I live at Duwamish Head, and have not heard what you describe, and I am up at 3am to go to work. The one sound that does go off is the fog horn on the Duwamish Head light, just off the Anchor Park. Maybe that is what you are hearing, it was going for about 2 hours last night.
I used to live on Avalon and heard it after midnight for months. I couldn’t pinpoint were it was coming from. It would stop, and then when I tried to get back to sleep again, it would start up. I even told the police about it.
WMO that might be what it is if you heard it last night. It was going off around 11 PM last night, and around 10 PM the night before. I have also heard it in the middle of the day on a Thursday.
It reminds me of when you hear someone’s alarm clock going and they won’t turn it off.
Hmmm. Truck backup alarms are pretty frequent, like every 2-3 seconds. Trucks do backup at Nucor when they are maneuvering, but it would be a fast beep..beep..beep. I don’t know if locomotives need alarms. Perhaps a rail fan can chime in (as it were).
