Bay 12 Games Forum

Dwarf Fortress => DF Dwarf Mode Discussion => Topic started by: JBlak on September 24, 2021, 01:56:42 pm

Title: Periodic spontaneous combusion in outdoors refuse pit. Hidden feature?
Post by: JBlak on September 24, 2021, 01:56:42 pm
After playing on this fort for nearing 5 in-game years now, I have observed this periodic phenomenon happening 3 times, too many times for it to be mere coincidence or circumstance.

My some tiles in my outdoors refuse pit would spontaneously combust. The fire doesn't spread beyond the refuse pit, I think because fire does not spread across z-levels. This is of course a relative safe and desirable event as it would save many dwarf-hours of clearing the refuse stockpile to the quantum dump site.

I did embark on a scorching embark. However this doesn't explain why the fires would only start in the refuse pit and nowhere else. I am beginning to think it's a undiscovered (or not widely known) feature. Has anybody else had this experience?

I can rule out magma (it is still very deep underground) and I can also rule out combusting/combustible creatures dead or alive. MAYBE it's something relating to scorching embark + dumped fat?

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Title: Re: Periodic spontaneous combusion in outdoors refuse pit. Hidden feature?
Post by: Mobbstar on September 24, 2021, 02:48:39 pm
The ignition point of fat is 10338 °U (https://dwarffortresswiki.org/index.php/DF2014:Temperature) according to the wiki (https://dwarffortresswiki.org/index.php/DF2014:Fat/raw), well above what scorching biomes are known to achieve.  Such temperature would certainly affect your dwarves by melting the fat underneath their skin.

Do you have any mods?  Is there any off-chance fire snakes got captured and then loose?  I am clueless what else could start fire like this.
Title: Re: Periodic spontaneous combusion in outdoors refuse pit. Hidden feature?
Post by: Thisfox on September 24, 2021, 03:03:48 pm
I've been on scorching embarks a few times, and never had that happen. Perhaps you have a vermin spawn bug, and are occasionally getting magma animals due to the temperature of the surface or something? It's not really all that hot though. Hmm. Does it only happen on the surface, or can indoor refuse piles also burst into flames?

(Also, how best to post images (http://www.bay12forums.com/smf/index.php?topic=162924.0) so that they're visible on the page, if it interests you.)
Title: Re: Periodic spontaneous combusion in outdoors refuse pit. Hidden feature?
Post by: Saiko Kila on September 24, 2021, 03:04:49 pm
This is a recurring bug apparently. I remember it from a decade ago - and it is usually bones (or teeth) which ignite. I've uploaded a save where the fire starts just after a tick (many years ago), and I've found several similar saves in the DFFD, even with the current version. This fire starts always from a specific item in a stockpile, but why it starts is a mystery.
Title: Re: Periodic spontaneous combusion in outdoors refuse pit. Hidden feature?
Post by: JBlak on September 24, 2021, 06:50:37 pm
Quote from: Mobbstar on September 24, 2021, 02:48:39 pm
The ignition point of fat is 10338 °U (https://dwarffortresswiki.org/index.php/DF2014:Temperature) according to the wiki (https://dwarffortresswiki.org/index.php/DF2014:Fat/raw), well above what scorching biomes are known to achieve.  Such temperature would certainly affect your dwarves by melting the fat underneath their skin.

Do you have any mods?  Is there any off-chance fire snakes got captured and then loose?  I am clueless what else could start fire like this.
No mods, just running the game through the latest 47.05 lazy newb pack. And I am quite certain it was not due to flaming animals.

Quote from: Thisfox on September 24, 2021, 03:03:48 pm
I've been on scorching embarks a few times, and never had that happen. Perhaps you have a vermin spawn bug, and are occasionally getting magma animals due to the temperature of the surface or something? It's not really all that hot though. Hmm. Does it only happen on the surface, or can indoor refuse piles also burst into flames?
(Also, how best to post images (http://www.bay12forums.com/smf/index.php?topic=162924.0) so that they're visible on the page, if it interests you.)
Thanks. Edited the original post.

Quote from: Saiko Kila on September 24, 2021, 03:04:49 pm
This is a recurring bug apparently. I remember it from a decade ago - and it is usually bones (or teeth) which ignite. I've uploaded a save where the fire starts just after a tick (many years ago), and I've found several similar saves in the DFFD, even with the current version. This fire starts always from a specific item in a stockpile, but why it starts is a mystery.
This seems like the most likely cause. Thanks for the insight. And my refuse piles are mostly body parts which eventually rot into bone piles and teeth from mouth trauma.