Bad Youtube info: medieval weaponry.

[M.J.Lampert]

8 minutes ago, Frosty said:

The internet is like any tool. The more effective it is, the more dangerous it is.

this is like the advancement of bombs the first where black powder some metal scraps in bamboo or paper this has now evolved into the highly effective and lethal hydrogen bombs that create many millions the destruction of the first ones. but this is efficient in what it does the first ones where meant to injure or sare the enemy

an atom bomb is meant to wipe out large industrial areas quickly these both do the job they where meant for 

back to Thomas' original post this is like when people say the German tiger was a bad tank, it was used in the wrong spot it was meant as a heavy breakthrough tank not as a steady fighter. when Germany bite to much off of the USSR they through every thing in even if they weren't designed for this. the tigers took a long down time  to repair this was good for attacking as they pushed through the hardest units and the rest of the army came behind to relive them establish a perimeter and finish sweeping out the enemy but when they had no tine to repair of course they had problems do you run a truck without changing oil or a motor if you know a gear is missing a few teeth you wont run it same thing they knew things where braking but didn't try to fix it as there was no time so then of course they broke down and people started to call them unreliable this is not the case the problem was a change in agenda they where made to attack not to defend thus when they where force to do a job they weren't meant for things went bad, like if you need to cut some metal but all you got is a wood saw it ight work but is gonna break something same with the tiger

sorry for the rant but I can get pretty fired up sometimes when its a thing that i care about especially when people miss inform  others on those things.

M.J.Lampert

[Frosty]

MJ: When a subject or opinion touches something you get excited about you might want to step back before responding. 

In your reply you seem to confuse "Explosives" with "Bombs," one is a general material the other is a specific use of that material. Explosives are used for many useful things from: mining, construction and demolition to mention a scant few. Bombs on the other hand have always been weapons.

The atomic bomb was an outgrowth of the reactor and very much harder to make work, the transition from a semi critical to a critical fission reaction is so quick heat expansion pushes the fissionables far enough apart to prevent a critical reaction.

This bit of physics is what makes a pebble bed reactor virtually impossible to MAKE melt down. 

Hey, I stepped back to do a little research to get the details right and realized describing how hard it is and what goes into atomic bombs let along fusion bombs was a pedantic ramble you guys don't deserve. There is lots of info on the web if you're interested. "The Demo core" is a good read and is a good primer for implosion devices. 

The original (2 stage) H bomb was developed as a weapon and later 3&4 stage bombs more terrifying weapons.

Atomic explosives on the other hand were proposed for many construction projects, but they tended to spray secondary isotopes all over the planet so aren't used. An enlargement of the Panama Canal was one proposal as were "instant harbors" and underground oil storage tanks, etc. 

As it fits in this discussion I'd rephrase your statement to real something like. Explosives are useful tools but are extremely dangerous if misused. 

Bombs are ALWAYS dangerous, it's their reason to exist and only useful if they're used on the other guys. 

Frosty The Lucky.

[George N. M.]

There were several demonstration underground nuclear explosions in the late '60s and early '70s to see if natural gas could be liberated from "tight" formations by an underground nuclear explosion.  These include Project Gasbuggy (1967) in NM and Projects Rulison and Rio Blanco in CO (1969 and 1973).  These were part of Operation Plowshare which explored peaceful engineering uses of nuclear explosives.  The blasts did liberate natural gas but it had traces of radioactivity from the explosions and was not commercially usable.

"By hammer and hand all arts do stand."

[JHCC]

1 hour ago, Frosty said:

"The Demo core"

The “Demon Core”, I think you mean. 
 

 

[Frosty]

Yes, Demon Core, I dropped the N again. <sigh> I don't know if the N key on my laptop is getting sticky or my I'm just not hitting it right but I miss N more than most anything else. I've been touch typing for more than 50 years, I should have it down by now.

Frosty The Lucky.

[JHCC]

For some reason, the keyboard on my office computer keeps typing “tt” on a single stroke of the “t” key. 

[Frosty]

Yeah, we're just old fashioned John, we're supposed to buy a new computer every year or so aren't we?

Frosty The Lucky.

[JHCC]

I'm lucky; my job provides me with my laptop and phone.

[SinDoc]

I have a general use laptop for off the wall things, or if I just don't want to be tied down to a desk. Otherwise I have my desktop which I built 8 years ago and all I do is replace a part every few years to keep it current.

In regards to the explosions/bombs conversation, I was always fascinated by the Chernobyl incident (and the mini series is to date in my top 3 favorite shows). Something that was said to be unable to ever explode, exploded and left a massive area effectively uninhabitable and killed who knows how many thousands of people (due to radiation sickness). I had a debate with my wife while watching the series and she said she doesn't understand why we use nuclear power if disasters like that happen. I told her that compared to other sources of energy, nuclear does overall the least damage to the environment (that the plant is located, an argument could be made for obtaining the fuel) and is typically considered one of the safest forms of power generation.

I hope that I get to see fusion reactors become sustainable in my life time. It is amazing that we have been able to replicate the process that happens inside stars here on our own planet.

[JHCC]

Interesting to note that of the two explosions during the Chernobyl incident, only one of them may have been a nuclear explosion; the other — and possibly both —  being a steam explosion from the superheated cooling water. One tends to associate steam explosions with the Industrial Age, not the Nuclear.

[M.J.Lampert]

46 minutes ago, SinDoc said:

I hope that I get to see fusion reactors become sustainable in my life time. It is amazing that we have been able to replicate the process that happens inside stars here on our own planet.

i saw a reactor in Germany last time i was there(2 years or was it three) didnt have time to do the tour of the thing though so all i saw was the cooling chimneys belching steam

canada was( not sure if still is) is a leading country on peace time usage of nuclear energy with our CANDU reactors which are used often in europe

fison power one bathtub of water IIRC would provide enough power (in split hydrogen) to last an entire liftime for one person

20 minutes ago, JHCC said:

Interesting to note that of the two explosions during the Chernobyl incident, only one of them may have been a nuclear explosion; the other — and possibly both —  being a steam explosion from the superheated cooling water. One tends to associate steam explosions with the Industrial Age, not the Nuclear.

yes also the 2011 disaster in japan was a water caused breakdown

M.J.Lampert

[SinDoc]

Kind of funny to think with all our technology, we mainly come up with different ways to boil water to steam to spin things 

[JHCC]

On the other hand, the campus of the college where I work is currently all torn up to remove the old steam heating pipes to replace them with lower-temperature hot water and cold water pipes for heating and cooling the buildings. We’re switching over to a geothermal system of heat pumps that will use substantially less energy than the old natural gas boilers (and even less than the coal-fired one they had when I first got here), and with the new heavily insulated pipes, you don’t have to worry about the heat loss that was a major argument for keeping steam. 

There’s a lot to be said for molten salt and thorium reactors, too. 

[Latticino]

John,

In a way that is a shame.  Campus wide steam distribution systems seem to be going the way of the horse and buggy, but they were a pretty efficient way to distribute heat from a large central plant (no pumps required).  Of course the piping for such systems was more difficult to design, and the steel pipes themselves tend to break down a bit faster than relatively low temperature hot water (particularly the condensate return), but the steam cycle phase change is a great way to store and release energy.  I think a big reason why the campuses are switching over is that you don't need a licensed boiler plant operator for banks of smaller hot water boilers, and the new condensing ones are pretty darn efficient.

I've been personally involved with the design for replacement in kind for steam tunnel pipes at a local VA Hospital complex and am currently working on one for a local SUNY State College.  In both cases the steam system was in excess of 40 years old and still functioning well.  The latter pipes are showing their age, but in both cases most of the damage was a result of poor tunnel design rather than a fault in the piping.

Actually it is kind of common for steam piping to be replaced by medium temperature hot water distribution systems, where pressure is used to allow the fluid to remain liquid far above the normal flashpoint of 212 deg. F.  It isn't unknown to have medium temperature hot water distribution up to 350 deg. F (and High temperature distribution systems can exceed 400 deg. F).  Horribly dangerous stuff as a small leak can easily flash to steam with explosive levels of expansion.

Sorry to ramble on, I'll skip an analysis of why you might still need central hot and cold water distribution if switching in general over to geothermal heat pumps.

[SinDoc]

Slight tangent here, but speaking of heating a building, we re-did the lighting in the Delaware county courthouse a couple years ago and retrofitted all of their lighting to LED. The building had quite a bit of T12 fixtures along side T8 fluorescent fixtures that were retrofitted with LED strips and such and was a decent size project. Well this was all done in the middle summer, and you might be thinking, why is that important? Well, apparently the building was so tightly designed that the engineer/architect took into consideration the heat output of those old lamps. Since the change was done in the summer, no one noticed any differences other than the building was cheaper to cool. The problem came during winter when they realized the building would no longer stay warm due to the loss of heat from the old lamps and that the boiler system wasn't large/strong/efficient enough without them to keep the building properly heated. 

No one at the time would have even remotely considered what the loss of the heat from the lamps would do to the building during the winter.

[JHCC]

I don't know all the factors in the decision to go this particular route, but I do know that the steam system is pushing 80 years old.

Also, having to cut down a bunch of trees in advance of excavations gives the alumni something to complain about.

SinDoc, I believe that one of the unforeseen consequences of changing traffic lights to LEDs was that the cooler operating temperatures made it easier for snow and ice to accumulate on the lenses, making it harder for motorists to see what the signal was showing.

[Latticino]

2 minutes ago, SinDoc said:

Well, apparently the building was so tightly designed that the engineer/architect took into consideration the heat output of those old lamps

That is unconscionably bad design.  The accepted standard is to take into consideration the penalty for the heat from lighting for your cooling design, but not the addition for heating.  My guess is that the situation is a bit more complicated and there have been other system changes as well (i.e. building management system sequence problems, long term clogging of pipes in coils, dirty filters, increases in outdoor ventilation air proportion...).  Of course the older lights did contribute around 1 watt per square foot, and the LED significantly less, but still something doesn't add up to me.

[JHCC]

There's a persistent urban legend about the main library on our campus, that the architects didn't take into account the weight of the books when designing the foundations, and so the building is slowly sinking into the Ohio clay. I get both alumni and students who repeat this to me as something they KNOW to be true, and can go through some pretty amusing mental gymnastics when I remind them of the complete absence of cracking in the surrounding pavement and the fact that all the doors still line up perfectly.

[SinDoc]

That is entirely possible. It was all second hand info to me while taking to the local maintenance guys who came in frequently. They were talking how busy they had been installing space heaters for the office areas since they have been running cold and said that supposedly the building was built with them in mind.

Being in my line of work, I have a love/hate relationship with architects/engineers. Mostly hate at this point 

 

JHCC, maybe the entire structure is sinking at the same time, the same distance perfectly? 

[ThomasPowers]

I had some friends who built their own house to have in floor heating; instead of a boiler they just have a standard hot water heater, (actually an apartment sized one), that they use for the hot water. Cheap and easily replaced and easily sourced!

I spent many a happy hour steam tunneling on a number of College Campuses when I was in my 20's...

[Latticino]

Yes I used to "steam tunnel" with my buddies in undergrad as well.  Had no idea how potentially dangerous it was at the time.  Strange, it was a lot more fun to be spelunking down in those tunnels back in the day then it is now...

Hot water is hot water... Actually radiant floors typically use relatively cooler water than things like radiators and air handler coils, so an instantaneous domestic hot water heater is not a bad choice. 

[JHCC]

I should have said that the exterior doors still line up perfectly. 

Thomas, one of our buildings is a Frank Lloyd Wright house (a residence that was the home of the director of our art museum; she gifted it to the college when she died) with in-floor heating. Unfortunately, the contractor decided to save a few bucks by using iron pipe for the heating rather than the specified copper, so the whole thing rusted out. Here's a fun challenge: how do you replace an in-floor heating system in a historic house without destroying the original floor?

[Latticino]

Unless there is a basement, you don't.  Actually these days most hydronic radiant heating floors are piped in PEX (plastic tubing).

[SinDoc]

Black voodoo magic, but only after you have done a special dance, sang a special song and sacrificed a cicada to the ancient gods.

[ThomasPowers]

At one college there was a steam "pressure relief valve" that would open up on a regular schedule; but that schedule would change depending on use factors.  The "old hands" at that school would start counting seconds between releases as soon as you got close enough to hear them and suddenly break into a run when you hit a certain spot at a certain time in the schedule.  The "newbies" would be confused but follow along; speeding up when the BOOOOMPH occurred and hot steam would flood a section of the passageways.  Ah the joys of youth!