Fire Studies: Lumberyard Fires

The deputy chief was monitoring his radio while responding to a lumberyard fire. He was familiar with the facility and knew it contained a mill shop to build windows and a building in which wooden moldings were fabricated. There were also a number of buildings that housed lumber and other materials.

The battalion chief had sounded three alarms for the nighttime fire and had more than 20 apparatus on the scene or enroute. The problem was that the exact location of the fire could not be determined due to the heavy smoke on the lumberyard grounds.

As the deputy arrived, he found heavy smoke at street level allowing minimal visibility. The heavy smoke limited his ability to do a comprehensive 360-degree walk-around of the facility. The progress reports from the different divisions reported similar conditions on all sides of the lumberyard. To compound the problem, the lumberyard was encircled on three sides by rowhouses that the police were evacuating. He knew that the density and the amount of the smoke indicated that a fast-moving fire could occur once the smoldering materials obtained a sufficient supply of oxygen.

Apparatus repositioned

The deputy immediately did a face-to-face with the battalion chief who was the current incident commander and assumed command. His first order was to move the engines that were connected to the nearby hydrants in front of the lumberyard to a safer location. Firefighters started to remove their hoselines from the hydrants when the lumberyard facility seemed to explode into flames. Oxygen had reached the seat of the smoldering fire in the high, one-story building in the center of the facility that fabricated the wooden moldings. The release of heat was tremendous and firefighters were driven back immediately. Some firefighters, seeing what was occurring, jumped into apparatus cabs and drove the engines away, tearing the hoselines that were attached to the hydrants from their couplings. Their apparatus sustained some heat damage, but were otherwise intact.

Simultaneously, a flamefront attacked the nearby dwellings, causing many of them to burst into flames. The life safety of those in the nearby dwellings and ensuring the immediate evacuation of the most severely exposed properties were critical. Firefighters assisted the police in this assignment.

The incident scene had already been divided into Divisions Alpha, Bravo, Charlie and Delta. Each division supervisor was giving similar progress reports of a fast-moving flamefront and multiple dwellings were afire on Bravo, Charlie and Delta Divisions. They were all requesting additional companies. The fourth, fifth and sixth alarms were sounded immediately. Apparatus that could not be removed from the hydrant locations near the lumberyard were now burning hulks of metal.

Progress reports indicated that all divisions had numerous problems and insufficient personnel. More than 50 dwellings were involved in fire to some degree, and Divisions Charlie and Delta reported that conditions could get worse. The incident commander on hearing these reports struck the seventh, eighth and ninth alarms. This situation had developed within eight minutes of his arrival. His priority now was to ensure that the responding units were assigned where needed. He notified dispatch to send the fourth alarm to Delta Division, the fifth alarm to Charlie Division and the sixth alarm to Bravo Division. The seventh alarm went to Alpha Division to replace apparatus that were destroyed. The eighth alarm was divided up to the divisions as needed. The ninth alarm was assigned to staging.

As master streams were being placed, the large wooden molding building in the center of the complex collapsed, causing an initial surge of a heat wave that was felt around the perimeter. It then appeared that the collapsing roof had a smothering effect on the fire that was burning within the building. Though it would only be a matter of time before the fire would burn through the roof, it could be valuable time to let additional companies arrive and set up master stream devices and attack the dwelling fires.

Reports of secondary fires being started by flying embers was addressed by the ninth-alarm companies. A 10th alarm was sounded and it took hours to fully control the fire. Eventually, more than 60 homes were destroyed or damaged. The lumberyard was a total loss. Two fire department pumpers were destroyed and a number of others damaged. There were a few minor injuries to civilians and firefighters, but remarkably no one died due to the actions and bravery of the firefighters and police operating at this incident.

Lumberyard storage and location

The vast amount of combustible materials heightens the problems associated with lumberyard fires. Heat generation can make exposure protection critical. Lumberyards can contain sawmills, millwork shops, woodworking factories and kilns. Sheds are often of frame construction, not sprinklered and built only to provide protection for the lumber from the weather. They are open toward the yard area to facilitate the loading and unloading of materials and are located close to other piles of lumber.

Lumberyards are often adjacent to railroad sidings or in locations accessible to ships. If situated on a waterway, a lumberyard blaze will require an attack from the waterside. Otherwise, the fire department will be restricted to attack from only three sides. One benefit of having a lumberyard on a waterway is an adequate supply of water for fighting fires.

Railways alongside a lumberyard fire must be shut down to ensure firefighter safety. Firefighters can dig under the rails to place a hoseline in operation until the shutdown can be accomplished. (Hoselines can be fed under the tracks; however, the use of large-diameter lines can restrict this practice.) This tactic does cause a delay in getting hoselines into operation. If confronted with life endangerment, hoselines will have to be stretched over the rails to provide immediate protection. It is important to remember that railroad tracks can mean dead-end water mains on a hydrant system, reducing the available water supply.

Piling of lumber

There are two distinct methods of piling lumber. The first allows for air to flow through the material by placing furring strips between the boards. When a lumberyard operates its own sawmill, the piles of lumber often have intervening wood strips that facilitate air-drying of the boards. With this piling method in use, fire can attack a much greater surface area of lumber.

The second method piles the boards one atop another, exposing only the surface and sides of the pile. This is the preferred method of piling of lumber and can help firefighters control a lumberyard blaze.

Piles of lumber are often found adjacent to roadways throughout a lumberyard to ensure easy loading of lumber onto and off of trucks. These piles can exceed 20 feet in height. Though the piles are evenly stacked facing the roadway, the rear of the pile can be uneven if various board lengths protrude against a pile from the opposite roadway. Uneven board lengths allow increased surface area for a fire to attack.

In yards that manufacture lightweight building components, stacked truss or wooden I-beams create natural air spaces. Fire reaching these products will have sufficient fuel and air available to culminate in a large, fast-spreading and difficult-to-control fire. As lumber businesses expand, the scarcity of yard space often reduces the spacing between piles. This increases immediate exposures, and piles can increase in height.

In addition to lumber, lumberyards carry other product lines. These can range from roofing materials to hot tubs to swimming pool supplies. Roofing materials may include propane tanks. Swimming pool supplies almost always include chemicals for filtration systems. Hot tubs are often constructed of fiberglass or plastic, which will burn furiously. Firefighters battling lumberyard fires should also expect to find plastic pipe and flammable adhesives.

Initial actions

First-arriving units at a fire involving a few piles or an involved shed of lumber must make an aggressive attack on the fire from the leeward side. They should wet down any immediate exposures in an attempt to contain the fire. A 2½-inch hoseline should be the minimum size used. A blitz attack with a master stream can be most effective. The object is to knock down the fire and prevent extension.

The large quantity of highly combustible material in exposed exterior piles of lumber and material stored in combustible buildings create a severe fire hazard. Lumberyard fires develop quickly, with intense heat and rapid fire spread. A fire past the incipient stages has enormous potential to escalate to major proportions and will necessitate a defensive attack on arrival. The spread of fire will be determined by the direction of the wind. The exposures on the leeward side will need immediate protection if the fire is to be contained.

The incident commander’s initial assessment must predict how long it will take to place effective water streams into operation. This prediction of time frames will let the incident commander know how far the fire will extend in the interim and what practical assumptions can be made on containment. It seems to be a rule that fire always extends in the direction that will tax a fire department the most.

The ability to maintain a position in front of a moving fire requires courage, experience and common sense. Courage needs no explanation. Common sense and experience require monitoring of the positions taken by firefighters. If positions become untenable, relocation to the flank, or side, will be required to control the fire. The division supervisors and the incident safety officer must constantly monitor the fire in relation to firefighter safety.

A fast-moving fire must be fought from the flanks of the fire. The aim when flanking a fire is to prevent further fire extension. Lines operated from elevated heights (roofs, elevated platforms or ladder pipes) can sweep a large area above, around and between burning piles. Water applied to the tops of burning piles will extinguish fire on the sides and bottom as it runs off.

Wind is unpredictable and can change direction without warning. This should be anticipated, and positions must not be so close that a wind shift will endanger firefighters. A wind shift can occur for only a short time, and then the wind can revert to its previous direction. If shifting winds are encountered, exposures on more than one front will require protection.

Next: Spread of fire