23 Jun
2004
23 Jun
'04
10:14 a.m.
I just assume
that the existing ones
won't be replaced any time soon (since they presumably
work) and that
the natural replacement rate is relatively low.
Extremely low. The tube rigs being replaced will become the
standby units, and the current standby units (many dating to
the 1950s) will go out to
pasture.