Track fastenings and sleeper preparation: Which of the following statements about laying rails on timber sleepers and associated fittings is correct?

Introduction / Context:
Laying track on timber sleepers requires appropriate surface preparation and fittings to ensure proper seating and load transfer. Different timber hardnesses call for different accessories, and rail section type dictates the fastenings used.

Given Data / Assumptions:

• Hard vs. soft wood sleepers behave differently under spikes and loads.
• Bull-headed rail sections need chairs; flat-bottom rails use baseplates and clips/spikes.

Concept / Approach:
All four statements reflect standard practices: (a) spikes fix rails to timber; (b) adzing provides a level, shaped seat for the rail; (c) bearing plates spread load on softer timber and reduce crushing; (d) chairs cradle bull-headed rails and hold gauge.

Step-by-Step Solution:

Verification / Alternative check:
Track manuals and historical practice align with all four statements in their respective contexts.

Why Other Options Are Wrong:

• Any single statement alone omits other equally correct practices; only the combined option is fully correct.

Common Pitfalls:

• Assuming one fitting (e.g., baseplate) applies to all rail types and sleeper hardnesses.

Final Answer:
All the above