Railway engineering history: In which year did Charles Vignoles introduce the flat-footed (Vignoles) rail section that replaced the early double-headed pattern in many countries?

Introduction / Context:
Railway permanent way history includes several standard rail sections. Early British lines used double-headed or bull-head rails with chairs. Charles Vignoles popularized a flat-footed rail that could be spiked directly to sleepers, simplifying construction and reducing cost. Recognizing the correct year for this innovation is a classic railway engineering fact-check.

Given Data / Assumptions:

• Question refers to the first adoption/invention year associated with Vignoles' flat-footed rail.
• We assume the conventional historical date used in railway engineering texts.

Concept / Approach:
The Vignoles rail (also called flat-bottom rail) displaced bull-head rails in many countries due to better stability and easier fastening. The key recall is the year: 1836 is widely cited in standard references as the date connected to Charles Vignoles' introduction of this rail form.

Step-by-Step Solution:

Verification / Alternative check:
Multiple railway history compendia and exam guides list 1836 as the year linked to the Vignoles (flat-footed) rail. The year also aligns with the period of rapid railway expansion and standardization in Europe.

Why Other Options Are Wrong:

• 1814: Too early; predates practical widespread rail standardization.
• 1846 or 1856: Later than the accepted introduction date; the section was already known.
• 1873: Far too late; by then flat-bottom rails had significant adoption in many regions.

Common Pitfalls:

• Confusing first patent filings with the popularly cited introduction year.
• Mixing up Vignoles' rail with Bessemer steel era timelines (steel rails became common later).

Final Answer:
1836