Rail section designation: A rail section is generally designated by which parameter?

Introduction / Context:
Rail sections are standardized and identified for procurement, design, and maintenance. A clear designation convention ensures uniformity across drawings, specifications, and logistics documentation.

Given Data / Assumptions:

• Rails of different profiles (e.g., 60 kg/m, 52 kg/m) used for various load and speed categories.
• Section properties scale with mass per unit length.

Concept / Approach:
Rails are generally designated by their mass per metre (e.g., 60 kg/m). This single metric is practical and correlates with section modulus, stiffness, and load capability. While area and inertia are important for analysis, the mass-per-metre designation is universally recognized for identification.

Step-by-Step Solution:
1) Recognize designation must be simple and uniformly applicable.2) Weight per metre succinctly captures section size and capacity.3) Hence rails are commonly referred to as ’’X kg/m’’ sections.

Verification / Alternative check:
Standards and catalogues list rail types by mass per metre, with associated drawings providing exact dimensions and properties.

Why Other Options Are Wrong:

• Total batch weight or total length does not identify section.
• Area or inertia alone is not the standard naming convention in practice.

Common Pitfalls:

• Confusing designation (kg/m) with total piece length (e.g., 13 m rails).

Final Answer:
Weight per metre length of the rail.