I have worked in a number of nuclear hardened facilities. Some more than others. There certainly are robust standards for this, as I recall quite a bit of fuss around even the small details. Typically what you see is everything is electrically isolated. On-site power, EMP hardened with shielding everywhere. All mechanical and electrical equipment suspended. Several feet of concrete on all sides. They told us it was intended to withstand near impact and I believed that it could. At least structurally. I’m not sure the people inside would fare the same.
I also spent some time inside Cheyenne mountain. That is next level hardening. I have no doubt you could hit it with 50 nukes and the people inside would hardly notice. Of course, other than it specifically being their job to know that we’re being nuked.
I know, we had something similar in the Netherlands (in fact we still do). An independent phone network for the government.
But my point is: You can protect the building. What about the trunk lines going all the way to those other bunkers? They're not immune to nuclear blasts and in the days it matters they were made of copper which can catch EMP directly.
These days they will be fibre which is EMP immune of course but the repeaters are not.
Long Lines had a vast network of nuclear-hardened microwave towers spanning the lower 48 that predominantly carried network traffic. From the article, the vents in the building in Manhattan also disguised microwave feed horns. There was some coax in the network where there wasn’t line of sight linking two nodes, but that was the exception and came later in the network’s existence, I believe.
I’m not sure what EMP protections could have been applied to microwave equipment on the towers, but my assumption is that it might have been easier to defend against than a massive piece of coax in the ground as a big EMP inductor.
Wow that is pretty severe, I would imagine cables would be much easier to EMP shield, by laying them in grounded metal pipes. Because this has to be done for the entire length this is still a huge problem of course. And not really feasible over long distances.
But a microwave antenna (especially one that size) is basically one giant EMP collector :) It's pretty impossible to protect that. I guess if they did that, they would have just let the receivers blow and replace them later with spare parts shielded inside the building. You can't practically shield them from EMP because then they won't work anymore, and overdimensioning them so they could cope with the EMP would be almost impossible considering the huge gain of those antennas.
I also spent some time inside Cheyenne mountain. That is next level hardening. I have no doubt you could hit it with 50 nukes and the people inside would hardly notice. Of course, other than it specifically being their job to know that we’re being nuked.