Technical Requirements For Rail Track
Strength: Rail tracks must withstand wheel load and temperature changes without exceeding specified stress and deformation limits. This requires sufficient strength, toughness, and wear resistance.
Roughness: Locomotives rely on friction between wheels and the rail's top surface for traction, necessitating a rough rail surface. However, for vehicles, excessive friction increases resistance, requiring a smoother rail surface. Balancing this contradiction, rails should maintain a generally smooth surface, with occasional sanding if needed for better locomotive wheel adhesion.
Elasticity: Rail tracks use their stiffness to resist bending under wheel load, but some elasticity is needed to reduce dynamic impact and prevent wear on rolling stock and tracks.
Tenacity: Given the small contact area between wheels and rail, and the high pressure, the rail needs sufficient hardness to prevent crushing and rapid wear. However, a balance is required to avoid excessive hardness that can lead to damage from impact, necessitating some tenacity in the rail.