U.S. ACTS TO AVERT RAIL STRIKE TODAY
Acting Sec Silberman seeks to head off strike by UTU, summons Union Pacific pres F Barnett, Southern Pacific pres B F Biaggini, Southern Ry pres W G Claytor, N&W pres J P Fishwick and C&NW pres L Provo to Labor Dept for talks; Chicago ct refuses to vacate restraining order that expires July 23 and permit UTU to strike C&NW; orders union to bargain with rr