Ground scrapers – What have we built?

I just finished attending an NSFA regional Conference in Gatlinburg and the SFPE Annual Meeting in Atlanta. At both events there were discussions about the size of buildings, either warehouses, retail or data centers and that fire protection for these buildings was a critical part of the building.

The NFSA noted 125 give backs permitted in the building and fire codes for sprinkler systems. These code changes for sprinkler systems allow larger footprints, higher number of stories, fewer interior cut offs, increased travel distances to exits and reduction in fire detection systems. History has shown that prior to the introduction of mega size buildings these tradeoffs were worked well.

A presentation described the Firefighter Air Replenishment System (FARS) that was used in high rise applications to extend operating times for first line companies. These systems allow the Self-Contained Breathing Apparatus (SCBA) to be refilled remotely in a stairwell.

This system was of great benefit to the fire service, and it was not required by any current national codes. FARS resides in the appendix of the codes.

The need to have standpipes in protected stairwells for firefighter safety were a topic that was raised in several sessions. Videos showing fire testing of retail storage arrays and the immediate evolution of cold smoke to the floor. An acknowledgement that the combination of sprinkler discharge and cold smoke made fire service Thermal Imaging Camera (TIC) ineffective.

At the SFPE conference there was a panel discussion about big box buildings and fire protection for these structures. At this panel discussion I heard a fire protection engineer question if the current fire protection decisions and code minimums were effective.

At an NFSA seminar I attended earlier this year the topic of big box buildings was the sole topic for two days with fire departments in attendance. This seminar advanced the fire department operating limitation of 135 feet into a fire involved building based on the limited air supply for SCBA. Couple this limitation with the inability of TIC to work in cold smoke and heavy sprinkler discharge and you have a recipe for disaster.

Some of the solutions were to extend standpipe systems and FARS into big box buildings. This sounds good on paper, but the history of these tools is found in fire protected stair towers in high rise buildings. The ground scrapers do not have fire rated corridors in the middle of the structure. Now you must find a standpipe and FARS system attached to a building column somewhere inside a smoke-filled structure. A design by someone who has never entered a burning building.

The comments from the SFPE panelist were that sprinklers in these big box structures must be designed to completely extinguish the fire. This would eliminate the urgency of the fire department to enter to control and mop up a fire. The current sprinklers codes differentiate between Control Mode Density Area (CMDA), Control Mode Special Application (CMSA), and Early Suppression Fast Response (ESFR) sprinklers. The two control mode sprinklers specifically say they are designed to control a fire. A 500 gallon per minute (GPM) hose allowance is provided to allow the fire department interior hoes streams for final fire control. ESFR systems are intended to suppress the fire, but there is still a 250 GPM hose stream allowance required for fire department use.

All of the testing done to list and approve CDMA, CMSA and ESFR sprinklers are conducted in testing facilities. Videos of the fire test are highlights of any session. When I watch these tests I think of Warren Zevon’s lyric in Werewolves of London, “I saw a werewolf drinking a pina colada at Trader Vic’s and his hair was perfect.” The flue spaces are laser straight and completely open. The aisle width is perfectly aligned and clear. There are a few rows of racks, and the facility fire fighters can always control the fire. From the view behind the glass, the systems work wonderfully. Now place the rack 400 feet inside the door, obstruct the flues, add some aisle storage, lower the smoke level to the floor, disable the TIC, and the hose stretch must snake through the building. A completely different result is in the future.

The intention for fire departments to enter the building is inherent in all of the sprinkler and fire protection designs. The inability of the fire departments to navigate inside the building and the ineffectiveness of TIC to find the fire has led to fire departments choosing to turn off the sprinklers, so they could find the fire. In most cases this choice led to the fire getting out of control before the fire department could react.

The building industry, the fire protection industry and the code enforcement bodies have been aware of the cold smoke issue, yet no one has advanced any ideas to manage this product of combustion. The cold smoke and its degradation of TIC performance are driving factors for large fire losses in big box buildings.

Allowing 250 to 400 feet travel distances in these big box buildings is in direct conflict of the fire department limitations of 135 to 150 feet entry depth. With cold smoke development and a waterflow alarm that can be five minutes delayed, you now must transit the distance of a football field to get out.

Allowing these buildings to grow to sizes that dwarf the ability of the fire service to manage the events does not serve public purposes. The major code organizations and industry groups have metro fire chiefs participate in these sessions. Most of the big box builds are in suburban and rural areas, they have the land. They also have a volunteer or part-paid fire department. In most of these agencies’ staffing is driven by Emergency Medical Services (EMS) needs, not fire suppression. The insurance industry takes a pass on this topic by allowing a fully sprinklered building to have no impact on the Public Protection Class (PPC) for a fire district. This disguises the impact of these facilities on local resources.

These buildings are the darlings of economic development. The people who design them, build them, and approve them are happy not to have the responsibility to fight the inevitable fire that will occur.