Rail fastenings: For holding the rail in position, chairs are not used with which rail section?

Introduction / Context:
Different rail sections require different fastenings. Traditional bull-head rails use cast iron chairs to support and locate the rail. Flat-footed (flat-bottom) rails, however, are fastened directly to sleepers via baseplates and clips, eliminating the need for chairs.

Given Data / Assumptions:

• Standard rail sections: flat-footed vs. bull-headed/double-headed.
• Conventional fastening systems and historical practice.

Concept / Approach:
Chairs are characteristic of bull-head track to cradle the rail and maintain alignment. Flat-footed rails have a wide base and are secured with spikes/clips and baseplates, making separate chairs unnecessary.

Step-by-Step Solution:

Verification / Alternative check:
Modern permanent way largely uses flat-bottom rails with elastic fastenings, confirming chair-less practice.

Why Other Options Are Wrong:

• Bull-headed and Double-headed rails: Historically require chairs; stating otherwise is incorrect.
• Both (a) and (b): Wrong because bull-headed needs chairs.
• None of these: Incorrect because (a) is correct.

Common Pitfalls:

• Assuming a single fastening system fits all rail sections.

Final Answer:
Flat-footed rails