Sprinkler Heads Nullify Smoke Vents In Warehouse Fire
Spray under automatic openings in roof keeps gases inside building
Sprinkler heads located so that they negated the effectiveness of dualpurpose smoke vent-skylights were the major problem in extinguishing a $175,000 fire in roll storage at a paper plant in Oxnard, Calif.
The smoke vents had 186-degree fusible links and in the center of each vent was a 1-foot-square sheetmetal heat deflector. Directly under the deflector was a 286-degree pendant sprinkler head. After the smoke vent link fused, the hot gases set off the sprinkler head, and the spray canceled out the vent’s designed effectiveness. The hot gases were forced down and outward so that they opened other heads away from the fire area. In all, 27 pendant and 15 wall sprinkler heads operated.
The fire led to the discovery of two other interesting facts. Safety chains to limit the opening of the vents were wired to keep the vents closed during their installation. These wires were not removed after installation. Also, when the vents were installed on the roof, workmen placed a wire across, each end to hold the vents in place. Of the 108 vents, 91 still had these wires in place at the time of the fire.
At 1:21 p.m. Monday, September 14, 1970, plant security reported a fire in zone 5 of the hard roll storage section of the Facelle Division of the International Paper Company at 800 Rice Avenue. The plant manufactures paper towels, napkins and toilet tissue, and the main building, which averages three stories in height, encloses 27 acres. This building is made of reinforced concrete with a built-up roof on a metal deck supported by exposed steel beams. The entire building is protected by 28 sprinkler systems.
Several seconds after plant security reported the fire, a security alarm system at the Oxnard central dispatching office indicated water flow at the Facelle plant. The first-alarm response consisted of two engine companies, one truck company and a battalion chief.
Smoke fills area
The writer arrived on the scene at 1:28 p.m. and found the hard roll storage area, zones 5 and 6, charged with smoke banked down within 18 to 30 inches of the floor. The floor area of zones 5 and 6 is 3.77 acres with a 36-foot ceiling. Engine 1 was ordered to take the fire department sprinkler connection, which had six 2½-inch inlets, and send all available manpower to the fire area. Snorkel 1 and Engine 3 were ordered to proceed to zones 5 and 6, according to our pre-fire plan. Investigating the interior of the area revealed deep-seated burning of stacks of tissue in the south section of zone 5.
Each roll of tissue was 4 feet high and 8 feet in diameter and weighed 3000 pounds dry. The stacks were six rolls high, making each storage stack 40 X 40 feet by 24 feet high. Fifty percent of the hard roll storage area was filled with identical piles of storage.
The fire was at the overlapping areas of sprinkler systems 5, 6, 9 and 10. Sprinkler systems 5, 9, and 10 were in operation. The plant fire brigade had 12 house lines around the perimeter of the stack. Engine 3 was ordered to take the hydrant east of zone 4 and advance 2½-inch lines into the fire area. Snorkel 1 was ordered to the roof to ventilate. One smoke vent was open, but the sprinkler head had fused, making the vent useless by creating a water barrier to smoke egress. The Snorkel company, assisted by the plant fire brigade, began opening smoke vents. However, due to the location of the deep-seated fire within the stack, the smoke was forced down by the sprinklers. The plant brigade was ordered out of zones 5 and 6 because the volume of smoke made the area untenable without selfcontained breathing apparatus. The fire area was surrounded with 2½-inch lines by fire fighters with self-contained breathing apparatus and the fire was brought under control.
The off-duty platoon was recalled at 1:51 p.m. Of the 17 members who responded, five members manned the reserve pumper at centrally located Station 3, 11 members reported to the scene and one member went to headquarters to assist the dispatcher. Mutual aid was initiated to the Ventura County Fire Department. Ventura County Engine 51 responded to headquarters at 2:10 p.m. Ventura County Engine 53 covered Oxnard Fire Station 2 from its station. Oxnard Engine 2 was ordered to the fire, arriving at 2:11 p.m., to set up a portable electric compressor and recharge air cylinders.
Sprinklers shut down
At this point, the solution for extinguishment became apparent. We secured the sprinkler systems, used fans and other devices to ventilate, and removed some of the stacks of paper. Sprinkler systems 5, 9, and 10 were secured by firemen and a standby was maintained at each OS&Y valve. The smoke ejectors and plant fans were placed in the doors of zone 5. The Snorkel company was ordered to cut a 20 X 20-foot hole directly above the involved stack. Hose lines were relocated to accommodate fork lifts.
Plant management contracted for two large skip loaders and several portable pumps. The overhaul consisted of fork lifts removing rolls to floor level. Spot fires on the rolls were extinguished with l 1/2-inch lines. The rolls were then removed to the northeast corner of the yard by the skip loaders. A 2 1/2-inch hose line was manned in the area to complete extinguishment.
Plant personnel set up portable pumps to remove water from pits, tunnels and converter car tracks. The plant janitorial force manned squeegees and assisted in placing several hundred pounds of sawdust around the fire area. Overhaul of this fire began at 3 p.m. and continued for 9 hours.
Cause of Fire
Investigation of the fire revealed that subcontractors were working inside as the plant was in the process of completion. A plant welder obtained a permit to assist a subcontractor’s welder in removing “ears” from converted car tracks with a cutting torch. Small fires were started and extinguished with portable extinguishers by the welders. The last cut was made at the lunch break. The angle of the cut on the ears was in a direct line with where the fire started 19 feet away. The welders had attempted to extinguish a spot fire in this stack on the first cut.
Draft curtains were not required because of the installation of smoke vents. However, smoke vents of the type used in this building need draft curtains and protection of exposed steel roof beams.
Water damage accounted for 96 percent of this loss. Storage pallets were not used because of the size of the paper rolls and the method of handling them. Also, there were no floor scuppers—a point once contested by the fire department but overruled by the plant’s fire protection consultant.
This was a preventable fire. Proper fire watches should be maintained during and after cutting and welding operations. The most modern occupancy can, and will, suffer large losses under improper conditions.