  The main linacs of the Next Linear Collider (NLC) will contain several
thousand X-band RDDS (Rounded Damped Detuned Structures). The transverse
wakefield in the structures is reduced by detuning the modal frequencies such
that they destructively interfere and by four damping manifolds per structure
which provide weak damping. Errors in the fabrication of the individual cells
and in the alignment of the cells will reduce the cancellation of the modes.
Here, we calculate the tolerances on random errors in the synchronous
frequencies of the cells and the cell-to-cell alignment.
