Operating procedures

from Wikipedia, the free encyclopedia

An operating procedure is a "system of operational rules and technical means for carrying out journeys with railway vehicles on a railway infrastructure ."

There are quite different operating procedures with regard to the management and security of train journeys. Which method is used depends on several factors, e.g. B. Significance and frequentation of the railway line or the safety philosophy of the railway company in the respective country.

There are operational procedures that focus on operational rules and use few technical means. Examples of this are the German train control operation or the North American operating procedure Timetable and Train Order . Other operating procedures, however, focus on technical aids such as B. the train detection operation.

The various operating procedures differ considerably in their practical implementation.

introduction

All current operational rules are based on the principle of keeping your distance. This states that a certain distance must be ensured between railway vehicles in order to prevent collisions. One distinguishes between:

Today, space-distance travel dominates the railways. Exceptions to this are trams and shunting trips , which in many cases are driven on sight. A train is a spatial section, z. B. a block route , provided for the sole use. The section must be free before the train enters and it must be ensured that no other journeys take place in the section from the time the driver's license is issued until the train has left the section again. The organization of which train, which section is made available, is called the regulation of the train sequence .

Classification of operating procedures

The following points are often considered to classify different operating procedures:

  1. the type of approval for train travel:
    • by means of a signal device (also called signal-guided)
    • by means of verbal or written orders (also not called signal-guided)
  2. the structure of the dispatcher management

The first point mainly relates to the aspect of signaling, the second point is largely influenced by the way the track is checked.

Classification of different operating procedures
country Operating procedures Driving license through Dispatcher
Signaling device Oral / written assignment decentralized central
Germany Train detection operation x x 1
Train control x 2 x
North America Timetable and Train Order x x
Track Warrant Control x x
Direct train control x x
Centralized traffic control x x
1 With modern interlocking technology, the dispatcher is also organized centrally
2 When the train control operation is signaled, the driver's license can also be issued by signal

Operating mode

The form of operation is the type of implementation of the railway operation within an operating procedure in which the local conditions with regard to functional requirements and technical equipment are taken into account. It is possible to deviate from the regular form of business if temporary changes to the operational sequence so require. The operating procedure is retained, but the operating mode changes, e.g. B. the preferred track (right-hand traffic, left-hand traffic), the type of traction ( sliding locomotive , drive with lowered pantograph), the type of train control (selective or continuous monitoring) or the condition of the infrastructure (railway system with local staff, remote control of signal boxes). The operating form thus always refers to a specific, local implementation of an operating procedure in a certain sub-network (or route / station).

Examples of different types of operation within the train detection operation operating procedure are:

  • Instead of a decentralized dispatcher, the dispatcher is arranged centrally
  • Instead of punctual train control (e.g. PZB 90), continuous train control (e.g. LZB, ETCS L2) is used
  • Instead of the right (regular) track, the left (opposite) track is used

Operating procedures in Germany

Today in Germany the two operating procedures, train detection operation and train control operation, or their derived operating forms dominate. The much larger part of the train operation is now driven in the train detection operation.

Train detection operation

In Germany, on so-called "fully operated" main and branch lines, the operating procedure train reporting is used , as provided for in the driving regulations of Deutsche Bahn (Ril 408) or in the driving regulations for non-federal railways (FV-NE). Both driving regulations are based on the German Railway Construction and Operating Regulations (EBO). In Section 15, Paragraph 1 of the EBO, the minimum requirement for securing the sequence of trains is a block of routes for main lines “with a particularly close sequence”. Today, however, there are only a few routes with particularly low traffic that are operated in train detection mode without a route block.

The train detection mode is also used with modern interlocking designs such as relay interlockings or electronic interlockings , but the train reports are carried out electronically with the help of train number reporting systems . In modern systems, central blocks are also set up in which the safety of the railway line works technically like a station driveway.

With the centralization of the signal boxes and the development of train number reporting systems, fewer and fewer train reports are exchanged. That is why the term train notification procedure is used less and less frequently.

Special forms of operation

Depending on the location, the type of implementation of the train detection operation operating procedure differs. Influencing factors can be the train control system used, deviations from regular operations, type of traffic control, etc.

Train control systems

Train control systems are used exclusively to monitor train personnel and are to be seen as part of the operating procedures. In Germany, Section 15 (2) EBO calls for train control on main and secondary lines that are driven at more than 80 km / h. Today almost all routes in Germany are equipped with train control systems. The following train control systems are currently in use:

Point train control is the most widespread. With a selective train control system, the maximum speed in Germany is limited to 160 km / h. For this reason, line control has been used for higher speeds since 1975. This means that the driver is continuously informed via cab signals that the route ahead of him is free. However, it is still driven at a fixed distance.

Before the introduction of the ETCS system, the radio-based driving operation (FFB) was developed , but this was not used. The FFB should work exclusively on a computer basis and make interlockings dispensable. The experience gained in developing the FFB was incorporated into the development of the ETCS system.

In the long term, the ETCS is intended to replace all other train control systems across Europe. There will be a significant change in the operating procedures in the future when ETCS Level 3 is used. This means that, for the first time, it is possible to drive with absolute braking distances and moving spatial distances .

Deviations from normal operation

The causes and effects of deviations and disruptions can be diverse in railway operations. The measures that are taken are correspondingly diverse:

  • Driving on command : written commands are the fallback level if other technical means have failed. So z. B. a written command instruct the driver to drive past the disturbed signal.
  • Driving on the opposite track: In Germany, double-track lines are generally used on the right track. If this is not passable, train journeys can be made on the opposite track. Depending on the technical means used, a distinction is made between the following types of operation:
Type of dispatcher

In the classic train detection system, each station is manned by a dispatcher and each train sequence position by a block attendant. Therefore, the train detection operation is to be assigned to the operating procedures with decentralized traffic control. However, with modern interlocking technology such as relay interlockings and, above all, electronic interlockings, the control lines of several stations can be combined into one central control line.

Train control

Since the train detection operation represents a high level of personnel, technical and financial expenditure, there is a simplified operating procedure for simple operating conditions on branch lines, the so-called train control operation . You can get along largely without pre- and main signals and without a route block and deviating regulations apply, which restrict the traffic regulations. In individual cases there are train control routes with special route block designs, e.g. B. the branch line block for single-track branch lines on which only one train runs. Routes in pure train control are only allowed to be operated today because of the protection of existing ones and only if the routes have a very weak load profile. More heavily used routes that are still not to be upgraded to full operation can be operated in one of the following operating modes, which are derived from train control:

These types of operation differ from classic train control operations in that they provide technical support for the staff.

Use outside of Germany

Many operating procedures outside of Germany are shaped by the German operating procedures. So z. For example, in Switzerland, Austria, Luxembourg, Eastern Europe, the Balkans and Scandinavia, operating procedures are used that are similar to the German system.

UK operating procedures

In contrast to the German operating procedures, the term “station” is missing in Great Britain, which means that no distinction is made between route and station. All interlockings have the same powers and are not subordinate to one another.

British block indicator

Locally manned signal boxes without a track vacancy detection system control and secure an area called station limit , which is limited by the first or last signal controlled by the signal box. To regulate the sequence of trains between the station limits, the staff ( signalers ) communicated with the help of so-called bell codes and block indicators . The first was a kind of Morse code and the second signaled the occupancy of the block section, but had no dependency on the signals, as is e.g. B. is realized in the German route block. A signal dependency was only added later. The distinction between command and guard interlockings, which are made dependent on a station block, is also unknown in Great Britain.

With the development of automatic track vacancy detection systems, the Track Circuit Block (TCB) operating procedure was developed , for which there are no longer any station limits. The signals used to be in automatic ( automatic ) and interlocking controlled signals ( controlled ) distinguished. Track areas with points always follow signals operated by signal boxes.

Transfer of a token

On single-track routes, counter-vehicle protection was guaranteed based on tokens . Only the train that was in possession of such a unique and unique token was allowed to enter the following section of the route.

Stationary token block devices were developed to allow several trains to run in the same direction one after the other . A token could only be taken from these if the following route section was free. Later this was equipped with a signal dependency, with which the signal could only be set to drive after the token was removed.

A current development is the Radio Electronic Token Block . After specifying his position, the driver requests a driving license for the next section from the signal box staff. If this section is free, the signal box staff sends an electronic token to the train by radio , which allows it to drive on the section. The signal box staff is monitored by computer technology.

UK operating procedures are also used in many UK controlled countries, e.g. B. India or Australia applied.

Operating procedures in North America

Operating procedures not guided by signals

Acceptance of a train order by a moving train

In North America, the vastness and low population density of the country played an essential role in the development of the railway system. In the early years of the railroad, North America applied the principle of driving at a time interval from the resulting large distance between the individual operating points . From 1854 the operating procedure Timetable and Train Order developed , which was widespread until the mid-1980s. The trains run according to a timetable that has been assigned safety responsibility. The prescribed minimum time interval between two train departures is so great that the train crew can warn the following trains in the event of unscheduled stops or delays. The counter-run protection is guaranteed by a train having to wait for all scheduled counter- trains at an intersection before it is allowed to depart. In the event of delays, there is a sophisticated system of priority rules ( superiorityrules ) with which train crossings can be relocated by train staff independently. The dispatcher can intervene by means of written instructions, so-called train orders , in order to avoid delays and stoppages and to insert special trains . The train orders were passed on by the dispatcher to locally manned operating points by telegraph or by telephone and then handed over to the trains by them. The occupied operating points indicated to the train staff via so-called train order signals whether a train order had to be taken. The train orders could also be received by moving trains.

As a rule, all switches in the Timetable and Train Order System are manual, so-called interlocking limits can only be set up at larger route nodes . In English, interlocking refers to systems in which points and signals are interdependent, as is the case e.g. B. is the case with German signal boxes. These are limited by signals with an absolute stop concept, which indicate whether the following route node may be used.

On some routes with a tight train sequence, such as that of the Pennsylvania Railroad (PRR), from 1864 onwards, in order to increase efficiency, travel in space was passed over. So-called manual block systems ( manual block ) have been set up. For this purpose, the route was divided into spatial sections ( block ), which were delimited by block stations . There, block operators ( operators ) used signals to indicate whether the following section is free ( block clear ) or occupied ( block occupied ). A train may only be allowed into the next section if the train in front has left the block. The control of the train sequence and its security was carried out by a manual reporting procedure.

With the invention of the track circuit in 1872 by William Robinson, automatic block systems could be used for the first time. This enabled the Timetable and Train Order System to be partially automated using the Automatic block signaling (ABS) system. If a vehicle drives into a block, the track circuit automatically stops all signals pointing into the block. In this way, the following protection is guaranteed. The counter-run protection is still guaranteed by the timetable and train order procedure. That is why the ABS system is mainly used on double-track lines in one-way operation.

The further development of the ABS system for single-track lines is the Absolute Permissive Block (APB) . Here the DC circuit stops all block signals in the opposite direction until the next turnout.

With manual block , ABS and APB systems, the rules of the timetable and train order system still apply . The signals are only used as a safety superimposition. For this reason, these systems are non-signal-guided operating procedures.

In 1906, the Interstate Commerce Commission reported that of the 194,726.6 miles of railroad lines in the United States, only 41,916.3 miles (~ 21.5%) with manual block systems and 6,826.9 miles (~ 3.5%) with automatic block systems were operated. Most of the rest (~ 75%) were operated in the timetable and train order system. It was only in the following years that the independent block systems spread more and more. In 1911, around 18,700 miles were already equipped with it.

With the development of powerful train radio systems in the 1980s, it became possible for the first time to exchange train movement reports and driving permits by radio between the train crew and the dispatcher. The operating procedures Track Warrant Control (TWC) and Direct Traffic Control (DTC) were developed . The main difference between the two methods is the logic of the route allocation. With the TWC , the dispatcher gives the train permission to drive up to a defined point, e.g. B. a mile post or an operating point. In contrast to this, with the DTC the route is divided into blocks by signal boards that are assigned to the train by the dispatcher with a driver's license.

Today the dispatcher is mostly supported by modern computer systems which prevent contradicting route assignments.

Signal-guided operating procedures

CTC in 1946

The Centralized Traffic Control (CTC) operating procedure was used for the first time at the end of the 1920s on sections of the route with a particularly dense train sequence . At CTC, the points and signals are remotely controlled centrally by the dispatcher and monitored by track circuits. The main difference to the previously mentioned systems, however, is that with this operating method a purely signal-guided operation was carried out for the first time. From an American point of view, this was a downright revolutionary step. Today the CTC process is based on computer technology and is used on around 60% of American routes.

literature

Individual evidence

  1. ↑ Jörn Pachl: Glossary of the system technology of rail traffic. Accessed January 31, 2018 .
  2. ↑ Markus Hecht: The Railway System: Manual . Eurailpress, Hamburg 2008, ISBN 978-3-7771-0374-7 .
  3. ↑ Jörn Pachl: System technology of rail traffic: plan, control and secure rail operations . 8., revised. u. exp. Edition. Springer Vieweg, Wiesbaden 2016, ISBN 978-3-658-12986-6 .
  4. ↑ Silko Höppner: Generic description of railway operating processes . Zurich 2015 ( ethz.ch ).
  5. ↑ Klaus Restetzki, Alexander Biehounek, Andreas Hegger: Basic knowledge of the railway . 9th edition. Europa-Lehrmittel, Haan-Gruiten 2018, ISBN 978-3-8085-2316-2 .
  6. ↑ a b c d e f g h Jörn Pachl : Special features of foreign railway operating procedures . Springer Vieweg, Braunschweig 2016, ISBN 978-3-658-13480-8 .
  7. ↑ Absolute block. In: http://www.railsigns.uk/ . Accessed October 30, 2018 .
  8. ↑ Track Circuit Block. In: http://www.railsigns.uk/ . Accessed October 30, 2018 .
  9. ↑ Radio Electronic Token Block. In: http://www.railsigns.uk/ . Accessed October 30, 2018 .
  10. ↑ a b c d Jörn Pachl: Transferability of US-American operating procedures to European conditions . In: Railway technical review . No. 7./8.2001 . Hestra-Verlag, Hamburg 2001, p. 452-462 ( archive.org [PDF]).
  11. ↑ Train Order Signals. March 5, 2016, accessed May 13, 2018 .
  12. ^ Mark D. Bej: PRR Book of Rules 1956/64. (No longer available online.) Archived from the original on February 1, 2013 ; accessed on May 13, 2018 . 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 / broadway.pennsyrr.com
  13. ↑ Carsten Lundsten: Railroad Signaling: APB. Retrieved May 13, 2018 .
  14. ^ J. Phillips: The USRA Era. (No longer available online.) In: http://pw2.netcom.com/ . 1997, archived from the original on July 24, 2011 ; accessed on November 30, 2013 (English). 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 / pw2.netcom.com
  15. ↑ Reiner Preuss: Lexicon inventors and inventions: Railway . Rev Decker's, G. Schenck, Heidelberg 1986, ISBN 3-344-00053-5 .
  16. ^ BJ Schwendt: NYC First to Install Complete Train Dispatching System . ( ekeving.se [PDF]).

Remarks

  1. ↑ In North America, any operating method that relies on space-distance travel is usually referred to as " block ". However, these systems must not be confused with the block fields customary in Germany, as there is usually no technical dependency between the route elements of two neighboring operating points.