OK, Widger, I'll bite!
The reason the 'tension in the ops room was palpable' should be obvious. If you were partcipating in an event which could result in the death of hundreds of innocent people within relatively few minutes, you might be a bit tense, too. The people on the telly weren't taking themselves seriously, they were taking their job seriously.
And the reason for the shouting is simple. It's the quickest way to get a piece of information to several people who need to know it straight away, and who are all busy doing stuff (and maybe even talking on other 'command lines'). It's only done in certain circumstances and is by no means routine.
So, Widger, as far as I'm concerned, you can RAM IT!
BM