Integra sign

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Signum track magnets for two signals: For the distant signal in the direction of travel the same as the direction of vision and the main signal (visible from behind) in the direction of travel against the direction of vision.

The Integra-Signum train protection system - also known as Signum or Integra - was used on Swiss standard-gauge railways from 1933 to 2018 . The name is derived from the manufacturer Integra Signum .

Integra-Signum was an inductive train control system with a constant magnetic field . At the distant signal it warned the driver if he was approaching a closed signal or if he had to reduce the speed significantly. It also triggered an emergency stop if the engine driver did not acknowledge the warning or drove past a main signal pointing to stop .

Integra-Signum was characterized by simplicity, robustness and great reliability even in winter when there was snow. In the course of time, it was no longer able to fully cover the increased security requirements and has been supplemented by ZUB in places with heavy traffic since the 1990s . Integra-Signum was in use on all 12,000 SBB signals around 2006. From 2012 to 2018, the Integra-Signum and ZUB were replaced by ETCS Level 1 Limited Supervision (ETCS). The Euro-Signum and Euro-ZUB versions, consisting of ETCS components, will remain in use for a few years.

history

Track magnets (transmission magnets) Integra-Signum
From 1934 to 1937, all SBB distant signals were equipped with the Integra-Signum.
Vehicle magnet on a Be 6/8 III
Driver's cab of one of the first locomotives to be equipped with the Integra Signum.
Blue: alertness button.
Green: signal lamp
Mobile Integra Signum permanent magnet, which is temporarily attached to the rail during track construction work.
Modern control elements for Integra-Signum in a BLS Re 465 locomotive . In the middle, the vigilance button with integrated signal lamp, on the right the maneuver button, which enables closed main signals to be passed when maneuvering.

At the beginning of electrical traction on the Swiss Railways around 1920 , the locomotives were always manned by two men. The driver 's assistant supported the driver in observing the signals. In principle, electric locomotives allow one-man operation, but a safety control and train protection are required . The impetus for the development of a train protection system was the serious railway accident in Bellinzona on April 23, 1924, which left 15 dead. In the accident , two express trains collided because one of them had run over a stop signal. The accident could have been prevented if the closed signal had automatically triggered an emergency brake .

In 1927 the first test drives with Integra-Signum were carried out on the Bern – Thun line . In 1930 the entry signals of the Gümligen station and the Ae 3/6 I 10677 were equipped with the Integra Signum train protection system. All 14 distant signals on the Bern – Thun line and another five locomotives followed later.

In the railway accident in Lucerne on December 13, 1932, the Lucerne – Meggen regional train collided with the Stuttgart – Zurich – Lucerne international express train in the Gütschtunnel near Lucerne. After a steam train had passed through, visibility was limited, whereupon a locomotive driver ran over a closed signal and caused the head-on collision. This accident left six dead and over ten injured. The SBB General Management then accelerated the decision to introduce train protection, with the following three systems in the selection process:

Since the other train protection systems showed no advantages over the already extensively tested Integra-Signum system, from 1934 to 1938 all entry signals and electric main-line vehicles of the SBB were equipped with Integra-Signum.

But only part of the danger points were secured, as the Tüscherz railway accident on October 2, 1942 on the Biel – Neuchâtel line showed. The asleep engine driver ran over the closed exit signal and crashed into a counter-train that he should have crossed in Tüscherz . From 1943 the exit pre-signals and the exit signals were also equipped with track magnets. The SBB was the first state railway to equip its standard gauge network with a comprehensive train control system. Advance signals at the speed limits were provided with permanent magnets . Later certain level crossings were also secured with track magnets. In the course of time, the standard-gauge private railways also equipped their vehicles and routes with the Integra-Signum.

After the railway accident in Sion between Sion and Saint-Léonard VS on the Simplon line on June 24, 1968, when a freight train collided with a special train, 12 dead and 103 were injured, after several years of testing between 1979 and 1989, the main signals were also used Integra Signum track magnets installed. The train protection has been extended with the stop evaluation , which distinguishes between the terms warning and stop. When driving past a closed distant signal, the vigilance button must still be operated, but when crossing a main signal indicating a stop, an emergency brake is triggered.

Several accidents showed the deficiencies of the previous train protection. After the accident at Oerlikon , from 1992 onwards Integra-Signum was supplemented by the more modern train control system ZUB 121 , which not only triggers simple warnings and emergency brakes, but can also actively monitor the regular braking process.

At the former Bodensee-Toggenburg-Bahn (BT), after the collision of two Appenzeller Bahnen trains in Herisau in 1997, a safety concept that can be implemented with simple means was developed in which the train is braked before the danger point. The BT concept , however, requires sufficiently long tracks, which is often not the case with other railways.

construction

Vehicle and track equipment

Sprues (yellow) attached to the track magnet housings prevent the direct impact of hanging train parts.
Schematic diagram of Integra-Signum

vehicle equipment (red)
with battery-powered exciter magnet:
B Vehicle battery
L 1 exciter magnet
L 2 receiving magnet
R receiving relay line equipment (blue): L 3 receiving-side transmission magnet L 4 excitation- side transmission magnet S short-circuit switch (closed when the signal is open)

An exciter magnet was attached to the locomotives and control car at the bottom in the middle of the track, as well as a receiving magnet on the left and right, with the receiving magnet on the left in the direction of travel being switched on. In the original version, the exciter magnets were designed as electromagnets fed by the vehicle battery.

The extension with the stop evaluation from 1979 to 1989 was also used to replace the battery-powered exciter magnets with permanent magnets and to install magnetic field probes instead of the receiving magnets. Because the magnetic fields emanating from permanent magnets outside of Switzerland could interfere with axle counters , traction vehicles that could be used internationally were again equipped with electromagnets as excitation magnets, which were switched off outside of Switzerland.

The track equipment consisted of the receiving-side transmission magnet in the center of the track and the excitation-side transmission magnet, which were attached to the left-hand side of the track in the direction of travel, as well as a cable junction box and the short-circuit switch on the distant signal. The cables leading to the magnet windings were routed twice to avoid vibrations. Sprues attached to the front and rear of the magnet housings prevented the direct impact of hanging parts of the pull. With the SBB, 11,000 signal points - i.e. masts with one or more signals - were secured with this, and with the private railways another 3000.

Function of the original version

If a traction vehicle drove past a distant signal indicating a stop or speed reduction, the vehicle magnet located above the center of the track induced a voltage pulse in the transmission magnet located between the rails, which the track magnet on the pathway transmitted back to the vehicle. A voltage was again induced in the receiving magnet, which switched the receiving relay, which was indicated by a signal lamp. If the distant signal was opened, a switch short-circuited the current received by the transmission magnet, which prevented the impulse from being returned to the vehicle. Otherwise, a signal lamp warned the driver and the receiving relay relayed the impulse to the safety control , which also made the driver aware of the need for braking with an acoustic signal. If the warning signal was not acknowledged by operating the vigilance button, the safety control switched off the main switch and triggered emergency braking. The warning signal was recorded on the speedometer strip.

The weak point was the possibility that the engine driver canceled the warning triggered by the closed distant signal and continued by turning the reset button or pressing the alert button. This deficiency was corrected by adding the stop evaluation.

Function with stop evaluation

When driving past a signal showing a stop or a warning, the magnet on the outside of the track transmitted two impulses to the vehicle, which were either positively or negatively polarized. The two magnetic field probes on the vehicle received these impulses, whereby they differentiated the information terms according to the polarity sequence and the time sequence of the transmitted impulses:

Concept of information Location Polarity order temporal sequence of the impulses
warning at pre-signals negative positive at the same time
Stop for main signals positive - negative at the same time
warning for speed restrictions positive - positive successively
Block diagram of the Integra-Signum
with stop evaluation : Main signal

line equipment (blue):
In the case of a main signal, the contacts on the transmission magnet L 4 on the exciter side were reversed compared to the distant signal, which changed the polarity sequence.
Block diagram of Integra-Signum
with stop evaluation : Advance signal

Vehicle equipment (red):
NS permanent magnet
MS magnetic field probes

Warning signals will continue to be acknowledged by pressing the alertness button, otherwise an emergency brake will be triggered after 100 meters or 5 seconds. When a main signal is passed in the stop position, automatic braking is also initiated, whereby resetting is only possible at a standstill. When maneuvering, the so-called maneuver button can be used to bypass the stop evaluation, but a speed limit is activated.

Integra-Signum does not check whether braking has been initiated after pressing the alertness button or whether the vehicle is approached after stopping against a closed signal. If a train drives over a closed main signal at full line speed, the slip path behind the main signal is usually not sufficient to stop in front of the danger point.

Speed ​​monitoring

With the help of Integra-Signum a speed monitoring could be realized. The vehicle magnet triggered a time delay which activated the track magnet with stop programming installed at the end of the measuring section. The set time delay was dependent on the permissible speed. If the train was too fast, the track magnet had not yet been switched off and triggered an emergency brake. Because this monitoring was very complex, it was only carried out in individual cases. In the Gotthard and Simplon Tunnels, with their straight tubes, it prevented a train from driving too fast on the curve at the end of the tunnel and derailing .

Vulnerabilities

The Integra Signum track magnet at the exit signal could not avoid the collision of an accidentally departed train with the opposite train.
Orange: Braking distance of the train braked by Integra-Signum

Thanks to the simple structure, Integra-Signum was very reliable. The track equipment was made up of purely passive components that did not require a power supply. Because of the punctiform transmission of the signal information, Integra-Signum was technically unsafe because the train protection worked according to the operating current principle. The failure of a track magnet could only be detected through periodic tests. Integra-Signum offered a great gain in security at a reasonable cost.

Because Integra-Signum only monitored the speed at certain points, it was not always guaranteed that a train would stop within the slip path:

  • if the vigilance button was pressed after driving past a distant signal, but braking was not sufficiently strong, or
  • after an intermediate stop when driving against a stop showing the main signal.

The addition of ZUB to Integra-Signum eliminated these security deficiencies. Due to the high costs, however, ZUB was only installed on around 2500 of the 11,000 main signals of the SBB, which were selected with a risk analysis.

In 2010 there were still around 100 SBB signals without an Integra sign. They were in marshalling yards and in places with speeds of less than 40 km / h.

BT concept

The BT concept brings an unauthorized train to a stop in front of the danger point because the track magnets - or today the ETCS balises - are not at the exit signal, but at the driving position indicators.

Before the introduction of kondukteurlosen operation and remote-controlled interlockings all trains were given a down command of Kondukteurs or the local dispatcher . Since then, the driver has been solely responsible for the departure. Because a track magnet installed at the exit signal can no longer bring a train that has started by mistake to a stop in time, there is a risk of collision with an oncoming train.

After two Appenzeller Bahn trains collided in Herisau in 1997, the Bodensee-Toggenburg Railway (BT) developed a safety concept that reduced this risk. Driving position indicators are set up on the individual tracks and the track magnets have been moved forward by the exit signal to the driving position indicators. A train departing by mistake could be braked in time by Integra-Signum - or today by ETCS - so that it does not get into the route of an opposite train.

After the merger of BT with Südostbahn , the southern network was also consistently converted to this standard. This solution was more cost-effective than equipping with ZUB. The SBB can only partially apply the BT concept because the tracks are often not long enough.

Euro sign

Transition from Integra-Signum to Euro-Signum: The Eurobalises had already been installed, but the Integra Signum magnets were still in use. RBDe 565 732 of the BLS in Kehrsatz
The ETM , also known as the “rucksack”, reads the ETCS telegrams and forwards the information to the Integra Signum and ZUB vehicle devices.
Vehicles that were not equipped with ZUB were equipped with the simplified ETM-S.

Integra-Signum and ZUB were supplemented by the uniform European train control system European Train Control System (ETCS) and later replaced. In a first stage, the track and vehicle magnets from Integra-Signum were replaced by balises and vehicle antennas from the ETCS range. To determine the direction of travel, a fixed data balise was installed a few meters in front of the transparent data balise . The track equipment converted in this way was called the Euro Signum. The Eurobalises emit an empty ETCS telegram , in the appendix of which "Package 44" reserved for national applications, the Switzerland-specific Integra-Signum information was transmitted.

Before the conversion to Euro-Signum, the individual signal locations were subjected to a risk assessment in order to decide which sections, e.g. B. were provided with a brake monitor . Such signal points were then equipped with Euro-ZUB instead of Euro-Signum.

To read the Euro-Signum and Euro-ZUB telegrams, the mainline traction units were equipped with a special additional device, the Eurobalise Transmission Module (ETM) . The ETM, also known colloquially as the “rucksack”, forwards the information to the Integra Signum and ZUB vehicle devices.

Initially, around 400 shunting and construction service vehicles were excluded from the conversion. Vehicles of shunting and Construction Service or historic vehicles that are not equipped with ZUB had been equipped by 2011 with the simplified ETM-S, which was limited to the Integra Signum functions.

→ See also: Section Euro-ZUB in Article ZUB 121

Uniform error disclosure

To detect errors such as For example, if an Integra Signum magnet failed, the infrastructure operator had to carry out regular test drives himself. The Federal Office of Transport (FOT) uses the technically available options for automatic error messages. Regardless of whether Integra-Signum or ETCS was used on a vehicle, the train radio transmits an SMS to a central fault management system in the event of a track-side error . This informs the infrastructure operator or the railway company , depending on the type of error .

→ See also: Section Uniform error disclosure in the article ETCS in Switzerland

Transition to ETCS

By 2018, all Integra Signum track magnets (exceptions see below) and ZUB track coupling coils in the Swiss standard gauge network were replaced by ETCS balises. Also since 2018, the balises have not only transmitted the national train control information in the appendix, but also ETCS-compliant information in the main part of the telegram. Locomotives operating in Switzerland only have to be equipped with ETCS on-board units and can thus run freely in Switzerland; Integra Signum and ZUB on-board units, Signum magnets and ZUB coupling coils can be dispensed with and they can be removed. Older Swiss vehicles do not have to be converted to ETCS for the time being and continue to evaluate the Integra Signum and ZUB information in the telegram attachment using ETM. Only on the La Chaux-de-Fonds – Le Locle-Col-des-Roches route and on the Uetlibergbahn operated by direct current will Integra-Signum remain in use until 2022 and probably until 2023.

The two access routes to the Gotthard Base Tunnel were equipped with ETCS Level 2 as early as 2016 , meaning that no train can reach the Gotthard mountain route without ETCS . Since spring 2017, vehicles without ETCS equipment are no longer permitted on the Simplon line because individual sections in connection with interlocking renewals have been converted to ETCS Level 2 . From 2025, in step with the replacement of interlockings throughout the network, various sections of the route will be converted to Level 2: This means that locomotives operating in Switzerland will have to be equipped with ETCS on-board units and Euro-Signum will lose its raison d'être.

→ See also: ETCS in Switzerland

literature

Web links

References and comments

  1. ^ Walter von Andrian: From Signum and ZUB to ETCS Level 1 Limited Supervision . In: Swiss Railway Review . No. 4/2010 . Minirex, Lucerne, p. 198-199 .
  2. ↑ Originally it was also called meter.
  3. ^ A b c Andreas Zünd, Hans-Peter Heiz: The network-wide implementation of ETCS in Switzerland . In: signal + wire . tape 98 , no. 7 + 8 , 2006, ISSN  0037-4997 , p. 6-9 .
  4. ^ A b Mathias Rellstab: Swiss migration to ETCS L1 LS largely completed . In: Swiss Railway Review . No. 2/2018 . Minirex, Lucerne, p. 99 .
  5. ↑ a b Stefan Sommer: ETCS in Switzerland - step by step to the goal . In: Swiss Railway Review . No. 7/2013 . Minirex, Lucerne, p. 351-353 .
  6. ↑ The Führergehilfe was still called a stoker even decades after the steam operation disappeared .
  7. ^ The official investigation into the Lucerne railway accident. (PDF; 301 kB) In: Liechtensteiner Volksblatt. January 7, 1933, p. 3 , accessed November 20, 2013 .
  8. ↑ Les résultats de l'enquête sur la catastrophe ferroviaire de Lucerne. (Le Temps - archives historiques) (No longer available online.) Journal de Genève, January 7, 1933, p. 3 , archived from the original on December 2, 2013 ; Retrieved November 20, 2013 (French). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.letempsarchives.ch
  9. ↑ Ascanio Schneider and Armin Masé write in Disasters on Rails (Orell Füssli Verlag, Zurich, 1968) that after a steam train had passed through the tunnel, visibility was limited, whereupon a locomotive driver ran over a closed signal. According to the official investigation report, however, the cause of the accident was not steam in the tunnel , but that a train traveling in the direction of Olten, hauled by a steam locomotive, encountered the train coming from Zurich at the time it passed the disregarded distant signal and obstructed the view (cf. the two previous individual records and the section on the cause of the accident in the article railway accident in Lucerne ).
  10. ↑ When developing Integra-Signum, the needs of the SBB, which was already largely electrified with alternating current , were taken into account. For use on direct current lines , inductive train influencing of the direct current design such as Integra-Signum is less suitable because of the large return currents .
    At Integra-Signum, the vehicle battery already present on electric locomotives was used to supply the exciter     magnet with direct current . In the Indusi system introduced by the Deutsche Reichsbahn , the alternating currents of various frequencies required by the vehicle magnet were generated with a turbo generator on steam locomotives . The disadvantage of influencing the trains of the direct current type of not being triggered when driving at very low speed was accepted.
  11. ↑ An exception was the narrow-gauge Brünig line , which was equipped with ZSI-127 in 2003 .
  12. ↑ Since, unlike signals, speed restrictions do not display several signal aspects, a permanent magnet is sufficient as track equipment.
  13. ↑ Ernst Th. Palm: Signal boxes of the Swiss railways . Orell Füssli, Zurich, ISBN 3-280-01271-6 , p. 103 .
  14. ↑ Integra-Signum with stop evaluation was compatible with the original version. The train protection of the vehicles equipped with stop evaluation also worked with track equipment that had not yet been retrofitted and vice versa. (Bruno Lämmli: Security is a top priority , accessed on April 20, 2013)
  15. ↑ Peter Winter: Reorientation in the areas of signaling, train protection and train radio at SBB . In: Swiss Railway Review . No. 4/1985 . Minirex, ISSN  1022-7113 , p. 124-128 .
  16. ↑ a b Tobias Gafafer: SBB accident would not have happened at SOB. In: tagblatt.ch. St. Galler Tagblatt, online edition, St. Gallen, August 11, 2013, accessed on September 6, 2013 .
  17. ↑ SBB regulations: P 20003821 . Chapter 5.2 (ex R 435.1 booklet 21-23).
  18. ↑ a b Bruno Lämmli: Security is a top priority , accessed on April 20, 2013.
  19. ↑ At an entry speed of 80 km / h, for example, the slip path is only at least 60 meters. There is a surcharge for slopes. ( Implementing provisions for the Railway Ordinance (AB-EBV) DETEC , July 1, 2016 (PDF; 3 MB). AB 39.3.a Track control  and safety )
  20. ^ André Schweizer, Christian Schlatter, Urs Guggisberg, Ruedi Hösli: Train control concept and implementation of the migration to ETCS L1 LS for the standard-gauge private railways BLS and SOB . In: Swiss Railway Review . No. 3/2015 . Minirex, ISSN  1022-7113 , p. 146-149 .
  21. ↑ Lorenz Buri, Pierre Senglet: An inexpensive signal for a new need: the trip position indicator . In: Swiss Railway Review . No. 12/1995 . Minirex, Lucerne, p. 536-542 .
  22. ^ Rapperswil - Pfäffikon SZ - Arth-Goldau and Wädenswil - Einsiedeln
  23. ↑ From 2008 onwards, Eurobalises were to be used in place of Integra Signum magnets for new routes and conversions.
  24. ↑ or EuroSignum or Euro-Signum-P44
  25. ↑ The ZUB track equipment that had been converted analogously was called Euro-ZUB .
  26. ↑ A central system for managing disruptions was already in operation at SBB in 2012.
  27. ↑ The SBB estimates the cost of limited supervision route equipment for a signal point at around CHF 30,000. The purchase and installation of an Integra Signum magnet only cost 15,000 francs.
  28. ^ Mathias Rellstab: ETCS migration: special solution for La Chaux-de-Fonds - Le Locle. In: Swiss Railway Review. No. 3/2018. Minirex, ISSN  1022-7113 , p. 115.
  29. ^ European Train Control System ETCS. Status report 2016. ( Memento of the original from February 28, 2018 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Federal Office of Transport (Ed.), P. 26 @1@ 2Template: Webachiv / IABot / www.bav.admin.ch
  30. ↑ Infrastructure service catalog. Sihltal-Zürich-Uetliberg-Bahn (publisher), September 28, 2017, p. 11
  31. ↑ Federal Office of Transport (FOT): ERTMS. Implementation in the standard-gauge railway network in Switzerland ( memento of October 24, 2014 in the Internet Archive ). Bern, December 2012.
  32. ↑ ETCS Level 2 entre Lausanne et Villeneuve - CFF press . In: CFF press . April 21, 2017 ( cff-presse.ch [accessed June 5, 2017]).