The answer is option 'B' - CST-9 sleeper.



CST-9 sleeper is the most commonly used sleeper in Indian Railways. Let's understand why it is preferred over the other options mentioned.


- The box sleeper is not commonly used in Indian Railways.
- It is a type of sleeper that is used in specific cases where there is a need for a more stable and strong foundation, such as in bridges or heavy-duty tracks.
- However, it is not widely used for regular railway tracks.


- CST-9 sleeper is one of the most commonly used types of sleepers in Indian Railways.
- It is a pre-stressed concrete sleeper that is designed to provide durability and strength.
- The sleeper has a rectangular shape and is reinforced with steel wires or strands.
- It is widely used for both broad gauge and meter gauge tracks.
- The sleeper has a longer lifespan and requires less maintenance compared to other types of sleepers.
- It provides good track stability and reduces the risk of track deformation.
- CST-9 sleeper is also cost-effective and easy to manufacture, making it a preferred choice for Indian Railways.


- Rail free duplex sleeper is not commonly used in Indian Railways.
- It is a type of sleeper that eliminates the need for rails by having flanged ends.
- This type of sleeper is more commonly used in metro systems or light rail networks.
- It is not suitable for heavy-duty railway tracks.


- LK sleepers are not commonly used in Indian Railways.
- LK stands for Longitudinal Key, which refers to the method of fixing the rail to the sleeper.
- These sleepers have a key-shaped longitudinal recess in which the rail is fixed using a key.
- While LK sleepers provide good lateral stability, they are not widely used in Indian Railways.

In conclusion, the most commonly used sleeper in Indian Railways is the CST-9 sleeper due to its durability, strength, cost-effectiveness, and ease of manufacturing.