Explain the working of semaphore arm at railway? 1.for a train which is entering a block station? 2.for a train departing a block station? 3.for a train which is shunting outside station limits? ?

1. When a train is entering a block station, the semaphore arm will be in the horizontal position, indicating that the track is clear for the train to proceed. The train will continue to move forward until it reaches the platform or designated stopping point.

2. When a train is departing a block station, the semaphore arm will be raised to a vertical position, indicating that the track ahead is occupied or not clear for the train to proceed. The train will need to wait until the track is clear before it can depart.

3. When a train is shunting outside station limits, the semaphore arm will be in the horizontal position, indicating that the track is clear for the train to move in the shunting process. The train will follow the instructions given by the signalman or shunter to safely move within the station limits.

1. For a Train Entering a Block Station

- Green arm: Indicates that the track ahead is clear and the train can proceed.
- Yellow arm: Indicates that the next block (the one following the current block) is occupied by another train. The train can proceed only after the yellow arm has been lowered.
- Red arm: Indicates that the block ahead is occupied by another train. The train must stop and wait until the red arm is lowered.

2. For a Train Departing a Block Station

- Green arm: Indicates that the train can proceed.
- Yellow arm: Indicates that the train should proceed slowly, as it will be entering a block that is occupied by another train.
- Red arm: Indicates that the train must stop and wait until the yellow arm is lowered.

3. For a Train Shunting Outside Station Limits

- Green arm: Indicates that the train can shunt within the designated area without affecting other trains.
- Yellow arm: Indicates that the train should shunt with caution, as it may encounter other trains in the area.
- Red arm: Indicates that the train must stop and wait until the yellow arm is lowered.

Additional notes:

- The semaphore arms are manually operated by station masters or signalmen.
- The color of the arm is determined by the position of a lever that is connected to the track circuits.
- The semaphore arms provide visual signals to train drivers, indicating the status of the track ahead and the movement of other trains.