This Document will help you understand what is being said by firefighters and their dispatchers on the radio. Also note that nearly all radio traffic used by firefighters is plain English. None of that "10-X" code you may encounter on police radio, with one minor (essentially slang) exception that is documented below.

  • Air Tanker (or just Tanker) - an aircraft modified to drop fire retardant on or near a fire. Not to be confused with a Water Tender.

  • A Side (and B Side, C Side, etc.) - building side designators. When fighting a structure fire it is necessary to be able to clearly specify a particular side of a building. To make this happen, the "primary" side of the building - usually the one facing the street, or containing the front door - is called the A Side. Additional sides are named the B Side, C Side, and so on, going around the building clockwise. In a simple rectangular house the C Side is the back.

  • Attack (or Air Attack) - the name of the command and control aircraft circling a fire and directing air operations. Usually the full name includes the fire's name as well, so "Summit Attack" would be the command and control aircraft working the "Summit fire".

  • Attack (or Fire Attack) - putting water on a fire.

  • Battalion WXYZ - Identifies a particular battalion chief. Similar to an engine number, but in this case it identifies a battalion chief in a command vehicle, rather than a crew on a piece of firefighting apparatus. Example: Battalion 1709.

  • Breathing Support - a specialized truck that can re-pressurize the tanks in SCBA units firefighters wear while fighting structure fires.

  • Code 4 - widely recognized slang for "Scene Is Secure". An OK for firefighters and medics to enter an incident where threats might have existed. See Scene Insecure for details.

  • Command Channel - the radio frequency on which the command and control radio chatter occurs. For Santa Cruz County Fire, this is generally the main dispatch frequency (named "CZU Local" with a dispatcher called "Felton") unless the incident gets large or complicated enough that the radio traffic from it makes dispatching to other incidents difficult. The same pattern applies for the Santa Clara Cal Fire unit, operating on "SCU Local", with a dispatcher named "Morgan Hill". Other Santa Cruz and Santa Clara fire organizations usually put command traffic on separate frequencies by default, which are assigned when the crews are first dispatched to the scene. See also: Tactical Channel.

  • Contained - a fire is contained when it is surrounded by fire line of some kind (cut by hand or bulldozer, for example), roads, or other obstacles that will keep the fire from escaping. It is still burning, but its eventual size is limited to the area within the lines surrounding the fire.

  • Controlled - a fire is controlled when it is actually out - extinguished.

  • Copter XYZ - Identifies a particular helicopter working an incident. Copter 106 would be the usual helitack unit coming from Alma Station. Similar to engine numbers.

  • Emergency Traffic - a phrase used by any firefighter on scene when a firefighter is seriously injured or an immediate response is needed to get a firefighter out of a particularly hazardous situation (trapped in a burning building, for example). Others are supposed to stop transmitting until the situation is announced and action to resolve the problem is organized.

  • Engine WXYZ - fire engine identification number. The number specifies a particular engine working an incident. What the different fire engine numbers mean is complicated, varies from department to department, and the numbering schemes don't always work, but here are a couple of examples:

    • Cal Fire

      • First two digits denote the ranger unit. (17 is Santa Cruz/San Mateo, 16 is Santa Clara.)

      • The third digit used to denote 4 wheel vs 2 wheel drive, but this is changing since most engines are 4x4 these days. (The old standard had 6 and 7 denote 4 wheel drive, and 8 and 9 denote 2 wheel drive.) What this digit is used for now isn't clear yet.

      • Fourth digit specifies the battalion the engine is associated with, but this doesn’t always work.

Example: Engine 1764 = Santa Cruz/San Mateo Ranger Unit, 4 wheel drive, battalion 4

  • Santa Clara County Fire Departments:

    • First two digits denote department or company

    • Third digit denotes type

    • Fourth digit indicates home station or quantity

Example: Engine 2513 = Scotts Valley Fire, Type 1 engine, 3rd type 1

Example: Engine 3621 = Company 36, Type 2 engine, 1st type 2

  • Fire behaviors - there are many words used to document fire behavior. This document won't cover them all. A few of the common ones:

    • backing - burning downhill, generally happens slowly

    • running - burning quickly along the ground in a particular direction, usually driven by the wind

    • spotting - embers are blown ahead of the main fire, creating spot fires ahead of the path of the main fire

    • topping - fire getting into the tops of trees, instead of burning on the ground

  • Fire Engine Types - There are numerous designators for fire engine types, and conditions at a particular fire may require an engine of a particular type. You can find a lot of details here: http://www.firescope.org/ics-guides-and-terms/ICS%20020-1.pdf. The common engine types in our area are:

    • Type 1 - An engine designed for fighting fires in cities and suburbs, particularly structure fires. Carries hose for coupling to fire hydrants, ladders, and other equipment for such incidents.

    • Type 2 - Also designed for urban fire fighting, but smaller and carries a different mix of equipment.

    • Type 3 - An engine intended for fighting wildland fires. Smaller, more maneuverable, and often having all wheel drive, with a different equipment mix favoring more rural fire fighting tasks.

Water tenders and other kinds of firefighting equipment also have different type numbers that don't come up in radio traffic all that often.

  • Hand Crew (or just Crew) - a crew of firefighters - sometimes low risk inmates from a local correctional facility - who specialize in cutting line around a fire. They bring tools and numbers to make the job easier, and can isolate a fire and keep it within a given area with these techniques.

  • IC - Incident Commander. The big cheese at an incident, responsible for decisions about how to resolve it, what additional resources to call in, and so on. At a small incident this can be the captain on a fire engine or (on a highway) the CHP officer in charge. As incidents get bigger battalion chiefs are common in this role. Very large forest fires and major events might be managed by specialized incident response teams dispatched by the federal government.

  • Landline - any phone, even a cellular phone. Generally used as part of a request to call the command center or a battalion chief. This can happen if there is too much information to move over the radio conveniently, or if the topic of discussion is too sensitive. (Some medical status information isn't transmitted over open radio frequencies, and often things like requests for the coroner go over the phone too.)

  • Large Incident Terms - When a big incident occurs and hundreds of people are working on it, the organizational hierarchy grows to handle the complexity and new terms get introduced. You may hear the terms Branch, Division, Section, and Group, usually with unique specifiers to designate locations or kinds of responsibility. Divisions are geographic in nature while groups are distinct by function. You may hear designators like Alpha and Zulu used as well, to refer to specific divisions, so Division Alpha might be working the West Flank of a large fire and Division Zulu might be working the East Flank. These hierarchies can get quite complex depending on the specifics of the incident. If you want all the details about how these terms are used, you can study ICS - the Incident Command System - where they are all defined in great detail.

  • Law Enforcement - Used by fire personnel to describe sheriff, CHP or police. Can also refer to the coroner. See also “SO” or "LE".

  • Life Safety Alert - a particular communication to personnel working an incident that some known danger exists on the scene, and to be watchful for it. The most common one in our area is "Life Safety Alert: Power Lines Down", but others are possible. Live ammunition at a fire scene, for example, or known toxins in a storage shed. When a life safety alert is declared, someone from each engine or other piece of equipment operating in the area must acknowledge the threat and make sure that all other members of his or her crew are aware of the situation. The required acknowledgement is very specific: "Engine 3621 acknowledges life safety alert, power lines down" for example. The dispatchers need to be 100% certain that everyone is aware of the problem to avoid injuries or deaths.

  • Medic X - an ambulance. The number specifies the specific ambulance responding. You may sometimes hear a request like "what's our medic unit?" so a fire engine can contact the ambulance by radio with information before they arrive. In Santa Cruz County, "Medic 100" is the medical supervisor on duty, and may come to a larger or challenging incident.

  • Parts of a fire:

    • Finger - a protruding area of active fire sticking out from the main body of the fire. Can be caused by specific features of terrain, for example.

    • Flank (also Left Flank, Right Flank, South Flank, and similar terms) - used to describe the edges of a fire, viewed as if you were standing at the Heel, looking out in the direction the fire is burning

    • Head - the active, hot part of the fire, consuming new fuel. Usually opposite the heel.

    • Heel - the base of the fire, generally near the point of origin.

    • Island - an unburned area surrounded by burned over ground.

    • Origin - where the fire started.

  • Prevention Officer (also just "Prevention" in context) - a fire department official who investigates fire causes and has both law enforcement training and authority.

  • Primary - the primary radio frequency used by a fire engine or other apparatus. Often used when an engine is done working an incident outside of their normal area. They report to the dispatcher they were working with that they are returning to their primary so the dispatch center knows they don't have to track them anymore. In particular you'll often hear this from Santa Clara county fire engines, Scotts Valley fire engines, and ambulances responding to the 95033 area.

  • Priority Traffic - Announced by dispatcher when they need to stop chatter on the radio to dispatch a new incident. Others are supposed to stop transmitting until the dispatch is complete.

  • Report On Conditions - an update from the first engine on scene, or the Incident Commander, or one of the aircraft working an incident to the command center giving the status of a fire. The goal is to provide a concise status of the incident "right now". The following elements are commonly part of a report on conditions, but not all are present in each one. And since these are just given in English sentences, the exact format varies all the time.

    • Fuel Type - light, flashy fuels like grass & weeds, brush, timber, others possible.

    • Potential - how big the person giving the report thinks the fire could possibly get if things get bad. Example: "This one has the potential for 50 acres or more."

    • Rate Of Spread - slow, moderate, fast, extreme, etc. May also call out fire behavior: wind driven, burning uphill, spotting, topping.

    • Resource Needs - what additional equipment the dispatchers should get started for this incident at this time.

    • Size - in various terms: radius, X by Y feet, acres.

    • Threatened Exposures - if structures or other important things are in the path of the fire.

    • Topography - on a hill, in a flat area, etc.

    • Weather - if the weather is a key problem it may be called out - winds, in particular.

  • RP - Reporting Party. The person (or people) who reported an incident to 911. As in "Did you get in touch with the RP to confirm the location?" or "RP is at 123 Some Street and can see the fire on the next ridge to the south from their deck."

  • Safety Officer - someone whose job it is solely to assure the safety of firefighters and others working incidents.

  • SCBA - Self Contained Breathing Apparatus. Air tanks and face masks firefighters wear in situations where the air is particularly bad, most notably structure fires.

  • Scene Secure (or Scene Is Secure) - indicates that law enforcement personnel have determined that it is safe for medical and fire personnel to enter an incident. See Scene Unsecure for details, and Code 4.

  • Scene Unsecure (or Scene Is Not Secure) - certain incidents - usually involving weapons and/or threats of physical violence - contain elements that fire and medical personnel are not trained to manage. In these cases law enforcement officers go in first and make sure the situation is made safe before firefighters and medical personnel are allowed in. Fire engines and ambulances stage nearby and wait for law enforcement to declare the scene is secure before coming in. See also Code 4 and Scene Secure.

  • Staging - a location that fire engines and other equipment congregate at in the vicinity of an incident, but out of the way. Can also refer to a support camp for large incidents. When access to an incident is difficult, equipment may "stage" waiting for the path in to be clear. When the location of an incident isn't certain but a large number of engines are coming, they may stage and wait for the best access routes to be determined by the first personnel to get to the scene. Finally, if a scene is not secure, equipment will stage nearby until law enforcement personnel have determined it is safe to proceed.

  • SO - Sheriff Officer, or Sheriff's Office.

  • Strike Team - a group 5 like pieces of firefighting equipment (engines, bulldozers, etc.) and a leader that that can communicate with each other. (Occasionally fewer than 5 units are in a strike team, but it's usually 5.) They are assembled - sometimes from different fire departments - and sent to assist in an incident elsewhere. That assistance can be anything from fighting a fire to covering fire stations and responding to other, local incidents while the usual fire crews and apparatus are busy.

  • Tactical Channel (aka Tac or Tac Channel) - a radio frequency assigned to an incident to allow people working the incident to talk to each other without interfering with the command frequency. Used for things like traffic control, water supply, and even (on large fires) for the crews working a given portion of the fire line. Large incidents may use more than one tactical channel. Note that these frequencies aren't sent through repeaters and thus are difficult or impossible to pick up with radios or scanners unless you have line-of-sight from your antenna to the incident itself. See also: Command Channel.

  • Taking Action - indicates that a crew from an engine is going start pumping water and putting a fire out. Usually stated because the engine is the first on scene and they will be busy, so the dispatchers know they aren't going to be as responsive to the radio.

  • Unified Command - a term that indicates multiple agencies are cooperating on the command and control of an incident. When an incident spans multiple response areas, or includes multiple threat types, several different agencies may be present. When they've got it sorted out who is running th e show and how decisions are being made, they're in Unified Command.

  • Utility WXYZ - Identifies a support vehicle that carries one or more people and possibly needed equipment to an incident. The numeric code identifies the specific utility vehicle.

  • UTL - Unable To Locate. Whatever crews were dispatched to cannot be found. That may include fire, smoke, an accident, etc. This can happen for many different reasons, but generally the fire folks don't stop looking until they are pretty certain there is no immediate threat of whatever it was they were sent to in that location.

  • Water Tender - a firefighting apparatus specifically designed to haul large quantities of water to an incident. Not to be confused with an Air Tanker.

  • Water Tender WXYZ - Similar to a fire engine numbers. The numeric code specifies which water tender. Example: Water Tender 3651.

 

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