Steam powered alarm bells

[Daniel]

Yes, they exist. I have one. I don't have a photo (since it is buried in a pile of boxes), but it looks like a regular electric alarm bell from the front. It came from a 1928-vintage boiler room and it was connected to a steam line and an electric valve. Under the gong, the steam line ends in a nozzle directed at a small paddle wheel, which in turn rotates an arm with two flails that strike the gong. A cloud of steam would pour from behind the gong as the bell was ringing. Has anyone ever seen or experimented with one of these? How rare are they?

[AllSafe]

I've been around some old boilers but haven't seen one. Have you tried running that bell on compressed air to see how well it works?

[Jim_Ferer]

It's definitely connected to an electric valve? It would seem the bell would be well suited as an automatic overpressure alarm; the relief would sound the bell at the same time. If the relief was too big then they could bleed off just enough for the bell.

It sounds like a great collector's item.

[kx250rider]

That is an iteresting item, and my curiostiy is jarred! I would think that if electricity is available, it's more efficient to just have an electric bell in most cases. So Jim_Ferer makes a good point about the steam bell being an alarm for over pressure. This is because it would act as an "audible gauge". So if the overpressure continued and increased, the frequency of the bell increases, and vice versa. Makes good sense And if this is the purpose, the electric valve would be an override to stop an unwanted alarm, and/or as a test mode.

Steam power in itsself fascinates me, and this would be a great topic for the non-siren thread!

Charles

[Daniel]

The idea of using the bell as a pressure gauge is a very plausible one, except that this bell came from the boiler room of a monastery where undue noise is generally avoided. They have several large tower bells which are pealed by 1/4 Hp. motors in different combinations for various liturgical events, but knowledge of immanent steam pressure doesn't normally fit into their horarium. Incense pressure, perhaps?