By Magnus Bostrom, EOD Technician in the Swedish Army & Business Development Manager for the Middle East, Africa and Europe at Dynasafe Protection Systems
In the US, the only hazardous material that is still allowed to be burned in the open for destruction on an industrial scale is explosives. Open Burning and Open Detonation operations are used to destroy excess, obsolete, or unserviceable munitions and energetic (i.e. explosive) materials. All other open burning of hazardous materials meant for destruction have been banned by the US Environmental Protection Agency (EPA). The reason for this is that in the past, open burning or detonation was the only safe way to dispose of these materials, and since they are hazardous reactive materials, they were the one exception under the Resource Conservation and Recovery Act (RCRA) which controls the destruction of hazardous waste.
Open burning and open detonation of explosive hazardous waste is, however, damaging to human health and the environment. Large amounts of dust (particulates), carbon monoxide, unburned hydrocarbons and nitrogen oxides are emitted whenever open burning or open detonation of explosives is performed. In addition, the noise and shockwaves transmitted through the earth can also cause damage as well as nuisance to nearby residences. Finally, the ground in and around the open burning or detonation site is frequently contaminated with explosives, heavy metals and sometimes even untreated munitions, all of which can contribute to pollution of the site and eventually pollution of the groundwater.
Today, that situation has changed. Dynasafe technology has been proven to be a safe, non-polluting alternative to open burning or open detonation. Virtually any excess or abandoned military munition or munition constituent, such as propellants and explosives, can be safely treated in a Dynasafe Static Detonation Chamber (SDC).
Dynasafe units have a history of over 10 years of processing military munitions, explosives and propellants, safely and effectively. Our SDC units come in several sizes to accommodate various needs, and some can even be moved from site to site, so that disposal of unstable explosives can be accomplished without having to transport the unstable explosives over busy public roads and highways.
Tens of thousands of tons of munitions and explosives have been safely processed in SDCs worldwide and SDCs have processed virtually every munition type out there. The SDC has in every respect been demonstrated to be a safe and effective alternative to open burning or open detonation.
So now the question is, is open burning and open detonation obsolete? We think the answer is yes. We are of the opinion that open burning and open detonation of explosives needs to be eliminated, except in cases where moving an unstable explosive or explosive item is so dangerous that it cannot be disposed of otherwise (for example terrorist bombs or fused and fired unexploded ordnance). The use of open burning or open detonation of explosives in most cases is no longer justified, given the technology available on the market today.
Outlining Requirements for a Mobile Explosive Containment Vessel
Mobile Explosive Containment Vessels (MECV), also known as Total Containment Vessels (TCV), are fully enclosed vessels designed to safely secure, transport, and test explosive devices. MECVs are used by first responders, public security bomb technicians and military EOD teams as explosive mitigation tools to help protect people and property from primary and secondary fragmentation debris and hazardous gases that are created from the detonation of an explosive device.
MECV’s are typically installed on a trailer or a truck for ease of transportation to the bomb threat location. Once the suspect package is contained in the chamber, the surrounding area is protected from blast effects of the explosive device up to the explosive rating of the chamber.
MECV Technology Overview
An MECV has four components: the explosive containment chamber, the gas-tight system, suspect package loading tray and the frame holding the chamber. The chamber is typically spherical and made of high-strength steel 25mm to 40mm thick. The chamber has an access door, an internal loading tray for holding the suspect packages, and a door locking system to keep the access door closed and gas-tight. Some MECVs have a protective layer of lead located between two layers of steel as a protective measure from radioactive materials, such as a dirty bomb.
All chambers are rated for a maximum internal blast pressure, which is called the trinitrotoluene (TNT) equivalent. The TNT equivalent for these vessels, typically measured in kilograms (kg), can range from 5 to 8 kg. A DDESB-certified MECVs have a safety factor of 25% above the explosive rated capacity of the chamber. Therefore, if a chamber has a DDESB certification of 5 kg of TNT equivalent, its actual explosive rating is 6.25 Kg of TNT (5 kg + 25% X 5 kg = 6.25 kg).
The size and location of the vessel’s access door is an important consideration. If the door opening is too small, the suspect object may not fit inside the vessel. If the door is in an inconvenient location, such as the top of the chamber, it may be difficult to access the explosive device for rendering safe procedure once it is in the chamber. Most chambers have side-loading openings ranging 457mm to 1030mm in diameter. Some chambers have a door opening that rotates up to a radius of 270° to facilitate the loading of an IED or a suspect package.
A loading tray mechanism inside the chamber enables smooth loading and unloading of suspect packages. Some chambers have a loading tray that is integrated into the door opening. The loading tray is automatically deployed when the door is opened with no operator interaction. The suspect package remains in the tray during transport.
DYNASEALR X10 ON A COVERED TRAILER
The capability of some MECVs to remain gas-tight is achieved in one of two ways. The first is a system consisting of two half-rings which tightly clamp together to hold the multiple rubber O-rings and the access door in a closed position. The clamping of the O-rings between the door and the chamber forms a pressurized seal resistant to high temperatures. The other system is to inflate pneumatic seals with 1000 PSI of nitrogen. The benefit of this approach is that the inflated pneumatic seal will expand and adhere to the contour of the chamber door and create an impermeable barrier to trap the hazardous gases generated from the explosion from passing into the environment.
The containment chamber is mounted on a steel or aluminum frame for support. The frame is designed to support one or two actuator button(s) for robot operation of the door, remote control, flood lights and other equipment. It also accommodates a retractable all-weather aluminum cover, designed to provide protection from the elements and conceal the vessel from the public.
Applications
Explosive containment chambers have many applications in law enforcement, security, and transportation for safely securing, transporting and testing explosive devices. Many government and commercial office buildings, including embassies, nuclear power plants, airports and other transportation facilities are prime targets for bomb threats. The MECV is designed to contain the bomb while being transported to an area where it can be rendered safe. Terrorist activities continue to escalate worldwide and MECVs are a great tool to meet bomb security needs.
Selection of an MECV
First-responder and military or public bomb squads that consider purchasing MECVs should carefully consider each product’s overall capabilities and limitations in relation to their agency’s operational needs. Important mission-critical factors need to be considered when purchasing an MECV:
- What is the explosive rating needed to meet the mission critical objectives? Is the maximum internal blast pressure of the chamber capable of mitigating and controlling a detonation of 5 kg of TNT equivalent? Is it 8 kg? More, or less? The larger the explosive rating, the safer it will be for the bomb technician and the area surrounding the suspect package.
- Is the number of repeat detonations that a chamber can withstand more important to the EOD mission than a one-time blast capacity? There is a chamber that can contain the blast pressure of a 20 kg of TNT from an improvised explosive device. Is the one-time blast capacity more valuable to the mission than a chamber that can withstand 10 repeat detonations of 8 kg of TNT? A balance needs to be found between safety and the economics of utilizing a chamber for render safe procedures. As stated above, the larger the explosive charge that the chamber can contain, the safer it will be for the bomb technician and the area surrounding the suspect package.
- What is the ideal door access diameter? The bigger the diameter of the door access, the larger the suspect package that can be loaded. The quicker the suspect package can be loaded, the safer the bomb technician and the surrounding area.
- What are maximum object dimensions (mm/inches) that will fit onto the tray inside the core chamber?
- What are the methods used to test and evaluate the chamber? Does the company utilize a third party to test their vessels? What type of tests are conducted? Is the chamber tested for its capability to contain gases after a detonation?
- Any explosive containment chamber that is for use in emergency situations where the threat is unknown should remain gas-tight at its maximum repeat detonation capacity. How long does the chamber remain gas-tight?
- What is the weight of the MECV? Will a dedicated vehicle or driver’s license be needed to transport the chamber?
- What is the weekly, monthly or annual maintenance requirement of the chamber? Fewer number of moving parts translates into reductions in required maintenance and more time dedicated to added value activities such as training.
