[en] A design of a bio-medical beam line is presented which accepts negative pi-mesons from a transmission target in the 800 MeV extracted proton beam of the Spallation Neutron Source being constructed at the Rutherford Laboratory. Though the distribution needs refining it is shown that a pion dose of 10 rad/min may be produced over an irradiated 'peak region' of 8 x 12 cm² x 7 cm depth at useful depths, with a lower entrance dose. This has the required characteristics for major scientific experiments and is at the lower end of the range quoted for dose rates necessary for eventual radiotherapy using pions. (author)