The Ins And Outs of Size-Up

By: Michael L. Walker

The process of “size-up,” the gathering of information about the scene, has been taught for decades. Unfortunately, during most training classes, size-up is discussed as an individual endeavor. The need for shared fireground size-up information is not always stressed. The proof of this deficiency is no more evident than when reading National Institute of Occupational Safety and Health (NIOSH) line of duty death (LODD) reports. Failure to perform size-up -or inadequate size-up- and not sharing size–up information, are always a factor in these reports. The continuous sharing of size-up information is a key element for success on the fire ground. In this article, we will discuss using two distinct locations to facilitate size-up that-if applied correctly- will greatly increase scene awareness and operational efficiency. The Incident Commander’s (IC) Exterior Size-Up

The Interior Officer’s Size-Up

Too often, incident commanders depend solely their own view of size-up as the “correct” fireground operation view; when in reality, size-up is more accurate when viewed and evaluated from two sides. The purpose of size-up should be to visualize and hear what is happening on the fireground from others outside of your sensory reach; and then be able to understand the implications of that information. The feedback from inside the structure provides a view no incident commander should be without.

Initial arriving officers must be mindful not to pull the tactics-trigger too quickly and succumb to the temptation of “just getting to work.” Take the time to process what you are facing so you do not waste time correcting any oversights. This goes for both the exterior size-up as well as the interior size-up.

For example, being able to visualize the smoke that is showing is not enough. What is the smoke telling us? How long the fire has been burning? Where is the fire burning inside the structure? What type of fuel is burning? Are there signs of backdraft or the precursors of flashover? These are all elements of a proper size up inclusion/exclusion process.

Time Factor

Depending on several variables -including how long the incident has been going on- one view of size-up may be more accurate than another view. Typically, early in the incident, the view from the interior has a more accurate perspective than the outside view. If the fire is still confined to the room of origin, the crews inside have a better perception of the environment because of their close proximity to what is actually burning. Conversely, later in the incident, the outside view may reveal more valuable information, especially pertaining to fire progression or fire extinguishment.

Outside View

When the Fire-Attack officer believes they have successfully knocked down the main body of the fire and orders the nozzle firefighter to shut down the line: The officer reports to command they have a knock down of the fire; all the while heavy fire is still issuing from a portion on the roof. In this example, the officer is not able to see the fire above so the IC must report to Fire-Attack what is actually happening. If the IC fails to maintain a vigilant watch on the exterior conditions, the crews on the interior may be heading for a devastating surprise.

As the necessary information is conveyed between interior crews and command, the process of continued size-up is used to its fullest potential. So what kinds of information should we convey? We know there is such a thing as too little information, but is there such a thing as too much information?

ICs and company officers should avoid giving long oratories on the radio. Too much talk can interfere with other necessary information exchanges; keep your words on target explaining what you see and what you are planning to do next.
Command should be sensitive to the challenges interior crews are facing; and refrain from pestering them by asking for too many progress reports. The IC should reserve requests for updates for particular times: If the operation is taking longer than expected, or if rapid-changes in smoke or fire conditions occur. Similarly, if conditions worsen inside the interior crews should immediately inform command.

Fire-Attack Crew

As the crew assigned to Fire-Attack finds the fire room and begins to extinguish the fire, the officer should transmit a message such as, “Engine One to command, we have water on the fire.” Command now knows the progress of Fire-Attack and compares the radio report with what is visible from the exterior. If command still sees flames, crews on the interior need to informed. The IC should relay where flames are issuing from and the fire’s volume. Once informed of this new information, current resources can both reach and extinguish the fire or other crews will be ordered to the area for final extinguishment.

Fire-Attack should communicate initiation of the attack, extinguishment progress, knockdowns, and unexpected problems. Items such as low attack line pressure, barriers preventing them access to the main body of fire, additional rooms of fire, or any other piece of information that paints a clearer picture of interior operations, and if assistance is required.

Search Crew

Crews assigned to search should give periodic size-up information to command as they obtain certain benchmarks. The search team should inform command when they locate the fire or another one within the building. If they can, the door in the room where the fire is located should be closed in order to slow fire progression; then the officer should state where the fire is located, and how much fire they observed. Search should also inform command when they have completed their search on a particular floor and are moving to another floor in the building. If they locate a victim, they should declare their discovery and where and how they plan to bring the victim out of the structure. If the search crew needs assistance, this too should be transmitted. When the primary search is completed, the officer must inform command. The completion of the primary search is a significant benchmark that many ICs use as a determining factor when deciding on further operational objectives. As soon as the possibility of saving a life is addressed, the need to keep interior crews in an IDLH atmosphere is lessened.

Ventilation Crew

The ventilation crew should also look for specific items that will help others on the scene get a better understanding of the incident. If the vent team is going to perform vertical ventilation, they should cite when they have completed the cuts and what the effect is. If the vent team reports heavy, hot smoke coming from the ventilation opening, command would hope to hear from interior crews that visibility is improving and heat is dissipating.

If the ventilation crew states that there is only light smoke coming from the ventilation opening the interior crews should also observe light smoke. If, however, the crews on the interior are enduring heavy smoke conditions and rising temperatures then the ventilation hole is ineffective and corrections need to be implemented immediately.

Ventilation should also inform command if they cannot complete vertical ventilation and why. Usually this occurs because conditions on the roof have become unsafe: which means either heavy fire exists, or the roof is showing signs of weakening. Either is a major safety hazard that must be communicated to command. If the ventilation crew cannot complete their assignment for any reason, command must be informed. The IC’s strategy will have to be modified upon receiving negative action reports.

If Positive Pressure Ventilation (PPV) is going to be implemented, the ventilation crew should inform interior companies when the blower is started; and the person assigned to observe the exit opening should state whether they see the desired effect of PPV: which is increased smoke volume or fire from the exit opening. If that is not seen within a minute, this should be transmitted on the radio so the fan can be shut off. This is also another cue ICs should use as a gauge as to how the action plan is progressing.

Building Construction

Any article about size-up would be remiss if it did not mention how important building construction is to size-up. Although it is beyond the scope of this article to address building construction adequately, the main point that must be stressed is that we must understand how critical building construction is to determining the correct approach to the given situation.

Firefighters of all ranks must dedicate themselves in expanding their knowledge of how fire affects a certain type of building. Each type of construction has typical pros and cons towards the amount of time firefighters can work within them and what type of tactics should be implemented. Construction knowledge allows crews to understand an element of the fire scene we cannot change and how to adapt our operations towards it. There is no such thing as a one size fits all approach to fires or buildings. For example, if a crew has implemented an interior attack inside a Type-II strip mall structure with a roof deck supported by metal trusses, and fire is beginning to impinge the roof supports. This should be transmitted to command so that either the decision to withdrawal personnel, or if scene staffing permits, establish a large diameter attack line to begin cooling the structural members while interior operations continue. Any company working on the roof will appreciate this information so that they can re-evaluate their safety. This bit of information will also clue the IC and other exterior operating companies to start checking for structural compromise on the exterior.

A final note concerning building construction is that if crews believe they are working with a particular type of construction, and it is discovered that the initial information is incorrect, this must be conveyed to everyone. Confusion on what type of construction is being confronted is common. With today’s “hybrid” buildings, it may be impossible to determine the construction methods from an exterior viewpoint. Single-family dwellings that look like a Type-V construction may in fact be a Type-II construction with light steel roof and/or ceiling supports. This bit of information will have a significant impact concerning ventilation options and length of work time inside.

Throughout the incident, conditions must be continuously observed, and information processed to allow for informed decisions. An important step to achieve a complete picture of the incident is to maintain a good dialogue between interior crews and command. A complete, ongoing size-up cannot be achieved through only the Incident Commanders perspective. When crews working inside and outside the structure know what to look for and what to do because they have communicated their size-up observations, it creates a more complete assessment of conditions and a safer fireground

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