I believe the substations have been "strengthened". To which the most logically conclusion would be someone could just either suicide boming or drive a Mcveigh truck of peace into it.
The problem with some equipment is that by its nature it really cannot be strengthened. When your relying on a dozen feet or more of open air for insulation it's very difficult to then confine that to a structure. At the same time this is the "arms race" kind of mentality I was trying to illustrate. I could go buy a mylar balloon
right now and pass multiple substations on my drive home that would be arcing and sparking if I were so inclined. Even at the hundreds of dollars for some sparky to hit a reset button, that's a damn good ROI. It's not like I'm in some high development area either.
Rail corridors have failsafes, theoretically have to hotlink the wire that run protections so the thermite doesn't separate the connection and turn the light/signal to STOP to the automated signalers.
Of course, the other method would to just to blow a bridge over a river for any transportation artery.
I fear/respect the rail companies enough not to detail the weak points other than to say they are there and easily exposed. Really there are too many avenues for them to simply plug all the holes in the metaphorical dyke with their fingers.
The only thing I can suggest that would be more effective than either of these theoretically is to just go yeet one of the telecom datacenter buildings in a large city with a dozer or truck. That would shut down the major airports, take down first responder radios (most are cell based now days), and people would riot in a few hours without internet access.
If you want to talk about actual hardened infrastructure, good luck with any of that. How long did that one dude knocking a place out with a bomb shut things down for? I think most issues were resolved within the day. People on scene shot and uploaded video of the detonation within minutes. OTOH Canada had a planned upgrade go fuckywucky and put a quarter of their population through a worse outage.
Unlike something that would get you the ole Timmy McVeigh treatment, going technical with something like an SDR would let you wreak much further havoc at much less risk. ADS-B is how most air traffic information works today. Larger control and tracking centers will have radar but will largely use that to confirm what ADS-B says. This is also an open protocol
widely explored by amateur enthusiasts.
Likewise, while cracking cell-based networks is hard, effectively jamming them with amateur equipment would be trivial. Encrypted radio, particularly the kind used by most government/police radios stateside also have a very unique weakness. You can spoof a "home station" signal that triggers a cascading failure that renders their encrypted mode completely inoperable. This weakness is so glaring and vulnerable the researcher found almost a majority were simply defaulting to unencrypted comms as a practical matter. While it was
very simple to trigger this cascading failure, the remedy requires bringing the radio to the home station to reconfigure it.
Gen Z wouldn't do any of this shit cause they're too lazy. I can't even get people to put things up properly when they're fucking color coded and I have written instructions for them.
These guys with the SDRs might be too old for Zoomers but it skews surprisingly young. Idle hands and the devil's handiwork and all that.
No FBI, I wouldn't do it because I like being to autistically work on my hobbies and slave my life away in a coal mine.
I would with the proper government authorization and a commensurate check from Uncle Sam for services rendered. Really more of a free agent I just think this stuff is really neat to theorize about.