  The packing chromatic number $\chi$ $\rho$ (G) of a graph G is the smallest
integer k such that its set of vertices V (G) can be partitioned into k
disjoint subsets V 1 ,. .. , V k , in such a way that every two distinct
vertices in V i are at distance greater than i in G for every i, 1 $\le$ i
$\le$ k. Recently, Balogh, Kostochka and Liu proved that $\chi$ $\rho$ is not
bounded in the class of subcubic graphs [Packing chromatic number of subcubic
graphs, Discrete Math. 341 (2018), 474483], thus answering a question
previously addressed in several papers. However, several subclasses of cubic or
subcubic graphs have bounded packing chromatic number. In this paper, we
determine the exact value of, or upper and lower bounds on, the packing
chromatic number of some classes of cubic graphs, namely circular ladders, and
so-called H-graphs and generalised H-graphs.
