In railway track maintenance, “Burnettising” (also spelled Burnettizing) is a chemical preservation process. It is primarily applied to which track component to protect it against biological decay, termites, and moisture-related deterioration?

Introduction / Context:
Timber used in railway tracks is susceptible to decay, fungal attack, and insect damage. To extend the service life of timber components, especially sleepers (ties), railways use preservative treatments. Burnettising is one such early method that injected preservative solutions into wood to resist bio-deterioration and moisture effects.

Given Data / Assumptions:

• The term Burnettising refers to a timber preservation process using salts (historically zinc chloride solutions).
• Typical track elements: sleepers (wood), rails (steel), ballast (stone, cinders, sand, etc.).
• Objective is durability against rot and pests, not mechanical strengthening.

Concept / Approach:

Preservation methods for timber include creosoting, Burnettising, and other salt-based processes. These methods target wood's vulnerability to biological attack. Rails are steel and protected by metallurgical quality and sometimes corrosion-protection systems, while ballast is inert mineral aggregate and does not need such treatments.

Step-by-Step Solution:

Verification / Alternative check:

Standard permanent-way textbooks list Burnettising alongside creosoting under timber preservation, specifically for sleepers, poles, and other wood components in contact with soil and moisture.

Why Other Options Are Wrong:

Rails are steel; preservation entails corrosion control, not Burnettising. Ballast is mineral aggregate and does not undergo chemical preservation. “None of these” is incorrect because sleepers are indeed preserved.

Common Pitfalls:

Confusing wood preservation with metal corrosion protection; assuming all track materials use the same treatment.

Final Answer:

Wooden sleepers