Which of the following statements about sleepers (railroad ties) is incorrect? Choose the statement that does not reflect correct engineering practice.

Introduction / Context:
Sleepers (ties) are critical to track stability: they support rails, maintain gauge, distribute loads to ballast, and provide resilience. On bridges they bear on stringers or ballast decks to transfer wheel loads to primary structural members. Understanding correct functions helps diagnose track defects and specify maintenance actions.

Given Data / Assumptions:

• Standard flat-bottom rail with sleeper fastening system.
• Inward rail cant = 1 in 20 (typical for modern practice).
• Curves may require gauge widening, but fastening integrity is maintained.

Concept / Approach:

Rails must be positively fastened to sleepers to maintain gauge and resist lateral forces, especially on curves where centrifugal forces and flange contact increase. Although slight gauge widening is provided on sharper curves, it is achieved by design (e.g., altered gauge setting) and does not mean the rails are “held loose”. Proper clips/chairs maintain clamping forces.

Step-by-Step Solution:

Verification / Alternative check:

Track standards specify minimum clamping forces and torque for fastenings; curve maintenance records show intentional gauge values but no practice of loose rails.

Why Other Options Are Wrong:

Options (a), (b), (c), and (e) reflect legitimate functions of sleepers, whereas (d) contradicts safety-critical requirements.

Common Pitfalls:

Misinterpreting gauge widening as fastening relaxation; neglecting rail cant which improves contact and reduces wear.

Final Answer:

Sleepers hold the rails loose on curves to permit free movement