  This work examines the commutator structure of some closed subgroups of the
wild group of automorphisms of a local field with perfect residue field, a
group we call $\Cal J.$ In particular, we establish a new approach to
evaluating commutators in $\Cal J$ and using this method investigate the normal
subgroup structure of some classes of index subgroups of $\Cal J$ as introduced
by Klopsch. We provide new proofs of Fesenko\rq s results that lead to a proof
that the torsion free group $T =\{t+\sum_{k\geq 1} a_kt^{qk+1}: a_k \in \Bbb
F_p\}$ is hereditarily just infinite, and by extending his work, we also
demonstrate the existence of a new class of hereditarily just infinite
subgroups of $\Cal J$ which have non-trivial torsion.
