Strele (software)

from Wikipedia, the free encyclopedia

STRELE is a computer program for calculating the performance of railway lines . The program predicts waiting times that are to be expected in rail operations (subsequent delays). The determined waiting time is compared to an evaluation standard, from which statements are made for the number of trains with premium, optimal, risky and poor (previous classification: very good, satisfactory and poor) operating quality. The sister program STRESI allows the simulation of the route allocation (timetable creation) and the operational sequence on railway lines on the same database.

The program is part of the SLS program package, which was developed by RWTH Aachen University for the German Federal Railroad and is now overseen by Schultze + Gast Ingenieure. STRELE is still widely used by Deutsche Bahn and Austrian Federal Railways . The name is an abbreviation and stands for "route performance".

Calculation method

The program is based on the procedure contained in the service regulation 405 of the Deutsche Bundesbahn at the time (now guideline R 405 of the Deutsche Bahn), which was developed in the dissertation of W. Schwanhäußer . In addition to this mean value method, the train sequence case-based method developed by Schwanhäußer is also available.

Calculating the waiting time

The operating theory methods are used to calculate the waiting time . Each train route section is viewed as a single-channel control system in which only one train can be located at a time. In front of the track there is a waiting room with infinite capacity , which represents the entire rest of the railway network. A line with several block sections is then the row-like arrangement of single-channel control points. If these control points are occupied, there are waiting times.

The input variable for the process is a table of minimum headway times for all train types and the number of train types. The table of minimum headway times contains the minimum time interval between two train journeys for each combination of train types. It is calculated by the program on the basis of the route and train data.

Calculation of the evaluation standard

The evaluation standard compared to the waiting times is the permissible waiting time. This is fixed for a period of time and is solely dependent on the proportion of passenger trains . This takes into account that travelers are much more sensitive to delays than freight customers.

The specification of a fixed amount of permitted waiting time means that with higher numbers of trains, shorter waiting times per train are accepted in order to achieve an overall satisfactory (according to the new DB language regulation, economically optimal) operating quality. The size of the evaluation standard was determined in the 1970s by W. Schwanhäußer u. a. determined by questioning dispatchers and dispatchers .

advantages

  • The procedure does not require a specific timetable. The specification of the number of trains is sufficient to obtain information about the performance of routes. The method is therefore very well suited for longer-term forecasts when a precise timetable is not yet known.
  • Due to the independence of specific timetables, the results are more generally valid than calculations based on a specific operating program.
  • The program delivers results relatively quickly.

disadvantage

  • The program regards the route as an isolated system, influences and interactions with other parts of the route network are neglected.
  • Since the calculation is based only on the number of trains, the program is not suitable for checking the feasibility of a specific timetable

Alternatives

  • STRELE is only widespread in German-speaking countries. Another method is to calculate the occupancy rate in order to estimate how well a railway system is being used. Before STRELE was introduced, this procedure was the standard procedure in Germany.
  • The UIC recommends an anabolic on the occupancy rate calculation method in their leaflet 406th
  • In order to examine specific timetables and network connections, the railway operations are simulated with simulation programs , taking delays into account, and the resulting delays are evaluated.

literature

  • Wulf Schwanhäusser: The measurement of buffer times in the railway timetable . Transport Science Institute of the Rheinisch-Westfälische Technische Hochschule, Aachen 1974, ( Publications of the Transport Science Institute of the Rheinisch-Westfälische Technische Hochschule Aachen 20, ISSN  0176-9359 ), ( Also : Aachen, Techn. Hochsch., Diss.).
  • Ingolf Gast, Kurt Schultze: "STRELE" - a term at Deutsche Bahn for 30 years . In: Your train . tape 43 , no. 5 , 2015, ISSN  0172-4479 , p. 54-63 .
  • Kurt Schultze: 30 years of "STRELE" - review and current developments in the analytical method . In: Railway technical review . tape 64 , no. 5 , 2015, ISSN  0013-2845 , p. 69-74 .

Web links

Individual evidence

  1. ↑ SLS-Schultze + Gast Ingenieure , accessed April 2, 2015
  2. ↑ DBAG guideline 405.0104 Track capacity, p. 6, 2008.