Railway Signaling

Absolute Block System:

In this traditional system, a block section of the track is only occupied by one train at a time, and the movement of trains is controlled by signals at each end of the block.

Automatic Block System:

This system uses track circuits and automatic signals to manage block sections. Trains are allowed to move into the next block only if it is clear.

Mechanical interlocking systems have been replaced by electronic interlocking systems for more precise control.

Semaphore Signals:

Traditional signals that use moveable arms (semaphores) to indicate the status of a track section.

Color-Light Signals:

Modern signals that use colored lights to convey information to train drivers. Different colors indicate aspects such as clear, caution, and stop.

Positive Train Control (PTC):

A safety system that uses GPS, communication, and automation technologies to prevent train collisions, derailments, and other accidents.

Automatic Train Control (ATC):

A system that automatically controls train speed and can enforce speed limits.

A system that allows centralized control of train movements over a large network. Dispatchers use computers to manage train routes and signals.

Signaling systems are also used at level crossings to control road traffic and prevent collisions between trains and vehicles.

Effective communication between trains, control centers, and signaling equipment is essential for safe and efficient railway operations.

Used for detecting wheel and track defects, contributing to maintenance and safety.