Rail-grinding tests are under way on clean premium rails in revenue service sites on NS, CN ,UP and at FAST. Work is continuing, but interim conclusions are: 1. At the NS, UP and FAST sites, only minor rail surface cracks and shells have been seen and unground control rails appear little worse than ground rails. 2. Unground rails at the CN sites show appreciable surface cracks and shells. The CN aggressive grinding is successful at controlling, but not wholly eliminating, rail surface damage. 3. As expected, rail grinding results in larger rates of railhead metal loss. 4. No rails have been removed from any of the sites, ground or unground, because of defects inside the rail head. 5. Comparing the damage at the CN sites with the lack of similar damage at the other sites, it may be that grinding is more important in areas where the railhead remains wet for appreciable periods. 6. The use of clean premium rail may be inhibiting internal defect formation. Therefore, grinding to suppress such defects may be more important for standard rails made from ingot steel.
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