Composite Sleeper Index Calculator

Composite Sleeper Index Formula:

\[ CSI = \frac{S + (10 \times H)}{20} \]

Composite Sleeper Index:

1. What is Composite Sleeper Index?

Definition: The Composite Sleeper Index (CSI) is a numerical value that combines the properties of strength and hardness of timber used for railway sleepers.

Purpose: It helps evaluate the quality and durability of timber sleepers for railway track applications.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ CSI = \frac{S + (10 \times H)}{20} \]

Where:

\( CSI \) — Composite Sleeper Index
\( S \) — Strength Figure (typically for green and dry timber)
\( H \) — Hardness Figure (for timber with 12% moisture content)

Explanation: The hardness figure is given 10 times more weight than the strength figure in this composite index calculation.

3. Importance of CSI Calculation

Details: A higher CSI indicates better quality sleepers that can withstand greater loads and have longer service life in railway tracks.

4. Using the Calculator

Tips: Enter the Strength Figure and Hardness Figure (both with ±5% accuracy). Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a good CSI value for railway sleepers?
A: Typically, values above 700 are considered good, but requirements vary by railway standards and expected loads.

Q2: Why is hardness given more weight than strength?
A: Hardness is more critical for resistance to wear, spike holding capacity, and long-term durability in sleeper applications.

Q3: How accurate are the input figures?
A: The figures have ±5% tolerance as they're derived from standardized tests on timber samples.

Q4: Can CSI be used for non-timber sleepers?
A: The CSI formula is specifically designed for timber sleepers. Other materials have different evaluation metrics.

Q5: Where can I find standard S and H values?
A: These are typically provided in timber testing reports or railway engineering specifications for different wood species.