alternative measuring geometries. Particularly worthy to mention here is what is referred to as HWD (blocked brake detection unit), TAS (Target Area Split) for which the HWD TAS detector looks at two different places (see Fig ). This FUES II EPOS configuration contributes at a very high degree to the further reduction of false alarms. Due to the modular structure the FUES II EPOS ensures short track access times, high availability and flexibility of the configuration. The individual FUES II EPOS modules each have one detector that scans with four elements and an internal focus for the necessary self-checking. The accuracy of these detectors is +/ 2 degrees K with 12 bit resolution. Beside an automatic calibration system the EPOS modules also have a self-diagnosis and fault detection system. For example, fouling of the mirror or the lens are reported and at the same time taken into account in the calculation by the system. Fig shows a possible configuration of the FUES II EPOS. Other variants are also possible. Progress Rail Office Software RAD (Remote Announcement Display) further functionalities are possible. Beside trending among these are alternative alarm concepts which change the priorities of successive alarms. With more than a total of 1,000 systems installed (systems FUES I, FUES II and FUES Fig : Possible Configuration of FUES II EPOS II EPOS) which are used in demanding passenger train traffic in Europe, the FUES covers the wide speed ranges from 3 km/h up to 500 km/h and is completely compatible with the different types of trains, wagons and existing brakes used by these railways. The FUES can adjust to the specific configuration of an operator s vehicles and rail infrastructure. In addition to the hardware the software is an integral part of FUES. By means of the software, five types of alarms can be configured. These alarms include: warm, hot, differential (warm and hot) and relative alarms. The interaction with the vehicle identification system FID of the FUES facilitates the allocation of these alarms to vehicles. Fig : Alarm Presentation of HWD (FBOA TAS) Likewise the FUES software has various classifiers for the purpose of the reduction of the effects of perturbing radiation (e.g. sun and exhaust). In Fig , a genuine alarm of a HWD TAS can be seen. What can be recognized there is the masking out of the perturbation area and assessment of the alarm. This alarm is a confirmed alarm. It is also possible to activate signals as a function of alarms. In interaction with the Fig : Principle of Multi-Beam Scanning PHOENIX MB 7

7 Hot box detection in European railway networks 3.4 Multi-Beam System PHOENIX MB (SST Signal & System Technik GmbH) Each PHOENIX MB scanner uses one infrared line detector with 8 pixels in a row (line detector). An area up to 12 cm wide (rectangular to the direction of travel) can be scanned at travelling speed up to 500 km/h. (Fig Principle of Multi- Beam scanning) In the standard configuration the complete system consists of three to four scanner modules inspecting the axle bearings, wheels and brake discs. An example of various possible scanning geometries is shown in Fig At the customer s request, the covering of other special measuring geometries is also possible; for instance in Scandinavian countries such as Finland both the temperatures of the axle bearing box and the axle journal are covered (two different target areas). Fig : PHOENIX MB Configuration of the Measurement Geometry The PHOENIX MB system (MB means Multi- Beam) is a completely new development of a hot box detection system available since Development was focused particularly on high availability, low false alarm rate and above all the easiest possible installation and maintenance. Remote diagnostic and remote control possibilities are standard features of the system. A scanner module in the track can be replaced in less than three minutes and is operational immediately. The modular design also of the electronics enables service in the shortest possible time. The system can be flexibly mounted and provides many opportunities for achieving desired measuring geometries and adapting specifically to the customers requirements. A controlled heating for winter times has been integrated into the system. Since the first homologation in 2002 over 1,000 PHOENIX MB systems have been installed worldwide in all climate zones. In Fig all axle bearing temperatures of an entire train including an alarm are shown. Additionally the temperature profiles of an axle bearing and a wheel are depicted. Clicking on the temperature bar of a wheel set in the train diagram the temperature profiles are shown of each axle bearing, wheel or brake disc. Two-dimensional measurement curves (2D) or a three-dimensional thermal image (3D) is selec-table. Through fast scanning and high image resolution temperature profile data of the measured area are gathered. The integrated software analyses these data to avoid false alarms caused by reflections or direct sunlight as well as sparks during braking. In that way non-confirmed alarms can be reduced at an extreme degree. The PHOENIX MB has a detailed self-diagnosis system. In order to ensure measuring accuracy, auto-calibration is an integral part of the scanners. A typical track installation is shown in Fig All components installed in the track including the winter heating are operated on low voltage. Fig : Train Temperature Data with Alarm and Temperature Profiles PHOENIX MB 8

8 Hot box detection in European railway networks n PHOENIX MB Hot Box Detectors are integral parts of a Central Monitoring System (CMSAT) into which various diagnostic devices (irrespective of the manufacturer) can be integrated for monitoring of rolling stock and railway infrastructure. Fig The PHOENIX MB system software facilitates identification of a wagon using the detected distances between axles or by reading electronic tags of vehicles. This enables trend analysis via train identification using a database driven monitoring system (CMSAT). The tracking of the temperature development of a particular axle bearing/wheel can be performed and thus the presentation of an alarm at an early stage is possible even if the temperature threshold has not yet been exceeded (trend analysis). Fig : Track Installation PHOENIX MB 3.5 Wide Scanning by Mechanically Oscillating Mirror System HOA400 (VAE) IR Detector (Single Beam) with Oscillating Mirror The HOA400 ranks among the older systems which were developed in the early 1990s. Although it does not have an infrared line detector, line scanning of the measuring surface is achieved with a mechanically oscillating mirror. Scanning Method The oscillating mirror in the beam s path of the infrared optics directs the visual beam of the HBD scanner with 2.4 khz according to the curve shown in Fig over the axle bearing of the rail vehicle. [7] The distance of the scanner from the middle of the track is set in such a way that the working beam is passed over the specified measuring area of the bearing box and in the area of the bearing cover an auto-collimation takes place. In this position of the oscillating mirror the infrared radiation originating Fig : Principle of the Scanning Method with Mechanical Oscillating Mirror Fig : Display Example of CMSAT Fig : Presentation of Measured Values HOA400 9

9 Hot box detection in European railway networks from the bearing box is reflected on the mirror of the detector element. The absolute temperature of the axle bearing box is determined. The temperature signal received via the detector is electronically scanned and processed. In order to obtain a scanning matrix which is equidistant over the bearing box, the electronic scanning frequency is varied within an oscillation between 20 and 120 khz. Depending on the train s speed, the number of scans and hence the number of measured values changes. They are averaged in a temperature chart with 120 measuring cells and displayed in a control room (Fig ). The system can be mounted alongside the rail as shown in Fig or also be fitted in a special hollow steel sleeper. 4 Current Distribution of the Hot Box Detection Systems in Operational Use in Europe During the last few years several European countries have carried out replacement programmes both for the replacement of older hot box detectors and for increasing the density of these systems within the rail network. Fig. 4.1 shows the current distribution of the different hot box detection systems in Europe presented in the last chapter (status as of 2010). Beside the systems shown in Fig. 4.1 a small percentage of older systems from various manufacturers still exists but is not shown. Important parameters for all hot box detectors are availability, reliability, the false alarm rate and service life. Specific knowledge of these data is valuable for all manufacturers of such systems to achieve further improvements of systems. Evaluation of appropriate statistics is in the hands of the operators. As a general rule it is very difficult to obtain reliable and meaningful values. The parameters stated are the result of an overall process, such as the measurement of temperature by hot box detectors, specification of alarm thresholds by the operator, alarm generation (special algorithms), suitable treatment of alarms by the operator as well as maintenance of the complete system (HBD, data transmission, control room). The function of the hot box detectors herein is only a part of the overall process. Therefore it is sometimes difficult, for example in the case of an unconfirmed alarm ( false alarm ), to decide at which point in the overall process the causes of this are to be searched for. Fig : VAE-HOA/ FOA 400 on Slab Track Nuremberg Ingolstadt, Germany 5 The new EN for the Harmonisation of the Demands Made on the Vehicles and Hot Box Detectors by European Regulations The new EN Railway applications Axlebox condition monitoring Interface and design requirements- Part 1: Track side equipment and rolling stock axlebox [8]. This standard specifies the minimal demands for the interface between track-side Fig. 4.1: Hot Box Detection Systems in Europe 10

10 Hot box detection in European railway networks Beside the essential measuring geometry further requirements are also defined in this standard for the vehicle and the hot box detector. For example a prohibitive zone on the vehicle in which no heat sources may be located (e. g. generators, exhaust pipes) which confuse temperature measurement in the target area or render it impossible. In the purely informative appendix (not normahot box detectors and rail vehicles. Only the requirements for the measurement of axlebearing temperatures are described. The detection of wheel temperatures and temperatures of brake discs is not the subject of this standard. In order to define this interface, both the vehicle and the hot box detector must be described. Target Area on the Vehicle On one hand requirements are put on vehicles such as the dimensions and the positions of the target area (TA) on the vehicle which must be visually accessible. This target area, for example on the wheel set bearing box refers to the centre line of the vehicle. On the other side of the interface the requirements put on measuring systems for hot box detection are described. Temperature Measuring Zone of Hot Axle Box Detectors For the stationary hot box detector installed, a minimum position area has been defined (referred to as a temperature measurement zone TMZ), relating to the centre line of track, so that within this zone at least one discrete measurement of the temperature can be taken. As both areas (moving target area on the vehicle and fixed temperature measuring area of the HABD) face a mutual relative movement due to the train s movement, in the standard a maximum lateral movement of the wheel set relative to the track position of less than ± 10 mm is assumed. The aim of the overall system vehicle hot box detector is that at least one individual measurement of the thermal radiation (temperature value) of the target area on the vehicle can be taken. For that purpose on the vehicle within an area of 1040 mm to 1120 mm, based on the vehicle centre line, an area which is at least 50 mm wide (target area) (lateral to the direction of travel) must be visually ac- Fig. 5.1: Target Area of Vehicle and Temperature Measuring Zone of HABD cessible in order for temperature values to be taken in this area (see Fig. 5.1). The hot box detector must be designed in such a way that within an area of 1040 mm to 1120 mm (relating to the centre line of the track) it can measure at least one temperature point. Due to the lateral movement of the vehicle and the related movement of the 50 mm wide target area relative to the stationary track centre line problems could arise in the case of the use of single-beam systems, if lateral movement of the vehicle might for whatever reasons be more than ± 10 mm. tive) examples of the HABD installation, the measuring accuracy and the setting of the temperature alarm thresholds are given. The new DIN EN :2009 compiles only the minimum requirements both for vehicle manufacturers and for manufacturers and operators of hot box detectors. References [1] Wissensspeicher Infrarottechnik, Fachbuchverlag Leipzig 1990 [2] Temperaturmessung in der Technik, Lothar Weichert, 5. erw. Auflage 1992, Expert-Verlag [3] Information of Ansaldo STS Hot Box and Hot Wheel Detectors HOA50, Ansaldo STS France [4] Information of ÖBB Hot Box and Hot Wheel Detectors TK99, ÖBB Vienna Austria [5] Information of Progress Rail Hot Box and Hot Wheel Detectors FUESII EPOS, Progress Rail Bad Dürkheim Germany [6] Information of SST Hot Box and Hot Wheel Detectors PHOENIX MB, Signal & System Technik GmbH Siershahn Germany [7] Information of VAE Eisenbahnsysteme Hot Box and Hot Wheel Detectors HOA400, VAE Eisenbahnsysteme Zeltweg Austria [8] EN Beuth Verlag Berlin, Norm: EN :