Why couldn't this innovation stop most highrise fires?

[Roland Deschain]

I had to watch a training film last week called Fire In the City (I think it was from The Learning Channel). Two of the blaizes featured involved highrises with loss of life (one was the MGM in Vegas, and the Other was a highrise in Philadelphia in the early 1990's). Basically, the film concluded that it was difficult or impossible to stop fires that started over around 200feet (or the highest that ladders can reach). They even covered several innovations being researched in Japan such as lateral access from adjacent buildings and even a fire helocopter.

Here's one possible "failsafe" idea that should stop most fires in their tracks that could be integrated into building designs. How about having huge water storage tanks on the roof of the buildings (think of an Olympic size pool that is twenty feet deep). These would be connected to an intricate network of "plumbing" that could dump water into virtually every room in the building if "the plug" were manually or electronically pulled. Furthermore, the "level" at which water would start pouring could be specified (thus if the fire was on the 15th floor, you could start flooding at the 17th floor, but spare above that level) with gravity doing most of the work. Obviously, this would cause a great deal of damage so it would be reserved for so called "infernos" or those that were quickly heading in that direction. I think that something like this might even have spared the WTC towers from collasping (although maybe not).

[Can Handle the Truth]

Ever hear of fire sprinklers?

[wolfstu]

Don't a lot of skyskrapers already have sprinkler systems?

[Uvula Donor]

You watched The Towering Inferno on AMC last week, didn't you?

[jayjay]

And not all fires are able to be extinguished with water.

[Garfield226]

I would guess that the amount of water involved would result in a prohibitive amount of weight.

A 3x3x3 meter cube would hold just over 7,000 gallons, but weigh nearly 30 tons.

Even just a 1 cubic meter tank would weigh over one ton (but hold only almost 265 gallons).

[Roland Deschain]

A couple of points:
1. The difference between this idea and sprinklers is the difference between a swimming pool and a lake.

2. This would be in addition to no in place of sprinklers.

3. Don't many highrise buildings already support swimming pools on top?

4. Actually, what gave me the idea was an article that I read in Popular Science about "fail safe" fission reactors several years ago. One idea involved building the reactor underneath a pond which could be released onto of the reactor in a meltdown situation.

[Smeghead]

Originally Posted by Roland Deschain

A couple of points:
3. Don't many highrise buildings already support swimming pools on top?

There's a huge difference between enough water for a swimming pool and enough water to fill the entire building. Or even a few floors of a building.

[picunurse]

Originally Posted by Roland Deschain

A couple of points:
1. The difference between this idea and sprinklers is the difference between a swimming pool and a lake.

2. This would be in addition to no in place of sprinklers.

3. Don't many highrise buildings already support swimming pools on top?

4. Actually, what gave me the idea was an article that I read in Popular Science about "fail safe" fission reactors several years ago. One idea involved building the reactor underneath a pond which could be released onto of the reactor in a meltdown situation.

The weight would be prohibitive in a pre-existing structure. Water is heavy.

[Roland Deschain]

Well we would really need someone knowledgable in structural engineering and architecture to carry the discussion much further. However, consider the following:

1. Currently there really are not any good options in fighting high rise fires. So even an idea which is difficult and expensive might be worth considering (providing it would be effective in most scenarios).

2. I'm not sure how much water we would need. I think that as little as ten to twenty tons or even less might do the trick since we don't need to flood every floor (just those on fire and those at risk of flashover ignition). In addition, a few inches of water on the affected floors would probably be sufficient.

3. How much weight can the average, modern highrise stand anyway? Those swimming pools that you see on the top of buildings cannot be light (how many tons is your average highrise pool)?

4. Perhaps the "pools" could be shared between several or even many buildings that were somewhat close together with elevated "tubes" connecting them. We might even consider constructing one super strong high rise near the center of a city (and higher than the surrounding buildings) which would serve as the "hub" for the water distribution. Of course it would still function as commercial space in its own right (but would be built to substanially higher and therefore more expensive standards to stand the additional weight). In this way the smaller buildings would not have to bare the load of the water (and after all one "pool" would be sufficient in almost all cases since these fires are extremely rare).

[danceswithcats]

One Meridian Plaza, in which three PFD firefighters perished was a combination of numerous factors. Without getting into overwhelming detail, the point of origin was on a floor being renovated, so smoke detector coverage was not adherent to code, there was a significant delay in retransmission of the alarm to PFD allowing fire to spread, the pressure reducing valves installed on the standpipe system were incorrectly set and precluded development of adequate fire streams, the electrical system of the building and backup generator failed owing to improper protection, absence of fire dampers in ventilation shafts permitted smoke and fire spread both vertically and horizontally. Although listed as fire resistive construction, once windows on the facade failed, there was exterior fire extension. Despite all of that, when fire finally reached a sprinklered floor, the sprinklers extinguished the blaze.

The MGM Grand was an unsprinklered occupancy. Fire marshals insisted on sprinklers, but MGM balked at the additional cost, and a County building official sided with the resort. 85 people died in that incident, and computer modeling has indicated that the fire which began with electrical equipment would have been controlled by a sprinkler system.

Sprinkler systems only fail to control/extinguish fires when they are ill-maintained, water supplies fail, intentionally compromised, or the occupancy is modified/changes in a way that renders them ineffective. Example would be an occupancy sprinklered for warehouse operations which is then used as a boat repair and storage facility. The head spacing for warehousing would not be effective for the higher hazard occupancy with greater volume of flammables with higher burn intensity.

There is one exception, and that is when a massive volume of fire fuses a large number of heads and water pressure cannot be maintained, or where an explosion damages the water distribution system, shutting down sprinkler flow. Examples would be the World Trade Center twin towers, and the K-Mart distribution center in Falls Township, PA.

[Roland Deschain]

So would a "gravity" dependent system such as the one described above have likely been effective in the case of the WTC? All in all it sounds like you are saying that a good sprinkler system is almost always the way to go. If that is the case maybe there's not a problem with stopping high rise fires after all.

[Duckster]

Originally Posted by Roland Deschain

4. Actually, what gave me the idea was an article that I read in Popular Science about "fail safe" fission reactors several years ago. One idea involved building the reactor underneath a pond which could be released onto of the reactor in a meltdown situation.

But it still would not stop the chain reaction. Instead, the water would boil over, turn to steam and possibly spread radioactivity over a large area. Then there is the contamination of the groundwater, yadda, yadda.

[Valgard]

Originally Posted by Roland Deschain

Well we would really need someone knowledgable in structural engineering and architecture to carry the discussion much further. However, consider the following:

1. Currently there really are not any good options in fighting high rise fires. So even an idea which is difficult and expensive might be worth considering (providing it would be effective in most scenarios).

2. I'm not sure how much water we would need. I think that as little as ten to twenty tons or even less might do the trick since we don't need to flood every floor (just those on fire and those at risk of flashover ignition). In addition, a few inches of water on the affected floors would probably be sufficient.

3. How much weight can the average, modern highrise stand anyway? Those swimming pools that you see on the top of buildings cannot be light (how many tons is your average highrise pool)?

4. Perhaps the "pools" could be shared between several or even many buildings that were somewhat close together with elevated "tubes" connecting them. We might even consider constructing one super strong high rise near the center of a city (and higher than the surrounding buildings) which would serve as the "hub" for the water distribution. Of course it would still function as commercial space in its own right (but would be built to substanially higher and therefore more expensive standards to stand the additional weight). In this way the smaller buildings would not have to bare the load of the water (and after all one "pool" would be sufficient in almost all cases since these fires are extremely rare).

I have my MS in structural engineering but I'm not practicing. That being said...

1. Is this really true? Building codes for high-rise structures certainly include fire resistance, sprinklers, etc. Floors can be sealed off and pressurized so that fire and gasses have a harder time spreading. If you have a raging inferno a few hundred feet up it's hard to get to (though there are specialized high-rise ladders and water pumps that can reach astonishing heights) but there are standpipes all the way to the top so the FD can plug their hoses in onsite.

2. I found one cite that says that the MINIMUM flow rate of sprinklers must dump 0.05 gallons per minute per square foot. I've seen those things go off and it's a frickin' downpour. At that minimum rate it'd only take ten minutes to have an inch of water on the floor which is probably faster than the local FD can get there anyhow. And remember that you don't have to turn the whole floor into an aquarium, you just have to douse the area that's on fire.

3. No hard and fast rule, there's an awful lot that goes into those calculations but "A Whole Lot". The problem isn't really that a big tank of water is going to break all the columns but that you'll overload a specific area and your 20 ton tank comes through the ceiling. Live and dead loads for floors are generally measured in tens of psf with safety factors tacked on, so let's say up to 200 pounds per square foot for an area with high dead loads, high live loads and high safety factors. Consider that a tank of water 3 feet deep exerts about 200psf right there and you can start to see the design concern. Water is really heavy stuff. I'd also be a little concerned about sloshing at the top of a building (where the swaying is greatest from wind and earthquake loads). 20 tons of water that starts moving might not stop easily.

4. Dunno that that'd work - you'd have to get cooperation from all the property owners and those buildings would have to be pretty darn close to make it feasible.

Not trying to be a wet blanket (my first project in college was to design an escape system for highrise buildings in the event of a fire!), I just think that strong firecodes will help more. Keeping the amount of fuel to a minimum (fire resistant furniture and so on), proper smoke alarms and sprinkler systems, fire resistant building materils (concrete, or steel with right coatings) will all make a huge difference. If you're talking about an extreme event such as 9-11 then all bets are off. You design the building so that as many people as possible will get out alive but you assume that the building will probably be a massive loss afterwards.

[Valgard]

Originally Posted by Duckster

But it still would not stop the chain reaction. Instead, the water would boil over, turn to steam and possibly spread radioactivity over a large area. Then there is the contamination of the groundwater, yadda, yadda.

I seem to recall reading that at Chernyobl when the emergency crews sprayed water that some spots were so intensely hot that H2O dissociated and became H2 and O2 with predictable results.

[Roland Deschain]

Originally Posted by Valgard

I seem to recall reading that at Chernyobl when the emergency crews sprayed water that some spots were so intensely hot that H2O dissociated and became H2 and O2 with predictable results.

Not that I know squat about nuclear reactors, but I think that the idea is to have the pond water kick in long before the reactor "melts". It's my understanding that the real danger of a reactor going critical is some sort of interruption in the water cooling process. By having a water supply that only requires gravity to be activated (as a fail safe) the idea is that you reduce the chances that such a interruption can occur.

[mks57]

Originally Posted by Roland Deschain

Not that I know squat about nuclear reactors, but I think that the idea is to have the pond water kick in long before the reactor "melts". It's my understanding that the real danger of a reactor going critical is some sort of interruption in the water cooling process. By having a water supply that only requires gravity to be activated (as a fail safe) the idea is that you reduce the chances that such a interruption can occur.

The problem is that you probably need pressurized water to cool the reactor. Ordinary water would just flash to steam. In some reactor designs, steam bubbles result in an increase in reactor power (positive void coefficient). Steam is also a poor conductor of heat. You want the fuel rod assemblies to be immersed in water, not steam.

[Mangetout]

I was watching a documentary the other day about some old filmstock that was discovered. Old nitrate film is very flammable and apparently, the National Film Archive stores it in a network of small, insulated, climate-controlled bunkers. Each bunker has a glass roof above which is a large water tank, the idea being that if a fire occurs in one bunker and it cannot be extinguished conventionally, the heat will break the glass ceiling and fill the bunker entirely with water, preventing the fire spreading to adjacent bunkers.

[danceswithcats]

Originally Posted by Roland Deschain

So would a "gravity" dependent system such as the one described above have likely been effective in the case of the WTC? All in all it sounds like you are saying that a good sprinkler system is almost always the way to go. If that is the case maybe there's not a problem with stopping high rise fires after all.

Personally, I would say no because:

The physical impact of the plane destroyed or severely impaired the fixed protection systems.

WTC was a 'protected steel' construction class, but engineers hadn't imagined impact forces and blast wave physically removing the sprayed protection. The comments you may have heard regarding the building being built to withstand impact of an airplane were true from a physical standpoint, and both towers remained standing after being impacted upon. The massive volume of Jet-A was not part of the calculation.

The effect of fire on ordinary unprotected steel construction is straightforward regarding structural failure. Although I wanted to have optomistic thoughts on the morning of 9/11, the little voice inside said it's not a matter of 'if', it's a matter of 'when'.

Some of the other problems with the gravity concept in addition to static loading of the structure are:

Provision for freeze protection in heating climates
Another structure to be maintained
HVAC lives there, antennae, signage all adorn building tops. It's really a crowded spot to think about putting something else.

Excepting the conditions expressed in my previous post, I don't recall a high-rise fire of any consequence in a fully sprinklered occupancy.

[danceswithcats]

Originally Posted by Mangetout

I was watching a documentary the other day about some old filmstock that was discovered. Old nitrate film is very flammable and apparently, the National Film Archive stores it in a network of small, insulated, climate-controlled bunkers. Each bunker has a glass roof above which is a large water tank, the idea being that if a fire occurs in one bunker and it cannot be extinguished conventionally, the heat will break the glass ceiling and fill the bunker entirely with water, preventing the fire spreading to adjacent bunkers.

Interesting. I'd think that they would want to protect that valuable material with FM-200 or one of the other 'clean agent' suppressants.

[scm1001]

Originally Posted by Valgard

Not trying to be a wet blanket

please do - it would be very useful if there was a fire

[Mangetout]

Originally Posted by danceswithcats

Interesting. I'd think that they would want to protect that valuable material with FM-200 or one of the other 'clean agent' suppressants.

It may be the case that this is part of their primary fire suppression plan; I think the glass roof thing is a last-resort measure to prevent an otherwise out-of-control fire (where the contents of the burning bunker are written off as lost, I suppose) from spreading to adjacent bunkers.

[jester21]

on an alternative way on how to escape a high rise fire. We (should) all know that during a fire, you never use the elevators. In a 200 story high rise, that's a WHOLE lot of stairs. I've read (here and elsewhere) that many handicapped people were as a result, unable to escape the WTC. So I had the idea, that they should intergrate a slide system into the stairwells....

This way, even handicappers could jest slide down to each landing. This would save a TON of time and energy. (Sometimes gravity can be our friend)

Since this would be of no benefit for firefighters... perhaps they could put landing docks in the buildings... say at the top and near the middle, so that Firefighters could be dropped off by helicopter (or Osprey if they can ever get the damn thing to work!) ... saving them Thousands of steps and thereby many minutes in time. Not to mention the energy they'll save for fighting the actual fire.

Jest some ideas that no one of importance will ever likely read

[Uvula Donor]

Originally Posted by jester21

on an alternative way on how to escape a high rise fire. We (should) all know that during a fire, you never use the elevators. In a 200 story high rise, that's a WHOLE lot of stairs. I've read (here and elsewhere) that many handicapped people were as a result, unable to escape the WTC. So I had the idea, that they should intergrate a slide system into the stairwells....

This way, even handicappers could jest slide down to each landing. This would save a TON of time and energy. (Sometimes gravity can be our friend)

And when the stairwells are filled with flames on the lower floors and you're sliding down the chute without any landings or ways to stop, what then?

[jester21]

Originally Posted by jester21

This way, even handicappers could jest slide down to each landing. This would save a TON of time and energy. (Sometimes gravity can be our friend)

read, from the very portion you quoted: This way, even handticappers could jest slide down to each landing.

If access to lower floors, via the stairwells, is blocked, and you can't use the elevators... well I guess yer jest screwed then ANYWAY huh?

[Zsofia]

Originally Posted by Mangetout

It may be the case that this is part of their primary fire suppression plan; I think the glass roof thing is a last-resort measure to prevent an otherwise out-of-control fire (where the contents of the burning bunker are written off as lost, I suppose) from spreading to adjacent bunkers.

Here at the University, they have a valuable news film archive, most of which is on nitrate stock. They keep it in old munitions dumps at Fort Jackson. (Recall that it gets hot enough here in the summers to set off aging nitrate, no problem.) No fires yet, although of course they take reasonable precautions in the form of molecular sieves, proper storage cans, etc. Unfortuantely, there isn't any money for reformatting.

[aahala]

(I like those Guinnes Stout commercials)

Use water to put out highrise fires. BRILLIANT

Store the water in a pool on the roof. BRILLIANT

[TheBoneyKingofNowhere]

Why can't enormous volumes of fire-extinguisher "solution" be stored and released ala a sprinkler system? 'Cause it's pressurized? Expensive?

[danceswithcats]

Originally Posted by TheBoneyKingofNowhere

Why can't enormous volumes of fire-extinguisher "solution" be stored and released ala a sprinkler system? 'Cause it's pressurized? Expensive?

This is done in specialized occupancies. Kitchen hoods/fryers and the like use a chemical suppression system.

A 3M plant in my first response district that mixed adhesives for tapes had a CO2 deluge system tied to optical flame sensors. When flame was detected, a klaxon sounded, and workers had about 30 seconds to bail out before the system dumped CO2 into the mixing wing.

Computer and other 'clean rooms' used Halon, but much of that has been withdrawn from the market owing to it's tendency to cause ozone depletion, Montreal Protocol, etc. FE-200 is one of the more environmentally friendly replacements. Yes, all of these systems are pressurized, and are more expensive than water, but do the job without ruining equipment that may be even more expensive.

Comments to jester21: We do use elevators, when safe to do so, but by using the fireman's control key we override normal operations. Starting at the top and going down has a problem or two. By the time you get a helo up and on location, I have 3 engines, 1 squad, and 1 ladder on location. In an urban setting, the only place one can usually land a helo is the rooftop, so how do you get the personnel, tools, handlines, scba, radios, etc. aboard the helo?

Comments to Uvula Donor: Typically the stair towers are a very safe place, provided that people don't compromise built in protection by propping doors open, the air handling system functions as designed, and proper housekeeping practices are followed. That's the reason why the standpipe connections and critical circuit raceways are usually located there.

[Padeye]

Originally Posted by danceswithcats

Interesting. I'd think that they would want to protect that valuable material with FM-200 or one of the other 'clean agent' suppressants.

AFAIK Nitrogen compounds like film stock are self oxidizing so smothering agents probably won't help.

[danceswithcats]

Originally Posted by Padeye

AFAIK Nitrogen compounds like film stock are self oxidizing so smothering agents probably won't help.

Hadn't considered that angle Padeye, but a little research confirms you to be dead on. Ignition can take place at moderately low temperatures (improperly stored goods may auto-ignite), and does produce nitrogen peroxide along with large quantities of CO. Storage recommendations for large quantities include vented cabinets and coverage by a sprinklered suppression system, although a National Park Service document mentions CO2 with the caveat extinguishment may not be possible. In these cases, a sprinkler system would serve only to extend evacuation time.

Thanks.

[SCSimmons]

Originally Posted by Roland Deschain

Not that I know squat about nuclear reactors, but I think that the idea is to have the pond water kick in long before the reactor "melts". It's my understanding that the real danger of a reactor going critical is some sort of interruption in the water cooling process. By having a water supply that only requires gravity to be activated (as a fail safe) the idea is that you reduce the chances that such a interruption can occur.

The concern with a nuclear reactor is preventing 'meltdown', where the cladding on the fuel rods melts & radioactive decay products are released into the system. Water alone isn't going to prevent this-it may slow it down by absorbing some of the heat, but a nuclear reactor produces a lot of heat if its running uncontrolled. If the water isn't constantly circulating to carry that heat away, the cladding will melt eventually anyway. 99% of nuclear reactors are water (or steam) cooled; there's already water in there, failure of the process just means that the water isn't circulating to the heat exchangers. Dumping extra water on/in it when the circulation process fails doesn't fix your problem-at best it buys some time.

What you need to 'smother' a fission reactor is something with a high cross-section for neutron capture, which will dampen out the chain reaction by absorbing the free neutrons from the current fissions before they cause other fissions. Cadmium is a popular choice ...

Originally Posted by valgard

I seem to recall reading that at Chernyobl when the emergency crews sprayed water that some spots were so intensely hot that H2O dissociated and became H2 and O2 with predictable results.

I don't remember hearing this particularly, but that's basically what happened in the core. The Chernyobl reactor was moderated with a graphite lattice; with the coolant circulation cut off & the cadmium control rods retracted, the reaction produced enough heat in the water coolant trapped in that lattice to dissociate it, ultimately resulting in the chemical explosion that compromised the containment ...

[dqa]

What are the issues, and how do they address them, in retrofitting older buildings with sprinklers?

I understand there is often a problem with the capacity of the original plumbing which makes retrofitting difficult, as with the Cook County Administration Building fire.

[Hakuna Matata]

I am an Architect and I do design Hirise buildings. Frankly they are very safe buildings and the codes specifically have items in place that help fight fires--I would go even so far as to say they are safer than most structures since much focus has been put on the issues involved in them.

The main problem I would see in putting water on top of a building and using it to fight a fire is that a building is made up of thousands and thousands of rooms and walls, and other obstructions. So if all that water was dumped--where would it go--would it naturally find its way to 'where' the fire was? Think of that old Chinese pinball game, I think it is called Pachinko (sp)--where you drop a ball at the top and it drops down these series of obstructions. It never goes where you want it to go. I would think water would do the same thing.

Water is going to find the path of least resistance--and guess where that is? The stair and elevator shafts--and stairs are the means that we use to exit people out of the building. All that water would do is drown those people. In addition these shafts are usually 2-4 hour rated and thus all this water would be behind a wall that in theory is safe for 2 hours and never touch the fire!

I trust sprinklers--they work fine if maintained properly.

Frankly as an Architect--water is my biggest enemy. Trust me on this one--water is an evil bitch! And it never goes where I think it is going to go--but usually I am fighting to keep it out of the building. Water can do an amazing amount of damage.

[Roland Deschain]

Well, it sounds like sprinkers are the way to go, but this is what I was envisioning. An elaborate "honeycomb" of pipes in the ceilings that would direct the water to virtually every room. These would run from "main lines" that could be shut off ABOVE (and maybe below) the areas that were on fire. Thus, if the fire if the out of control fire is on the 20th floor the system would let the water fall to the 22nd floor or so before being diverted to the "honeycomb" system for that floor, and below.

However, it sounds like you guys are saying that other than a WTC type disaster that sprinkers will stop almost any fire. If so clearly they are the route to go.

QUOTE=Hakuna Matata]I am an Architect and I do design Hirise buildings. Frankly they are very safe buildings and the codes specifically have items in place that help fight fires--I would go even so far as to say they are safer than most structures since much focus has been put on the issues involved in them.

The main problem I would see in putting water on top of a building and using it to fight a fire is that a building is made up of thousands and thousands of rooms and walls, and other obstructions. So if all that water was dumped--where would it go--would it naturally find its way to 'where' the fire was? Think of that old Chinese pinball game, I think it is called Pachinko (sp)--where you drop a ball at the top and it drops down these series of obstructions. It never goes where you want it to go. I would think water would do the same thing.

Water is going to find the path of least resistance--and guess where that is? The stair and elevator shafts--and stairs are the means that we use to exit people out of the building. All that water would do is drown those people. In addition these shafts are usually 2-4 hour rated and thus all this water would be behind a wall that in theory is safe for 2 hours and never touch the fire!

I trust sprinklers--they work fine if maintained properly.

Frankly as an Architect--water is my biggest enemy. Trust me on this one--water is an evil bitch! And it never goes where I think it is going to go--but usually I am fighting to keep it out of the building. Water can do an amazing amount of damage.[/quote]

[Ludovic]

I would think that 1 gallon dumped over 1 minute onto a square foot of fire would do better than 1 gallon dumped over 10 minutes. After all, firefighters aim at the base of the fire rather than an arc so that as little water as possible will be lost to vaporization.

If you dump all the water at once onto the fire, would it not be true that less of it would be lost to vaporization?

[danceswithcats]

Originally Posted by Ludovic

I would think that 1 gallon dumped over 1 minute onto a square foot of fire would do better than 1 gallon dumped over 10 minutes. After all, firefighters aim at the base of the fire rather than an arc so that as little water as possible will be lost to vaporization.

If you dump all the water at once onto the fire, would it not be true that less of it would be lost to vaporization?

Let's look at your query from the reverse, shall we? Which is easier to ignite, a 2x4 just as you get it from the lumber yard, or that same 2x4 after it's been run through a planer and reduced to shavings and dust?

That latter is much easier to ignite, because the finely divided fuel is able to readily absorb heat to the point that combustion is achieved.

Water (in addition to being cheap) is also dandy for fire suppression owing to it's ability to absorb heat. The expansion ratio is 1:1700 when converted from a liquid state to steam.

When I crawl the hall to a bedroom fire, those two factors work effectively for me. Assuming the truckies have taken out a window, as soon as I open the nozzle, fog position is choice #1. Aimed at the ceiling where things are hottest, the stream is swirled for a moment, and all of those droplets of water absorb heat and expand, taking a goodly volume of heat and fire gases out the window. The fog pattern also draws air from behind me, owing to Bernoulli effect. Also, when attack is done this way, the total volume of water is reduced, along with collateral damage. After things are knocked down, then straight stream application to the seat of the fire is performed. Even when operating a master stream from an aerial, I aim for the ceiling of a room, attempting to bounce off that plane and break up the stream.

Regarding your query dqa: The biggest challenge in a retrofit is not tearing the building apart to install the piping. For historic structures the architectural importance is high and those projects are costly. For less sensitive occupancies, the piping is simply installed below the ceiling and painted to match decor. That's what was done in some of the dormitories at the National Fire Academy, because the idea was life safety first, appearance second.

The Europeans are ahead of us on residential sprinkling using cross linked polyethylene or PEX to construct a combined potable water/sprinkler system. The flexible piping can be snaked through and around obstructions with a minimum of fittings, and because of the grid appraoch has the added benefit of being almost silent when water flows for domestic use. The US has been slow to embrace the concept, and has been opposed by trade unions, presumably because it is very easy to install, compared to traditional metallic distribution systems. The effectiveness is proven-over 50 years in Europe, and extensive fire testing in Canada-PEX based systems are a solid product.

[jester21]

Originally Posted by danceswithcats

The Europeans are ahead of us on residential sprinkling using cross linked polyethylene or PEX to construct a combined potable water/sprinkler system. The flexible piping can be snaked through and around obstructions with a minimum of fittings, and because of the grid appraoch has the added benefit of being almost silent when water flows for domestic use. The US has been slow to embrace the concept, and has been opposed by trade unions, presumably because it is very easy to install, compared to traditional metallic distribution systems. The effectiveness is proven-over 50 years in Europe, and extensive fire testing in Canada-PEX based systems are a solid product.

Of course. The Unions would rather have people die than risk losing high paying Union jobs