New Cross Soundscape

Richard at Baggage Reclaim has posted a sound recording of one of his favourite London sounds, to be found on the train 'somewhere between Lewisham and New Cross ... Every morning I take the 7.07 train from Hither Green, which is mercifully quiet, and listen to the sound on this recording. I think it's the sounds of the springs below the carriages compressing and expanding as the train sways from side to side. The sound seems to run through an almost musical sequence of harmonics". Check it out - it does sound like some strange mechanical singing.