chemical weapon
A chemical weapon (CW) is a specialized munition that uses chemicals formulated to inflict death or harm on humans. According to the Organisation for the Prohibition of Chemical Weapons (OPCW), this can be any chemical compound intended as ...
developed by the United States in the 1950s. The United States Army produced both Sarin and VX unitary warheads for the M55.
History
In 1951, the US Army
Chemical Corps
The Chemical Corps is the branch of the United States Army tasked with defending against and using chemical, biological, radiological, and nuclear ( CBRN) weapons. The Chemical Warfare Service was established on 28 June 1918, combining activit ...
and Ordnance Corps initiated a joint program to develop a 115mm chemical rocket. The US Army Ordnance Corps designed the 115mm T238 and launcher in 1957 to provide the army a means to attack large area targets with chemical agents. Artillery and mortars are for small area targets; and due to different spin stabilities, warheads intended for explosives are not ideal for chemical delivery. The 115mm rocket was subsequently accepted as the M55 rocket with M91 launcher. Produced from 1959 to 1965, the M55s were manufactured at
Newport Army Ammunition Plant
The Newport Chemical Depot, previously known as the Wabash River Ordnance Works and the Newport Army Ammunition Plant, was a bulk chemical warfare, chemical storage and destruction facility that was operated by the United States Army. It is loc ...
and tested at
Aberdeen Proving Ground
Aberdeen Proving Ground (APG) is a U.S. Army facility located adjacent to Aberdeen, Harford County, Maryland, United States. More than 7,500 civilians and 5,000 military personnel work at APG. There are 11 major commands among the tenant units, ...
. The Army produced unitary warheads filled with
Sarin
Sarin (NATO designation GB nerve_agent#G-series.html" ;"title="hort for nerve agent#G-series">G-series, "B" is an extremely toxic organophosphorus compound.VX
nerve agent
Nerve agents, sometimes also called nerve gases, are a class of organic chemistry, organic chemicals that disrupt the mechanisms by which nerves transfer messages to organs. The disruption is caused by the blocking of acetylcholinesterase (ACh ...
s for the M55.Croddy, Eric and Wirtz, James J. ''Weapons of Mass Destruction: An Encyclopedia of Worldwide Policy, Technology, and History'', Google Books , ABC-CLIO, 2005, p. 42, (), accessed November 8, 2008.
Disposal and storage programs
Storage
During the 1960s the Army stored many M55s at Black Hills Army Depot. The M55 was also stored at the
Rocky Mountain Arsenal
The Rocky Mountain Arsenal was a United States chemical weapons manufacturing center located in the Denver Metropolitan Area in Commerce City, Colorado. The site was completed December 1942, operated by the United States Army throughout the ...
and in
Okinawa
most commonly refers to:
* Okinawa Prefecture, Japan's southernmost prefecture
* Okinawa Island, the largest island of Okinawa Prefecture
* Okinawa Islands, an island group including Okinawa itself
* Okinawa (city), the second largest city in th ...
Federation of American Scientists
The Federation of American Scientists (FAS) is an American nonprofit global policy think tank with the stated intent of using science and scientific analysis to attempt to make the world more secure. FAS was founded in 1945 by a group of scient ...
'', updated June 15, 2000, accessed November 8, 2008. The rockets in Japan were moved to
Johnston Atoll
Johnston Atoll is an Unincorporated territories of the United States, unincorporated territory of the United States, under the jurisdiction of the United States Air Force (USAF). The island is closed to public entry, and limited access for mana ...
during Operation Red Hat where they were destroyed during the 1990s.
Disposal issues
Disposal operations for the M55 are made more difficult because of the rocket's design.Noyes, Robert. ''Chemical Weapons Destruction and Explosive Waste: Unexploded Ordnance Remediation'', Google Books , William Andrew Inc., 1996, page 32, (). The rocket propellant was a double base composition
nitroglycerin
Nitroglycerin (NG) (alternative spelling nitroglycerine), also known as trinitroglycerol (TNG), nitro, glyceryl trinitrate (GTN), or 1,2,3-trinitroxypropane, is a dense, colorless or pale yellow, oily, explosive liquid most commonly produced by ...
(NG) and
nitrocellulose
Nitrocellulose (also known as cellulose nitrate, flash paper, flash cotton, guncotton, pyroxylin and flash string, depending on form) is a highly flammable compound formed by nitrating cellulose through exposure to a mixture of nitric acid and ...
(NC) propellant. Besides the NG and NC, M28 contains
2-nitrodiphenylamine
2-Nitrodiphenylamine is an organic chemical with the formula . It is a nitration, nitrated derivative of diphenylamine. It is a red solid, usually found in form of flakes or powder. It is polar but hydrophobic.
Diphenylamine is used to extend t ...
(NDPA) as a stabilizer.The propellant is known by the military nomenclature M28 propellant. See: ''Effects of Degraded Agent and Munitions Anomalies on Chemical Stockpile Disposal Operations''. The rocket propellant cannot be removed from the warhead without cutting open the rocket.Committee on Review and Evaluation of the Army Chemical Stockpile Disposal Program,
U.S. National Research Council
The National Academies of Sciences, Engineering, and Medicine (NASEM), also known as the National Academies, is a Congressional charter, congressionally chartered organization that serves as the collective scientific national academy of the Uni ...
. ''Review of Systematization of the Tooele Chemical Agent Disposal Facility'', Google Books , National Academies Press, 1996, p. 86, ().
The propellant itself presents a hazard, because it becomes unstable as it ages.Langford, Roland E. ''Introduction to Weapons of Mass Destruction'', Google Books , Wiley-IEEE, 2004, page 282, (). Specifically, the danger of
autoignition
The autoignition temperature or self-ignition temperature, often called spontaneous ignition temperature or minimum ignition temperature (or shortly ignition temperature) and formerly also known as kindling point, of a substance is the lowest temp ...
is present as the stabilizer ages and becomes depleted.Peterson, Carl R.,
U.S. National Research Council
The National Academies of Sciences, Engineering, and Medicine (NASEM), also known as the National Academies, is a Congressional charter, congressionally chartered organization that serves as the collective scientific national academy of the Uni ...
, et al. ''Recommendations for the Disposal of Chemical Agents and Munitions'', National Academies Press, 1994, Google Books , p. 46-48, (). The
U.S. National Research Council
The National Academies of Sciences, Engineering, and Medicine (NASEM), also known as the National Academies, is a Congressional charter, congressionally chartered organization that serves as the collective scientific national academy of the Uni ...
and other sources called the M55 the most dangerous weapon in the American chemical arsenal because of this and other hazards.
Another danger is agent leakage. Army reports have indicated that nerve agent GB can corrode the metal casings of the munitions over time. As Sarin decomposes it forms acids which can corrode the aluminum casings found around the agent in the M55.Committee on Review of Army Planning for the Disposal of M55 Rockets at the Anniston Chemical Agent Disposal Facility, U.S. National Research Council, ''Assessment of Processing Gelled GB M55 Rockets at Anniston'', Google Books , National Academies Press, 2003, page 11, (). M55 rockets containing GB have accounted for the majority of leaking American chemical weapons. In mid-2002, over 4,000 munitions in the U.S. chemical stockpile were found to be leaking agent; of that number 2,102 were Sarin-containing M55s.
Disposal completion
The United States signed the
Chemical Weapons Convention
The Chemical Weapons Convention (CWC), officially the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction, is an arms control treaty administered by the Organisation for ...
in 1993, which obligated it to destroy all chemical weapons by an extended deadline of April 2012. The U.S. missed the deadline, but completed the destruction of all declared chemical weapons on July 7, 2023, at
Blue Grass Army Depot
Blue Grass Army Depot (BGAD) is a U.S. Army Joint Munitions Command storage facility for conventional munitions and chemical weapons. The facility is located in east central Kentucky, southeast of the cities of Lexington and Richmond, Kentucky ...
in
Kentucky
Kentucky (, ), officially the Commonwealth of Kentucky, is a landlocked U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders Illinois, Indiana, and Ohio to the north, West Virginia to the ...
. The final chemical weapon to be destroyed was a sarin nerve agent-filled M55 rocket.
Specifications
The M55 is long and in diameter. The weapons can hold
warhead
A warhead is the section of a device that contains the explosive agent or toxic (biological, chemical, or nuclear) material that is delivered by a missile, rocket (weapon), rocket, torpedo, or bomb.
Classification
Types of warheads include:
*E ...
s filled with about of GB or VX. The warhead comprises about total, and consists of several components. The M34 and M36 Burster utilize
composition B
Composition B (Comp B), also known as Hexotol and Hexolite (among others), is a high explosive consisting of castable mixtures of RDX and TNT. It is used as the main explosive filling in artillery projectiles, rockets, land mines, hand grenade ...
or
tetrytol
Tetrytol is a high explosive, comprising a mixture of tetryl and TNT. Typically, the proportion of ingredients (by weight) is 65%, 70%, 75% or 80% tetryl to 35%, 30%, 25% or 20% TNT. Tetryl and TNT do form a eutectic with a setting point of 67.5 ...
and total about of the total weapon weight. The agent, as stated, comprises about of the weight with the rest lying in the casing and M417
fuze
In military munitions, a fuze (sometimes fuse) is the part of the device that initiates its function. In some applications, such as torpedoes, a fuze may be identified by function as the exploder. The relative complexity of even the earliest fu ...
Anniston Chemical Activity
Anniston Chemical Activity was a U.S. Army chemical weapon storage site located in Alabama. The Army had stored approximately seven percent of the nation’s original chemical weapons stockpile at the Anniston Army Depot since the early 1960s. In ...
*
Johnston Atoll Chemical Agent Disposal System
Johnston Atoll Chemical Agent Disposal System (JACADS) was the U.S. Army's first chemical munitions disposal facility. It was located on Johnston Island, at Johnston Atoll and completed its mission and ceased operation in 2000.
Background
Prior ...
*Committee on Review and Evaluation of the Army Chemical Stockpile Disposal Program, Committee on Review and Evaluation of the Army Chemical Stockpile Disposal Program,
U.S. National Research Council
The National Academies of Sciences, Engineering, and Medicine (NASEM), also known as the National Academies, is a Congressional charter, congressionally chartered organization that serves as the collective scientific national academy of the Uni ...
. ''Effects of Degraded Agent and Munitions Anomalies on Chemical Stockpile Disposal Operations'', Google Books , National Academies Press, 2004, p. 55, ()