The present invention relates to a winding (20) of a rotor of a rotating electrical machine, in particular, to C-shaped or U-shaped half-coils (8,8') used for the winding (20) of a rotor after a re-winding operation. Moreover, the invention includes a method of a winding of an electrical machine rotor which comprises a reduced axial length due to the re-winding operation. According to preferred embodiment of the invention, said half-coils (8,8'), instead of being manufactured as double hollow conductors, are provided in the form of two separate conductors (9,10), which comprise a single hollow each and which are adjacently embedded within respective slots of the rotor body.