Revisting the Fire in Sprinklered Texas Warehouse with High Piled Storage disaster. 9

[SprinklerDesigner2]

Remember this thread from 2012 having having to do with the Grand Prairie, Texas warehouse fire?

Looking at a possible project where the building height is 45' and storage of aluminum cans to 40' and from what I have heard the storage matches exactly what was in the Grand Prairie warehouse including the slip plastic sheets separating layers of cans.

I remember Scott's presentation (no longer available) where he pointed out the slip plastic ("slip plastic" is a term used by the owner) liquefied into a combustible liquid something not pointed out in the Fire Engineering article.

So everyone knows the design criteria will be coming from the insurance company that is not FM. I wouldn't touch fixing the design criteria with a ten foot pole myself but I am curious as to what it might be given the commodity and heights.

I can't find anything that would fit in NFPA #13 2013 and I can't find it in any special head listings either but I haven't reviewed all of them yet.

Anyone have experience with this?

 

[LCREP]

Why not ESFR?

 

[SprinklerDesigner2]

LCREP, I am worried about the commodity classification is it Class IV or Group A plastic?

The Tyco heads I was looking at are good for Class I through IV to 48' but not non expanded plastic. Thinking about it the plastic sheets could weigh more than one would think.

 

[LCREP]

The sheets I have encountered are Grp A plastic nonexpanded. Is the product on racks or pallet storage?

 

[SprinklerDesigner2]

Solid pile that appears to be exactly what was encountered in the Texas fire.

I've seen the slips before but never gave it much thought until I ran across the article here.

 

[LCREP]

Yea they have a problem, max roof height is 40' for solid pile with ESFR and exposed nonexpanded.

 

[SprinklerDesigner2]

LCREP,

That is what I figured and even if the building height is limited to 30' they will have a problem with the water supply.

 

[LCREP]

This would be a good one to pass on...LOL

 

[SprinklerDesigner2]

This is a good customer and I would rather be the bearer of bad news now than after the building is built. One of those projects where you need to be smart enough to exercise a lot of caution.

 

[stookeyfpe]

You looking for this?

This fire is probably in litigation but I was able to obtain the details on this fire.

From your description it's uncartoned Exposed Group A plastic.

 

[stookeyfpe]

Let me try again.

 

[SprinklerDesigner2]

Stookey, I couldn't get either one to work.

 

[stookeyfpe]

It appears the original file was too large. I changed the layout of the Power Point slides. Hopefully this works.

 

[stookeyfpe]

Well that didn't work. Send an electronic message to afdhm at yahoo dot com and I'll e-mail it to you. Sorry for the complications.

 

[SprinklerDesigner2]

I have exactly the same situation as what was at the Texas warehouse and I have some photos and a video I wanted to share with you.

The slip sheet measures 44"x56" and is thinner than a dime.

So being curious and wanted to see how it would burn. Using our highly protected scientific burn lab I cut off a small sliver and lit it up.

Being plastic I fully expected to see it burn but what I saw amazed me. A little sliver maybe 1" wide by 5" long and this is what we got. In a million years I didn't expect to see this and I can only wonder what a full pallet pile 32' high would look like fully engulfed in flame.

Video of Slip Sheet

Building peak is 33' with storage to 25' so it looks like I will be using ESFR K16.8 @ 52psi.

Last aluminum can warehouse I did was an FM job but they were using cardboard slip sheets a big difference.

Many thanks to Stookey for his original post on the Texas fire that alerted me to all this.

 

[cdafd]

SD2

I bet it is even better in vertical burn!!!

 

[stookeyfpe]

Glad to help Sprinkler Designer 2.

I had a discussion with a beverage plant in my jurisdiction that used to bottle the soda water that was moved from Austin to San Antonio. All the high piled storage was supposed to be Class II commodity but I found a huge amount of HDPE cases for beverages. I have issued my report and we'll see what happens. I told the plan manager that the service life of his building has expired from the fire protection perspective and if new mains and cross mains are installed, it will require a structural evaluation per the IEBC. It's easily a $150K sprinkler retrofit. Low ceiling heights are his savior.

Your video is a god send. Please send it to me. Multiply that video by 100 and that's what Grand Prairie experienced. The plastic is literally unzipping into light molecular weight hydrocarbons, which behave as a Class II combustible liquid.

FYI, I define the NUCON CORP product a slip sheet because it had a great enough surface shear to prevent the cans from slipping. Scary part is those pallet loads are assembled with plastic strap in compression. When those straps fail, everything slips of the pallet. Those slip sheets slipping engulfed two firefighters (noted in my Powerpoint Presentation). The fire department briefly lost 2 firefighters during that incident.

High Piled Combustible Storage requires a high level of analysis by a qualified engineer or experienced NICET tech.

Final Note: The Grand Prairie Fire and your building are both UNLIMITED AREA under the 2012 IBC because the building is sprinklered. Sprinkler contractors bidding these project need to consider the adequacy of these systems because the architects are placing International Building Code compliance on your design.

Not to be greedy but I think a star is warranted. I worked with a industry counterpart and this will be fixed in the 2015 International Fire Code.

 

[LCREP]

I see some folks missing the impact of a higher commodity stored in with a lower commodity has on the overall commodity classification. Below is from 2011ED of 13. This is a great example, metal cans a class I commodity, add the plastic and what do you have perhaps a Grp. A plastic. Now add in the plastic cases and now you have a big problem. A warehouse designed for a class I commodity and a fire occurring is going to result in a total loss.

As noted below 10 pallet loads of a higher commodity in a 40k sq. ft. warehouse is not much But the impact is significant. Add in the idle pallet storage and the fun really begins. Consider the limitations of ESFR sprinklers which few pick up on and now you know why 50% of the warehouses we look at the sprinkler protection is not adequate. No problem for us we get off the account or write the risk as a nonsprinklered and the business just pays more. They are happy to pay a few$$ more in insurance premium instead of paying many $$$ to upgrade the sprinkler system. But the FD does not have this option.

I agree good post and real life example, here is your star.

5.6.1.2 Mixed Commodities.
5.6.1.2.1 Protection requirements shall not be based on the
overall commodity mix in a fire area.

5.6.1.2.2 Unless the requirements of 5.6.1.2.3 or 5.6.1.2.4 are met, mixed commodity storage shall be protected by the requirements for the highest classified commodity and storage arrangement.

5.6.1.2.3 The protection requirements for the lower commodity class shall be permitted to be utilized where all of the following are met:
(1) Up to 10 pallet loads of a higher hazard commodity, as described in 5.6.3 and 5.6.4, shall be permitted to be present in an area not exceeding 40,000 ft2 (3716 m2).
(2) The higher hazard commodity shall be randomly dis- persed with no adjacent loads in any direction (including diagonally).
(3) Where the ceiling protection is based on Class I or Class II commodities, the allowable number of pallet loads for Class IV or Group A plastics shall be reduced to five.
5.6.1.2.4 Mixed Commodity Segregation. The protection requirements for the lower commodity class shall be permitted to be utilized in the area of lower commodity class, where the higher hazard material is confined to a designated area and the area is protected to the higher hazard in accordance with the requirements of this standard.

 

[stookeyfpe]

LCREP:

When Section 5.6.1.2 was first introduced in either the 2004 or 2007 edition of NFPA 13, myself and another FPE had a What The Hell moment. If one takes the time to review FM LPDS (Loss Prevention Data Sheet for the new folks) 8-9, FM summarizes a series of test fires where they introduced one pallet load of a Cartoned-Unexpanded Group A plastic in a 3-tier height rack of Class II commodities (Empty steel cans inside of fiberboard cartons). From what I recall, FM set up the rack with 11 pallets of the Class II commodity and 1 pallet of the Group A plastic. They performed 3 fire test with the one pallet of Group A plastics on the bottom, center and top tier of the rack. In every case, the fire test revealed that the one pallet load of Group A plastic dominated the heat release and burning rate of a fire and as a result, it should be the basis for designing the sprinkler system.

Right now, I have this same scenario playing out on a plan review for a 114K square foot beer warehouse. The sprinkler designer and owner called it Class II commodity. I surveyed their current warehouse (unsprinklered because of its age) and agreed that the beer was Class II. What they failed to evaluate was all the beer coozies, plastic signs, clothing, frisbees, and other marketing materials. 1/3 of their new warehouse will have pallet loads of this stuff, which I classified as a mix of Expanded and Unexpanded Cartoned Group A plastic. The other problem is the plastic pallets. Based on the unit load weight of a palletized load of beer in aluminum cans on a plastic pallet, the commodity remains Class II based on the 2012 IFC and FM LPDS 8-9 criteria. (FYI, I pallet load of beer in aluminum cans weighs about 1,400 pounds and its all supported by a 36 pound high density polyethylene pallet) All of the idle plastic pallets however are Uncartoned Unexpanded Group A plastic. The plastic idle pallets and the cartoned marketing merchandise forced the designer to purchase a fire pump and completely redesign the sprinkler system in the building areas with these commodities are stored.

Personally speaking I think the current classification system in NFPA 13 sucks dog turds. Unless one is really well versed in plastics classification and the nuances of solid piled versus palletized versus rack versus automated storage/retrieval systems, most owners and sprinkler designers are just throwing a dart at a board when it comes to commodity classification. For me, my current default for any warehouse is Unexpanded-Cartoned Group A plastics. I feel comfortable with that classification based on research from the UL Firefighter Safety Research Center who has done a fantastic job of evaluating the legacy contents of single family dwelling to what is currently being purchased by consumers and placed inside of homes:

http://ulfirefightersafety.com/category/projects/comparison-of-modern-and-legacy-home-furnishings/

. My position is that NFPA 13 needs to establish a minimum requirement for speculation warehouses, which is easily justified in my simple mind based on the UL fire tests and examination of what consumers are purchasing.

Once again Sprinkler Designer 2 gets kudos from me for asking a simple question about one commodity. The scary factor for me is the number of permutations of his scenario is tremendous and I know they are not being evaluated closely.

 

[SprinklerDesigner2]

I found a video of the fire that is still available for viewing at NBCDFW.COM

Warehouse Catches Fire in Grand Prairie

I started laying out systems 40 years ago using NFPA #13 1974 which was a little tiny book you could actually fold in half to put it in your back pocket. Of course we had NFPA #231 and #231C but if I remember right they didn't have much on plastics (if anything) and most any warehouse was done using Class III or pipe schedule if storage was kept below 12'-0".

Today I recognize nearly everything I did in those early years aren't appropriate anymore because over half of the warehouses I see today involves Group A plastics in one form or another. 40 years ago we didn't have much of any that I remember.

I collect old sprinkler drawings and the oldest one I have is of the Pell City Mfg. Co. which was a cotton mill in Alabama.

Yep, really is sprinkler they were using Grinnell (Glass Button) sprinklers.

The drawing is a real work of art, it's colorized looking like something you would expect from Michelangelo Big plant too, the main building covered 155,000 sq ft.

Point is things change and sometimes some of us don't like to recognize that because it gets in the way of "business" which is the real reason we do what we do.

We don't have to go back that far to see changes either, there are a lot of them in just the past 10 to 20 years much less 109.

Another big change I've noticed is how design parameters have changed. 40 years ago we always received specific design criteria from FM, IRI or ISO and that is what we designed to, the drawings were always reviewed by the insurance company who would approve them for installation at which time the installation companies were pretty much clear of most liability as long as the installation conformed to the approved drawings. Life was easy but today that seems to be all changing and it is seldom I get "specifications" anymore. On the project that sparked this thread I received a letter from the insurance company that outlined what they found, though not a word was mentioned about the plastic slip sheets, and they are leaving the design pretty much up to me by simply saying "make sure your design is to NFPA #13 - 2013" and that's all you get.

The sprinkler system design of 2013 is not your grandfathers design of 1980.