a new subway tunnel is being built in the harbor area of hamburg's inner city. the tunneling produces waste and the waste needs to be disposed of. in this case sand and shredded rubble are mixed with groundwater in order to be pumped out through steel tubes with a diameter of approximately 80cm. the sounds that are produced in the tubes are object of field recordings that i made at different times and places on site. it was immediately apparent that the continuum of the basic sounds that i used for my compositions already sounded formed in its randomness and diversity. the real surprise though, was that commonplace noises such as flowing water and rippling sand were completely inaudible, instead a steady progression of sophisticated rasping and quiet metal jangling was present. besides the polymorphism of the basic sounds it was the total artificiality of the signal that interested me, acoustic manifestations of sand and water subject to the conditions of technical and functional canalization. (a. tietchens)