This publication is a revision and compilation of the handbooks on American explosive ordnance published during World War II by the U.S. Navy Bomb Disposal School. With some exceptions, it should serve as an encyclopedia of U.S. explosive and pyrotechnic ordnance as of Februar 1946.

Included are: U.S. guided missiles, bombs, rockets, land mines, grenades, pyrotech-nics, and Navy projectiles. Not coverd are: Army artillery ammunition, demolition explosi-ves and equipment, underwater or floating ordnance, small arms ammunition, or catapult charges, etc.

Such characteristics of construction and operation as are significant to the ordnance student receive thorough treatment. Other technical details are omitted.

Most of the items are grouped according to size; but, where this is impracticable, numerial or type arrangement is employed.

To make the publication more serviceable for peacetime use, practice items are inclu-ded in their appropriate sections.

Ordnance included was that classified as service, together with some obsolete, obsol-escent, and experimental types. The experimental items were those being actively deve-loped in the spring of 1946, with the probability that they would soon be standardized.

Obsolete and obsolescent equipment described was that which might still be in exist-ence in depots or dumps at the time of writing.

When a Navy ordnance item is approved for testing, it is assigned its Mark number. It retains this Mark number whether finally approved for service use or rejected. Modificat-ions to the original Mark design are treated likewise. Army items under development are assigned "T" numbers. If the item is standardized by the Army's Ordnance Technical Committee, the "T" designation is dropped and an "M" number is assigned. When a modi-fication on a "T" item is made, the change is given en "E" number: for instance, "T1E1". If the modification is adopted as a standard item, the modification gets an "A" number in sequence of change on the standard item: for instance, "M66A1, M66A2". The Army's Chemcial Warfare Service uses "E" and "R" designations for experimental items instead of the "T" and "E" numbers, respectively, of the Ordnance Department. For aircraft ordnan-ce there are items which are standardized for both the Navy and the Army. These are given the letters "AN" before their original standard name; thus, AN-Mk 33 or AN-M63A2.

Prior to June 1925, the Army's nomenclature for bombs was by a Mark and Roman nu-meral, like the early Naval Mark designations, but the modifications were distingushed by the letter "M" and another Roman numeral (Mk I M II) where the Navy used the abbrevia-tion "Mod", (Mk 1 Mod 2). In 1925, the Army adopted the "M" system. The Army-Navy Standardization Board was created in June, 1941.

Two scales are employed to compare sensitivity of explosives. The first of these is the "Laboratory Impact Sensitivity" in which the ratio of the drop of a given weight ne-cessary to detonate the explosive under discussion to the drop necessary to detonate TNT, is expressed on a percentage basis. TNT will be given as 100. The second is a scale of "Bullet Impact Sensitivity" with RDX rated at 0 and TNT at 100. The other explosives are expressed in relation to these two. Velocity of detonation varies directly with the density to which the explosive is cast or pressed, all other factors being constant. The veloicty of detonation wll, therefore, be given for a definite density of loading.

TNT (Trinitrotoluol): TNT is powerful, brisant, easy to load by casting since is melt-ing point (Grade A) is 80.2 degrees C., stable under all stowage conditions, insensitive enough to stand all normall handling, and even capable of standing bullet impact when cast. The Navy uses it wa a booster in a pressed granular form is which it is more sensi-tive to detonator action.

The velocity of detonation is 22,300 ft./sec. at a density of 1.55. Its Laboratory Im-pact Value is 100. Its Bullet Impact Value is 100. Its color is yellow to buff.

Tetry (Trinitrophenylmethylnitramine): Tetryl, because of its combination of high power, brisance, and sensitivity, is the standard U.S. booster charge, although the Navy still uses an appreciable amount of granular TNT. It has been treid for main charge loads in small caliber projectiles, but has proved too sensitive to withstand the setback in all but 20-mm. It is used as a base charge in compound detonators. This, in effect, makes it a small booster in intimate contact with the initiating explosive. The melting point of Te-tryl (130 degrees C.) is too high to allow it to be melted and cast. It is loaded by being mixed with small quanities of graphite or stearic acid which serve to lubricate it while it is being pressed into pellets. Tetryl is quite safe to handle and is exremly stable in stow-age. Exposed or loose Tetryl should not be handled, as it may cause dermatitis.

The velocity of detonation is 24.400 ft./sec. at a density of 1.55. Its color is light yellow, but it is usually gray because of the graphite. It is more powerfull than TNT. Its Laboratory Impact Value is 45. Its Bullet Impact Value is 61.

Explosive D (Ammonium Picrate): Explosive D is the standard main charge for ar-mor-piercing bombs and projectiles and other Navy projectiles. While its power and bri-sance are slightly inferior to TNT, it is much more insensitive to shock and will stand im-pact on armor plate without being deflagrated. It has two other disadvantages: (1) Its melting point is too high for it to be melted and cast, and it is therefore loaded by being pressed into cases by a hydraulic ram; (2) It reacts with metals to form extremely sensi-tive compounds. This is counteracted by covering the interior of bombs or projectiles with acid-proof lacquer.

Its rate of detonation is 21,300 ft./sec. at a density of 1.48. Its power and brisance are about 95% those of TNT. Its Laboratory Impact Value is 99; its Bullet Impact Value is over 100. Its color is yellow or yellow-orange.

RDX (Cyclonite Cyclotrimethylenetrinitramine): RDX is the most powerful and bri-sant of the military high explosives, and it is considered much too sensitive to use alone. It seems to be about half way between Tetryl and PETN in sensitivity. RDX is being used extensively in mixtrue of other explosives and inerts which reduce the sensitivity to a safe range, while the mixture have a very high brisance and power due to the RDX. It has excellent stowage qualities, but, because of its sensitivity, it is shipped immersed in water like an initiating explosive. The velocity of detonation is 28,000 ft./sec. at a den-sity of 1.70. Its Laboratory Impact Value is 34. Its Bullet Impact Value is 0. Its color is white.

PETN (Phentaerythritetetranitrate): PETN resembles RDX in its characteristics. It is somewhat most sensitive, but almost equal in power and brisance. It is appreciably more sensitive to percussion and impact than Tetryl and is, therefore, not used alone as a booster, though it is being used as a base charge in some compound detonators in the way Tetryl is. The tendency of PETN to burn is much less than that of similar explosives. Its main use alone, PETN is combined with a small quantity of wax to densitize and lubri-cate it, and is loaded by pressing. It is important to known that PETN in primacord is very insensitive to flame, shock, and friction, and therefore must be detonated by a cap.

The velocity of detonation of PETN is 26,000 ft./sec. The velocity of detonation of primacord is 20,500 ft./sec. Its Laboratory Impact Value is 22. Its Bullet Impact Value, though not given, would be aout equal to RDX (0). Its color is white.

Haleite (EDNA, Ethylenedinitramine): Haleite is a new explosive that probably will not be used alone, but will be used in combination with other explosives. It is somewhat more powerful than TNT. Its sensitivity is about the same as Tetryl. It melts at 180 de-grees C., but one report states that it may detonate in the manner of an initiating explo-sive at that temperature of a little lower. If loaded alone, it would be pressed. Its rate of detonation is 25,000 ft./sec. at a density of 1.5. Its Laboratory Impact Value is 46. Its Bullet Impact Value is not available.

Nitroguanidine: Nitroguanidine is the explosive incorporated in the Navy's new doub-le-based propellant powder, SPCG. It is unusual in being a high explosive that is so cool in its reaction that it explodes without flash. It is comparable in strenght to TNT, and its senisitivity is of the samer order. Its rate of detonatin is 24,400 ft./sec. at a density of 150.

Amatol: Amatol, a substitute for TNT, is a mixture of ammonium nitrate and TNT; the percentage of ammonium nitrate, depending upon the availability of TNT, has varied from 40% to 80%. Its power and brisance decrease with the increasing percentages of nitra-te, and its sensitivity decreases at the same time. However, it is still a fairly good high explosive, even when the TNT is reduced to 20%. 80/20 cannot be cast, since it is not fluid enough to pour even when TNT is molten, and it therefore must be loaded by ex-trusion. Amatol has a disadvantage in that it is very hydroscopic and therefore is usually protected by a sealing pure of poure TNT.

The velocity of detonation of 50/50 is 19,700 ft./sec. at a density of 1.54. Its Labo-ratory Impact Value is 93. Its Bullet Impat Value is about 100. Its color is buff.

Composition B: Composition B is intended to be used as a more powerful replacement for TNT in the loading of some of the large size G.P. bombs, and in fragmentation bombs. It will be used where an explosive with more power and brisance is of tatical advantage and there is no objection to a slight increase of sensitivity.

Composition B1 is a mixture of 59% RDX, 40% TNT, and 1% wax. Composition B2 is a mixture of 60% RDX, 40% TNT. The TNT cuts down the sensitivity of the RDX to a safe range and lowers the melting point to 81 degrees C., allowing the material to be cast-loaded.

Composition B might be detonated at low order by bullet impact, but it is almost as in-sensitive as TNT in this respect. It has an extremely high shaped-charge efficiency. Its velocity of detonation is 24,500 ft./sec. at a density of 1.60. Its total energy of blast in air is about 116% of that of TNT. Its Laboratory Impact Value is 79. Its Bullet Impact Value is 79. Its color is yellow to brown.