US Patent 10392939 Gas turbine arrangement

A gas turbine drive shaft arrangement, comprising: a hollow compressor drive shaft, a first hollow turbine drive shaft for driving a first turbine stage and a second hollow turbine drive shaft for driving a second turbine stage, wherein the compressor drive shaft has a spline on an internal surface that is meshed with a spline on an external surface of the first hollow turbine drive shaft, the first turbine drive shaft further comprising a spline on an internal surface thereof that is meshed with a spline on an external surface of the second hollow turbine drive shaft.