Causes of Damage
The most usual cause of damage is drag braking on severe gradients. Because the brake blocks apply directly on the tyre, it is heated up, relaxing the interference fit. It is not feasible to fit the tyre with such a heavy interference as to eliminate this risk entirely, and the retaining ring will ensure that the tyre can only rotate on the wheel centre, maintaining its alignment. In rare instances the rotation could be so severe as to wear the retaining ring down till it breaks, which could result in derailment.
Severe braking or low adhesion may stop the rotation of the wheels while the vehicle is still moving can cause a flat spot on the tire and localised heat damage to the tire material.
Tires are reasonably thick, about 3 inches, giving plenty of room for wear. Worn tyres or tyres with flats are reprofiled on a wheel lathe if there is sufficient thickness of material remaining.
Read more about this topic: Railway Tires
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