The purpose of this Building Type page is to assist in the planning and/or design of new Ammunition and Explosive (AE) storage magazines for the Department of Defense (DoD) by providing definitions, descriptions, requirements, and standards of drawings and specifications as available. The information is intended to offer a general introduction into the design and approval of AE storage magazines. For additional information refer to the DoD Component-specific explosives safety documents and the DoD explosives safety manual referenced below.
The Department of Defense Explosives Safety Board (DDESB) has established uniform minimum AE safety standards for personnel and property that have the potential of being exposed to the effects of an accidental explosion. These standards govern the design, construction, and use of all AE storage magazines within the Department of Defense.
Earth Covered Magazine (ECM) structures are built to store AE. They are not designed to resist the damaging effects from an internal explosion, although they can effectively contain the effects from an explosion of very small AE quantities. ECMs are designed to protect their contents and prevent propagation of an explosion that may occur in an adjacent magazine. Proper siting of an ECM, from other Potential Explosion Sites (PES) and Exposed Sites (ES) including operations buildings, piers, aboveground magazines, rail sidings, classification yards, etc, ensures against unacceptable damage and injuries in the event of an accidental explosion.
Facilities are sited from a PES using the appropriate Explosive Safety Quantity- Distance (ESQD) relationship and based upon the Net Explosive Weight (NEW) at the PES.
DoD explosive safety standards are contained in DoD 6055.09-M. Explosive safety standards that implement the DoD standards are contained in the following:
A. ECM Designs
ECM designs fall within three basic structural hardness classifications; "7-Bar", "3-Bar" and "Undefined" depending upon the relative ability to resist blast loadings. The DDESB has established design criteria for each of the ECM classifications, and approved the classification of previously designed ECMs. DDESB Technical Paper (TP) 15 summarizes the development of AE storage facilities and documents approved protective construction designs.
Approved ECM designs may be site-adapted or tailored to the requirements of a specific site. Site specific tailoring primarily involves adapting the foundation and the drainage system to suit local soil and site characteristics. In addition, certain AE may require additional consideration for utilities, security, electrical, grounding, or humidity and temperature limits.
Any changes to approved designs, other than minimal site adaptation, that in any way may affect the explosive safety of the magazine design will not be used for construction without coordination and approval from the appropriate design agency and from the DDESB.
- "Undefined" (Nonstandard) Designs
An Undefined ECM provides the lowest level of blast resistance and requires the greatest siting separation distances. An Undefined ECM may store up to 500,000 pounds NEW of hazard division 1.1, however many of the designs are based upon a lower storage capacity.
B. Siting Criteria
Siting criteria for ECMs has been developed by the DDESB to define the minimum required separation distances between an ECM as a PES and ES that would be impacted from an accidental explosion. Minimum separation distances have been established between ECM and other magazines, operating buildings, inhabited buildings, and public traffic routes to ensure uniform minimum explosive safety standards for DoD facilities. Minimum separation distances are determined by the level of protection mandated by the applicable explosive safety standard, the ECM classification, the ES type, the quantity and type of AE within a PES, the physical orientation between the PES and the ES and the potential presence of barricading.
For most PES—ES orientations involving an ECM, it can be generally stated that the required siting separation distances are typically greater for a 3-Bar than a 7-Bar ECM and greater still for an Undefined ECM.
C. Approval Requirements
Plans for ECM projects must be reviewed and approved by the DDESB to ensure that minimum DoD explosive safety considerations have been addressed. Situations requiring approval include:
- New construction or major modification
- Changes in utilization of facilities that affect the siting separation distances
If pre-approved ECM designs are used, the project site plan along with the drawing numbers of the ECM design must be submitted for approval.
All new 7- and 3- Bar ECM designs must be approved by the DDESB before they can be used. The approval will require the submission of test results and/or detailed structural calculations.
All new Undefined ECM designs require approval from the DDESB to ensure minimum design and construction criteria are met.
For a description of the minimum requirements to validate explosive safety protective construction see the Department of Defense Explosives Safety Board Memorandum DDESB-PD , dated 21 October 2008.
D. ECM Design Resources
The tables for ECM design resources are currently undergoing a refresh for the new WBDG. Our staff are reviewing graphics, references, links, etc. to bring you the most up-to-date information. As the data is completed for each table, it will be linked below.
Previous ECM designs have been grouped into four categories described by the following tables. The tables include information related to the design of the magazines including size and maximum stowage capacity. Only the designs within the first category, Table 1, are pre-approved as 7- or 3- Bar ECM Designs for new construction. The source of these tables is DDESB TP 15.
An individual summary page for each of the approved magazine designs is linked from Table 1. Electronic drawing files in PDF format are also provided along with additional information, if available, including guide specifications, AutoCAD or Micro Station drawings that can be downloaded and tailored for site-specific conditions, DDESB approval letters, and other relevant data.
- Table 4—Magazines (Earth-covered and Aboveground) and Containers that have reduced net explosives weight (NEW) and/or reduced quantity-distance (QD)—The contents of this category lists a number of AE storage structures and containers that have been approved by the DDESB for specific NEW and/or reduced QD. These items were generally designed for a particular application; however, as approved items, they can be used for other applications, providing all conditions, restrictions, design elements, etc., are observed. All documentation pertaining to the use of the storage structure or container must be obtained prior to their use. Table AP1-4 of TP-15 identifies restrictions or conditions for the use of these magazines or containers.
E. Typical ECM Features
- In the case of a box-type ECM, the walls and roof may be constructed of reinforced concrete or of prefabricated concrete panels that are assembled in the field. Earth cover, lightening, and grounding criteria described above also applies to box-typed ECM.
F. ECM Types
Listed below are the descriptions of the cross-section of magazines.
Arch—Also known as a circular arch. A single radius is used to define the interior face of the arch, which may be constructed of reinforced concrete, steel (corrugated, laminated, or single gage), or a combination of reinforced concrete and steel to form a composite arch (steel interior arch with overlying concrete).
Arch, Oval—This arch is in the shape of an oval, with the lower portion of each sidewall bowing in towards the direction of the centerline. The arch can be constructed of steel, reinforced concrete, or a composite of both. The shape is defined by the use of a single radius for the majority of the arch, with a separate radius called out for the lower portions of the arch. The modified FRELOC-Stradley ECM design is an example of an oval-arch ECM.
Arch, Semi-Circular—The sidewalls are elongated with the arch defined by a radius that originates approximately 3 to 5 feet above floor level. A radius originating at the opposite sidewall defines the lower portion of the arch. The arch can be constructed of either reinforced concrete or steel.
Stradley—This reinforced concreted ECM is characterized by vertical sidewalls that blend into the arched roof. Three radii are used to define the arch and the transition from the vertical sidewalls to the roof arch. Another feature of the Stradley ECM is that its walls are significantly thicker at the base of the sidewalls and thinner at the crown of the arch. There are currently no Stradley designs approved for new construction.
FRELOC-Stradley—The FRELOC-Stradley ECM is constructed of reinforced concrete. Its interior shape is similar to a Stradley ECM, except that the sidewalls and arch have the same thickness.
Modified FRELOC-Stradley—This ECM design was the first ECM constructed with an oval arch. See the information above for the oval arch. There are currently no Modified FRELOC Stradley designs approved for new construction.
Box—This term describes any ECM that has an internal box shape. Explosives limits can range from less than a pound NEW of hazard division 1.1 to 500,000 pounds NEW hazard division 1.1.
Dome—The domed shape is used for only the Corbetta ECM design. The interior wall is approximately three times the height of the magazine. There are currently no Dome designs approved for new construction.
G. ECM Selection
The selection of an ECM is based primarily on the type and quantity of AE that will be stored in the magazine and the cost of construction. Siting restrictions, potential operational considerations, AE compatibility, and other considerations may also factor in the selection of the magazine.
Individual summary sheets for each of the approved 7- and 3- Bar ECM designs within Table 1 are provided to help in the selection process. The information provided in the summary sheets include the physical dimensions of the magazine, approved drawing number, number and size of doors, maximum NEW storage capacity, and comments related to the use of the design.
Individual services may also provide additional guidance on the selection of magazine designs.
Suggested storage layout plans for various AE within many of the approved magazine designs are available to assist in the effective use of the magazine and as a tool to estimate the potential stowage capacity. The U.S. Army Technical Center of Explosives Safety (USATCES) develops and maintains several tools and documents related to the storage of AE.
- NAVSEAINST 8024.2
- U.S. Army Command drawings 19-48-75-5
Barricades are protective structures that can act as a barrier between a PES and an ES. When properly sited and constructed they are an effective protection against low angle fragments and for reducing shock overpressures near the barricade. To protect against low angle fragments barricades must be high enough to intercept the ballistic trajectories of fragments and thick enough to reduce the fragment velocity to acceptable levels.
Relevant Codes and Standards
- The Air Force Sustainment Center
- The Defense Ammunition Center
- Department of Defense Explosives Board (DDESB)
- The Naval PHST Center
- The Naval Safety Center
- The U.S. Army Engineering and Support Center, Huntsville, AL
- The U.S. Army Technical Center for Explosives Safety
- DDESB TP 15 Approved Protective Construction by Department of Defense Explosive Safety Board.
- DDESB-PD Memorandum, 21 Oct 2008, Minimum Requirements to Validate Explosives Safety Protective Construction by Department of Defense Explosives Safety Board.
- EP 1110-345-102 Engineering and Design Explosives Storage Magazines by Department of the Army, Army Corps of Engineers.
- NAVSEAINST 8024.2 Magazine Stowage Layout Standards by Department of the Navy, Naval Sea Systems Command.
- TM 5-1300/NAVFAC P-397/AFR 88-22 Structures to Resist the Effects of Accidental Explosions by Departments of the Army, the Navy, and the Air Force.
- U.S. Air Force Munitions Facilities Standards Guide, Vol. 1
- U.S. Air Force Munitions Facilities Standards Guide, Vol. 2
- U.S. Army Material Command Drawings 19-48-75-5 by U.S. Army Ammunition Center and School (USADACS).