  The elastic crust of a neutron star fractures repeatedly as it spins down
electromagnetically. An idealised, macroscopic model of inhomogeneous crustal
failure is presented based on a cellular automaton with nearest-neighbour
tectonic interactions involving strain redistribution and thermal dissipation.
Predictions are made of the size and waiting-time distributions of failure
events, as well as the rate of failure as the star spins down. The last failure
event typically occurs when the star spins down to approximately 1% of its
birth frequency with implications for rotational glitch activity. Neutron stars
are commonly suggested as sources of continuous gravitational waves. The output
of the automaton is converted into predictions of the star's mass ellipticity
and gravitational wave strain as functions of its age, with implications for
future observations with instruments such as the Laser Interferometer
Gravitational Wave Observatory (LIGO), the Virgo interferometer, or the Kamioka
Gravitational Wave Detector (KAGRA).
