Insurance // Property Risk Engineering / GAPS. Dark Warehouses: Loss Prevention, Fire Protection Challenges and Risk Mitigation Measures

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1 Insurance // Property Risk Engineering / GAPS Dark Warehouses: Loss Prevention, Fire Protection Challenges and Risk Mitigation Measures

2 Dark Warehouses: Loss Prevention, Fire Protection Challenges and Risk Mitigation Measures By Luis Arango, CFPS, PE Senior Loss Prevention Consultant Table of Contents Introduction...1 Dark Warehouse Overview...1 Loss Prevention and Fire Protection Challenges...3 Statistical Causes of Fires and Trends...4 Risk Mitigation Measures for Dark Warehouses...7 Building Design...7 Natural Catastrophes...8 Fire Protection...9 Loss Prevention Programs Conclusions References Contact... 14

3 1 Introduction Dark Warehouses Overview Companies looking for ways to cost-effectively manage the storage and delivery of goods to customers are taking more advantage of new technologies and optimized warehouse space. And many are not afraid of the dark. In other words, they are turning to Dark Warehouses, a heavily-automated distribution center operation that requires minimal lighting and pushes new boundaries on just how high shelving and storage configurations can go. Since ideal warehouse locations are in centralized locations with good access to transportation, and those can be more pricey locations, companies are continuously looking to maximize a warehouse s operations. High real estate values, land conditions, available autonomous technologies and increasing labor costs are all playing a major role in determining the size and the capacity of these warehouse facilities of the future. This whitepaper explores trends in the warehousing in industry, the challenges of very high piled storage in so-called Dark Warehouses, their benefits, loss prevention and fire protection challenges, and recommended risk mitigation measures to reduce the potential for high property damage and business interruption. Advances in technology have made it possible for better utilization of warehouse space by increasing vertically their storage capacity, which result in higher storage density or increase in the number of pallet load positions. It is now common to encounter warehouses storing commodities over 40 ft. and even 100 ft. A Dark Warehouse is a term used for a storage facility that does not require the use of lighting for normal operation. The storage facility is usually located near shipping and receiving area, and uses vision-guided robotic equipment for picking up goods from the palletizer area to the storage location, and automated and storage retrieval system for transferring palletized cased goods to and from the racks. Depending on the type and size of goods handled, these warehouses operate automatic guided vehicles, which include palletizers, self-guided forklifts, and automatic retrieval systems. Stacker cranes are also utilized in this type of warehouses; the cranes are designed to work in narrow aisles nearly 100 feet off the ground. The cranes are fitted with optical equipment that use laser measuring devices for controlling the drive and lifting position, detecting crossbeams on racks to allow for precise stacking the pallet on a specific postion within the rack. The automated equipment is programmed to pick up goods at a central location or production area, and carries it to the palletizer area where the pallet is assembled, and then the goods are transported to the warehouse using either conveyor belts or robotic equipment where a crane picks up the pallet load to place it in a specific location within the rack. Photocells and laser measuring technology used by automated material handling equipment allows for distinguishing the rack s structure supports, measuring distances to the racks crossbars and uprights, and recognizing aisles, as well as barcode scanners read codes for stacking products in the right position. Dark warehouses with very tall storage configurations are more appropriate for handling same-sized items, including automotive parts, pharmaceuticals, beauty aid products such as cosmetics, and in facilities with harsh operating environment such as refrigerated warehouses, especially those handling frozen goods. Warehousing utilize double row or multiple row open frame steel racks, which have been coded according to the desired location of the goods; usually determined by rate of turnover and/or type of goods. See figure 1 for photos of dark warehouses.

4 2 Figure 1 Building with 90-ft. high Multi-Row Racks (Semi-Dark Warehouse) Robotic Equipment transporting commodities from palletizer to racks, and from racks to shipping area Plastic Products in +60 ft. high Rack Storage (Dark Warehouse) From the business operations standpoint, the benefits of highly automated facilities using high-density storage facilities with storage up to 100 feet is very significant as they provide means for nearly 100% error-free operation, optimize storage with nearly perfect alignment of goods within the racks, result in low rejection of goods due to proper handling, and help track goods from point of origin to shipping by real-time inventory control. In comparison to conventional warehouses, the use of automated dark warehouse facilitates the management of warehousing, it maximizes the available space in the building by allowing stacking product to very high levels, and reducing the potential for damage due to mishandling of goods, causing significantly less errors, and therefore resulting in lower cost and faster delivery of the goods to the customer. +90 ft. storage in double and multi-racks storage configuration

5 3 Loss Prevention and Fire Protection Challenges Warehouses are used for the storage of various commodities, including goods and packaging materials that, from a fire protection standpoint, present their own challenges. In addition to the classification of the commodities, other factors such as the size of the facility, storage configurations, building construction and location of the facility also need to be considered during the design and protection of these facilities. The National Fire Protection Association (NFPA) has long recognized that warehouses present special challenges for fire protection because their contents and layouts are conducive to fire spread and present obstacles in manual fire suppression efforts. An increase in the number of very large and tall warehouses in recent years, has resulted in an increase of the potential fuel loads. As such, it has an impact on the warehouse fire loss experience and warehouse fire protection systems, specifically the response by emergency personnel for firefighting, and the effectiveness of automatic sprinklers for promptly detecting and controlling a fire. Although the risk of accidents and damage to the racks is negligible, the very tall warehouses utilize the rack system, which is usually integrated into the building during construction; the racks support the building roof. This arrangement presents a potential for roof collapse under severe fire conditions, as the rack s upright members of the racks, are under compression loads and unless adequate protection is provided they will lose its loadcarrying capacity, causing supports to buckle and eventually the collapse of the entire rack system and roofs. This also constitutes a life-threatening potential to emergency responders. Warehouse sites located in a region exposed to natural catastrophes such as flood, wind, tornado, earthquake, and lightning presents high property damage and business interruption loss potential. These exposures should be taken under consideration in the design and construction of the facility and the rack system. Dark warehouses operate with very minimum lighting. Usually, lights, operating under dimmed conditions, are limited to the warehouse s emergency exit locations. Under normal operating conditions, personnel will not be present in the warehouse; but, this presents a challenge to emergency personnel such as the fire brigade or fire department to respond to a fire situation, and may reduce their effectiveness with fire fighting. Overload of storage racks, mechanical failures of equipment associated with automated warehouses present a potential for property damage. Failures of stacking equipment could cause damage to goods, some of which may include materials that present unique challenges such as aerosols, alcohol or solventbased products, exposed and expanded plastics. Incidents involving this type of commodities are potentially conducive to fires that might result in high property damage and interruption to warehousing and logistics operations. Automated tall dark warehouses usually operate under narrow aisles. This dark warehouse characteristic, along with the presence of high-density smoke within the building, would be major obstacles to emergency responders in particular the fire department for manual fire fighting efforts. Storage heights exceeding 40 ft. and 45 ft. which are the currently recognized maximum heights for ceiling sprinkler only fire protection by the NFPA 13 and FM Data Sheet 8-9, present major fire protection challenges. Therefore, dark warehouses require several considerations for the design of effective fire protection. Sprinklers approved for fire protection of commodities storage require minimum 6 ft. or 8 ft. aisles. For narrower aisles, fire protection requires the use of combination ceiling and in-rack sprinklers to limit the spread of a fire.

6 4 Statistical Causes of Fires and Trends The electric installations associated with the automated equipment such as the cranes or other retrieval systems, battery systems, and programmable logic controllers introduces a potential source of ignition to the warehouse. Regardless of the cause of a fire within a dark warehouse, high fire growth accompanied by high heat release rate is expected in warehouses containing open-frame storage racks. The type and size of commodities, the storage configuration, the height of the storage, and other factors present unique challenges in designing appropriate fire protection for dark warehouses. Early fire detection and quick response by the fire protection system are imperative for property loss prevention and control. According to a report issued by the U.S. Fire Administration s (USFA s) National Fire Incident Reporting System (NFIRS), and the NFPA s annual fire department experience survey, during the fiveyear period of , U.S. fire departments responded to an estimated average of 1,210 fires in warehouse properties per year (excluding refrigerated or cold storage). These fires caused an annual average of $155 million in direct property damage, three civilian deaths, and 19 civilian injuries. The statistical data shown in Figure 2 was published by the NFPA Research Foundation on a report issued in January 2016: The data indicates that nearly one-fifth of these fires were set intentionally. Electrical distribution or lighting equipment was involved in 18% of fires. Arcing is the most common heat source (13% of fires) in warehouse fire. Electrical failure or malfunction was the leading factor contributing to the ignition of warehouse fires, as well as in contributing to 17% direct property damage. Therefore, implementing proper loss prevention and control programs and protective measures such as surveillance, proper design, and installation of electrical and heating equipment, preventive maintenance for all equipment, and smoking control will reduce the potential for property loss from these factors. The NFPA Research report indicates that fires in warehouse properties have declined substantially over the past 30 years. The number of structure fires in U.S. warehouses has been reduced by 74% since 1980, falling from 4,700 fires per year in 1980 to 1,200 in However, the value of direct property damage caused by warehouse fires has not shown a similar decrease when adjustments are made for inflation. Figure 2 Leading Causes of Warehouse Structure Fires: Intentional 18% 32% Electrical distribution or lighting equipment 18% 17% Heating equipment 3% 8% Exposure fire Smoking materials 5% 7% 7% 11% Fires Property damage

7 5 Figure 3 Structure Fires in Warehouses by Leading Cause: Annual Averages (Top 5 are listed) % 18% Intentional 32% 38% 18% 17% Electrical disribution and lighting equipment 8% 0% 3% Heating equipment 7% 0% 7% Exposure fire Fires Civilian Injuries Direct Property Damage 5% 0% Smoking materials 11% As shown in Figure 3, intentionally set fires caused 32% of direct property damage, while electrical distribution and lighting equipment accounted for 17% of direct property damage. Timing of warehouse fires: Warehouse fires were less likely to take place on a Saturday (12% of fires) or Sunday (11% of fires), as is generally the case with business properties, with all the other days of the week accounting for 15% or 16% of fires. In general there was little seasonal variation in the distribution of fires by month, with all months having between 8% and 9% of the total. This implies that loss prevention and control measures should be consistently maintained during the course of the week and month of the year; however, warehouses exclusively devoted for storage of seasonal products is expected to have some correlation with the timing of the warehouse fires. As figure 4 shows, warehouse fires were less common during evening or overnight hours, but these fires were associated with higher property loss. Fires between midnight and 6 a.m. accounted for 17% of fires, but 26% of direct property damage, while fires between 6 p.m. and midnight accounted for 26% of fires, but 29% of direct property damage. The data suggest that higher property damage is likely to be experienced during unattended periods of the building as response may be delayed. Therefore, it suggests that developing a pre-fire plan in conjunction with the implementation of surveillance systems that includes security guards and alarm systems may have positive impact on property loss experience. Rubbish, trash, or waste was the item first ignited in 12% of warehouse fires, and they caused just 2% of direct property damage. Flammable and combustible liquids and gases, piping and filter were the item first ignited in 6% of fires, but these fires caused 12% of direct property damage. (See Figure 5). Figure 4 Structure Fires in Warehouses by Time of Day: Fires % 26% 25% 43% 17% 18% 32% 38% 27% 26% 14% 29% Civilian Injuries Direct Property Damage % Midnight - 6 am 6 am - 12 pm 12 pm - 6 pm 6 pm - Midnight

8 6 According to NFPA data, wet pipe sprinklers were effective in 84% of the fires in which they were present and contributed to a 61% reduction in dollar loss in those fires. Other protective measures generally applicable to warehouse properties include automatic alarms to the fire department and building security systems. Pre-fire inspections and planning are recommended in order to identify appropriate protection measures for specific warehouse environments. The above-reference data is useful for identifying the leading causes of fires, timing, and contributing factors to property damage. The data also suggests that implementation of loss prevention and control management programs including proper pre-fire planning and training, in conjunction with surveillance systems for early detection, proper maintenance of electrical and heating equipment, and installation of appropriate fire sprinkler systems strongly correlate with the probability of a fire and direct property damage. Figure 5 Structure Fires in Warehouses by Item First Ignited: % Fires Civilian Injuries Direct Property Damage 20 18% % 0% 2% Rubbish, trash or waste 8% 5% 6% 7% Electrical wire or cable insulation Unclassified item first ignited 6% 6% 12% Flammable and combustible liquids or gases, piping and filter 6% 0% 5% Structural member or framing

9 7 Risk Mitigation Measures for Dark Warehouses As more businesses look to maximize their warehouse operations, many more may be moving to dark warehouses and autonomous technologies to take advantage of optimal storage configurations. There are a variety of property loss preventions considerations that companies can take to make sure their dark warehouse are built and operated to minimize any potential property losses. Building Design Appropriate building codes should be used in the design of very tall dark warehouses. This should include the latest State and Local Codes for building construction, and appropriate reference to applicable fire protection standards and guidelines from reputable sources. All walls and their supports should be designed for loads in accordance with the ASCE-7 Standard Minimum Design Loads and Associated Criteria for Buildings and Other Structures; this Code describes the methods for determining dead and live loads, and loads associated with natural catastrophe events such as earthquake and wind loads, and their combinations for general structural design. An engineer registered to practice structural design in the jurisdiction in which the project is located should be employed to design the building, storage racks, and bracing systems for nonstructural elements. The building roof should be designed to resist the effects of dead loads in combination with the more demanding of the roof live load or environmental loads exerted from snow, rain, and any superimposed roof live loads, to account for the use and maintenance of the roof. For very tall warehouse buildings with rack storage exceeding 30 ft., it becomes very important that the design of the slab is relative to lower clear height buildings. Taller racks mean larger slab loads, and therefore the floor slab would require greater thickness and tighter specification to ensure rack and load stability. The steel supports for the racks and the roof would require being thicker for adequate load bearing. To control fire spread and protect warehouses from other operations in the facility, the warehouse and associated shipping and receiving areas should be separated by walls of at least 2-hour fire rated construction from adjacent areas housing manufacturing, support and service areas. The following loss prevention guidelines should be implemented for equipment and supports facilities associated with the automated warehouse: The control room that contains the computer servers and/or programmable logic controllers for the automated materials handling equipment should not be located adjacent to the warehouse, or any hazardous operation. Construction should consist of minimum 1-hour fire rated construction, and raised floors and ceiling tiles of 1-hour fire rating. Adequate fire protection using standard wet pipe or pre-action sprinkler systems, or as a suitable option install an approved clean agent fire extinguishing system.

10 8 Battery charging operations for automated materials handling equipment should be located outside warehousing areas, in a well ventilated area, or in a cut off room equipped with adequate mechanical exhaust ventilation designed to dissipate hydrogen vapors generated during battery charging. The charging area should be provided with spill containment, power disconnect, and automatic sprinkler protection. All pipe and conduit penetrations should have a steel sleeve and then be sealed with a UL Listed and/or FM Approved wall and floor penetration fire stop with material of an equal or greater hourly rating than the wall. Because the high value of the goods stored in very tall warehouses, a more stringent design might be required for the building walls and supports, and/or additional interior subdivision of the rack storage space using the Maximum Foreseeable Loss (MFL) concept may be appropriate; the use of this concept should be determined based on underwriting guidelines. The MFL concept incorporates the design of walls to stop the spread of an uncontrolled fire when existing fire protection is impaired and manual fire fighting is limited or delayed. MFL or high-challenged walls have 4-hour fire rating and are designed to be free-standing or remain stable under fire exposure condition. Guidelines for the design of MFL Walls can be found in the FM Data Sheet 1-22 and in the NFPA 221 Standard for High Challenge Fire Walls, Fire Walls, and Fire Barrier Walls. Natural Catastrophe One of the first steps in building design is determining the potential exposure to natural catastrophe from events such as earthquake, wind, flood, rain, snow, and lightning among others. The following guidelines can be used to help determine the magnitude of the exposure and recommended building design consideration, and loss prevention and control measures to mitigate these exposures: International Code Council, USA. International Building Code. International Conference of Building Officials, USA. Uniform Building Code. Appropriate Country Building Code for locations outside USA GAP Guideline Windstorm GAP Guideline Seismic Bracing FM Data Sheet 1-28 Wind Design FM Data Sheet 1-2 Earthquake FM Global Data Sheet 1-34 Hail Damage FM Data Sheet 1-54 Roof Loads For New Construction Earthquake Locations exposed to earthquake activity require an earthquake resistant building design that incorporates seismic bracing for the structural members to preserve the structural integrity of the building. Seismic bracing should be also used to restrain storage racks, battery fixtures, building appliances, and warehouse equipment. Design buildings, and equipment and content load-resisting elements and anchorage using the earthquake acceleration parameters appropriate for the location of the facility. Anchor floor mounted equipment such as indoor transformers and switchgear; these need to be secured and braced at the top to structural elements. Brace floor stands for items such as battery racks, programmable logic controllers, and supports for other equipment in two opposing directions as required to resist movements in the lateral and longitudinal direction. For existing buildings of steel construction, earthquake resistance can be enhanced by strengthening the structural frames providing bracing of designs ranging from X-brace and K-brace to tension rod bracing. Floors and roofs which typically transmit forces in the horizontal plane can be strengthened by tightening fastenings and improving attachments of wall to foundations connectors to resist uplift and to resist shear. The potential for rupture of water, gas and fuel, electrical supply and communication conduits (piping or wiring) is high, particularly where materials are brittle types. Therefore, providing isolation valves and switches, excess flow safety devices, seismic gas shutoff valves and disconnects are recommended to minimize damage and retain as much service as possible during an earthquake. A remote shutoff for electrical service is also essential. Sprinkler piping and other piping systems that can leak water or gas should be provided with proper restrains and seismic bracing to prevent failure during an earthquake. A structural engineer familiar with seismic response applications must design restraint devices at facilities located in earthquake hazard to meet anticipated acceleration per earthquake hazard zone rating. Windstorm Protection against damage from exposure to high wind exposure such as from tropical cyclones begins with a structural design to withstand the pressure of cyclone wind speeds, quality workmanship in construction and good maintenance. Code designs incorporate resistance to the strongest winds normally anticipated within a region. Significant property damage can result when warehouses are not properly designed to withstand the anticipated wind loads associated with severe storms. Damage to the building cladding,

11 9 doors, roofs, and roof-top equipment can occur from direct impact by high wind forces or windborne debris. When sections of the building component are dislodged, wind and/or wind driven water will penetrate the warehouse through unprotected openings and result in high property damage and interruption of operations. It is highly recommended to design the buildings to the wind speed associated with Risk Category IV, as specified by the Applied Technology Council (ATC) or other recognized insurance industry guidelines. Note that data collected by FM Global for tornado activity indicates that for a period of average annual tornado counts per 10,000 square miles between 1991 and 2010, the average gust wind speed for over 97% of the tornadoes documented was mph. Therefore, buildings designed to 135 mph will provide a reasonable resistance to tornado exposure. Flood Widespread damage can be caused by flooding water resulting when a body of water rises above the top of established channeling, such as a river bank, and overflows onto land. Conditions sufficiently adverse to create flooding are capable of damaging the building, indoor equipment, and storage of goods. The most common cause of flooding is rainfall, whereby a combination of conditions interacts to maximize surface runoff. The Federal Emergency Management Agency (FEMA) has defined flooding as a general and temporary condition of partial or complete inundation of normally dry land from: The overflow of inland or tidal waters. (Riverine & coastal flooding respectively) The unusual and rapid accumulation or run-off of surface waters from any source. (Surface water run-off) In the United States, riverine flooding is shown on Flood Insurance Rate Map (FIRM) published by FEMA. These maps show the 100 yr. and 500 yr. flood recurrence. Other countries around the world project other intervals of flood recurrence such as 200 yr., 1000 yrs., etc. Canada forecasts on 200 yr. basis. North Sea studies looked at 400 and 2000 yr. events. When the site is located within flood prone areas, if possible the warehouse and support facilities should be built outside flood exposed areas; otherwise the facilities should be constructed at least 1 ft. above the 500-year flood level. Rainstorm The building roof should be equipped with adequate storm drains and the support members should be designed to carry the anticipated loads. Designing roof drain systems based on 1-hour rainfall intensity with a 1% chance of occurrence is recommended. It is also wise to design flat roofs with a secondary drainage system. Snow The building snow load design should be based on ASCE 7 for Risk Category IV buildings or other recognized insurance industry guidelines. Lightning Electrostatic energy discharge produced during a thunderstorm can strike buildings, particular very tall buildings. Unless adequate protection is provided, such a strike could be an ignition source. Thus, lightning protection to protect buildings and structures should be provided for facilities located where there is a known history of thunderstorms. Protect the warehouse and associated support facilities from direct lightning strikes by installing lightning protection systems meeting the requirements of NFPA 780, UL 96A or LPI-175. Use components listed to UL 964. Protect buildings and structures from lightning induced surges traveling along incoming electric power and communications lines by installing surge arresters at electrical service entrances to divert these surges to earth. Use listed or certified installers. Fire Protection The risk associated with automated dark warehouses presents a potential for very high property damage loss due to the high value that is usually associated with the storage. High concentration of combustible materials, the configuration of the storage, specifically the height of the storage (100 ft. or more), the presence of narrow aisles, and lack of lighting, present high challenges to the design of fixed fire protection systems, and manual fire fighting. Depending on the type of goods stored, a fire will cause release of large amount of heat and smoke creating adverse conditions for fire fighters. Under these conditions and unless proper protection is provided, there is high chance for collapse of racks and the structure in a building whose roof is supported by the rack steel frame. Therefore, it is utmost important to properly design automatic sprinkler protection based on widely recognized standards to control the fire. Proposed fire protection using non-conventional methods and applications are also outlined in this article as they use technologies that have been recognized for effective fire protection of ordinary combustibles and high-hazard materials such as flammable and combustible liquids.

12 10 Loss Prevention Programs In addition to proper building construction, loss prevention and control management programs should be implemented for safe operation of warehouses and to reduce the loss potential. These programs should consider the following: The material handling equipment such as crane stackers, conveyor belts, and robotic equipment should be equipped with protective devices such as overload, over reaching, over temperature, high voltage and over current protection, heat protection for the electric motors, and other protection measures recommended by the equipment manufacturer for safe operation. An inspection and preventive maintenance program for the electrical equipment including power distribution equipment, automated equipment, and their safety protective switches and sensors. The program should include infrared scanning of electrical equipment. Set up the program in accordance with the equipment manufacturer guidelines, and the NFPA 70 B: Recommended Practice for Electrical Equipment Maintenance. Establish comprehensive pre-emergency and response plans for fires, flood, windstorm, earthquake, and other conceivable emergency situations. A pre-fire plan should be developed and discussed with the first and secondary emergency responders. Salvage and cleanup procedures should be incorporated in the pre-emergency plan. Set up a checklist-based inspection program for the storage racks to verify that they are in good condition, and well secured. An inspection and functional test program for the fixed and portable fire protection program. A work permit system that will require task safety analysis before maintenance work is allowed to be performed. This should include formal hot work permit system, and deenergizing all electrical equipment prior to allowing personnel entering a Dark Warehouse. Surveillance systems such as on-site security, video cameras, and fire and burglar alarms should be provided in all warehouses for early detection of abnormal operating condition, and for intrusion detection. Fire Protection by Conventional Methods In selecting the type of fire protection, contributing factors such as the total value of the goods stored in the building, and their susceptibility to damage from smoke, heat, and water play a significant role in this decision. For early fire detection and depending on the commodities stored and operating environment (ambient vs. low temperature), consider the installation of very early suppression system, or a linear heat detection system installed at all levels of the storage racks. Additionally, the systems should be arranged to transmit a local audio visual alarms, and also to transmit the alarm to a constantly attended location and UL Listed Alarm Monitoring Central Station. The installation of the fire detection system should be completed in accordance with the requirements of the NFPA 72: Fire Alarm and Signaling Code. Adequately designed automatic sprinkler systems are essential for proper fire protection. The design and installation should be based on the requirements of the NFPA 13: Standard for the Installation of Automatic Sprinkler Systems. A sprinkler design scheme should be selected from this standard and/or from the FM Data Sheet 8-9: Storage of Class 1, 2, 3, 4, and Plastic Commodities. Because the height of the rack storage exceeds the maximum level of storage and building specified by these standards for ceiling sprinkler protection only, the installation of in-rack sprinklers in every level of the racks using the horizontal layout that is specified in the standard is required for adequate fire protection. The spacing and location of the sprinkler is dependent upon the configuration of the rack, (single row, double row, or multiple rows). This will include the installation of in-rack sprinklers along the longitudinal flue space, at midpoint between transverse flue space, and along the face of the racks; in-rack sprinklers on these positions should be staggered vertically. Only sprinklers that are listed or approved by a recognized testing laboratory for storage applications should be utilized. Providing horizontal barriers at prescribed intervals is also an acceptable fire protection arrangement; however, the use of these barriers generally reduces the number of in-rack sprinklers required per level; but, it does not reduce the number of in-rack levels required. Water Supply for Fire Protection Factors such as high value contents, the dimensions of the racks, the height of storage, and presence of narrow aisles will restrict the capabilities of firefighting, and therefore total reliance must be placed upon sprinkler protection for initial control. This supports the concept for using the MAXIMUM RELIABILITY approach.

13 11 According to the GAP Guideline Maximum Reliability for High Rack Storage Protection, this concept uses a carefully coordinated protection design that ensures reasonable control of fire in high racked storage facilities despite any credible single impairment, such as impairment to a water supply or a valve closure to any interior or exterior piping. Accordingly, to avoid total loss to a warehouse, minimum acceptable in-rack sprinkler protection must be maintained under any reasonably adverse circumstance. The following arrangement should be implemented on the design of the firewater distribution system, piping, and sprinklers: Water Supplies: Provide two reliable water supplies; each one capable of meeting NFPA s design demands for hose stream, ceiling sprinklers, and in-rack sprinklers. This should consist of preferably diesel engine driven fire pumps, or electric motor driven pumps with connection to emergency power generators. Each pump should take suction from an aboveground storage tank of enough capacity to meet the combined water requirements of the sprinkler system and hoses for a period of minimum 120 minutes. Exterior Piping: Arrange the underground mains as either looped or gridded and with control valves installed so that any single impairment (valve closure or piping rupture) would not interrupt both water supplies to the rack area, or affect all of the in-rack protection, or any in-rack protection simultaneously with the ceiling protection. Interior Piping: Arrange interior piping so that a single impairment will not affect all the in-rack protection or one of the in-rack systems and the ceiling protection. To achieve this goal implement the following: Feed ceiling sprinklers by a separate riser and feed main from the underground loop. Arrange in-rack sprinklers with two separate feeds from the underground loop so that under any credible impairment or single valve closure, no more than 50% of such protection within the warehouse will be affected nor will all the in-rack protection in any one rack be impaired. Arrange in-rack sprinkler protection so that no more than one tier level, approximately 5 ft. (1.5 m), at the top of the rack will be unprotected, if the ceiling sprinkler system should be impaired. Sprinklers: Install ordinary temperature, ESFR type ceiling sprinklers and ordinary temperature, quick response rated in-rack sprinklers. Fire Protection by Non-Conventional and Innovative Proposals To initiate a discussion on possible solutions, the Fire Protection Research Foundation held a workshop on high-challenge warehouses during the Suppression and Detection Research and Applications Symposium, or SUPDET, held in February, 2010, in Orlando, Florida. The workshop case study focused on a hypothetical high-bay warehouse in a rural community a common location for today s mega-warehouses, in fact, due in part to availability of affordable land. The case study warehouse was 55 feet (16.7 meters) wide, 150 feet (45.7 meters) long, and 70 feet (21.3 meters) high, constructed of steel, and stored cartoned Group A plastics in a 13-level multiple rack array 65 (19.8 meters) feet high. Storage would be handled by an automatic storage and retrieval system operating in five-foot-wide aisles. The main rack would be four pallet loads wide. The local fire chief says firefighters would only enter the building in an effort to save salvable lives. During the SupDet workshop presentations from the various participants offered their visions on the approach for fire protection for the case study using fixed fire protection approaches designed to extinguish the fire without fire service intervention. The approach is based on commercially available fire protection systems applied in unconventional ways. The fire protection methods are presented here only as hypothetical possibilities in conceptual form, not as detailed engineering realities that have been reviewed by the fire protection community or subjected to rigorous scientific analysis. The intent is to stimulate further discussion on a matter of critical importance to industry, insurers, the fire service, and standards development organizations such as NFPA, and to press for further work to create solutions that are both realistic and cost effective. Proposal by Aon: Utilization of Early Suppression Fast Response Sprinklers (ESFR) and Carbon Dioxide (CO2): The storage space is divided into zones with horizontal and vertical barriers. A Low Zone for storage of high challenge commodities, and a high zone for ordinary commodities. The high zones rely on ESFR sprinklers only, while the low zones are protected by ESFR sprinklers at the top of the zone, and supplemented by local application of carbon dioxide to reduce the oxygen content in the zone to the point where open burning is not possible. A system of heat detection installed in the upper and lower zones is used for alarm actuation and ESFR activation. The ESFR sprinklers are installed in the flue spaces at only two levels of the 70-foot-tall (21.3 meters) structure, avoiding the installation of in-rack sprinklers at every level. The benefit of using CO2 is its ability to handle fires involving flammable and combustible liquids; however, it introduces the personnel safety hazard, and therefore this installation would require incorporating early warning systems to allow evacuation of personnel, and a discharge delay as required by the NFPA 12 Standard.

14 12 Proposal by FPI Consortium and Hughes Associates: Utilization of high-expansion foam designed and installed in accordance with NFPA 11, Low-, Medium-, and High-Expansion Foam. The design principle consists of using total flooding in a zoned area to a depth that submerges the fire. To reduce the total water supply requirement, solid or fabric vertical barriers are used to divide the space into four equal protection zones. Two methods of heat detection were considered: ceiling and in-rack spot heat detectors, and linear heat detection located within the racks, with lines alternating front-to-back and side-to-side at each level up the array. Flame detection was also proposed to cover open building areas and aisles. Video imaging detector (VID) systems were offered as an option that could detect either flaming or smoldering fires. Foam concentrate is delivered to a foam proportioning system arranged to proportion 3 parts concentrate and 97 parts water to form a foam solution. The foam solution is then delivered to a high-expansion foam generator, where one part of foam solution is mixed with between 500 and 1,000 parts of air to form high-expansion foam. The foam is delivered by ceiling- or wall-mounted foam generators that would completely fill the protected zone and extinguish the fire. The use of which has already been proven for protecting high-challenge fire hazards including aircraft hangars, flammable liquids storage, rolled paper storage, rubber tires storage, and a number of other applications. The proposal is very significant as it utilizes proven technology for high hazard fire protection. It reduces the amount of water requirement to less than 20 percent of the water requirement for automatic sprinklers, which means less runoff of contaminated water. The ability to divide the warehouse space into multiple zones would further reduce water demands, as well as stock damage, due to contact with foam. The automatic storage and retrieval system was assumed to be hardened to allow operation during a fire. The system would carry a pallet-mounted, self-contained fire extinguishing system. The pallet-mounted extinguishing system would incorporate an infrared camera to locate burning or smoldering material. A monitor nozzle would apply up to 600 gallons of compressed air foam to achieve final fire extinguishment. Proposal by Rolf Jensen & Associates: The proposal consists of use of water mist technology that employs a system of air dampers and exhaust fans to pull water mist through the rack array. Water mist is a recognized fire suppression system for a broad range of challenges, from light-hazard occupancies such as ballrooms to plastic clean-room wet benches where flammable liquids are in use. NFPA 750, Water Mist Fire Protection Systems, provides guidance for applying water mist systems where the system has been specifically listed for the hazard to be protected. The system is designed to automatically operate in a zoned manner based upon the location of the detected fire. A linear heat detection system is installed at each tier of storage in the rack array as well as at the ceiling above the racks. Highpressure water mist nozzles are positioned along the rack faces on the air louver side of the arrays. Nozzles run parallel with the aisles at every level up the rack arrays, and are zoned vertically from floor to ceiling. Unlike carbon dioxide and high-expansion foam, the water mist approach does not involve zoning of the warehouse space with horizontal or vertical barriers. While no estimates of water demand were developed for this model, it is anticipated that water mist would use even less water than the high-expansion foam approach. For rural locations with limited water supplies, water mist could offer a cost-effective option to automatic sprinklers supported by fire pump and large water-storage tanks. The concept of combining water mist and airflow is intended to reduce smoke generation and remove from the building a portion of the smoke that is generated. This delivers the benefit of improved visibility within the building, along with the potential for reduced smoke damage to stock. However, this combined approach is new and would require testing and the development of design guidelines. In addition, the development of a listed water mist design for warehouse fire extinguishment would have to be pursued, since NFPA 750 requires such systems to be specifically listed for the hazard being protected.

15 13 Conclusions The risk associated with automated dark warehouses presents considerable loss potential due to usually high value of the contents; a fire in this type of warehouse without appropriate fire protection is likely to result in major property damage and cause interruption of the supply chain. Dark warehouses pose significant fire protection challenges because of their high-density storage arrangement, building layout, ceiling heights, and types of commodities stored within their walls. The lack of lighting and potential for building or rack collapse would present a challenge to firefighting. To minimize those risks, it s crucial to conduct a risk assessment, starting at the conceptual design stage of the facility for identifying the potential risk exposures and the required preventive and protective features. Pre-emergency planning and business continuity planning area also essential for proper loss control. The installation of automatic sprinklers is essential for control of a fire situation, and although in most cases sprinklers do not extinguish the fires, properly designed sprinkler protection will control the fire to provide a degree of safety for access for firefighting. According to the NFPA Journal, properly designed sprinkler systems are an essential element of warehouse fire protection. In the most recent NFPA report on the U.S. experience with sprinklers, fires in warehouses are large enough to activate sprinklers and wet pipe sprinklers were effective in 84% of the fires in which they were present and contributed to a 61% reduction in dollar loss in those fires. It is also important to develop a pre-fire plan in conjunction with the fire department that incorporates the resources needed for complete fire suppression. Loss experience data presented by the NFPA Research Foundation indicates that fires caused by electrical equipment or wiring failures is one of the largest contributing causes, and therefore, emphasis should be placed on the design and installation of electrical equipment as required by the National Electric Code (NFPA 70). The installation of surveillance systems in warehouses and providing on-site security will provide a deterrent to intentional set fires, which is the second contributing cause to fires. The control of other potential sources of ignition such as smoking, heating equipment, and improperly managed hot work is also important to loss prevention. References Report issued by the U.S. Fire Administration s (USFA s) National Fire Incident Reporting System (NFIRS), and the National Fire Protection Association s (NFPA s) annual fire department experience survey, during the five-year period of NFPA 13: Standard for the Installation of Automatic Sprinkler Systems FM Data Sheet 8-9: Storage of Class 1, 2, 3, 4 and Plastic Commodities. GAP Guideline Windstorm GAP Guideline Seismic Bracing GAP Guideline Maximum Reliability for High Rack Storage Protection FM Data Sheet 1-28 Wind Design FM Data Sheet 1-2 Earthquakes FM Global Data Sheet 1-34 Hail Damage FM Data Sheet 1-54 Roof Loads for New Construction NFPA , Standard For The Installation Of Lightning Protection Systems, National Fire Protection Association UL 96A-2007, Standard for Installation Requirements for Lightning Protection Systems, Underwriters Laboratories Inc. LPI-175, Lightning Protection Institute Standard Practice, Lightning Protection Institute, Harvard, IL.

16 Dark Warehouses: Loss Prevention, Fire Protection Challenges and Risk Mitigation Measures Contact Luis Arango Senior Loss Prevention Consultant To learn more, visit the website xlcatlin.com/gaps.com MAKE YOUR WORLD GO Global Asset Protection Services LLC (XL GAPS) is a leading property loss prevention service provider and a subsidiary of XL Group Ltd. XL GAPS provides property loss prevention and risk assessment reports and other property loss prevention services, as requested. Our personnel, publications, services, and surveys do not address life safety or third party liability issues. Any services addressing life safety or third party liability are provided by others. XL GAPS specifically disclaim any warranty or representation that compliance with any advice or recommendation in any document or other communication will make a facility or operation safe or healthful, or put it in compliance with any standard, code, law, rule or regulation. XL Catlin, the XL Catlin logo and Make Your World Go are trademarks of XL Group Ltd companies. XL Catlin is the global brand used by XL Group Ltd s (re) insurance subsidiaries. In the US, the insurance companies of XL Group Ltd are: Catlin Indemnity Company, Catlin Insurance Company, Inc., Catlin Specialty Insurance Company, Greenwich Insurance Company, Indian Harbor Insurance Company, XL Insurance America, Inc., and XL Specialty Insurance Company. In Canada, coverages are underwritten by XL Specialty Insurance Company Canadian Branch. Coverages may also be underwritten by Lloyd s Syndicate #2003. Coverages underwritten by Lloyd s Syndicate #2003 are placed on behalf of the member of Syndicate #2003 by Catlin Canada Inc. Lloyd s ratings are independent of XL Catlin. Coverage may not be available in all jurisdictions. Information and ratings (if listed) accurate as of September , Global Asset Protection Services, LLC., an XL Group Ltd company. 1650_09/2017