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Massachusetts gas fires: Another technological tragedy

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Re: Massachusetts gas fires: Another technological tragedy

#111
post #91
post #79

Earlier quoted context omitted.

That's confusing. "Air cooled" usually means exactly that there is no "intermediary coolant". At the end of the day almost all equipment cools to the atmosphere after all. The difference between liquid cooled and air cooled cars/bikes is exactly that extra equipment of coolant lines and radiators versus just having airflow directly over the things you want to cool.

I wasn’t very clear, if the NaK is liquid it could flow through a radiator and could still be considered air cooled. While there are some pure air cooled engines, lawn mowers, motor cycles, etc. A typical car engine is also considered air cooled since it gives off its heat to atmosphere even with assistance of a coolant radiator system. Most marine engines, some power plants and some industrial equipment is considere…

> A typical car engine is also considered air cooled

We just have different definitions then. In car circles your typical car is definitely water cooled. I had never seen your definition but it also makes sense. The typical one is describing what fluid contacts the hot parts and yours is describing what mass the heat is transferred to.

Re: Massachusetts gas fires: Another technological tragedy

#112
post #91

Earlier quoted context omitted.

I wasn’t very clear, if the NaK is liquid it could flow through a radiator and could still be considered air cooled. While there are some pure air cooled engines, lawn mowers, motor cycles, etc. A typical car engine is also considered air cooled since it gives off its heat to atmosphere even with assistance of a coolant radiator system. Most marine engines, some power plants and some industrial equipment is considere…

> A typical car engine is also considered air cooled We just have different definitions then. In car circles your typical car is definitely water cooled. I had never seen your definition but it also makes sense. The typical one is describing what fluid contacts the hot parts and yours is describing what mass the heat is transferred to.

This gets a bit blurry in (some) motorcycles.

My late 90s era Ducati is considered my most people to be "air cooled", but it has oil galleries that circle around the cylinder walls and an air-oil radiator. (Pedants might call it "oil cooled", but those are mostly the same people who "well actually" you when you call it a V Twin. "Well, actually, it's an _L_ Twin..." - just because it's a 90 degree V Twin rolled forward so the front cylinder is roughly horizontal and the read is mostly vertical...)

(And to further complicate matters, the 900cc two valve "air cooled" Ducati motors have those cylinder cooling oil galleries, but the 750cc motors also have oil coolers, but do not circulate the oil in the cylinder walls. The 600cc motors use the same oil galleries as the 750s, but do not come with the oil cooler...)

Re: Massachusetts gas fires: Another technological tragedy

#113
post #80

Earlier quoted context omitted.

Supposedly, old lines like these are low pressure lines to the house. Thus nobody has a pressure regulator in their home. It seems crazy today but these lines are antique, from the days when electrical wire was run by knob-and-tube.

Residential gas piping hasn't changed much over the years. Threaded steel pipe from 1910 should be able to hold a couple orders of magnitude more pressure than it should ever see. The real determining factor is not age but whether the installer was lazy and hand tightened it all (which you can get away with at 1/2psi, but not much more).

If there's no pressure regulator (due to systems being designed that way a hundred years ago), and the pressure spikes, it doesn't matter how the pipes were put together- your pilot lights become blowtorches.

Re: Massachusetts gas fires: Another technological tragedy

#114

  Next year we may see the first models without a 
  steering wheel or a brake pedal—there goes the 
  option of asking the driver (passenger?) to take 
  over.
This is bad news for everyone. This is the network effect exploitatively writ large, such that, surely you can prevent yourself from being inside such a thing, but as a lone individual, without laws in place to ban such a thing, you, your children, your family, your friends are all endangered by a blameless force that everyone can simply shrug at, and point to statistics claiming that there is even just an incremental improvement over ordinary human performance.

You can stop yourself from posting selfies on social media, under your real name. You cannot stop other people from taking pictures, which your acquaintances discover and tag with your real name.

This is kind of horrific. At least as horrific, or moreso than, current traffic statistics, because the moral hazard in play is abysmally worse.

There was an effective arms race that took shape with SUVs and road rage in the late 1990's. I think something similar will take shape, as self driving cars ramp up. It may surprise some, to find that a self driving incident won't be accepted as blameless, glitchy software errors. Owners may see themselves villified directly, for things a car they chose to own, had subsequently carried out.

I think there are three turns of consequence to a botched self driving car deployment.

One: some will choose harm the legal owner as an individual, lawfully or lawlessly.

Two: others will harm dealerships, mostly through sabotage.

Three: overt action against the manufacturers. At all levels, and not limited to ordinary civil disobedience.

These consequences are nothing to be sniffed at. Aviation shows us that spotty disasters don't result in civil unrest, but with a human in the loop survival was incentivized. Automotive deployments like this will be a fire and forget scenario, and the corporations loosing the reigns, have a demostrable history of neglect. I wonder if they anticipate, in the rush to market, just how severely the general public might react to finding their roads on the receiving end of software glitches that kill their firends and relatives like deer?

Re: Massachusetts gas fires: Another technological tragedy

#115

"All of these events feel like unnecessary disasters—if we were just a little smarter, we could have avoided them—but the fires in Lawrence are particularly tormenting in this respect. With an aircraft 35,000 feet over the ocean, you can’t simply press Pause when things don’t go right. Likewise a nuclear reactor has no safe-harbor state; even after you shut down the fission chain reaction, the core of the reactor gen…

Other kinds of consequences like cost of mitigation, value of lost property (and lost value of property what wasn't destroyed by itself - you can easily see thousands of homes near, but not in evacuation zone deprecating severely), costs of health checks for hundreds of thousands of people etc. - are worse in nuclear accidents.

Fans of the nuclear industry doesn't like to columnize the costs of 'externalities'.

For one, they rarely mention the amount of US government subsidies ($hundreds of billions) poured into getting the early plants up and running. For another, the unwillingness of insurers to take an interest in those operations.

When Rocky Flats spilled a little Pu dust into the Denver suburbs, they just raised the 'safe' exposure by a factor of 10. Easy peasy.

Re: Massachusetts gas fires: Another technological tragedy

#116

Earlier quoted context omitted.

Not sure why you were downvoted. You're entirely right. Oil is incredibly destructive for the environment and society, yet it's accepted because that's just how things are.

Our entire civilization runs on energy, mostly from coal and oil. Until recently it was not feasible to use alternatives. Change takes time.

"Recently" was — conservatively — thirty or forty years ago.

Re: Massachusetts gas fires: Another technological tragedy

#117
post #105

Earlier quoted context omitted.

Donald Norman's Design of Everyday Things helped cure my technophilia, maybe even turning me into a humanist. http://a.co/d/dSsOfxJ Aha, looks like there's a new version (dated 2013).

Ah, referal link. How sneaky.

Crap. Unintentional. I just cut & paste. I'll be more careful in the future. Thanks for the heads up.

Re: Massachusetts gas fires: Another technological tragedy

#118
post #85

"All of these events feel like unnecessary disasters—if we were just a little smarter, we could have avoided them—but the fires in Lawrence are particularly tormenting in this respect. With an aircraft 35,000 feet over the ocean, you can’t simply press Pause when things don’t go right. Likewise a nuclear reactor has no safe-harbor state; even after you shut down the fission chain reaction, the core of the reactor gen…

Airplanes coast down fine after a (double) engine failure, but they don't coast nicely when your primary instruments aren't working. The Air France flight didn't just loose airspeed indication, they got invalid readings and all associated warnings. Unfortunately that is the common failure mode for flight instruments, they don't just show nothing, they show wrong values. Fortunately pilots are trained to know how inst…

What I remember reading of the Air France flight was that both people flying understood perfectly well the situation, and had plenty of time to get out of it, but one panicked and tried to pull up even though that was exactly the wrong thing to do. The other problem was that no one else realised that one of them was trying to pull up and the plane averaged the actions of the two sticks (pull up and dive) causing effectively zero net action. (Other planes feedback each stick's action to the other so the other person would soon have realised what was going on.) They had so long to fix the problem that the captain (who had been sleeping) had time to wake up and enter the cockpit, and he finally managed to coax out the information that one of the copilots was trying to pull up, and for them to stop. By that point they were only seconds from the water and it actually was too late.

Re: Massachusetts gas fires: Another technological tragedy

#119

Earlier quoted context omitted.

Well...that's a very unfortunate example. Pressure cookers' blowout disks can get clogged by whatever you're cooking (beans specifically) and the whole lid blows out (embedding itself in the ceiling and painting the kitchen). Scary stuff.

I have a Presto pressure cooker. The blowout disk is a piece of rubber/plastic built into the cap. I have a hard time imagining it getting contaminated in a way that surpasses the strength of the stainless steel lips on the lid/pot. Its design hasn't changed since 1977. It's not a tube that a bean could get into. Maybe you're thinking of the vent pipe? When that gets clogged, the overpressure plug is what blows away…

Well...I have seen the whole lid, firmly embedded in the ceiling. IDK what the brand was, but apparently the failsafe (a rubbery thing, off-center of the lid) failed to fail-safe in that case.

Looking into RAPEX, I see multiple recalls for this specific issue (pressure buildup leading to uncontrolled blowout); all for brand names that are unfamiliar to me.

Re: Massachusetts gas fires: Another technological tragedy

#120

Earlier quoted context omitted.

Compared to heating oil, which is the other viable option in the Northeast US, natural gas is cheaper, generally more efficient, and largely idiot-proof. With heating oil, a big, very common problem is people not scheduling deliveries appropriately, so the tank runs dry, and sucks up sludge that has settled to the bottom, and then you have to do expensive maintenance to clean the system, bleed the lines, etc. Worse,…

I'd love to use electric heat. Too bad electricity costs in my state are stupidly high. It's just beyond insane to heat with electricity here. If my state could do away with the ineptitude, graft and taste for purchasing energy based on political optics that cause those high prices I'd consider electric heat but there's still the always-on issue that would give me pause. Gas infrastructure is much more "always" than…

In my state electricity is relatively cheap (~$0.10 per kWh) but gas is more like $0.01 per kWh equivalent energy yield. Given that the US (with fracking) is basically the Saudi Arabia of gas, it makes sense to bet on gas for the long run. Even with very efficient air source heat pumps (~300% efficiency) it still makes sense to go with gas heat, especially in a place that has many heating degree days.
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