The warehouse door is locked, smoke seeps from the bottom, and the key is stored in an empty office drawer. At this point, the emergency response team faces forcible entry: forcibly opening access to a closed space with tools, to rescue people or extinguish a fire.
It sounds like just a matter of strength and a crowbar. The operational guidelines of the UK fire service (NFCC) and research from the UL Fire Safety Research Institute (FSRI) in the United States reveal two other things. Most decisions are made before the tools touch the door. And an open door also changes the behavior of the fire.
Six questions before forcibly opening the door
NFCC requests a brief risk assessment before force is applied. It can be summarized into six questions:
| Question | Why it's asked |
|---|---|
| Is the location correct? | A wrong door means damage without results |
| Is it necessary, urgent, and justified? | If lives are at risk, immediate action is justified. If not, choose the method that causes the least damage |
| Have all doors, windows, and other access points been checked? | There may be an unlocked entry point |
| Which entry point is the best? | The first entry point should be temporary |
| What method is the safest and simplest? | Incorrect techniques can injure the responders themselves |
| What tools are most appropriate? | The right tools cause minimal damage |
Building security features also come into play. Steel doors, bars, or card access influence the tools and techniques chosen.
NFCC categorizes tools into three groups: cutting, prying, and striking tools; mechanical equipment, including cylinder lock pullers; and hydraulic tools. The Forcible Entry class from Texas A&M Engineering Extension Service (TEEX) uses the same cutting, prying, and striking classification, targeting doors, windows, and even walls.
An open door also gives the fire air
FSRI states it plainly: forcing the front door must be treated like horizontal ventilation. Once the door is opened for responders, it is also open for airflow, and the fire can gain a new air supply.
The Coordinated Fire Attack study from FSRI, funded by a DHS/FEMA grant, tested this in real buildings: residential homes, three-story apartments, and a 12-unit shopping complex. The results can be read as a cause-and-effect table:
| Situation in the experiment | Measured outcome |
|---|---|
| An opening was made just before or after water was sprayed | No significant temperature increase outside the burning room |
| An opening was made, spraying was delayed | Temperature exposure increased throughout the burning apartment unit |
| The unit door was left open | Temperature and carbon monoxide increased in the shared stairwell |
| Shopping complex: opening without extinguishment | Heat release rate and temperature increased |
| Shopping complex: extinguishment simultaneous with opening | No measurable increase in temperature or pressure |
Controlling the door to keep the opening small (door control) is a tactic that has proven to limit gas flow to the stairwell. In the residential experiment, conditions improved most rapidly at the point closest to the entry after water was sprayed. So, while an open door can enlarge the fire, it can also help trapped individuals. The key factor is the delay between the door being opened and the water following.
A candid note: these experiments were conducted in residential and commercial buildings in the United States, not in processing facilities. The direction of the findings is consistent across all three types of buildings, but the numbers cannot be directly transferred to refinery or collection station areas.
Entry points are also exit points
TEEX emphasizes that forcible entry is not just about getting in. Responders must also be able to exit if conditions or tactics change. NFCC translates this into action: if the first entry point is compromised or narrow, clear away glass shards and debris, or open the door from the inside after entering through a window. The location of alternative exit routes should then be communicated to all personnel on the ground.
What can be prepared before an incident
NFCC refers to specific location risk information and inspection visits as preparation. Responders who are familiar with the models of doors, windows, locks, and security devices in their area will be quicker to choose a method. For K3 supervisors in facilities, this preparation can be a simple checklist:
- Which doors are locked outside of working hours, and who holds the keys.
- Doors with special security features: steel, bars, card access.
- Alternative entry routes to frequently locked rooms.
- Who to contact to secure the area after forcible entry.
The last item is often overlooked. NFCC reminds us that after operations are completed, properties need to be left in a safe condition, and the owners should be informed that access was forcibly opened.
If you prefer to see the explanation directly, there is a short clip about forcible entry from the K3 Migas Supervisor class.
Sources
- National Fire Chiefs Council (NFCC), National Operational Guidance: Gain access or entry, updated August 22, 2024.
- UL Fire Safety Research Institute: Study of Coordinated Fire Attack Utilizing Acquired Structures, findings from residential, apartment, and commercial experiments.
- UL Fire Safety Research Institute: Analysis of the Coordination of Suppression and Ventilation in Multi-Family Dwellings, June 23, 2020.
- UL Fire Safety Research Institute: Tactical Considerations Ep. 13: Forcing The Front Door Must Be Thought of as Ventilation, August 28, 2018.
- Texas A&M Engineering Extension Service (TEEX): Forcible Entry, CEF009.