I worry what you just heard was "bring me a lot of bacon and eggs". What I said was "Bring me all the bacon and eggs you have".
this post was submitted on 20 May 2025
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Navy here. We used to say that if you locked a Marine in an empty room with a bowling ball and come back in an hour, he'll have either lost it, broken it, or fucked it. I thought it was all hyperbole until I caught a couple of them having a chin-up contest on a section of waveguide for the air search. If it broke, they'd have been dead before they hit the deck. Damn fine shots though.
Why would they be dead? Long drop?
Because waveguide is like a tuned, hallow, pipe to carry microwave energy to the antenna for emission. It's fairly thin metal with a rectangular cross section. The SPA-49 Air Search Radar in question has a peak power of 360 thousand watts. If you were to point that much microwave energy directly at your torso, it'd boil and vaporize the water in your body and you would literally explode in the worst case. Yes, it is very clearly marked as "non-load bearing"...
I was a radarman in the army. As far as i’m aware uncollimated radar doesn’t do a whole lot even at really high power since it isn’t ionizing. If it did then sidelobe radiation would be a seriously problem for anyone near the antenna. Feel free to correct me with sources as it’s been almost two decades since i touched a radar but i don’t think it would be a big a problem as you say. Expensive to fix, sure. Probably not instantly deadly though.
You're correct that microwaves are not ionizing radiation in the same way that gamma radiation is for example, but it is still dangerous. The microwaves the radar uses are at a very similar wavelength to what is used in your microwave oven at home which impart kinetic energy, and therefore heat, to small polar molecules such as water. It won't knock off electrons and give you cancer at low doses, which is why side lobing is okay-ish, but it will still flash boil water that gets in the way. I've seen videos of birds that fall out of the air after flying through the radiation path of the illuminators for the Sea Sparrow missile system.
Read my reply to the other commenter. I’ve stood in front of high powered radar while transmitting. They do nothing to you. If collimated beams of microwave radar do nothing then uncollimated rays are going to do even less.
My radar was about 1/3 the power of this one you describe. If these radars were so deadly we wouldn’t have them on ships and we sure as heck wouldnt set them up near artillery like we currently do. My radar was right beside the guns pointed at them. It did nothing to the cannon crews at all and they sat in the beams for days.
Couple things: number one, you shouldn't have. Two, the energy isn't collimated coming out of the feed horn, but it sure as hell is going through a 6x12 in wave guide. Three, if you touch something, it's not an RF burn anymore, you just touched a hot thing. Four, there do have to be precautions in place when you're using radar around munitions, but microwaves don't heat up metal very much in most cases, so it's less of a concern than for either walking bags of water and lopids, or micro scale electronics, which are definitely affected. If microwave radiation is as harmless as a declawed kitten, then why is there so much attention paid to radiation safety when working around radars? If none of that is thought-provoking, then I'm curious why you feel that the same microwaves that can turn pizza cheese into magma in your kitchen, are harmless when they're multiplied by 100,000 coming out of an antenna.
If none of that is thought-provoking, then I’m curious why you feel that the same microwaves that can turn pizza cheese into magma in your kitchen, are harmless when they’re multiplied by 100,000 coming out of an antenna.
Because I understand that the frequency in my microwave is 2.4ghz and the one in the radar i used was ~8ghz and the radar you described was 900mhz. Modern radar doesn't heat things the same way that old school ones did.
If the power is what's causing the problem then sidelobe radiation would cook everyone on the ship since it's around 50% the power and extends around the radiation source 360 degrees. Also the power is only about 10 times the power of a microwave on average.
edit: a word
If you want a source, check here: https://www.dau.edu/cop/e3/resources/radiation-hazards
Seems like they would receive some nasty RF burns if they’re touching it while the radar is transmitting but they would get the same from any other transmitting antenna, radar or otherwise. They aren’t going to flash boil or explode though.
Ionizing just means whether or not it causes cancer etc. Power is still power. Meaning if it points at you, you are cooked.
Please note that you are more transparent to some wavelengths than others. E.g. the water heating microwaves are particularly nasty. But you might be transparent to others (e.g. XRay, Warning: that's ionizing so unsafe)
I’ve stood in front of high powered radars. They don’t do anything to you. Also my radar operated in the microwave band at about 1/3 the power of this navy one. So if mine did nothing to me i doubt the navy one would do anything.
They probably use a frequency that does virtually nothing to humans then. The power feed may feature additional modes that are less safe to be fair.
It uses a low L band frequency so as i said in my first comment, not harmful to humans and for sure isn’t going to vaporize you like op said.
If you’re touching the radar while it is transmitting you’ll probably receive an RF burn for your troubles but otherwise it should be fine.
What were they’re favorite (crayon) flavors?
Crayola. They're Marines
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