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Torpex is a
secondary explosive
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An expl ...
, 50% more powerful than
TNT
Trinitrotoluene (), more commonly known as TNT, more specifically 2,4,6-trinitrotoluene, and by its preferred IUPAC name 2-methyl-1,3,5-trinitrobenzene, is a chemical compound with the formula C6H2(NO2)3CH3. TNT is occasionally used as a reagen ...
by mass. Torpex comprises 42%
RDX
RDX (abbreviation of "Research Department eXplosive") or hexogen, among other names, is an organic compound with the formula (O2N2CH2)3. It is a white solid without smell or taste, widely used as an explosive. Chemically, it is classified as a ...
,
40% TNT and 18%
powdered aluminium
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...
. It was used in the
Second World War
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
from late 1942, at which time some used the names Torpex and RDX interchangeably, much to the confusion of today's historical researchers. The name is short for ''torpedo explosive''. Torpex proved to be particularly useful in underwater munitions because the aluminium component had the effect of making the explosive pulse last longer, which increased the destructive power. Besides torpedoes,
naval mine
A naval mine is a self-contained explosive device placed in water to damage or destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, any ...
s, and
depth charge
A depth charge is an anti-submarine warfare (ASW) weapon. It is intended to destroy a submarine by being dropped into the water nearby and detonating, subjecting the target to a powerful and destructive Shock factor, hydraulic shock. Most depth ...
s, Torpex was only used in the
Upkeep,
Tallboy and
Grand Slam bomb
The Bomb, Medium Capacity, (Grand Slam) was a earthquake bomb used by RAF Bomber Command against German targets towards the end of the Second World War. The bomb was originally called Tallboy Large until the term Tallboy got into the press an ...
s
as well as the drones employed in
Operation Aphrodite
Aphrodite and Anvil were the World War II code names of United States Army Air Forces and United States Navy operations to use Boeing B-17 Flying Fortress and Consolidated PB4Y bombers as precision-guided munitions against bunkers and other har ...
.
Torpex has long been superseded by
H6 and
Polymer-bonded explosive
Polymer-bonded explosives, also called PBX or plastic-bonded explosives, are explosive materials in which explosive powder is bound together in a matrix using small quantities (typically 5–10% by weight) of a synthetic polymer. PBXs are normally ...
(PBX) compositions.
It is therefore regarded as
obsolete and Torpex is unlikely to be encountered except in old munitions or
unexploded ordnance, although a notable exception to this is the
Sting Ray
Stingrays are a group of sea rays, which are cartilaginous fish related to sharks. They are classified in the suborder Myliobatoidei of the order Myliobatiformes and consist of eight families: Hexatrygonidae (sixgill stingray), Plesiobatidae ( ...
lightweight torpedo, which as of October 2020 remains in service with the Royal Navy and several foreign militaries. The German equivalent of Torpex was
Trialen Trialen was an explosive developed in Germany. It was used during World War II in the V-1 flying bomb and Arado E.377 glide bomb, among other weapons, as an enhanced blast explosive. Trialen was the German equivalent of the British explosive Torpe ...
.
Development
Torpex was developed at the
Royal Gunpowder Factory, Waltham Abbey, in the United Kingdom as a more powerful military alternative to TNT.
RDX
RDX (abbreviation of "Research Department eXplosive") or hexogen, among other names, is an organic compound with the formula (O2N2CH2)3. It is a white solid without smell or taste, widely used as an explosive. Chemically, it is classified as a ...
was developed in 1899. Though very stable and serving as the reference point by which the sensitivity of other explosives are judged, it was too expensive for most military applications and reserved for use in the most important products, such as torpedoes. Aluminium powder was also added to the mix to further enhance the effect. Although both RDX and TNT have a negative
oxygen balance
Oxygen balance (OB, OB%, or Ω) is an expression that is used to indicate the degree to which an explosive can be oxidized. If an explosive molecule contains just enough oxygen to fully oxidize the other atoms in the explosive. For example, fully ...
, the superheated aluminium component tends to contribute primarily by extending the expansion time of the explosive product gases.
Beeswax
Beeswax (''cera alba'') is a natural wax produced by honey bees of the genus ''Apis''. The wax is formed into scales by eight wax-producing glands in the abdominal segments of worker bees, which discard it in or at the hive. The hive workers ...
was also added as a
phlegmatizing agent, to reduce sensitivity to shock and impact. Later, beeswax was replaced with
paraffin wax
Paraffin wax (or petroleum wax) is a soft colorless solid derived from petroleum, coal, or oil shale that consists of a mixture of hydrocarbon molecules containing between 20 and 40 carbon atoms. It is solid at room temperature and begins to m ...
, and
calcium chloride
Calcium chloride is an inorganic compound, a salt with the chemical formula . It is a white crystalline solid at room temperature, and it is highly soluble in water. It can be created by neutralising hydrochloric acid with calcium hydroxide.
Ca ...
was added as a moisture absorber to reduce the production of
hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...
gas under high humidity.
The production of RDX in the USA skyrocketed following the
attack on Pearl Harbor
The attack on Pearl HarborAlso known as the Battle of Pearl Harbor was a surprise military strike by the Imperial Japanese Navy Air Service upon the United States against the naval base at Pearl Harbor in Honolulu, Territory of Hawaii, j ...
by the Japanese. In April 1942, 100 tons of Composition C (88% RDX and oil desensitizer), also known as C4, was ordered by the Office of Strategic Services. By 8 May 1945 (
Victory in Europe Day
Victory in Europe Day is the day celebrating the formal acceptance by the Allies of World War II of Germany's unconditional surrender of its armed forces on Tuesday, 8 May 1945, marking the official end of World War II in Europe in the Easter ...
) the Holston Ordnance Works had been in full production of RDX with no end in sight. In July of that year government officials informed the plant to not exceed production quotas (as had been the practice to that point) since they knew that the atomic bomb was near completion.
See also
*
Amatol
*
Hexanite
Hexanite was a castable German military explosive developed early in the 20th century before the First World War for the Kaiserliche Marine, intended to augment supplies of trinitrotoluene (TNT), which were then in short supply. Hexanite is slight ...
*
List of explosives used during World War II Almost all the common explosives listed here were mixtures of several common components:
* Ammonium picrate
* TNT (Trinitrotoluene)
* PETN (Pentaerythritol tetranitrate)
* RDX
* Powdered aluminium.
This is only a partial list; there were ma ...
*
Minol (explosive) Minol (pronounced ''mine-ol'') is a military explosive developed by the Admiralty early in the Second World War to augment supplies of trinitrotoluene (TNT) and RDX, which were in short supply. The aluminium component in Minol significantly prolon ...
*
Tritonal
Tritonal is a mixture of 80% Trinitrotoluene, TNT and 20% aluminium Powder (substance), powder, used in several types of ordnance such as air-dropped bombs. The aluminium improves the total heat output and hence Impulse (physics), impulse of the ...
Sources
*
*
References
Further reading
* {{cite report , last1=Rowland , first1=Buford , first2=William B. , last2=Boyd , title=U.S. Navy Bureau of Ordnance in World War II , location=Washington, D.C. , publisher=Government Printing Office , date=1947 , url=http://www.ibiblio.org/hyperwar/USN/Admin-Hist/BuOrd/BuOrd-6.html
British inventions
Explosives