What Is the Mysterious, Reverberating Sound We Hear in North Bernal?

/ Todd_Lappin

bernalencounters

This week, several residents of Precitaville have heard a strange, deep-throated rumbling sound echoing through the air.

It’s been a topic of discussion in various neighborhood mailing lists — and Bernalwood’s inbox.

Indeed, your Bernalwood editor has actually heard the sound a few times as well. Personally, I thought it sounded like a very large diesel engine at idle, or a massive extraterrestrial spacecraft hovering over Bernal Hill. Or, at least, what I imagine a massive extraterrestrial spacecraft would sound like, if it was hovering over Bernal Hill.

Yesterday Neighbor John wrote to Bernalwood:

Does anybody know what that rumbling sound is?  I’ve heard it for a couple of days now, runs through the night too.  Weird.

Neighbor Linda heard it again this morning:

The noise is back. Time for some sleuthing.

As far as I can tell, it started on Monday afternoon/evening and continued until Tuesday morning. It started again Tuesday around noon, but quieter. I’m going to attribute that to the weird atmospheric noise bounce we get sometimes (remember Beyonce?). It’s also possible it was going the entire time and I just didn’t hear it.

Right now it’s loud and clear.

I can’t figure out where it’s coming from.

Yesterday evening I set out to figure it out. I walked Bessie to Precita to Shotwell, across to Cesar Chavez, down Cesar Chavez to Folsom, all around St. Anthony’s, up Folsom to Precita to Flynn school, and down Harrison to Cesar Chavez. Most of the time it was really quiet and of course the noise from Cesar Chavez made it inaudible. But when I crossed the pathway in the park I could hear it distinctly on Precita between Treat and Harrison.

I gave up and went home. Based on this I’m guessing it’s coming from the other side of Cesar Chavez, maybe down Harrison. I might try to drive around later but don’t have much time.

Maybe an intrepid reader of Bernalwood knows what this strange sound is.

Neighbor John says it sounds familiar:

Back before the Iraq invasion, the Navy did lots of training on the Bay. Might be the same. Seaborne pilot rescue. As I recall, they were doing some kind of mine clearing operations back in ’02 that had those big Sea Stallion helicopters dragging some kind of device thru water. Sound carries real well over water. Might be it.

I had a somewhat similar thought; that the noise might somehow be connected to Fleet Week, which happens this weekend. Or, possibly, the arrival of the amphibious assault ship USS America in town on Monday morning, which could validate Neighbor John’s Navy helicopters-at-sea-level theory.

Neighbor Andy was on the scene to report the USS America’s arrival:

So, maybe that?

Or, a massive extraterrestrial spacecraft hovering over Bernal Hill. Possibly with a cloaking device.

UPDATE 5;17 pm: Neighbor Rusty did some field research, and he thinks the noise is definitely coming from the USS America:

I’m 99% certain it’s the USS America (LHA-6) which is docked at the end of Bryant street at Pier 32. It’s the same sonic signature that I hear from north Bernal. I drove down to Mission Rock and could hear it coming from the direction of the Bay Bridge. Drove down the Embarcadero and sure enough the sound was quite apparent over the sound of traffic right in front of where LHA-6 was docked.

Here’s a visual of USS America here, now, courtesy of Raul:

USS America (LHA-6)

And, a corroborating video!

22 thoughts on “What Is the Mysterious, Reverberating Sound We Hear in North Bernal?”

  2. We Just took a dog walk to the top of Bernal hill with trusty field glasses in hand and can report that, while the noise was present, we did not see any helicopters doing training exercises. However, we did see that the Navy ships mentioned earlier are moored directly across the bay from us in the general direction from which the thrumming / rumbling sound is coming.

  3. I too heard that the other night, Coso at Lundy’s. I had heard that before, about two or three months ago, and could not figure out what it was. It sounds like maybe a waterpump, or fan motor, and I think it was stationary. Very difficult to localize, though I only tried it by sticking my head out the window, not by walking around the neighborhood at 4:00 am.

  4. That rumbling has been going on since I was here. I came in 1966. It used to be from engine testing at the Alameda Naval Air Station across the bay. Where it comes from I don’t know, but it’s nothing new.

  8. I just called 311 and also checked sf311 on line to no avail. I think the sound is getting worse. So is my headache. The nice 311 lady didn’t know nor did she know about Bernalwood blog (gasp! she does now). She said she’d look into the source of the noise since she figured others would call w the same question.

  10. Neighbor Rusty went for a visit to the USS America, and he thinks it’s the source:

  11. I’m 99% certain it’s the USS America (LHA-6) which is docked at the end of Bryant street at Pier 32. It’s the same sonic signature that I hear from north Bernal. I drove down to Mission Rock and could hear it coming from the direction of the Bay Bridge. Drove down the Embarcadero and sure enough the sound was quite apparent over the sound of traffic right in front of where LHA-6 was docked.

  14. We notice that when its hot and the air is still the rumble of the freeway is heard easier. At night is when we hear it most. Maybe its that?

  15. Definitely the ship. I have working here on delancy st all morning. Been hearing hums, pings, horns and rumbles all morning.

  17. It is definitely from the USS America. This was happening starting Sunday/Monday in Potrero and we have verified the source. Malia Cohen is working of fixing the situation. Poor Marine life having to deal with this! :/

  19. It’s REALLY loud at the ship itself. Here’s a quick video I took when I was there today. http://instagram.com/p/t8uyI-C1mn/ Some places are louder than others, think it has to do with the dual
    stacks that cancel each other out a bit in some directions and amplify things in others.

  21. I remember that hum back around 2000-2001. Can’t believe it’s still going on. A bit spooky at night.

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