Abstract: A gas turbine engine having a turbine rotor assembly with a free standing sideplate assembly is disclosed. Various construction details are developed which provide a sideplate assembly which is not radially or axially supported by the web or rim of the adjacent disk. In one particular embodiment, a rotor assembly includes a rotor disk, having a rim, a web, and a bore, and a sideplate assembly, having a web and a bore. The web of the sideplate is radially supported by the bore of the sideplate and includes a disk seal and an aperture. The disk seal is engaged with the rotor disk and has an axially directed seal force provided by an axially interfering fit between the sideplate and rotor disk. The aperture provides fluid communication between a source of cooling fluid and the rotor disk.