  The Burau representation enables to define many other representations of the
braid group $B_n$ by the topological operation of ``cabling braids''. We show
here that these representations split into copies of the Burau representation
itself and of a representation of $B_n/(P_n,P_n)$. In particular, we show that
there is no gain in terms of faithfulness by cabling the Burau representation.
