Historical permanent-way design: Which rail section was first adopted on Indian Railways during the early era of track construction?

Introduction / Context:
Understanding the evolution of rail sections helps students of railway engineering appreciate how track technology migrated from earlier British practices to modern flat-footed rails. The first section historically used on Indian Railways reflects that heritage and the fastening systems available at the time.

Given Data / Assumptions:

• The question asks for the earliest rail section adopted on Indian Railways.
• Candidates include double headed, bull headed, and flat footed rails.
• Context is historical adoption, not current practice.

Concept / Approach:
Early Indian tracks followed British permanent-way practice. Initially, double-headed (DH) rails were seated in cast-iron chairs to be reversible after head wear. In practice, the “bottom” also suffered damage (“secondary head” theory proved impractical). This led to bull-headed (BH) rails still using chairs, and eventually to flat-footed (FF) rails which use base-plates or direct fastening systems, offering better economy and simplicity.

Step-by-Step Solution:

Verification / Alternative check:
Historic permanent-way texts and early Indian Railways records indicate DH rails in chairs were the initial standard before BH and later FF became prevalent. This matches the typical British sequence exported to colonies at the time.

Why Other Options Are Wrong:

• Bull headed: Adopted later than double headed, still with chairs, after the drawbacks of reversing DH were recognized.
• Flat footed: A later development, widely adopted in the 20th century for economy and simpler fastenings.
• (a) and (b) simultaneously: Not historically accurate; DH preceded BH.

Common Pitfalls:

• Confusing the most common modern section (flat footed) with the earliest historical section.
• Assuming BH preceded DH due to its apparent design improvement.

Final Answer:
double headed