[en] The design of systems for the extraction of an intense pulsed beam of 800 MeV protons from a fast cycling synchrotron and for the transfer of the beam to an external target for the Spallation Neutron Source (SNS) is described. The system comprises (a) fast extraction from the synchrotron, (b) achromatic transfer to the entrance to the beam transport line and (c) transport to the spallation target. The design involves the use of existing buildings and magnets and the orientation of the system is such that future development of the facility within the present complex is feasible. (U.K.)