Plant engine company configurations
Vol. 26 Winter
Our last article concluded a series on the likelihood of public fire department intervention at industrial facilities. We were reminded that even if the fire department is willing to intervene, the average engine company is not set up with industrial hose stretches in mind.
Most engine companies are configured for their bread and butter operations; that is, the two story residence. Preconnected 2.5" (65 mm) hose lines are typically limited to 150 feet (50 meters).
Standpipes can eliminate the need for such a long stretch; however, it is important to remember that NFPA 13, Automatic Sprinklers, does not require standpipes. They may be required by a local code, but our experience is that standpipes are frequently not provided. Small hose stations are more typically provided but they are not standpipes and cannot support 2.5" hose. Even if 2.5" standpipe outlets are provided, the difficulty of locating them deep inside a large facility should also be considered.
The potential for public fire department use of yard hydrants has been discussed in past articles. They usually do not have a large pumper (suction) outlet because of the potential for robbing the sprinkler system. Where they have been provided, the insurance company may have asked for them to be welded shut. Therefore, connection to 2.5" outlets should be anticipated. Needless to say, fire department hose threads need to be compatible with the yard hydrant.
Preconnected portable master stream appliances capable of flowing 350 - 500 gpm (1300 - 1900 liters/min) are becoming popular on both urban and suburban engine companies. Besides the limited hose length previously discussed, there is a danger that they will overtax the sprinkler water supply. A typical sprinkler system will have 250 – 500 gpm (950 – 1900 l/min) reserved for hose streams. Sometimes there is more but almost never more than 1000 gpm (3800 l/min). It would be very easy to exceed the hose stream allowance with these devices. If the sprinklers are properly designed, there should be no need to exceed the hose allowance.
This author is aware of a recent warehouse fire where several of these portable master streams were deployed at a deep-seated fire because they could be set up and left unstaffed. Unstaffed nozzles were desired because of the long duration overhaul and the potential for pile collapse. Although the hose allowance was greatly exceeded, the sprinklers were supplied by a very large diameter public water main. This same situation in an area with a more typical water supply could have easily resulted in the loss of sprinkler control. If unstaffed nozzles are needed for safety reasons, fewer nozzles and/or lower flow settings may be needed to avoid robbing the sprinklers but still providing the benefit of the unstaffed nozzles.
Vehicle mounted master stream devices will not usually be valuable at interior operations in industrial facilities. If sprinklers are doing their job, the master stream flow is likely to rob the sprinkler system. If the sprinklers are not doing their job, a vehicle mounted master stream may not be able to provide the necessary stream reach. Once sprinklers have failed, water flow requirements are often so high that direct extinguishment is not possible and only a containment strategy can be used effectively.
Besides hose issues, the common 30-minute rated air cylinder may not provide enough air to get into the building, have any reasonable operating time, and then retreat. Longer duration breathing apparatus should be considered.
Considering the above, the best preparation is likely to be the practiced and proven ability to deploy 2.5" hose streams (with appropriate duration breathing apparatus) deep within the industrial facilities you face.
Feel free to contact this author at John.Frank@xlgroup.com or at +1 404-431-2673.
1) in length. A hose stretch of 300 - 500 feet (100 - 150 meters) (or more) might typically be needed in a large industrial facility. Enough hose for a backup line must also be available. Some suburban engine companies (where many industries are located) don’t even carry this much 2.5" or 3" (75 mm) hose. The staffing to make a stretch of this length should be part of the first alarm assignment. Practicing this operation also makes for an excellent training evolution.
1Metric conversions will be made to the nearest practical metric unit. For example, a 91.44 meter hose stretch would not match any standard combination of hose lengths.
John Frank, P.E., CFPS is with XL Global Asset Protection Services, LLP (XL GAPS), a property loss prevention consulting firm and an XL Group company. The XL Group plc, through its operating subsidiaries, is a leading provider of global insurance and reinsurance coverages to industrial, commercial and professional service firms, insurance companies and other enterprises on a worldwide basis. More information about XL GAPS is available at www.xlgaps.com and more information about XL Group plc is available at www.xlgroup.com.