I. CONTROL SYSTEMS
Control of Movement of Trains:
One of the basic objects of signalling is to control the movement of trains with a view to ensure safety by preventing accidents. The ambit of a signalling system can be divided into two parts namely the station area and the section of track which is between any two adjacent stations.
Technically the section of track between two adjacent stations is known as the “Block Section” and the procedures set up to operate trains through this section is known as the “System of Working”
On the Indian Railways (IR) there are mainly three Systems of Working namely:
The Absolute Block System of Working
The Automatic Block System of Working
The Permissive Block System of Working.
Out of the above three systems the first two are the most extensively used on the IR.
The Absolute Block System and Permissive Block System of Working will be explained later in the report under the “Development of Railway Signalling” part. Before explaining the above systems, a few definitions are mentioned below: