Waterloo & City Line train.

UK: Britain's national measurement institute is measuring sample gear cases from trains on London Underground's Central and Waterloo & City lines every three months to ensure that they remain within specified tolerances.

The National Physical Laboratory has been working for two years to validate the geometry of final drive gear cases for the trains, and following modifications to the design is providing independent calibration of the tolerances.

'The cutting-edge equipment that we have access to ensures that we can provide the innovative engineering measurement methods that are essential to industry', said David Flack of NPL's Engineering Measurement team.