
Stench gas - raldi
https://everything2.com/title/Stench+gas
======
abalone
_> air allows mines to use a very interesting way to communicate_

This is a very important point to remember about subterranean tunnel systems.
It is exactly what came to my mind when I watched the Boring Company video
about a huge network of 3D tunnels.[1] The tech press, which had probably
never even covered a construction project yet alone tunnels, was basically
like "what about earthquakes"? But tunnel collapse is not the primary safety
issue.

It's fires. Smoke and toxic gases from fires spread very quickly through
tunnels.

I am a huge fan of the concept, by the way, but I want to emphasize that most
fatalities from traffic tunnels have been from fires (apart from ordinary
traffic accidents).[2][3][4][5] And Elon Musk has stated that what makes this
vision feasible from a cost perspective is smaller tunnel diameters. Which
makes air "communication" all the more accelerated and safety critical. Thus
any vision of tunneling without detailing fire safety, evacuation systems and
firefighter access is significantly incomplete, as these can add significant
cost and fundamentally constrain designs.

[1]
[https://www.youtube.com/watch?v=u5V_VzRrSBI](https://www.youtube.com/watch?v=u5V_VzRrSBI)

[2]
[https://en.wikipedia.org/wiki/Caldecott_Tunnel_fire](https://en.wikipedia.org/wiki/Caldecott_Tunnel_fire)

[3]
[https://en.wikipedia.org/wiki/Gotthard_Road_Tunnel#2001_coll...](https://en.wikipedia.org/wiki/Gotthard_Road_Tunnel#2001_collision_and_fire)

[4]
[https://en.wikipedia.org/wiki/Kaprun_disaster](https://en.wikipedia.org/wiki/Kaprun_disaster)

[5]
[https://en.wikipedia.org/wiki/Mont_Blanc_Tunnel#1999_fire](https://en.wikipedia.org/wiki/Mont_Blanc_Tunnel#1999_fire)

~~~
zkms
> Smoke and toxic gases from fires spread very quickly through tunnels

It's not just the confined-space aspect that causes the fire gases to have
such high lethality (although it's certainly extremely significant), it's also
the rate of gas production.

Most solids and liquids don't actually burn; they emit flammable gases when
exposed to heat, and it's _those gases_ which actually undergo combustion.
These gases are created by endothermic processes (pyrolysis and evaporation),
and the more heat is available to convert unreactive solid/liquid combustibles
into reactive gases, the faster the fire will burn. Therefore, less heat loss
(to the outside environment or to non-combustibles) will enable a higher
combustion rate and the fire will produce more heat.

Tunnels are quite good at retaining heat, so most of the heat produced by a
fire will feed back right into heating combustibles -- enabling devastating
heat release rates in the tens to hundreds of megawatts. The heat release rate
is roughly proportional to the fire's fuel consumption rate; which will be
roughly proportional to the rate of lethal gas (CO/HCN/CO2) production and
oxygen depletion.

The radiant heat flux _alone_ can make the fire unapproachable by even
appropriately-equipped firefighters -- the massive production of superheated,
oxygen depleted, CO/HCN-containing gases can kill -- far beyond the range that
the heat flux is deadly.

~~~
personjerry
The tunnel becomes something like a stone oven right? I imagine you'd have to
let it cool off before trying to approach it.

~~~
dredmorbius
From the Wikipedia page of the Mont Blanc tunnel fire:

"Some victims escaped to the fire cubicles. The original fire doors on the
cubicles were rated to survive for two hours. Some had been upgraded in the 34
years since the tunnel was built to survive for four hours. The fire burned
for 53 hours and reached temperatures of 1,000 °C (1,830 °F), mainly because
of the margarine load in the trailer, equivalent to a 23,000-litre (5,100 imp
gal; 6,100 US gal) oil tanker, which spread to other cargo vehicles nearby
that also carried combustible loads."

It was _days_ before the tunnel cooled enough for recovery crews to enter.

~~~
zkms
With this sort of heat release rate and amount of combustible material, fire
doors alone are useless. Even if the fire doors miraculously remain intact and
gastight, the walls and doors will eventually conduct enough heat to make the
temperature in the fire refuges untenable for human life.

------
quadstick
100 years ago, yesterday, was the worst hard rock mining disaster in the US,
in Butte, Montana. They didn't have this way of warning the miners back then
and 168 miners died due to a fire in one of the shafts. Most died from
asphyxia.

Michael Punke, the author of the Revenant, wrote an excellent non-fiction book
about it called "Fire and Brimstone: The North Butte Mining Disaster of 1917".

------
userbinator
_They remain there until an all-clear is given, which may include a distinct
all-clear scent such as wintergreen._

If you search for "stench gas" you will find some... interesting photos of the
control panel for these systems:

[http://c1.staticflickr.com/2/1686/24201183892_c8a2dffc3b_h.j...](http://c1.staticflickr.com/2/1686/24201183892_c8a2dffc3b_h.jpg)

(Something about buttons marked "release stench gas" and "release anti-stench
gas" seem amusing in a rather comical fashion.)

~~~
dwringer
Something OCD in me is rather disturbed by the "release stench gas" being
located to the right of the "anti-stench gas".

~~~
mickronome
It should clearly (or likely) be the other way around, at least in any country
with a left-to-right reading order, OCD or not :)

We scan information faster in the preferred reading direction, and flipping
the warning​ gas on half a second earlier will likely, sooner or later save
somebody from harm. Not that there aren't other ways to improve safety in
mines, but each small part counts, I guess?

------
Herodotus38
Just reading about that article triggered an olfactory memory of the related
compound 2-mercaptoethanol (or beta-mercaptoethanol as it was labeled in the
lab). Used to reduce disulfide links in proteins (edit: see more correct
response below) so that they would unravel a bit and separate by size more as
they travel through the western blot matrix.

Unlike carbon monoxide this compound had a very "this will kill you" smell to
it.

[https://en.wikipedia.org/wiki/2-Mercaptoethanol](https://en.wikipedia.org/wiki/2-Mercaptoethanol)

~~~
cynicalbastard
is that the nasty sour smelling chemical? sort of like sulfur, vinegar, burnt
gunpowder, and vodka, mixed together? i used to get a whiff of it at my dad's
bench at his workplace.

~~~
cornchips
Acetic acid and Butyric acid. Used for those clear tool handles. [1][2] It
gets nastier once you realize you are smelling the odor of vomit with hints of
vinegar.

[1]
[https://en.wikipedia.org/wiki/Butyric_acid](https://en.wikipedia.org/wiki/Butyric_acid)

[2]
[https://en.wikipedia.org/wiki/Cellulose_acetate](https://en.wikipedia.org/wiki/Cellulose_acetate)

~~~
XorNot
No worse then a Hershey's chocolate bar...

~~~
Stratoscope
For anyone unfamiliar with the connection, Hershey's milk chocolate is made
with a process that produces butyric acid:

[https://en.wikipedia.org/wiki/Hershey_bar](https://en.wikipedia.org/wiki/Hershey_bar)

------
thomk
Everything2 is still around?!?! Awesome.

~~~
jordigh
Yeah, Jay Bonci is still running the damn thing. And people still log in. And
nobody seems to have any plans to shut it down.

Dude even still writes root logs:

[https://everything2.com/title/What+is+the+plan%253F+-+March+...](https://everything2.com/title/What+is+the+plan%253F+-+March+2017)

[https://everything2.com/user/jaybonci/writeups/root+log%253A...](https://everything2.com/user/jaybonci/writeups/root+log%253A+May+2017)

Whenever a big event happens, like some big e2 celebrity dies, there's a surge
of people logging into the site to pay their respects. Weddings and funerals,
they say, but for e2 it seems to be only funerals.

------
hitekker
If our noses were "sharper", i.e., able to distinguish on a deeper more
meaningful level like a dog, could we transmit complex information with
olfactory encoding?

Right now the smells are simple signals; I'm curious if a scent could be
engineered to contain a language. Like paper and writing.

I'm asking for my story, in which sapient rats struggle against two-legged
monsters with opposable thumbs.

~~~
bglazer
I've wondered if one could build a device that outputs different combinations
of distinct scents for training dogs. Like condition the dog to understand
"sit" = "bacon smell" and "shake" = "cat". My theory was that dogs have more
cognitive resources dedicated to processing olfactory information and so they
could also be trained to understand and perform more complex tasks. Like,
"bacon + cat + shoe smell" = "bark while running left"

------
rcarmo
I wonder if we could tie this to Jenkins for when a build breaks. Would make
for a nicer alternative than sirens and flashing lights, although I suspect
people would tend to clear the office...

------
rmm
It smells absolutely wretched, and is totally unmistakable.

Had it go off on a couple sites I've been on, and it's remarkable how it
reaches every corner of the mine.

~~~
jessriedel
Would love to hear more. What prompted it, and how did everyone respond? Was
the wintergreen "all clear" signal used after the problem was resolved?

------
pjs_
I instinctively hovered my mouse over the link to wintergreen, my brain fully
expecting to click and experience the smell - as I would with any image,
video, or sound. Took me a few seconds to manage expectations!

------
cobbzilla
See also:
[https://en.wikipedia.org/wiki/Ethanethiol](https://en.wikipedia.org/wiki/Ethanethiol)

And if you want to buy some: [http://www.zacon.ca/stench-
gas.asp](http://www.zacon.ca/stench-gas.asp)

~~~
krallja
"Employees of the Union Oil Company of California reported first in 1938 that
turkey vultures would gather at the site of any gas leak. After finding that
this was caused by traces of ethanethiol in the gas it was decided to boost
the amount of ethanethiol in the gas, to make detections of leaks easier"

~~~
raldi
Aw, I thought that story was going to end with them breeding vast flocks of
turkey vultures to patrol the pipes.

~~~
sk5t
And then stocking the area with extra carrion to sustain all the new vultures?
Hmmmm what could go wrong...

------
smsm42
Same principle in fire alarm for the deaf:

[https://www.techdirt.com/articles/20080310/020944491.shtml](https://www.techdirt.com/articles/20080310/020944491.shtml)

They use wasabi.

------
toomanybeersies
I remember seeing this for sale on BOC's website when looking for CO2 a while
back ([https://www.boc.co.nz/shop/en/nz/stench-
gas](https://www.boc.co.nz/shop/en/nz/stench-gas)). I briefly considered
buying some for nefarious purposes, but I think I figured that they probably
wouldn't just sell it to any random person.

------
rabboRubble
Reminds me of the Friends' episode where Ross goes on and on with the (bored
and weirded out) pizza delivery girl about the smelly chemical added to
natural gas in order to make it olfactible & safer to use.

Found it...
[https://youtu.be/kH5JhYsfNMA?t=1m10s](https://youtu.be/kH5JhYsfNMA?t=1m10s)

~~~
dredmorbius
And if you've ever wondered whose blood those regulations arose from, it's the
300 souls lost in the New London School Explosion:

[https://en.m.wikipedia.org/wiki/New_London_School_explosion](https://en.m.wikipedia.org/wiki/New_London_School_explosion)

~~~
rabboRubble
Yeah, we lose the collective memory of the "why" behind many of our
regulations. Thanks for telling me about this. I certainly did not know!

------
hammock
Same compound that is added to propane

------
__s
I think my family went to that exhibit while I was pre adolescent. I got
scared so only my mother & sister went, while I stayed topside with my father.
We window shopped the souvenir shop

Nowadays my sister suffers claustrophobia & I feel most comfortable shoved
into small crooks. But I think I was mostly offset by anxiety related to
ventilation

Visited Timmins this May, another northern Ontario city. It was snowing

