 It took nearly six years for the network to be fully operational; 17 radars have been modified and installed thanks to the joint efforts of local authorities, the state, federal agencies and a university.The APS-2F modified by Texas A & M University, although not actually part of the tornado surveillance network, was at least once used for warning purposes on April 5, 1956.After 1956 the modification of the APS-2F radars in their WSR-1, WSR-1A, WSR-3 and WSR-4 versions was assigned to the Weather Office headquarters which had to move some antennas that had originally been installed to locations where it was difficult to ensure the maintenance.