  We study numerically propagation of energy in a one dimensional Ding-Ding
lattice, composed of linear oscillators with ellastic collisions. Wave
propagation is suppressed by breaking translational symmetry, we consider three
way to do this: a position disorder, a mass disorder, and a dimer lattice with
alternating distances between the units. In all cases the spreading of an
initially localized wavepacket is irregular, due to appearance of chaos, and
subdiffusive. Guided by a nonlinear diffusion equation, we establish that the
mean waiting times of spreading obey a scaling law in dependence on energy.
Moreover, we show that the spreading exponents very weakly depend on the level
of disorder.
