Explosives and ammunition are stowed in magazines or areas designated for the specific materials. NAVSEASYSCOM designs and designates all magazines or storage areas. The type and amount of material that may be stowed in any magazine depends on the type of magazine in relation to the explosive safety quantity-distance requirements. 

Types of Magazines

KEYPORT - The keyport magazine is earthcovered and arch-shaped with a prefabricated concrete construction. It has interior floor dimensions of 6 feet by 8 feet 8 inches. The height of the arch is approximately 6 feet.

BOX - A box magazine is of concrete construction, rectangular shape, and normally measures 12 feet by 17 feet.

CORBETTA - A corbetta magazine is of concrete construction and is shaped like a beehive or dome.

GALLERY - A gallery magazine is a tunnel or cave, and the dimensions will vary.

The physical dimensions of the miscellaneous or nonstandard magazine depend on the type of stowed material and the location of the magazine. 

OPEN STORAGE - The type and amount of explosives stowed in open stowage depend on the size and location of the storage area.

PREFABRICATED MAGAZINES.—Advanced base magazines are prefabricated, earth-covered, arch-type structures that are used to provide weatherproof storage for ammunition of all types. The barrel of each advanced base magazine is an arch made of sheets of corrugated sheet metal bolted  together to form a semicircular-arch roof.  Two screened, sheet metal ventilators are mounted on top of the arch, one at the front of the magazine and one at the rear. The rear wall is constructed of corrugated sheet metal. The front wall is constructed of wide, heavy-gauge metal plates, which are reinforced with angles and channels. The front wall extends above and to each side of the outer limits of the magazine, providing retaining walls for the earth fill. The ends of the plates that extend beyond the limits of the magazine are secured to the structure by turnbuckle rods. The magazine floor is a concrete slab placed on compacted gravel or broken stone fill. A pair of 8-foot, double-leaf doors is placed in the front wall of the magazine. Screened louvers are placed in each door for ventilation. The table below lists the available magazine sizes, maximum storage capacities, and the recommended separation distances between the magazines. A barricade is placed opposite the front wall of each magazine used for the storage of high explosives or fuzes and detonators. The barricade extends to the height of the inside crown of the magazine arch. The barricade must be at least 3 feet wide at the crest and slope to a grade on the natural slope of the earth used as fill.

IDENTIFICATION OF FACILITIES

Buildings and magazines, including open storage sites that contain ammunition, explosives, or chemical and inert components, are marked according to a standard system of identification so you can rapidly identify the hazards associated with their contents. This identification and numbering system is used in addition to any other numbers on the buildings. These standard identification markings are stamped out over other markings, if present. The standard identification system consists of the magazine designator and the symbol indicator. The magazine designator is a three-group symbol, composed of numbers and letters. It identifies a magazine by location of the magazine group, the number of the magazine within the group, and the type of magazine construction. The magazine group number, the type of magazine and capacity letter(s), and the magazine sequence number form the three-group symbol that makes up the magazine designator.

The magazine group number is the first number of the magazine designator symbol. It shows the  magazine group in which the magazine is located. Each physically separated group of magazines or, at smaller stations, each noncontiguous magazine area is assigned a number, making it easy to identify the group. The group numbers begin with 1 and continue in ascending numerical order. If only one magazine group exists, the number 1 is used. For example, the numeral 4 in the first position of the magazine designator 4XTX4 indicates that this magazine is located within magazine group 4. 

Magazine Type and Capacity Letter(s)  The magazine type and capacity letter(s) shows the type and capacity of the magazine. For this reason, magazines of certain sizes are assigned a letter designation as indicated in the tables below. To show the type of magazine, for example, the letter T is added if the magazine is earth-covered and barricaded. If the magazine is earth-covered but not barricaded the letter C is added. If the magazine is not earth-covered but is barricaded, the letter S is added. Therefore, in the magazine designator 4XTX4, the letter X in the second position indicates that the magazine size is miscellaneous or nonstandard, and it is normally used for storing high explosives. Also, the normal explosive storage limit depends on the magazine's size, location, and type of construction. The explosive limits contained in the tables below are maximum capacities. They are based on magazine design and construction characteristics. These limits are further subject to the ESQD considerations discussed previously. Additional limitations are shown in the magazine designator. When the ESQD relationship, as indicated in the tables, doesn't permit using the explosive capacity design of a standard magazine because of  insufficient separating distances, the letter X, Y, or Z is added to the designator. These letters indicate the magazine contains mass detonation hazards, mass fire hazards, or fragment producing hazards, respectively. For example, in the magazine designator 4XTX4, the letter X in the fourth position tells you that the magazine doesn't have a sufficient separating distance from other structures or magazines. Before 1985, naval facilities used to store or maintain ammunition or explosives used a standard two-part system of identification—a color-hazard indicator and amagazine designator. 

Magazine Designators for Mass Detonating Hazard of High Explosives (Bulk, Depth Charges, Mines, Warheads, Bombs, etc.), Fuzes, Detonators, Exploders, and Black Powder

Magazine Designators for Fire Hazard of Powder (Bulk or Semifixed Ammunition), Pyrotechnics, Ignition Fuzes and Primers, Small Arms, Smoke Drums, and Explosive-Loaded Chemical Ammunition

Magazine Designators for Fragment Hazard of Projectile and Fixed Ammunition

Magazine Designators for Miscellaneous Magazines

Identification of Magazines and Open Storage Sites

3. A number designating the sequence of the magazine within the magazine group or area. Letter designators for advanced base storage are indicated in table below. To indicate the nature of the construction of the magazine, the letter T is added if the magazine is earth-covered and barricaded; the letter C is added if the magazine is earth-covered, but the door isn't barricaded. The letter T is  also used to designate open storage. Advanced base magazines, buildings used as magazines, caves, tunnels, and open storage sites do not conform to the standard magazine sizes prescribed in NAVSEA OP 5, volume 1. Therefore, the letters X, Y, or Z that identify explosion hazard, fire hazard, or fragment hazard, respectively, are used in place of the standard letter designators. Accordingly, XT is applied to an earth-covered, barricaded, advanced base magazine that is used for storing high explosives. In addition, the following information must be conspicuously posted on one door in each magazine or building that contains ammunition: 

1. The hazard classification of ammunition (explosion, fire, or fragment) stored there.

LIGHTNING PROTECTION SYSTEMS

LIGHTNING MAST SYSTEM.—This type of primary system consists of lightning masts (freestanding air terminals) placed around a facility and connected to a buried primary girdle. A sufficient number of masts are used to protect the entire structure within the combined cones of the masts. The dimensions of the structure determine the number and height of masts required to adequately protecting a structure.

WIRE SYSTEM.—This system consists of overhead lightning protection conductors spanned between lightning masts above a facility. The conductors are connected to a buried ground girdle or to ground rods only, depending upon the type of installation.

The secondary lightning protection system consists of a buried girdle to which all metal parts are connected at the lowest point. This implies that electrical access to all reinforced steel must be provided during construction. The normal wire ties are considered  sufficient to provide electrical connection between the sections of reinforced steel that are in contact with each other.

Nonclimbable fences protect magazine areas. All the entrances are locked unless guards are posted. Post a sign at all the entrances to restricted areas. The sign indicates that every vehicle must stop, that each person must present proper credentials to the guard, and that all articles prohibited within the area must be given to the guard. The exact wording of the signs are left to the discretion of the commanding officer. However, the word explosive doesn't appear on the sign, and the sign isn't attached to the magazines. Special precautions are taken to guard or patrol the areas that not protected by suitable fencing. Magazine and explosives areas where ammunition, explosives, and other items of high-security classification are stored must be adequately guarded at all times. Don't let unauthorized personnel enter or remain in any magazine or explosives area. Personnel involved in ammunition handling operations are authorized in magazines or buildings that contain explosives only as required, and theymust enter and leave explosives areas at designated points. Additional information on the requirements for posting, fencing, unguarded facilities and vehicles, emergency events, and security alarm systems is found in Department of the Navy Physical Security Instruction for Sensitive Conventional Arms, Ammunitions and Explosives (AA&E), OPNAVINST 5530.13.

MAGAZINE/MAGAZINE AREA INSPECTIONS

• Ensure magazine repairs are made, if needed.

• Ensure that safety regulations, particularly those that involve cleanliness and elimination of fire hazards, are observed.

• Ensure that magazine contents are not deteriorating into an unsafe condition, and they are stored in an orderly, compatible, and approved manner. The magazine area inspections are designed to make sure the following actions are being maintained: 

• Firebreaks are being maintained.

• Fire protection equipment, when required, is available and serviceable.

• Roads are good and in usable condition.

• Fences are secure.  

At times area inspections are performed more often than magazine inspections, particularly during seasons when grass or brush fires are most likely to occur.

The majority of the ordnance items in the Navy inventory are designed to withstand temperatures in the range of 130° to 160° Fahrenheit. Temperatures within conventional ordnance storage  magazines seldom exceed 105° Fahrenheit. Therefore, you don't have to closely monitor the temperatures within these magazines. However, in the case of special magazines, such as certain missile/missile components, torpedoes, and mine magazines that require environmental control, control-system monitoring is still required.

You must record the date and hour of each inspection in a magazine inspection log above the signature of the person who made the inspection. Promptly report substandard or abnormal conditions to the officer or supervisor in charge of correcting it. Then annotate the observed conditions in the log. Note satisfactory and normal conditions in the log by the entry normal. Magazine inspection logs may be destroyed 1 year from the date of last entry.