Track ballast quantity: What is the quantity of stone ballast required per metre of tangent track (standard practice)?

Introduction / Context:
Ballast provides load distribution, drainage, resilience, and track stability. Estimating the required volume per metre is essential for budgeting, logistics, and maintenance scheduling for tangent (straight) track sections.

Given Data / Assumptions:

• Question asks for typical ballast volume per metre of tangent track.
• Standard sleeper density, shoulder width, and ballast cushion depth are implied by conventional practice.

Concept / Approach:
Ballast volume per metre is a function of sleeper spacing, ballast cushion thickness under sleepers, and shoulder/side slope widths. Tangent track (no extra for curvature) represents the baseline requirement. Among close values provided, the conventional rounded figure used in planning references is taken as the correct choice.

Step-by-Step Solution:

Verification / Alternative check:
Practical design manuals often quote a planning figure close to 1.15 m^3/m for straight track, with adjustments for curvature, heavier axle loads, or different sleeper types.

Why Other Options Are Wrong:

• 1.11–1.14 m^3: Slight underestimates relative to the commonly adopted planning figure.

Common Pitfalls:

• Treating this as an exact invariant; in practice, ballast volume varies with sleeper type, cushion thickness, and ballast profile standards.

Final Answer:
1.15 m3