The size-up process has been defined in many ways over the years, but they all boil down to determining what the problem is and what the incident commander needs to do about it.

Conducting an accurate initial size-up is critical to safe and successful fireground outcomes. The initial size-up is going to determine what strategic priorities the incident commander selects, what initial actions are going to be taken to address these priorities, and what resources will be needed to carry out these desired actions. In turn, this will determine the size and scope of the command system needed to maintain command and control over the incident.

A chief officer's size-up must be based on current conditions and the potential situation five, 10 or more minutes out.

The fireground is a dynamic place with conditions constantly improving or deteriorating. Therefore, a chief officer must continue the size-up process throughout the incident and be willing and able to adjust the plan of action to meet these changing conditions. Perhaps the only aspect of size-up more important to an effective fire attack than an accurate initial size-up is an accurate ongoing size-up.

Fireground decision-making is based more often on intuitive reactions to visual cues than on a classical decision-making method. These cues often are recognized throughout the size-up process. For example, when a chief pulls up to a structure fire, he does not consciously ask himself what the apparent smoke conditions indicate for the potential fire spread and the risks to attack crews. Instead, when he arrives and sees dark smoke churning out of the front door and windows of the structure, his mind knows that flashover is about to occur, and that concern begins to drive his decisions.

Over the years, many methods have been developed to help chief officers and potential chiefs learn and recall the most common factors affecting size-up. Chief Lloyd Layman outlined 18 “facts and probabilities for mental evaluation by the officer in charge of a fire.” Most discussions on size-up center on the 13-point list of size-up factors, summarized by the common acronyms COAL WAS WEALTH or WALLACE WAS HOT. Both acronyms are useful for the purpose they serve — remembering a list of various size-up factors — but have limited application in actually conducting a size-up on the fireground.

While learning William Clark's 14 points of size-up from his Firefighting Principles and Practices, I realized that four of the 14 points deal with resources available, including water supply, apparatus, personnel and internal protection. I saw that the remaining 10 points deal with the situation at hand and can be broken down into three other categories: the building, the fire and conditions. From there, I began playing with the size-up factors until I had four factors listed under each of the four categories. This creates an easy method to remember the size-up factors and places them into groupings that are usable to chief officers during the size-up process. (See “4×4 Size-Up Method,” below.)

Layman asserted that fire officers could be taught strategy and tactics by learning a method or process to follow. He developed the basic divisions of firefighting tactics and the basic mental evaluation system for this very purpose. Likewise, chiefs can learn good size-up techniques by consistently considering fireground factors in a logical sequence. Early in their careers, new chiefs consciously can force themselves to move through this process. As they become more experienced, this process will occur subconsciously, through a natural flow of information, observations and cues. The 4×4 method facilitates either the forced process or the natural flow.

To show that this system works for any chief, consider Chief Smith, a full-time shift battalion chief in an urban setting, and Chief Jones, a volunteer fire chief in a small town. Both chiefs are sly veterans who will move through the process naturally, but they could just as easily be newly promoted chiefs, training their minds to think through the sequence of factors.

When Smith arrives at the station to begin her shift, she checks weather forecasts for the day. Jones does the same when he starts his day. If the forecast predicts any significant weather conditions, both chiefs instinctively begin thinking of how such conditions could affect any fire responses. They will begin planning, at least mentally, what they will need to do to counter those effects.

If the forecast shows single-digit temperatures and snow, Smith may call all the companies in her battalion to ensure they are prepared for cold-weather operations and arrange for portable heaters to be available, if needed. If the forecast shows high heat and humidity, Jones notes to himself that he will call for mutual aid at the first indication of any working fire and will contact the spouses' auxiliary to bring water and sports drinks to the scene. These chiefs already are starting the naturalistic, cue-based size-up process before they even know if they are going to get an alarm that day.

When they are toned out for a fire, each chief subconsciously notes the time of day and the day of the week, which automatically cues them to any factor affected by the time of day or day of week. This could include the life hazards in the fire buildings or response times and staffing levels.

Each chief also will gather information from the dispatcher about any conditions reported by the caller. On hearing the address or perhaps a business name, both chiefs will begin to form a mental image of the types of buildings in that area or of the specific building, if known. They initially would rely on their own knowledge of their response area, which hopefully will be supported by consulting written preplans as soon as possible.

Smith immediately thinks of response conditions, such as the availability of the normal first-due engine, already on another call, or the first-due ladder running an old reserve piece at the moment. Jones also would consider response conditions, for example that the address given is at the far corner of the response district, and the county is doing roadwork in the area.

As the chiefs are getting into their vehicles, they have begun naturally running through the size-up process.

Both chiefs would consider their resources early on. As a full-time fire chief, Smith would have an advantage because she would know her staffing levels and their abilities before the alarm comes in. Jones would immediately begin considering his available staffing levels based on the time of day and the day of the week. He may not know what his staff will consist of until he hears that first-out engine transmit that they are responding.

Both chiefs should know the status and availability of their apparatus, which are mechanically in service or out of service. Again, Jones may not know for sure which pieces of apparatus he is going to get on the response.

Both chiefs should have an idea of the water supply in the area. Smith may have no concerns if the area has a good grid of 10-inch mains, or she may start sweating if the fire is in an older, low-service section of the water system. Jones, on the other hand, knows he'll be relying on a tanker shuttle or a drafting site about a quarter mile from the fire.

Both chiefs should know from their knowledge of the buildings in their response area or from their preplan data whether or not the building to which they are responding has any form of built-in fire protection.

By now, half of the size-up factors have been considered and neither Smith nor Jones is even on the scene yet.

Depending on how well Smith or Jones knows the response area, many of the building factors also can be considered while the chiefs are still en route to the fire. When dispatched to the Acme Shoe Factory for a fire in the warehouse, Smith immediately pictures the 4-story, block-long, heavy-timber construction building and its freight elevator shaft in the northeast corner. Or Jones, when dispatched to 1212 Royal Estates Dr., quickly envisions the average 3,600-square-foot mega home with a possible walk-out basement in the rear, steep-sloped slate-tile roof and lightweight floor truss system typical of new subdivisions that sprung up over the past two years. Otherwise, the building factors may not be considered, or at least confirmed until the chiefs are approaching the fire scene. One of the first building factors that strikes a responding chief is the size of the building. Incredibly large buildings offer obvious challenges, while an unusually small structure could alter their decisions in a completely different manner.

All chiefs also should be able to recognize on sight the type of construction of any given building. Once the type of construction is noted, characteristics of the style that present collapse hazards or promote fire spread should throw up red flags in the chiefs' minds.

Both Smith and Jones should consider the building's occupancy from both life-hazard and fire-loading aspects. Estimating and confirming the life hazard and fire load within a structure will play a significant role in the chiefs' action plans.

Access to the building normally is considered only when a problem with access is present. For example, Smith will curse when she arrives to find a locked gate at the factory and Jones may cringe when he arrives and sees the house on fire sits 500 feet off the road with a steep narrow winding driveway.

Information from the dispatcher may include clues about the fire situation such as, “The caller advises smoke coming from the third floor windows,” or, “Report of a fire in the basement.” But the smoke and fire factors normally are viewed on arrival.

The first cue the chief sees on the scene normally deals with the size of the fire or amount of smoke present. Does Smith arrive to find fire venting from one window or six? Does Jones note light wisps of smoke coming from the eaves of the house or heavy black smoke churning from several windows?

The amount of fire and/or smoke, the intensity of the fire, the color of the smoke or the occupancy of the building all give indications as to the type of fire, or in other words, what is burning. One key factor is to determine whether the fire only involves the contents of the structure or the structure itself.

The location of the fire may be the most critical factor of all, as this will determine the level of threat the fire has for extending. If Smith arrives at the shoe factory to find the top floor fully involved in flames, she obviously has a large fire that will probably occupy the remainder of her shift. She knows she has time to set up master streams, consult the water maps and request the coffee wagon. However, if she arrives to find moderately sized trash fire at the bottom of the freight elevator shaft, she realizes she is pressed to get adequate water on the fire as quickly as possible to prevent the fire from spreading up the shaft.

Likewise, while flames showing from the front bay window of the 3,600-square-foot house may look impressive to Jones, indications of even a small fire involving the light-weight floor assembly space may have devastating consequences if not recognized early.

The size and location of the fire will then determine what exposure problems or extension possibilities exist. Are there external exposures that are threatened by the volume of fire venting from the top floor of the shoe factory, or is the heat going to raise through the elevator shaft and ignite the underside of the heavy-timber roof?

While the 4×4 method separates the size-up factors into distinct categories, many of the factors are interrelated. Time of day may affect the occupancy load of the building. The wind direction may affect the exposure problem. Response time may affect the size and location of the fire.

All pertinent factors must be considered during the initial size-up whether they stand alone or correlate to one another. Instinctively, the chief officer will consider each factor as cues draw his attention to them, as opposed to going through a standard checklist of options. But, as described here, the 4×4 method offers a practical, realistic format for those instincts to flow.

New or inexperienced chiefs can be trained, through the use of various simulation or visualization exercises, to consistently use the 4x4 size-up method until their size-up techniques develop into more natural, cue-based instinctive reactions.

This flow will take chiefs from factors they may have already been thinking of before the alarm was received, right up through considering where the fire is located and where it is going. These two factors provide the perfect launching point into the development of an action plan, as, other than life safety, these two factors will normally dictate which initial actions to take.

---

Rick Ennis is the fire chief for the city of Cape Girardeau, Mo. He is a third-generation fire chief with more than 27 years of experience, including nearly 12 years as a fire chief. He earned an associate's degree in fire administration and a bachelor's degree in urban affairs and public administration, and is a graduate of the National Fire Academy's Executive Fire Officer program.

4×4 Size-up Method

RESOURCES

• Staffing
• Apparatus/equipment
• Water supply
• Built-in protection

CONDITIONS

• Weather
• Time
• Dispatch/preplan info
• Response conditions

THE BUILDING

• Size
• Construction type
• Occupancy
• Access

THE FIRE

• Size
• Type
• Location
• Extension/exposures