After a site visit with residents, at long last TfL have established the cause of the high pitched tube rail noise that is disturbing residents, after grinding took place last year. They say that on the left hand rail which is the high-rail (there's a slight curve) there is some very short-wavelength corrugation over a distance of 50m. TfL believes that this corrugation is the source of the tonal noise that residents experience. However, TfL now refuses to do anything whatsoever about it, including refusing the suggested noise baffling fence as mitigation. Will you look at this again and see what can be done to alleviate the nuisance the trains are causing, including at night with the night tube?