Chuck O’Connor: Each urban detonation is its own separate reality, but despite these abstract realities, these procedural guidelines have proven effective. Caution, you never stop seeing something new. Never be complacent during any urban detonation experience.

About the author

Chuck O’Connor is a retired Navy SEAL with 44 years of tactical explosive experience, 38 years dedicated to explosive entry operations performed in active urban environments, not range facilities.

Chuck has developed multiple counter terrorism training and advisement programs for LE, military special duty assignments and bomb squads throughout the world.

His explosive entry course is DHS/FEMA approved and funding for hosting of the course is eligible through the Homeland Security Grant Program.

Chuck is looking forward to get your feedback or actively discuss the topic of this article with active operators and/or industry SME. Do not hesitate to reach out:

Contact Chuck at:


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Discussion Part 3: Establishing Urban Detonation Study and Documentation Procedures

The Article

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Based on threat conditions, operators have different entry tools for selecting the optimal method or combinations to access fortified crime scenes.

Explosive entry provides capabilities not possible with the other methods of entry:

  • Significantly faster access through fortified entry points
  • Allows access through other portions of the crime scene to avoid surveillance, ambush, IEDs, and unknown fortifications at expected entry points

Photo: Initiation of an IED during Entry

Explosive entry also exposes operators, the public, and crime scene occupants to significant hazards compared with the other methods of entry.

The following procedures are the starting point and continuation process in preparation for operational explosive entry detonations in active urban environments and following legal proceedings (both non-linear systems).

Priorities for urban detonation study, risk assessments, and TTPs development are in preparation for suspect-initiated operations.

Suspect-initiated operations prevent detailed crime scene information collection, analysis, or rehearsals.

Documented urban detonation study and TTP development is the rehearsal for suspect-initiated operations.

This process is also for documenting:

  • Factual charge performance
  • Identifying all hazards unique for each urban detonation on both sides of the entry point
  • Validating accurate load data
  • Identifying post-detonation effects that could further cause operator injuries and jeopardize the tactical response
  • Develop efficient TTPs and operational safety procedures with tactical team participation

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Significant Urban Detonation Realities are never replicated on Ranges

Each urban detonation is its own separate reality, but despite these abstract realities, these procedural guidelines have proven effective.

Caution, you never stop seeing something new.

Never be complacent during any urban detonation experience.

During an operation:

  • The optimal charge configuration and strength from your factual load data are not based only on the type of breach point.
  • Safety for operators and crime scene occupants is never based only on procedures developed from narrow-focused, overpressure research/study projects.
  • Other explosive disciplines’ procedures and technologies have proven inadequate.

The priorities for documenting charge performance are your pre-constructed charges designated for rapid threat response.

When opportunities are available, detonate these charges against every type of door, door frame, window, window frame, floor, wall, and roof (based on what is pre-constructed for use) to document these charges’ performance.

There are many real-time features, and conditions range training can never replicate that can only be experienced during urban detonations.

Decades of misusing explosive equations from narrow-focused overpressure procedures applied on ranges have never properly developed the ability to identify all hazards prior to detonation.

One example is illustrated in these photographs showing operators staged at a calculated incident overpressure distance but not recognizing the dangers of positioning in front of a window.

Operators will perform as conditioned.

If tactics are flawed from artificial environment conditioning narrow-focused on overpressure, the operational response will be equally flawed with no ability to understand self-correcting actions.

Examples of Urban Detonation Realities

There are many features that are not replicated on ranges using façades that affect efficient TTP development and safe entry team positioning.

Examples include porches, balconies, landings, thick vegetation, and property items creating obstacles.

Often, the terrain is not level, or the optimal entry point is elevated, requiring ladders for charge placement and entry.

Along with documenting all hazard risk assessments, charge performance, and confirming charge load data, environmental activities and conditions must also be documented.

Examples: my urban detonation training program has thousands of detonations without causing unidentified damages or disruption of activities in and around:

  • City halls during working hours
  • Neighborhoods with occupying residents (day and night)
  • Level 1 trauma centers performing surgeries
  • Filming studios during recording sessions
  • Active pedestrian, vehicle, and rail traffic (day and night)
  • Airport terminals during flight operations
  • Schools, casino resorts, professional sporting events

Detonations have also been conducted without damaging various utilities.

Photos: Wall Entries with no damage or disruptions to active traffic, powerlines, and natural gas lines

Photos: Detonations must also be conducted during twilight and nighttime.

Incident, Reflective and Amplified Overpressure Hazards in Urban Environments

Overpressure is an obvious hazard to operators, the public, crime scene occupants, and property.

At times, incident overpressure is the only hazard to the operators and lessens the injury risk to crime scene occupants.

Example 1: This wall entry point had no close reflective surfaces, and the charge’s optimal NEW produced low-speed wall debris that slid across the room’s floor with low overpressure venting in with the debris field.

Photos: Wall Entry with no Reflective Surfaces is Safer to detonate (SME Witnesses felt less overpressure than a Distraction Device).

It is critical to identify when physical conditions negate safe detonation with a charge’s optimal load on both sides of the breach point that requires the selection of another entry point or method of entry.

Example 2: this close reflective surface forced amplified overpressure, high-velocity wall debris, and enhanced flames into the room and negates safe detonation though the NEW is optimal for this wall.

Photos: The reflective surface deflected amplified overpressure, increases wall debris velocity and flame into the room.

Example 3: detonation within this enclosed space forced amplified overpressure into the room, produced high-velocity wall debris that projected through the room, and broke through the far wall.

Amplified overpressure also created structural damage to the residence wall (left side), the back wall of this car port, and the wall where the charge was placed.

Though this charge is the optimal NEW for this type of wall, the physical conditions negate safe detonation for the room occupants and the surrounding property.

Overpressure is not the only hazard that must be identified and considered to determine if the charge is safe to detonate and safe positioning.

Projected Debris Hazards

Example: projected debris is a risk to the entry team and containment personnel.

Shockwave Hazards

Example 1: shockwaves can cause additional risk at the entry team’s position that the calculated incident overpressure distance never identifies.

At the calculated 4 PSI incident overpressure distance, shockwaves can break windows, drop rain gutters, or roof materials on the entry team, causing injury.

Annealed glass shards are large and dangerous when falling on the operators.

Example 2: shockwaves can cause structural compromise to a structure’s corner negating safe detonation of the charge.

Photo: The charge is the optimal load but placed too close to the corner.

Safety note: instruct your operators to never lean against the wall during a detonation.

Fire Hazards

Example 1: certain charge configurations may create a fire within the wall or roof that operators must immediately extinguish after initial entry.

Operators must plan for immediate fire suppression because fire services may not deploy while the threat conditions remain active.

Example 2: if flammable dust or vapor conditions are present on either side of the entry point, a catastrophic fire or explosion could occur

When fire is identified as a potential risk, use charge configurations that extinguish the incendiary effect during detonation.


Additional Considerations

These potentially hazardous conditions that eliminate the use of explosive entry must be known prior to detonation.

These experiences also identify the extent of cosmetic damage that must be explained in detail before the detonation.

Threat conditions may justify some cosmetic damage but never structural compromise or other catastrophic results.

The tactical team must also participate during urban detonations in order for each operator to learn how to self-identify risk and self-implement corrective actions.


Decades of executive and tactical leaders, legal representatives, city risk managers, agency insurance underwriters, and explosive safety oversight professionals’ urban detonation participation have confirmed their firsthand experiences could never be intellectually understood by any other process.

These are the only professionals that provide the certifying authority for an operator to perform urban detonations.

This discussion reviewed example risks and hazards to mission essential personnel, crime scene occupants, the public, and property that can never be replicated on range facilities with façades.

Limited and narrow-focused overpressure training using ranges have been responsible for decades of:

  • Avoidable injuries (including TBI)
  • Subsequent costs associated with injury treatment
  • Tactical response disasters
  • Extensive, unpredicted property damages repair or replacement costs
  • Loss of using this explosive capability
  • Liability for the agency and individual officers
  • Sources stating that range training provides every aspect critical to know and recognize to perform safe operational urban detonations or provide the experiences for liability reduction are not urban detonation SMEs.

Your urban detonation SME knowledge and success with the two non-linear system challenges can only be achieved through documented firsthand urban detonation experiences.

Discussion Four will review how to identify the optimal charge NEW load and obstacle clearing requirements.


Chuck O’Connor


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Photos by Chuck O‘Connor