CAG finds Lucknow metro rails softer than required, raising wear-and-tear concerns

LUCKNOW: The comptroller and auditor general (CAG) has raised concerns about the quality of rails used in the Lucknow metro’s rolling stock system, specifically regarding their hardness levels.

As per Indian Railway standards, metro rails must meet strict hardness requirements to ensure durability and safety. Rails used in depot areas (HH 880 grade) should have a minimum hardness of 260 BHN (Brinell Hardness Number).
While for main line tracks (HH 1080 grade), the required hardness range is between 340 and 390 BHN. Harder rails generally last longer and reduce wear and tear.


To verify quality, IIT Kanpur tested rail samples using certified hardness testing machines, said CAG.

The results showed that the hardness of depot rails ranged between 229 and 242 BHN, while main line rails ranged between 254 and 308 BHN in repeated tests. These values were significantly below the prescribed standards.

According to IIT Kanpur, lower hardness means the rails may wear out faster. This can increase maintenance costs and reduce the lifespan of both rails and train wheels. If wheel hardness does not properly match rail hardness, wheels may deform over time, potentially affecting the stability and smooth movement of metro trains.

When the CAG raised the issue, the state govt argued that the IIT had not followed the correct testing method.

“They claimed IIT Kanpur used less load than what the rules required. However, IIT Kanpur strongly disagreed. It said its team had followed the national testing standard (IS 1500:2005) correctly and even repeated the tests using higher loads to remove any doubt. Even then, the rails failed to meet the hardness levels,” read the audit report.