Which one of the following rail failures is caused by loose fish bolts at expansion joints? A. crushed head B. angular break C. split head D. transverse fissures

The correct answer is: A. crushed head.

A crushed head is a type of rail failure that is caused by loose fish bolts at expansion joints. When the fish bolts are loose, the rail is not held in place properly and can move around. This movement can cause the rail to bend and eventually break.

The other options are incorrect because they are not caused by loose fish bolts at expansion joints.

• A angular break is a type of rail failure that is caused by a sudden impact, such as a derailment.
• A split head is a type of rail failure that is caused by fatigue.
• Transverse fissures are small cracks that run across the rail. They are usually caused by stress, such as from heavy traffic.