  We study the creation of disoriented chiral condensates with some initial
boundary conditions that may be expected in the relativistic heavy ion
collisions. The equations of motion in the linear $\sigma$-model are solved
numerically with and without a Lorentz-boost invariance. We suggest that a
distinct cluster structure of coherent pion production in the rapidity
distribution may emerge due to a quench and may be observed in experiments.
