SirensOfAustralia wrote: ↑Thu Jun 06, 2024 7:03 am
Snowpix wrote: ↑Sun Jun 02, 2024 5:12 pm
The P-50 had already been decommissioned previously after seizing from ingesting fibreglass. However, fibreglass ingestion doesn't seem to be the issue here. The rotor was already damaged from coming to a sudden stop before, and likely had microfractures that were undetectable. Those fractures opened up during operation forming a crack, which expanded the rotor until it rubbed against and ultimately friction welded the stator. The videos don't show any fibreglass falling from the siren, even after the siren violently shakes upon failing. In addition, the sound goes flat shortly before the siren fails, which suggests the rotor rubbing against the stator.
That would make a lot of sense since fibreglass would just be shredded into smaller pieces. So does that mean the chopper caught the stator? It went from max RPM to zero RPM within the blink of an eye.
It had already eaten some pieces of fiberglass already, which had caused microcracks in the chopper itself. The reason it stopped so fast was because as the siren was going off, the centrifugal force had caused the cracks to get bigger, ultimately causing the chopper to expand and friction-weld it to the rotor. It didn't actually eat anything at SirenCon!
Proud owner of a E.A Labs Sireane Jr, a Uniden radio scanner, and a Sure-Lites emergency light!
Also the proud owner of the FULL 508 siren map!
https://rb.gy/bgjrm1
I'm probably the go-to person to learn about my city's siren history.