The Siren Board

Just had a thought, would it be possible to mount a siren upside down? Like maybe under an overpass or something? It might be possible with really strong bolts, and a generally light siren, but what about a larger one, something like an STH-10 or Model 5, something like that. It's a wild idea, but I want to know your thoughts about it!

Sentry88 wrote: ↑

Tue Apr 30, 2024 3:33 pm

Just had a thought, would it be possible to mount a siren upside down? Like maybe under an overpass or something? It might be possible with really strong bolts, and a generally light siren, but what about a larger one, something like an STH-10 or Model 5, something like that. It's a wild idea, but I want to know your thoughts about it!

I have never seen that before .
And I don't think so.
Nice idea.

It could be possible in theory. In practice it's quite difficult and definitely not recommended.
Also, it's nice to see you again.

It's been done numerous times. There's an STH-10 mounted upside down, a pair of first gen Federal Type Mach. Bs, a Sireno vertical, and a few others come to mind.

Theoretically, a vertical siren mounted upside down won’t really have any serious impacts, unless the intake is on the bottom (like an STH-10). If not properly covered with a supplemental housing that would lead to ice build up if in a cold environment.

A horizontal siren mounted so the ends are vertical on the other hand could have serious negative effects on its life, as bearings that were designed to support a transverse load (perpendicular to the shaft) may not support an axial load (in line with the shaft) nearly as well.

Snowpix wrote: ↑

Wed May 01, 2024 12:16 am

It's been done numerous times. There's an STH-10 mounted upside down, a pair of first gen Federal Type Mach. Bs, a Sireno vertical, and a few others come to mind.

Wow, didn't know that! What are your thoughts about a rotating one? Would that be possible? (In theory, it should be)

That's what the first gen FS&S 500-SH basically is. The Thunderbeam as well, technically.

Snowpix wrote: ↑

Wed May 01, 2024 12:16 am

It's been done numerous times. There's an STH-10 mounted upside down, a pair of first gen Federal Type Mach. Bs, a Sireno vertical, and a few others come to mind.

That STH-10 is/was at Smith & Edwards in Ogden, UT, which is a sports/fishing warehouse. Not a permanent installation, unfortunately.

In theory, it could be possible to mount a simple siren upside down. You would need very strong bolts, and depending on the size of the siren you might need even longer bolts or extra reinforcement. Gravity would be pulling the siren down just the same as if it were mounted right side up, to it could be done. If you're talking Thunderbolt or P-50 levels, even if you somehow pulled off mounting it successfully upside-down, it still might break, as they aren't made to be upside down and some components couldn't work properly!

Greenrid wrote: ↑

Wed May 01, 2024 7:36 pm

In theory, it could be possible to mount a simple siren upside down. You would need very strong bolts, and depending on the size of the siren you might need even longer bolts or extra reinforcement. Gravity would be pulling the siren down just the same as if it were mounted right side up, to it could be done. If you're talking Thunderbolt or P-50 levels, even if you somehow pulled off mounting it successfully upside-down, it still might break, as they aren't made to be upside down and some components couldn't work properly!

A few appropriately-sized grade 5 or 8 bolts should be able to keep most sirens attached to their structure upside-down no problem.

I kinda doubt that a Thunderbolt blower can operate upside down because of the way oil likely flows around the rotors to keep everything lubricated. Try running any car engine upside-down and see what happens with the engine oil - I imagine the same awful thing might happen to an upside-down roots blower!