  We study the formation and evolution of an interconnected string network in
large-scale field-theory numerical simulations, both in flat spacetime and in
expanding universe. The network consists of gauge U(1) strings of two different
kinds and their bound states, arising due to an attractive interaction
potential. We find that the network shows no tendency to ``freeze'' and appears
to approach a scaling regime, with all characteristic lengths growing linearly
with time. Bound strings constitute only a small fraction of the total string
length in the network.
