  Vortons are closed loops of superconducting strings carrying current and
charge. A formalism has been developed to study vortons in terms of an elastic
string approximation, but its implementation requires knowledge of the unknown
equation of state, relating the string tension to the energy per unit length.
Recently, a planar analogue of the vorton, known as a kinky vorton, has been
introduced. In this paper we derive an exact formula for the equation of state
of a kinky vorton and use it to calculate the properties of the associated
elastic string, such as the transverse and longitudinal propagation speeds. In
particular, the elastic string approximation predicts a complicated and highly
non-trivial pattern of intervals of instability, which we are able to confirm
using full field simulations. The implications of the results for vortons are
also discussed.
