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52-501: Prior to GNT the tilting control was added as a subset of the Linienzugbeeinflussung (LZB) train protection system that has been in service on high-speed lines since the 1960s. It turned out that the switch from PZB to LZB on some regional lines was considered to be too expensive. As such Siemens was tasked to provide ZUB balises that would work on top of the existing line side signalling and their PZB controlled restrictions. It

104-401: A "response telegram" at 600 bits per second at 56 kHz ± 0.2 kHz. Call telegrams are 83.5 bits long: One might note that there is no "train identification" field in the telegram. Instead, a train is identified by position. See Zones and Addressing for more details. There are 4 types of response telegrams, each 41 bits long. The exact type of telegram a train sends depends on

156-502: A Eurobalise antenna. This includes the successor DB Class   612 as well as the series of ICE   T (Class   411 and 415) and ICE   TD (Class   605) trains. In general the GNT ZUB balises are placed slightly before the PZB inductor signalling an override speed information so that the traditional PZB on-board system is temporarily disabled at that PZB control point. In

208-440: A LZB control centre. The control centre computer receives information about occupied blocks from track circuits or axle counters and locked routes from interlockings. It is programmed with the track configuration including the location of points, turnouts, gradients, and curve speed limits. With this, it has sufficient information to calculate how far each train may proceed and at what speed. The control centre communicates with

260-404: A buzzer and display the distance to and speed of the restriction. As the train continues the target distance will decrease. As the train nears the speed restriction the permitted speed will start to decrease, ending up at the target speed at the restriction. At that point the display will change to the next target. The LZB system treats a red signal or the beginning of a block containing a train as

312-412: A full-screen computer generated "Man-machine interface" (MMI) display rather than the separate dials of the "Modular cab display" (MFA). LZB operates by exchanging telegrams between the central controller and the trains. The central controller transmits a "call telegram" using Frequency-shift keying (FSK) signalling at 1200 bits per second on a 36 kHz ± 0.4 kHz. The train replies with

364-478: A new "change of section identification" telegram and gets a new address. Until the train knows its address it will ignore any telegrams received. Thus, if a train doesn't properly enter into the controlled section it won't be under LZB control until the next section. The main task of LZB is signalling to the train the speed and distance it is allowed to travel. It does this by transmitting periodic call telegrams to each train one to five times per second, depending on

416-729: A speed restriction of 0 speed. The driver will see the same sequence as approaching a speed restriction except the target speed is 0. LZB includes Automatic Train Protection . If the driver exceeds the permitted speed plus a margin LZB will activate the buzzer and an overspeed light. If the driver fails to slow the train the LZB system can apply the brakes itself, bringing the train to a halt if necessary. LZB also includes an Automatic Train Operation system known as AFB (Automatische Fahr- und Bremssteuerung, automatic driving and braking control), which enables

468-450: A stopping point, the monitoring speed follows a braking curve similar to the permitted speed, but with a higher deceleration, that will bring it to zero at the stopping point. When approaching a speed restriction, the monitoring speed braking curve intersects the speed restriction point at 8.75 km/h (5.44 mph) above the constant speed. DB Class 610 The DB Class 610 is a Diesel Multiple Unit (DMU) train type operated by

520-438: A train is approaching a speed restriction the control centre will transmit a packet with an XG location set to a point behind the speed restriction such that a train, decelerating based on its braking curve, will arrive at the correct speed at the start of the speed restriction. This, as well as deceleration to zero speed, is illustrated with the green line in the "Permitted and supervised speed calculation" figure. The red line in

572-727: Is a cab signalling and train protection system used on selected German and Austrian railway lines as well as on the AVE and some commuter rail lines in Spain . The system was mandatory where trains were allowed to exceed speeds of 160 km/h (99 mph) in Germany and 220 km/h (140 mph) in Spain. It is also used on some slower railway and urban rapid transit lines to increase capacity. The German Linienzugbeeinflussung translates to continuous train control , literally: linear train influencing . It

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624-766: Is also called linienförmige Zugbeeinflussung . LZB is deprecated and will be replaced with European Train Control System (ETCS) between 2023 and 2030. It is referenced by European Union Agency for Railways (ERA) as a Class B train protection system in National Train Control (NTC). Driving cars mostly have to replace classical control logic to ETCS Onboard Units (OBU) with common Driver Machine Interface (DMI). Because high performance trains are often not scrapped or reused on second order lines, special Specific Transmission Modules (STM) for LZB were developed for further support of LZB installation. In Germany

676-487: Is based on the Siemens ZUB   122 system which uses balises that are put next to the PZB indusi inductors on the outer side of the rails. The second generation of GNT has switched to the Siemens ZUB   262 system which is based on Eurobalises being under test since 1997. The functionality has not changed however and the balises work in conjunction with the PZB train protection system. The development of EuroZUB for

728-483: Is obvious. In mode ETCS L1 Limited Supervision (L1LS) as a successor of PZB it is possible to deploy GNT in the same manner like ZUB   262 before. In 2014 the DB Class ;610 were put out of service. The DB Class 611 had been partly converted from ZUB 122 to ZUB 262 but they have ended their regular service at the end of 2017. All other tilting trains in Germany are based on ZUB   262 with

780-522: Is only activated on trains running more than 70 km/h (43 mph). If the GNT system is switched off then the PZB signals are used to control the line speed. Trains without GNT can use the same lines as they respond to the existing PZB control. If the following PZB point is missing then a GNT equipped train is limited to 100 km/h (62 mph). In Germany, the following Deutsche Bahn trains are equipped with GNT: The ICE T trains sold by Deutsche Bahn to

832-403: Is still restricted to a maximum of 160 km/h (99 mph) as the traditional line side signalling is used for train operation. Running a train on-sight is limited to that speed throughout Germany. In current practice the system allows up to 30   % more speed in curves thereby limiting the lateral acceleration to a maximum of 1.0   m/s². In current operation the tilting functionality

884-563: The Austrian railways introduced LZB into their systems, and with the 23 May 1993 timetable change introduced EuroCity trains running 200 km/h (120 mph) on a 25 km (16 mi)-long section of the Westbahn between Linz and Wels . Siemens continued to develop the system, with "Computer Integrated Railroading", or "CIR ELKE", lineside equipment in 1999. This permitted shorter blocks and allowed speed restrictions for switches to start at

936-721: The Deutsche Bahn in Germany . They were built from 1991 to 1992 by MAN and Duewag . The class uses a tilting Hydraulic Fiat system used in Italian Pendolino trains. The trains were ordered for the Nürnberg to Hof, Bayreuth and Regensburg routes which include a large number of curves. The units worked well from 1992 to 2000 when cracks in the bogies meant they had to be taken out of service. The wheelsets were replaced and they were back in service in 2001. The class now all wear

988-399: The "Group identity" in the call telegram. The most common type of telegram is type 1, which is used to signal a train's position and speed to the central controller. It contains the following fields: {LZB p3} The other telegrams are used primarily when a train enters the LZB controlled section. They all start with the same synchronization and start sequence and a "group identity" to identify

1040-474: The "Ü" light to indicate that LZB is running. From that point on the train's location is used to identify a train. When a train enters a new zone it sends a response telegram with the "vehicle location acknowledgement" filed indicating that it has advanced into a new zone. The central controller will then use the new zone when addressing the train in the future. Thus a trains address will gradually increase or decrease, depending on its direction, as it travels along

1092-746: The Austrian Federal Railways were initially the only GNT-equipped vehicles that did not belong to DB. Because the RABe 503 of the Swiss Federal Railways run at high speed on the Munich–Lindau–Zurichroute, they also had to be equipped with ZUB 262. Most lines with Siemens ZUB   122 exist in Southern Germany from Basel to Stuttgart, Frankfurt, Nürnberg, Regensburg. The lines with Siemens ZUB   262 may exist alongside to

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1144-482: The Fulda-Würzburg segment that started operation in 1988, it incorporated LZB into the lines. The lines were divided into blocks about 1.5 to 2.5 km (0.93 to 1.55 mi) long, but instead of having a signal for every block, there are only fixed signals at switches and stations, with approximately 7 km (4.3 mi) between them. If there was no train for the entire distance the entry signal would be green. If

1196-674: The Swiss network had been the original cause with an expectation that a switch to ETCS would be made soon. The German network operator Deutsche Bahn has ensured, that tilting information was finally added to the European Train Control System (ETCS) in version 3.4.0 (like it has done and never used in LZB). In the ETCS mode L2 all information for speed allowance is provided by Radio Block Center (RBC), so there are no additional balises needed and GNT

1248-453: The ZUB   122 equipment with new lines extending north to Erfurt and Leipzig in eastern Germany and north to Goslar and Hildesheim in western Germany. Additional lines in southern Germany were connected like those to Passau and Ulm. All lines equipped with GNT are shown in an interactive map on the internet by DB Netz AG . Linienzugbeeinflussung Linienzugbeeinflussung (or LZB )

1300-516: The computer-based LZB L72 central controllers and equipped other lines with them. By the late 1970s, with the development of microprocessors, the 2-out-of-3 computers could be applied to on-board equipment. Siemens and SEL jointly developed the LZB 80 on-board system and equipped all locomotives and trains that travel over 160 km/h (99 mph) plus some heavy haul locomotives. By 1991, Germany replaced all LZB 100 equipment with LZB 80/L 72. When Germany built its high-speed lines, beginning with

1352-417: The crossing the signal phase angle is changed by 180° reducing electrical interference between the track and the train as well as long-distance radiation of the signal. The train detects this crossing and uses it to help determine its position. Longer loops are generally fed from the middle rather than an end. One disadvantage of very long loops is that any break in the cable will disable LZB transmission for

1404-431: The distance between the main and distant signal. But, this would require longer blocks, which would decrease line capacity for slower trains. Another solution would be to introduce multiple aspect signalling. A train travelling at 200 km/h (120 mph) would see a "slow to 160" signal in the first block and then a stop signal in the 2nd block. Introducing multi-aspect signalling would require substantial reworking for

1456-481: The driver to let the computer drive the train on auto-pilot, automatically driving at the maximum speed currently allowed by the LZB. In this mode, the driver only monitors the train and watches for unexpected obstacles on the tracks. Finally, the LZB vehicle system includes the conventional Indusi (or PZB) train protection system for use on lines not equipped with LZB. In the 1960s, the German railways wanted to increase

1508-419: The entire section, up to 12.7 km (7.9 mi). Thus, newer LZB installations, including all high-speed lines, break the cable loops into 300 m (984 ft) physical cables. Each cable is fed from a repeater, and all of the cables in a section will transmit the same information. The core of the LZB route centre, or central controller, consists of a 2-of-3 computer system with two computers connected to

1560-412: The existing lines, as additional distant signals would need to be added onto long blocks and the signals reworked on shorter ones. In addition, it wouldn't solve the other problem with high-speed operation, the difficulty of seeing signals as a train rushes past, especially in marginal conditions such as rain, snow, and fog. Cab signalling solves these problems. For existing lines it can be added on top of

1612-428: The existing signalling system with little, if any, modifications to the existing system. Bringing the signals inside the cab makes it easy for the driver to see them. On top of these, the LZB cab signalling system has other advantages: Given all of these advantages, in the 1960s, the German railways chose to go with LZB cab signalling instead of increasing the signal spacing or adding aspects. The first prototype system

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1664-401: The figure shows the "monitoring speed", which is the speed which, if exceeded, the train will automatically apply the emergency brakes. When running at constant speed this is 8.75 km/h (5.44 mph) above the permitted speed for transited emergency braking (until speed is reduced) or 13.75 km/h (8.54 mph) above the permitted speed for continuous emergency braking. When approaching

1716-421: The first block was occupied it would be red as usual. Otherwise, if the first block was free and a LZB train approached the signal would be dark and the train would proceed on LZB indications alone. The system has spread to other countries. The Spanish equipped their first high-speed line, operating at 300 km/h (190 mph), with LZB. It opened in 1992 and connects Madrid , Cordoba , and Seville . In 1987

1768-415: The first generation the ZUB   122 and PZB balises were put next to each other using the same installation pattern on the outer side of the rails and connecting to the same line side signal. The second generation ZUB   262 places the balise in the middle of the rail as any other Eurobalise. While the GNT system allows a maximum of 50 km/h (31 mph) extra speed over the normal line speed it

1820-573: The interlocking system from which they receive indications of switch positions, signal indications, and track circuit or axle counter occupancy. Finally, the route centre's computers communicates with controlled trains via the cable loops previously described. The vehicle equipment in the original LZB80 designed consisted of: The equipment in newer trains is similar, although the details may vary. For example, some vehicles use radar rather than accelerometers to aid in their odometry. The number of antennas may vary by vehicle. Finally, some newer vehicles use

1872-454: The number of trains present. Four fields in the call telegram are particularly relevant: The target speed and location are used to display the target speed and distance to the driver. The train's permitted speed is calculated using the trains braking curve, which can vary by train type, and the XG location, which is the distance from the start of the 100 m (328 ft) zone that is used to address

1924-406: The opposite. When a train enters a LZB controlled section of track, it will normally pass over a fixed loop that transmits a "change of section identification" (BKW) telegram. This telegram indicates to the train the section identification number as well as the starting zone, either 1 or 255. The train sends back an acknowledgement telegram. At that time the LZB indications are switched on, including

1976-484: The outputs and an extra for standby. Each computer has its own power supply and is in its own frame. All 3 computers receive and process inputs and interchange their outputs and important intermediate results. If one disagrees it is disabled and the standby computer takes its place. The computers are programmed with fixed information from the route such as speed limits, gradients, and the location of block boundaries, switches, and signals. They are linked by LAN or cables to

2028-433: The packets and displays the following information to the driver: If there is a long distance free in front of the train the driver will see the target speed and permitted speed equal to the maximum line speed, with the distance showing the maximum distance, between 4 km and 13.2 km depending on the unit, train, and line. As the train approaches a speed restriction, such as one for a curve or turnout, LZB will sound

2080-410: The same deceleration, a train travelling 200 km/h (120 mph) would require 1,543 m (5,062 ft) to stop, exceeding the signalling distance. Furthermore, as the energy dissipated at a given acceleration increases with speed, higher speeds may require lower decelerations to avoid overheating the brakes, further increasing the distance. One possibility to increase speed would be to increase

2132-565: The signals harder to recognize. In either case, changes to the conventional signals wouldn't solve the problem of the difficulty of seeing and reacting to the signals at higher speeds. To overcome these problems, Germany chose to develop continuous cab signalling. The LZB cab signalling system was first demonstrated in 1965, enabling daily trains at the International Transport Exhibition in Munich to run at 200 km/h. The system

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2184-706: The speeds of some of their railway lines. One issue in doing so is signalling. German signals are placed too close to allow high-speed trains to stop between them, and signals may be difficult for train drivers to see at high speeds. Germany uses distant signals placed 1,000 m (3,300 ft) before the main signal. Trains with conventional brakes, decelerating at 0.76 m/s (2.5 ft/s ), can stop from 140 km/h (87 mph) in that distance. Trains with strong brakes, usually including electromagnetic track brakes , decelerating at 1 m/s (3.3 ft/s ) can stop from 160 km/h (99 mph) and are allowed to travel that speed. However, even with strong brakes and

2236-455: The standard distance from a distant signal to its home signal is 1,000 metres (3,300 ft). On a train with strong brakes, this is the braking distance from 160 km/h. In the 1960s Germany evaluated various options to increase speeds, including increasing the distance between distant and home signals, and cab signalling . Increasing the distance between the home and distant signals would decrease capacity. Adding another aspect would make

2288-408: The switch instead of at a block boundary. See CIR ELKE below for details. The LZB control centre communicates with the train using conductor cable loops. Loops can be as short as 50 metres long, as used at the entrance and exit to LZB controlled track, or as long as 12.7 km (7.9 mi). Where the loops are longer than 100 m (328 ft) they are crossed every 100 m (328 ft). At

2340-582: The telegram type, and end with the CRC. Their data fields vary as follows: Before entering an LZB controlled section the driver must enable the train by entering the required information on the Driver Input Unit and enabling LZB. When enabled the train will light a "B" light. A controlled section of track is divided into up to 127 zones, each 100 m (328 ft) long. The zones are consecutively numbered, counting up from 1 in one direction and down from 255 in

2392-413: The track. A train identifies that it has entered a new zone by either detecting the cable transposition point in the cable or when it has travelled 100 metres (328 ft). A train can miss detecting up to 3 transposition points and still remain under LZB control. The procedure for entering LZB controlled track is repeated when a train transitions from one controlled section to another. The train receives

2444-402: The train using two conductor cables that run between the tracks and are crossed every 100 m. The control centre sends data packets, known as telegrams, to the vehicle which give it its movement authority (how far it can proceed and at what speed) and the vehicle sends back data packets indicating its configuration, braking capabilities, speed, and position. The train's on-board computer processes

2496-422: The train. If the train is approaching a red signal or the beginning of an occupied block the location will match the location of the signal or block boundary. The on-board equipment will calculate the permitted speed at any point so that the train, decelerating at the deceleration indicated by its braking curve, will stop by the stopping point. A train will have a parabolic braking curve as follows: where: Where

2548-481: Was developed and introduced under the title P unktförmiges D atenübertragungs- S ystem (transl. "Punctiform Data Transfer System"). Because of conflicts of the abbreviation PDS with a political party PDS , it was changed in 1990. The first train-born equipment was added to 20 trains of DB Class 610 which were operated on lines in Upper Franconia and Upper Palatinate since May 1992. The original system

2600-605: Was developed by German Federal Railways in conjunction with Siemens and tested in 1963. It was installed in Class 103 locomotives and presented in 1965 with 200 km/h (120 mph) runs on trains to the International Exhibition in Munich. From this Siemens developed the LZB 100 system and introduced it on the Munich-Augsburg-Donauwörth and Hanover-Celle-Uelzen lines, all in Class 103 locomotives. The system

2652-406: Was further developed throughout the 1970s, then released on various lines in Germany in the early 1980s and on German, Spanish, and Austrian high-speed lines in the 1990s with trains running up to 300 km/h (190 mph). Meanwhile, additional capabilities were built into the system. LZB consists of equipment on the line as well as on the trains. A 30–40 km segment of track is controlled by

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2704-400: Was overlaid on the existing signal system. All trains would obey the standard signals, but LZB-equipped trains could run faster than normal as long as the track was clear ahead for a sufficient distance. LZB 100 could display up to 5 km (3.1 mi) in advance. The original installations were all hard-wired logic. However, as the 1970s progressed Standard Elektrik Lorenz (SEL) developed

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