scope:

Introduction

Automatic Route Setting (ARS) is a system to be used within a railway signalling and control centre to assist the signalman by performing functions such as setting routes for trains and monitoring the state of the railway.

In general the ARS is installed under a resignalling scheme together with other modern signalling systems such as Solid State Interlocking (SSI) and Signalman's Display Systems (SDS). The signalling centre is then known as an Integrated Electronic Control Centre (IECC). IECC installations are now at several sites in the UK. ARS is also provided for part of the Waterloo Area resignalling scheme, although this uses relay interlocking and conventional panels.

ARS is designed to provide a system for routesetting applicable to anywhere in the BR network.

A very important feature of ARS is that it obtains most of its information on the planned running of trains from the Train Service DataBase (TSDB), which is a national timetable database which is maintained by the Train Planning Units (TPUs) and is used in the production of the Passenger Timetable, Working Timetables (WTTs) etc.

Application of ARS is not expected to give rise to additional work in the TPU. However, it must be realised that the data obtained from the TSDB is used by ARS in setting routes for trains without any further human intervention ie the process is entirely automatic. This is therefore probably the application of TSDB data which has the most direct effect on railway operation. For this reason timetable quality does directly affect services.

In order to ensure that the timetable data thus supplied to ARS is correctly interpreted, it is necessary for the TPU and the Signal Engineer to agree the rules which are used. These rules fall into 2 categories, timing and coding rules. Timing rules define the locations at which trains are timed and the coding rules define the use of line, path and platform codes. This note describes what is required for each. In most cases this will merely involve determining the existing practices and recording them, because the TPUs work in a systematic manner. Occasionally a slight inconsistency may be found which will require a small change to current practice.

Once rules have been agreed, then any changes which become necessary will have to be notified to the Signal Engineer in order that ARS may be reconfigured. This may not be a simple task so it is important that the rules are not changed too frequently.