The East Coast Railway (ECoR) removed the last Semaphore Signal (mechanical signal with arms) under its jurisdiction on Thursday.
The removal of this signal at the Tureikela Road station near Kantabanji in Balangir district marked the complete shift to the modern signalling system. The Semaphore Signal at Tureikela Road was replaced with the Modern Multiple Aspect Colour Lights Signalling system.
The advantage of colour-light signalling over semaphore signalling is the higher reliability of electrical control over the signals compared to the mechanical means for operating semaphore signals.
Colour-light signals do not suffer from distance limitations, allowing signal controls to be placed conveniently together even if the signals themselves are far away.
In addition, the electrical circuitry naturally allows for monitoring, interlocking and detection of failure conditions, all of which are achievable but far less reliably with mechanical means in semaphore signalling. In colour-light signals, a junction route indicator or directional type route indicator is commonly used to indicate diverging routes. This consists of an additional set of five lunar white lamps in a row at an angle attached to the main signal.
The angle of the junction route indicator corresponds in a rough manner to the angle made by the diverging route. When these additional lamps are lit, they indicate that the signal applies to a diverging route. Otherwise, the signal is taken to apply to the main route.
Notably, the ECoR had removed eight Semaphore Signals in 2018.
