  We construct all higher order conserved charges from a general
two-dimensional zero curvature condition using a Gardner transformation.
Employing two of those charges in the definition of a Hamiltonian allows to
view the Hirota equations as an integrable $\mathcal{PT}$-symmetric extension
of the nonlinear Schr\"{o}dinger equation. We construct new degenerate
multi-soliton solutions from Hirota's direct method as well as Darboux-Crum
transformations based on Jordan states. We study the properties of these
solutions, computing their asymptotic time-dependent displacements and also
show that their scattering process has a distinct characteristic behaviour
different from the nondegenerate counterparts allowing only for interactions of
absorb-emit type.
