The minimum composite sleeper index for wooden sleepers used over bridge girders is?

Railway Engineering MCQ

⭕ A. 1352

⭕ B. 1455

⭕ C. 1555

⭕ D. 1652

📚 Explanation:

The Composite Sleeper Index (CSI) is a measure of the strength of timber sleepers, calculated from the modulus of elasticity and modulus of rupture.

Indian Railways specifies a minimum CSI of 1455 for wooden sleepers used on bridge girders to ensure structural integrity under dynamic loads.

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👉 Therefore, the correct answer is: B. 1455

Key Concepts on Composite Sleeper Index (CSI):

• CSI = (S+10H)/20, Where S= Strength of timber & H= Hardness of timber
• Indicates the load-carrying capacity of timber sleepers
• Minimum required CSI for sleepers over bridge girders is 1455
• Ensures safety under repeated train loading
• Used in inspection and acceptance of wooden sleepers