  The continuity equations expressing conservation of string defect charge can
be used to find an explicit expression for the string velocity field in terms
of the order parameter in the case of an O(n) symmetric time-dependent
Ginzburg-Landau model. This expression for the velocity is used to find the
string velocity probability distribution in the case of phase-ordering kinetics
for a nonconserved order parameter. For long times $t$ after the quench,
velocities scale as $t^{-1/2}$. There is a large velocity tail in the
distribution corresponding to annihilation of defects which goes as
$V^{-(2d+2-n)}$ for both point and string defects in $d$ spatial dimensions.
