A co-acting signal is a duplicate signal to the main signal located in the same location, usually on the other side of the track or lower or higher than the main signal. Its purpose is to give a better sight line when the main signal may not always be visible due to obstruction.

What is a Coacting signal?

A co-acting signal is a duplicate signal to the main signal located in the same location, usually on the other side of the track or lower or higher than the main signal. Its purpose is to give a better sight line when the main signal may not always be visible due to obstruction.

What is co-Acting signal in railway?

A co-acting signal is a duplicate signal provided on the same mast as a stop signal, which always shows the same indication as that stop signal.

What is a permissive signal?

permissive signal. A fixed signal that is normally controlled by the passage of rail traffic and its normal indication is a Proceed Authority. A signal that can be passed at STOP without the authority of a Signaller or Special Proceed Authority (SPA) if it is considered safe to do.

What is repeater signal in railway?

A repeating signal or repeater is one placed to the rear of a signal in order to provide early indication of the indication of the signal. It is an advisory signal and therefore permissive and may always be passed. A repeater has only two positions, on and off.

When were semaphores used?

Before the invention of the telegraph, semaphore signaling from high towers was used to transmit messages between distant points. One such system was developed by Claude Chappe in France in 1794, employing a set of arms that pivoted on a post; the arms were mounted on towers spaced 5 to 10 miles (8 to 16 km) apart.

What is shunt signal?

(1) (a) A Shunt signal is a subsidiary signal and shall be either- (i) a white disc with a red bar across it, or (ii) a position light signal. (b) under special instructions, a Shunt signal may be a miniature semaphore arm. (2) Shunt signals control shunting movements.

What is Warner signal?

Warner Signals. A warner signal is used only in two-aspect signalling (2LQ, MLQ, 2CL). Its purpose is to warn of an approach to a stop signal further ahead, or to advise a driver of the condition of the block section being entered.

What is a shunt signal?

Shunt signals, whether mechanical or position lights, are the authority to proceed on a specific route(s) as far as the route is clear or until the next stop signal. Old FR Point Indicators were just indicators of the position of the points – they gave no authority to proceed.

What is a subsidiary signal?

Subsidiary signals. Subsidiary signals are those which usually control only shunting moves, as opposed to train movements. Under this category come permissive signals and shunting signals.

What is semaphore Signalling?

The Semaphore flag signaling system is an alphabet signalling system based on the waving of a pair of hand-held flags in a particular pattern. The flags are usually square, red and yellow, divided diagonaly with the red portion in the upper hoist.

How does semaphore work?

Semaphores are integer variables that are used to solve the critical section problem by using two atomic operations, wait and signal that are used for process synchronization. The wait operation decrements the value of its argument S, if it is positive. If S is negative or zero, then no operation is performed.

What is IBS in railway?

1.1.1 Intermediate Block Signalling (IBS) IBS is an arrangement made on a Double Line Section for increasing the Section Ca- pacity by splitting of a long Block Section into two Sections namely ‘Rear Section’ and ‘Advance.

What is subsidiary signal?

Subsidiary signals are those which usually control only shunting moves, as opposed to train movements. Under this category come permissive signals and shunting signals.

What is semaphore and Warner signal?

Semaphore: The semaphore arm of a warner signal has a vee-notch at the end; it is red in front with a white stripe (V-shaped) at the end, and white at the back with a black stripe (V-shaped) at the end. Aspects are as shown below.

What is station limit?

(52) “Station Limits” means the portion of a railway which is under the control of a Station Master and is situated between the outermost signals of the station or as may be specified by special instructions; SR 1.02.

What does a white shunt mean?

proceed at caution
Shunt signals It has three lights in a triangular shape and two white lights mean proceed at caution whereas any other indication should be taken as a stop signal or a malfunction.