FIREFIGHTING OPERATIONS IN HIGH-RISES UNDER CONSTRUCTION

FIREFIGHTING OPERATIONS IN HIGH-RISES UNDER CONSTRUCTION

BY JERRY TRACY

It is dangerous to work on or within buildings that are under construction. The construction period is probably one of the most hazardous periods in the life of a high-rise. During the construction phase, a combination of construction activity is underway that, at its peak, involves many trades simultaneously. A tremendous fire load of building materials and debris is present during a time when the building`s fire control systems may not yet be complete and operative.

Structures constructed of reinforced concrete are susceptible not only to damage from fire but also to extensive collapse. Vast amounts of lumber–called “formwork” or “falsework”–are used. They are constructed into forms into which the concrete is poured. Before the forms are erected into the shapes intended to be used as foundations–before they are connected to other portions of the structure and become monolithic–they may be nothing but free-standing walls.

As the building progresses in height, the forms are used to shape columns, floors, and beams. The forms are shored up from dimensional lumber used as columns and joists, commonly referred to as legs, ribs, and stringers. Sheets of plywood are used as the base and walls of the forms (called stops). These sheets are often coated with oils to keep them from adhering to the concrete.

In southern climates, this lumber readily dries out. In the northern, colder climates, repeated exposures to heating from salamanders used to help expedite the curing of the concrete cause the lumber to become extremely dry and susceptible to ignition. Oils used to coat one side of this plywood increase the susceptibility. Builders are erecting literally a forest of lumber.

Entire floors may be in danger of collapse should these forms become involved in fire. The forms are supporting the tremendous weight of the recently poured concrete that has not yet set or cured enough to support its own weight.

During the construction phase, many unguarded floor openings are present. The outer perimeter of the floors may be inadequately protected. There is the ever-present danger of falling or tripping over construction material and debris into any one of these vertical openings, especially when crawling around in smoke and darkness. The protection that may have been provided in the form of barriers made of wood, ropes, or synthetic fencing can be destroyed by fire. Another problem these openings pose is that burning debris may fall down into the vertically aligned opening, spreading fire and endangering firefighters who are using these openings as access to the fire or upper-floor areas.

Many combustibles in addition to lumber are prevalent around the site. The following is a partial representation:

Accumulated debris.

Various chemicals.

Membrane rubber used as moisture barriers for windows and doors to exterior openings.

Refuse in containers and strewn loosely around the site.

Stored flammable and combustible liquids.

Tar in pails and tarpaper used for roofing and moisture barrier work.

The hazardous gases propane, oxygen, and acetylene.

PVC cable pulled and drawn throughout the structure for distributing electricity–with the associated piles of scrap.

Shanties built of lumber used as offices, locker rooms, and storage areas.

Friendly fires used to keep workers warm or to burn and reduce the accumulation of refuse.

OPERATIONS

The strategy of our operations is based on the fire`s location and what is directly involved or exposed. The objective is to mount an offensive attack (apply water on the fire as quickly as possible).

Water is the most important resource for providing fire protection and life safety at a construction site. In the urban setting, obtaining water generally is not a problem. In rural areas and undeveloped sections of cities, the availability of water mains or another water source must be established. The location of this resource in relation to the site must be analyzed, and tactics that are operationally feasible must be employed. Until temporary or permanent mains and hydrant connections are provided, water relay and augmentation evolutions must be established. Preplan these evolutions and train personnel to execute them efficiently.

Ways to access the site must also be established. The general contractors running the job–concerned about security and protection against pilferage–may want only one point of access and egress. Depending on the site`s size, location, and topography, one access point may be inadequate in terms of providing an emergency response within a time frame that will maximize the chances of protecting and preserving life in fires or medical and other emergencies. More than one access point may be required on sites that encompass many acres.

TIME IS OF THE ESSENCE

When fire is destroying elements of a building under construction–which may be the temporary or primary supports of the structure–a quick response and knockdown of the fire are paramount. In the case of accidents, such as when a worker is pinned under heavy equipment or steel and is close to death, quick response could mean the difference between life and death.

ON ARRIVAL

On arrival, your size-up is as important as it is at any other response. Determine the following:

Where is the fire located?

What is burning?

What is exposed?

What is the immediate life hazard?

If workers are present, are they trapped?

Are fire service members in danger?

Will the stability of the elements supporting the fire area or entire building be affected by the fire?

Be aware that buildings and structures in the early stages of construction are generally in an open, uncompartmented state. A relatively small fire will rapidly gain in proportion because ample oxygen and fuel are available. In the time it takes to establish a positive water supply and position attack lines, the fire may already have weakened the structure or other appurtenance. Other collapse dangers include scaffolds, lumber stored at the floor`s edge ready for reuse on an upper floor, and rigging and supports for the elevator hoist or the tower crane.

TACTICS

All members on the scene must coordinate their efforts to ensure the effectiveness of the offensive attack tactics deployed by the first-in units. The first-in unit will gain access to the site should security gates be closed and locked.

Water Supply

The first-in engine must have a positive water source. Lay a supply line before entering a site, connect to a hydrant close to the point of operation, or have the supply relayed as per a prefire analysis or plan.

Fires within a structure located near grade level and below will probably be best attacked with handlines or master streams that have the volume and reach to extinguish a fire from a safe vantage point.

When combustibles are involved in fire and no part of the supporting structure is endangered, extinguish the fire directly. When support elements are exposed, it may be critical to extinguish or cool those features before attacking and extinguishing the main body of fire.

Fire located abovegrade will require that a water supply or standpipe system be operational and have the means to support the firefighters` needs. The system may be a dry system. If it is a wet system, the supply of water may be very minimal. It must be capped off and serviceable at the end of the workday. It should rise to at least two floors below the uppermost floor that has been erected.

As the members are starting up to the upper floors with their equipment, the engine chauffeur or motor pump operator (MPO) should connect a supply line to the fire department siamese connection to the building. The system should be supplied with water as soon as all the connections are made. This procedure should be followed when it is obvious that a fire will have to be extinguished with handlines from the standpipe system. It should not be standard practice to charge the systems automatically without a size-up and confirmation of a fire.

A dry system will begin to accept water and then stop at some point until a selected valve is opened to bleed the system of air. Should the MPO note a continued flow of water, the incident commander (IC) should be told that there is a continuous flow and some valves in the system may be open. When flowmeters on the apparatus show an excessive amount of water flowing, this is an indication that more than one valve is open or that a riser was not capped or is open in some manner. The IC must ensure that adequate personnel are deployed to inspect the system to uncover and resolve the problem. Too often, deficiencies of the standpipe system are encountered when the system is needed to combat fires in buildings under construction. The list of deficiencies is endless: outlet valves installed in the open position, section valves in the closed position, hose fittings not threaded in (the male nipple), hose valves with the wrong thread, mechanical couplings not tightened down, and the top of the riser not capped off.

Some departments have adopted the standard procedure of having one unit responsible for walking the stairs and inspecting the riser on the way up to uncover and correct any of these deficiencies. One member will also be sent to the basement or lower levels to ensure that no valves are open and being used to drain the system. Not having the cooperation and compliance of the building contractors in maintaining an operational system could cost the lives of construction workers trapped in a structure or firefighters attempting to save an unoccupied structure and other property from being destroyed.

Gaining Access to Upper Floors

Firefighters must gain access to the upper floors. The approach will depend on the height and the availability of means. The stairs that will become the permanent artery to the building are a sure method of ascent. The fire-rated door assemblies for the stair shafts may not be in place. They are generally installed when the structure has been completely poured and compartmentation work has begun.

Outside construction elevators are another means of ascent–the personnel elevators, not the materials hoist. During the workday, an elevator operator is present to run the elevator. After the end of the workday, no one may be available to run it. On your inspection visits to the site during the early stages of construction, your department members should learn how to supply power to the elevator and operate it so that they can use it after hours if it becomes necessary. This equipment is not guaranteed to be safe. It may be exposed to falling debris or the fire itself, depending on the severity and location of the fire.

Ladder Apparatus

If ladder apparatus can be used for access to an upper floor, use it. Position the apparatus so that the ladder can be used for any needed immediate rescues and for gaining access to the upper floors to expedite operations. Officers of the ladder units should ensure that their members devote their efforts to facilitating the positioning and operation of the first attack line.

Tower ladder platform apparatus should be positioned so that its master stream can be used if the need arises. The same applies to aerial apparatus with ladder pipes. This equipment may be used as a standpipe to support the operation of a handline if the required standpipe is not operational.

The officer of the ladder unit may deploy one member on arrival to inspect the standpipe riser. Engine units may not have adequate staffing to perform this inspection.

On arrival at the target floor below the fire, size up the floor and note the location of the standpipe riser(s) at that level. Determine which riser will allow the attack team to be in a position to begin its attack with the wind at its back (if the building is in an open condition) and also a position that will afford it a means of retreat should conditions worsen.

Since these buildings are in an open state, the attack does not have to be launched from an enclosed stairway. The stairways may not yet be enclosed. Other vertical openings in the floor may give access to various points of the fire floor, allowing for positioning that is favorable to wind conditions and the least punishing on the attack team attempting to extinguish the fire.

The IC must be aware of and warn all operating units and members that the force of the master streams or handheld lines may blow debris and loose material off the fire floor. Areas below may have to be vacated and secured from entry while operations are in progress. Buildings in close proximity to the fire building may be subject to exposure and fire extension from burning embers and debris. Adequate personnel and equipment must be available for that eventuality.

SAFETY

For safety during operations on the fireground, and especially at construction sites, all ranks must respect and practice it. From the moment of arrival, your decisions and actions should be deliberate, and you should proceed with caution, beginning with the positioning of apparatus and members. Observations made during size-up should ensure that members and apparatus are clear of all collapse zones of the structure or equipment supporting or attached to it. All members must be aware of the hazards at construction sites and of the following:

that concrete poured within a short time period (less than 24 hours) may not have set or cured enough to remain in place.

that should the formwork fail or burn away, extensive collapse could occur.

that members must not be positioned under a potential collapse situation. The reach of hose streams provides safety in distance.

that even after the concrete has cured, a heavy fire will cause spalling. Large sections of the concrete may fall or sometimes explode down onto firefighters operating below.

that there exists the potential for falls through open shafts or off the edge of the building.

TRAINING

Training can be defined as instruction and practice in a particular skill. Our skill or trade, if you wish to call it that, involves more than shooting water from a hose. Laborers can perform such tasks. Firefighters are not laborers; we are craftsmen.

Our knowledge and skills are not acquired through osmosis but by physically experiencing and performing the many facets of our trade. Using our tools and equipment, we learn not only our capabilities and limitations but also those of the equipment and tools on which we rely.

The heat generated from fires at times cannot be explained in mere words. It destroys matter and life. The by-products of combustion are not only toxic but may be also highly flammable and explosive. We are acutely aware of the power and speed with which fire spreads and ravages.

Practicing the techniques for using our tools and equipment will enhance the speed of our performance whether it be stretching, positioning, and operating hoselines; forcible entry; ventilation; or search.

TIME IS NOT AN ALLY

The fire service is called on in times of emergency. There is no time for training when life is threatened. Decisions that affect life and death have to be made in a split second and with accuracy and merit. Knowing and reviewing what to do, how to do it, and which tools and equipment to use to accomplish the task–all have to be thought of and practiced in advance of the response. Training may save your life.

High-rise building under construction. (Photos by author.)

(Top left) Vast amounts of lumber are used to create forms, called “formwork” or “falsework.” (Top right) Forms are supported by legs, ribs, and stringers. (Bottom left) Unguarded floor openings create hazards for responders.

Sign depicting the location of the fire department water supply connection. An early, steady water supply is vital to saving lives and property.

Lumber at the floor`s edge awaiting transport to upper floors for reuse adds to the collapse hazards at a construction site.

(Left) Upper floors can be accessed by apparatus ladders or (right) outside personnel construction elevators, which are not guaranteed to be safe.

(Left) Fire can damage formwork and (right) concrete (through spalling).

JERRY TRACY, a 20-year veteran of the fire service, is captain of Tower Ladder 35 of the City of New York (NY) Fire Department. He is an instructor and developer of training courses at the FDNY Training Academy and lectures on firefighting operations, strategy, and tactics involving structures including high-rise, commercial, and residential buildings, as well as hotels.