OT: question for SSBN Sailors or shipyard guys

[timmyg00]

Got a question for any of you guys who sailed on Ohio-class boats, or even on older boomers; some of you yardbirds might know the answer as well....

I work in the telecom industry, and I work with a guy who claims to have installed large PBXs in submarines.

Now, the only way I can figure that this is true is that these PBXs were installed in SSBNs. But I can't figure out why a PBX was needed... based solely on my experience on an SSN, on which we only had 2-3 land lines (control room, goat locker, wardroom) when we pulled into port.

Were the SSBNs wired for normal telephone circuits in many more areas than SSNs, in addition to the sound-powered circuits and IC circuits?

TG