U.S. Explosive Ordnance, OP 1664, 1947, describes and illustrates United States Navy projectiles, Army and Navy rockets, pyrotechnics, grenades, land mines, bombs, and guided missiles.
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OP 1664 (VOL. 1)
U.S. EXPLOSIVE ORDNANCE
28 MAY 1947
This publication is CONFIDENTIAL and will be safeguarded in accordance with security provisions of U.S. Navy Regulations, 1920, Article 76.
BUREAU OF ORDNANCE
WASHINGTON, D. C.
28 MAY 1947..
ORDNANCE PAMPHLET 1664
UNITED STATES EXPLOSIVE ORDNANCE
1. Ordnance Pamphlet 1664 describes and illustrates United States Navy projectiles, Army and Navy rockets, pyrotechnics, grenades, land mines, bombs, and guided missiles.
2. This publication contains information on the characteristics of construction and operation of value to the student of ordnance.
3. This publication supersedes the handbooks on American explosive ordnance published by the U. S. Navy Bomb Disposal School, all copies of which shall be destroyed in accordance with applicable security regulations.
4. This publication is CONFIDENTIAL and shall be safeguarded in accordance with the security provisions of U. S. Navy Regulations, 1920, Article 76.
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 February 1946.
Included are: U.S. guided missiles, bombs, rockets, land mines, grenades, pyrotechnics, and Navy projectiles. Not covered are: Army artillery ammunition, demolition explosives 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, numerical or type arrangement is employed.
To make the publication more serviceable for peacetime use, practice items are included in their appropriate sections.
Ordnance included was that classified as service, together with some obsolete, obsolescent, and experimental types. The experimental items were those being actively developed 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 existence 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. Modifications
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 modification on a "T" item is made, the change is given an "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 Chemical Warfare Service uses "E" and "R" designations for experimental items instead of the "T" and "E" numbers, respectively, of the Ordnance Department. For aircraft ordnance 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 a Roman numeral, like the early Naval Mark designations, but the modifications were distinguished by the letter "M" and another Roman numeral (Mk I M II) where the Navy used the abbreviation "Mod", (Mk 1 Mod 2). In 1925, the Army adopted the "M" system. The Army-Navy Standardization Board was created in June, 1941.
American high explosives
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 necessary 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 velocity of detonation will, therefore, be given for a definite density of loading.
TNT (Trinitrotoluol): TNT is powerful, brisant, easy to load by casting since its melting point (Grade A) is 80.2 degrees C., stable under all stowage conditions, insensitive enough to stand all normal handling, and even capable of standing bullet impact when cast. The Navy uses it as a booster in a pressed granular form in which it is more sensitive to detonator action.
The velocity of detonation is 22,300 ft./sec. at a density of 1.55. Its Laboratory Impact Value is 100. Its Bullet Impact Value is 100. Its color is yellow to buff.
Tetryl (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 tried 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 Tetryl (130 degrees C.) is too high to allow it to be melted and cast. It is loaded by being mixed with small quantities 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 extremely stable in stowage. Exposed or loose Tetryl should not ')e 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 powerful 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 armor-piercing bombs and projectiles and other Navy projectiles. While its power and brisance are
slightly inferior to TNT, it is much more insensitive to shock and will stand impact 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 sensitive 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 brisant 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 mixtures of other explosives and inerts which reduce the sensitivity to a safe range, while the mixtures 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 density of 1.70. Its Laboratory Impact Value is 34. Its Bullet Impact Value is 0. Its color is white.
PETN (Pentaerythritetetranitrate): PETN resembles RDX in its characteristics. It is somewhat more 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 in the service is in primacord. When used alone, PETN is combined with a small quantity of wax to desensitize and lubricate it, and is loaded by pressing. It is important to know 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 about 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 degrees C., but one report states that it may detonate in the manner of an initiating explosive at that temperature or 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 double-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 strength to TNT, and its sensitivity is of the same order. Its rate of detonation 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 nitrate, 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 extrusion. Amatol has a disadvantage in that it is very hygroscopic and therefore is usually protected by a sealing pour of pure TNT.
The velocity of detonation of 50/50 is 19,700 ft./sec. at a density of 1.54. Its Laboratory Impact Value is 93. Its Bullet Impact 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 tactical 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 insensitive 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.
Torpex: Torpex is one of the explosives developed during this war to be used mainly in underwater ordnance. The original Torpex (Torpex 1) was a mixture of 45% RDX, 37% TNT, 18% Aluminum powder (1% wax added). Torpex 2, which is now being used, is 42% RDX, 40% TNT, 18% Aluminum powder (1% wax added). It is used in mines, torpedo war heads, and depth bombs. Torpex is more sensitive than TNT; its bullet impact and drop test sensitivities are of the same order as those of Tetryl. It is quite stable in stowage, though it produces gas, causing pressure in the case. It is insensitive enough to stand all normal handling. Its melting point is low enough for it to be cast-loaded. Its velocity of detonation is 24,000 ft./ sec. at a density of 1.72. It is 141% as powerful as TNT. Its Laboratory Impact Value is 53. Its Bullet Impact Value is 48. Its color is slate gray.
DBX (Depth Bomb Explosive): DBX is another aluminized RDX mixture, and its name
suggests its intended use. It is 21% RDX, 21% Aluminum Nitrate, 40% TNT, 18% Aluminum. It was designed to replace Torpex, which it closely resembles in sensitivity, strength, brisance, and energy of shock in water, but half of the strategic RDX in Torpex is replaced by Ammonium Nitrate in DBX. It will probably not be used, as the present supply of RDX seems adequate to meet the demand. DBX can be cast, though its melting range of 98-105 degrees C. is about the upper limit. Its velocity of detonation is 22,300 ft./sec. at a density of 1.68. It is 143% as powerful as TNT under water. Its Laboratory Impact Value is not given. Its Bullet Impact Value is 51. Its color is gray.
HBX: HBX is a new mixture designed to replace Torpex in depth bombs. It has been loaded in the Flat Nose Bomb AN-Mk 54 Mod 1. HBX is 40% RDX, 38% TNT, 17% Aluminum powder, 5% desensitizer. Tests indicate that it will be about 98% to 100% as powerful as Torpex, that it will definitely be less sensitive than Torpex in both Laboratory Impact and Bullet Impact, that it will be slightly more sensitive in these respects than TNT, and that it will be about the same order as Composition B.
A difficulty with Torpex and HBX is that they produce gas and build up pressure in the case during stowage. It has been discovered that 0.5% by weight of calcium chloride added to the mixture will absorb all the moisture and eliminate the production of gas. It has been recommended that this percentage be added and that the resulting mixtures be designated Torpex 3 and HBX 1.
Composition A: Composition A is a mixture of 91% RDX and 9% plasticizing oil. The oil content is sufficient to desensitize the mixture and lubricate it enough to allow it to be pressed into A.A. shells, which will probably be its principal use. It is less sensitive than TNT in both drop and bullet impact tests. It is appreciably more brisant and powerful, as is indicated by its velocity of detonation of 27,000 ft./sec. at a density of 1.62. Its Laboratory Impact Value is 105. Its Bullet Impact Value
is over 100. Its color may be white or buff, depending upon the color of the oil.
Tetrytol: Tetrytol is a mixture of Tetryl and TNT (70/30 is a frequent ratio.) It is designed to obtain a Tetryl booster that may be cast. This mixture is slightly less powerful and less sensitive than Tetryl. Its particular use is in burster tubes for chemical bombs, in demolition blocks, and in cast shaped charges. It cannot be used where the loaded item is immersed in hot explosive, as are the auxiliary boosters in the loading of Army bombs, because it will be remelted by the heat and separation will result. It is approved for use in all other boosters.
Its velocity of detonation is 24,000 ft./sec. at a density of 1.60. Its Laboratory Impact Value is 45. Its Bullet Impact Value is 65. Its color is yellow.
Pentolite: Pentolite is a mixture of TNT and PETN, usually 50/50. Its chief uses have been in small shell loading, in grenades, and in cast shaped charges. It has a very high shaped-charge efficiency. It is not as stable as TNT in stowage, and separation of PETN may occur. Efforts should be made to keep it cool. Its sensitivity is such that it cannot be drilled, and the fuze cavities in shells that must be drilled are poured with 90/10. It is about the same sensitivity as Tetryl in drop tests, and more sensitive than Torpex to bullet impact. Its brisance and power are equivalent to Composition B. At a density of 1.65, its rate of detonation is 24,000 ft./sec. Its Laboratory Impact Value is 47. Its Bullet Impact Value is 48.
Ednatol: Ednatol is a mixture of 57% EDNA and 43% TNT, designed to ease the shortage of RDX. In the near future, it will be loaded as a substitute for Composition B in large G.P. bombs and fragmentation bombs. It is somewhat more powerful than TNT and comparable in sensitivity. It becomes soft enough to pour at 80 degrees C. and it is, therefore, cast. It is entirely stable in stowage. At a density of 1.60, it has a velocity of detonation of 24,300 ft./sec. Its Laboratory Impact Value is not given. Its Bullet Impact Value is 83. Its color is yellow.
PTX-1: PTX-1 is a new ternary explosive that is undergoing tests and may be adopted for loading in shells, bombs, grenades, mines, demolition blocks, and shaped charges. It is a mixture of 30% RDX, 50% Tetryl, and 20% TNT. This mixture gives a very high explosive equal to Composition B and Pentolite, and superior to Tetrytol and Ednatol. It is less sensitive than Tetrytol and more stable. Its velocity of detonation is 24,200 ft./sec. at a density of 1.66. Its Laboratory Impact Value is 40 (estimated). Its Bullet Impact Value is not given. Its color is yellow.
PTX-2: PTX-2 is another ternary explosive mixture undergoing study for possible future use. It consists of 43.2% RDX, 28% PETN, 28.8% TNT. It is slightly more sensitive in drop and bullet impact tests than Composition B, but a little less sensitive than Pentolite. It is more brisant than any of the binary mixtures now used, which would include Composition B, and is about 10% more effective than Tetryl as a booster. It may be used as a booster, as a main charge for fragmentation ammunition, and as a shaped charge. Its melting point is such that it will be cast. Its velocity of detonation is 26,200 ft./sec. at a density of 1.69. Its Laboratory Impact Value is 50 (estimated). Its Bullet Impact Value is not given. Its color is yellow.
Composition C: Composition C-3 is the only one of the Composition C series now in production, though quantities of the others may be found in the field. It is 77% RDX, Tetryl, 4% TNT, 1% Nitrocellulose, 5% MNT (Mononitrotoluol), 10% DNT (Dinitrotoluol). The last two, while they are explosives, are oily liquids and plasticize the mixture. The essential difference between Composition C-3 and Composition C-2 is the substitution of 3% Tetryl for 3% RDX, which improves the plastic qualities. Composition C-1 was 88.3% RDX and 11.7% plasticizing oil. The changes have been made in order to obtain a plastic composition that would meet the requirements of an ideal explosive for molded and shaped charges and that would maintain its plasticity over a
wide range of temperature and not exude oil.
Composition C-3 is about 1.35 times as powerful as TNT. Its velocity of detonation is 26,000 ft./sec. at a density of 1.58. The Laboratory Impact Value is 98. Its Bullet Impact Value is over 100. Its color is brown.
PEP-3: This is a new plastic explosive being tested for future use. PEP-3 is a mixture of 86% PETN and 14% plasticizing oil. PEP-2 was 85% PETN and 15% oil, but it was a little too soft. PEP-3 is about 90% as powerful and brisant as Composition C, but its stowage stability and plastic range are much better. Its sensitivity is about the same as Composition C, though it has much less tendency to burn.
Picratol: Picratol is a mixture of 52% Explosive D and 48% TNT. It is currently used in the 2000-lb. S.A.P. Bomb M103 and is under consideration for appliance in other Army A.P.'s and S.A.P.'s. Picratol's stability is about equal to that of Explosive D and TNT. It has a rate of detonation of 22,875 ft./sec. at a normal loading density of 1.625. Brisance tests, peak pressure tests, and impulse tests indicate that Picratol's destructive force is somewhat less than that of TNT, but greater than that of Explosive D.
Cyclotol 70/30: Cyclotol 70/30, a mixture of 70% RDX and 30% TNT, closely resembles Composition B except for the altered proportions of the components, and is designed as a replacement for Pentolite. It will not, however, have Pentolite's resistance to flame. Though results of tests are not available, Cyclotol may be anticipated to be more sensitive than Composition B, but considerably less than Pentolite.
Tritonal: Tritonal is composed of 80% TNT and 20% Aluminum powder and is contemplated for use in some 4000-lb. Light-Case Bombs AN-M56, in the JB-2, and in several G.P. bombs (Army 500- and 1000-lb. G.P.'s) , where maximum blast effect is desired. Tritonal is cast, segregation of the aluminum being prevented by a pellet loading technique. The Laboratory Impact Value is 89; Bullet Impact Value is 64; and velocity of detonation is 18,000 ft./ sec. at a density of 1.70.
Mercury Fulminate: Mercury Fulminate is an initiating explosive that may be used as either a primer or a detonator. It may be detonated by flame, friction, or percussion, and in turn detonate a booster; or it may be mixed with other materials to form a primer composition and used to ignite a propellent charge. Its melting point is much too high for it to be cast, and it is loaded by being pressed into caps. It has one disadvantage for military use in that it will decompose in stowage at tropical temperatures and at the end of about three years may be rendered useless. Compared to high explosives, it has lower power and brisance, a fact which is indicated by its velocity of detonation of 16,500 ft./sec. at a density of 4.00. Its Laboratory Impact Value is 8. Its color is light yellow.
Lead Azide: Lead Azide may be used where a detonation is caused from flame, but Mercury Fulminate is generally preferred where the cap is to be set off by a firing pin. It does have
a distinct advantage over Mercury Fulminate in being completely stable in stowage at elevated temperatures. Its rate of detonation is of the same order as Fulminate, 17,500 ft./sec. at a density of 4.00. Its Laboratory Impact Value is 19. Its color is white.
DDNP: This is an initiating explosive which has been used for some time in commercial detonating caps and is now being used to some extent in military types. It is more insensitive to shock than Mercury Fulminate and Lead Azide, though it may be detonated by a sharp blow. It will, therefore, probably be used only where it will be set off electrically or by miner's safety fuse. It has an advantage in being more powerful than other initiating explosives and being comparable in strength to Tetryl. If unconfined, flame will cause it to flash but will not detonate it. This, combined with its insensitivity to shock, makes it much more safe to handle.