BLACK POWDER
Gunpowder, also known since the late 19th century as black powder, was the
first chemical explosive and the only one known until the mid-1800s. It is a
mixture of sulfur, charcoal, and potassium
nitrate (saltpeter)—with the sulfur and charcoal acting as fuels, while the
saltpetre works as an oxidizer.[2][3] Because
of its burning properties and the amount of heat and gas volume that it
generates, gunpowder has been widely used as a propellant in firearms and
as a pyrotechnic composition in fireworks.
Gunpowder was, according to prevailing academic
consensus, invented in the 9th century in China,[4] and
the earliest record of a written formula for gunpowder appears in the 11th
century Song Dynasty text, Wujing
Zongyao.[5] This
discovery led to the invention offireworks and
the earliest gunpowder weapons in China. In the centuries following the Chinese
discovery, gunpowder weapons began appearing in the Arab world, Europe, and India. The technology
spread from China through the Middle East,
and then into Europe.[6]The
earliest Western accounts of gunpowder appear in texts written by English
philosopher Roger Bacon in the 13th century.[7]
Gunpowder is classified as a low explosive because of its relatively
slow decomposition rate and consequently low brisance. Low
explosives deflagrate (i.e., burn) at subsonic speeds,
whereas high explosives detonate, producing a supersonic wave.
Gunpowder's burning rate increases with pressure, so it will burst containers
if contained but otherwise just burns in the open. Ignition of the powder
packed behind a bullet must generate enough pressure to force it from the
muzzle at high speed, but not enough to rupture the gun barrel.
Gunpowder thus makes a good propellant, but is less suitable for shattering
rock or fortifications. Gunpowder was widely used to fill artillery shells and
in mining and civil engineering to blast rock roughly until the second half of
the 19th century, when the first high
explosives (nitro-explosives) were discovered. Gunpowder is no
longer used in modern explosive military warheads, nor is it used as main
explosive in mining operations due to its cost relative to that of newer
alternatives such as ammonium nitrate/fuel oil (ANFO).[8] Black
powder is still used as a delay element in various munitions where its
slow-burning properties are valuable.
Formulations used in blasting rock (such as in quarrying)
are called blasting powder.
CONTENTS
HISTORY
Gunpowder was invented in China. Chinese
military forces used gunpowder-based weapons (i.e. rockets, guns, cannons) and explosives (i.e. grenades and
different types ofbombs)
against the Mongols when
the Mongols attempted to invade and breach city fortifications on China's
northern borders. After the Mongols conquered China and founded the Yuan
Dynasty, they used the Chinese gunpowder-based weapons technology in their
attempted invasion of Japan; they also used gunpowder to fuel rockets.
The mainstream scholarly consensus is that gunpowder was
invented in China, spread through the Middle East, and then into Europe,[6] although
there is a dispute over how much the Chinese advancements in gunpowder warfare
influenced later advancements in the Middle East and Europe.[4][9] The
spread of gunpowder across Asia from China is widely attributed to the Mongols.
One of the first examples of Europeans encountering gunpowder and firearms is
at the Battle of Mohi in 1241. At this battle the
Mongols not only used gunpowder in early Chinese firearms but in the earliest
grenades as well.
A major problem confronting the study of the early
history of gunpowder is ready access to sources close to the events described.
Often enough, the first records potentially describing use of gunpowder in
warfare were written several centuries after the fact, and may well have been
colored by the contemporary experiences of the chronicler.[10] It
is also difficult to accurately translate original alchemy texts, especially
medieval Chinese texts which employ metaphor to describe unexplained phenomena,
into contemporary scientific language with its rigidly defined terminology. The
difficulty in translation has given rise to errors or loose interpretations
bordering on artistic licence.[11][12] Early
writings potentially mentioning gunpowder are sometimes marked by a linguistic
process where old words acquired new meanings.[13] For
instance, the Arabic word naft transitioned from denoting naphta to
denoting gunpowder, and the Chinese word pao evolved from meaning
catapult to referring to cannon.[14] According
to science and technology historian Bert S. Hall: "It goes without saying,
however, that historians bent on special pleading, or simply with axes of their
own to grind, can find rich material in these terminological thickets."[15]
CHINA
Saltpeter was known to the Chinese by the mid-1st century
AD and there is strong evidence of the use of saltpeter and sulfur in
various largely medicinal combinations.[16] A
Chinese alchemical text dated 492 noted saltpeter burnt with a purple flame,
providing a practical and reliable means of distinguishing it from other
inorganic salts, thus enabling alchemists to evaluate and compare purification
techniques; the earliest Latin accounts of saltpeter purification are dated
after 1200.[17]
The first mention of a mixture resembling gunpowder
appeared in Taishang Shengzu Danjing Mijue by Qing Xuzi (c. 808); it
describes mixing six parts sulfur to six parts saltpeter to one part birthwort herb
(which would provide carbon).[18] The
first reference to the incendiary properties of such mixtures is the passage of
the Zhenyuan miaodao yaolüe, a Taoist text
tentatively dated to the mid-9th century AD:[17] "Some
have heated together sulfur, realgar and saltpeter with honey; smoke and
flames result, so that their hands and faces have been burnt, and even the
whole house where they were working burned down."[19] The
Chinese word for "gunpowder" isChinese: 火药/火藥; pinyin: huŏ
yào /xuou yɑʊ/, which
literally means "Fire Medicine";[20] however
this name only came into use some centuries after the mixture's discovery.[21] By
the 9th century Taoist monks or alchemists searching
for an elixir of immortality had serendipitously
stumbled upon gunpowder.[6][22] The
Chinese wasted little time in applying gunpowder to the development of weapons,
and in the centuries that followed, they produced a variety of gunpowder
weapons, including flamethrowers, rockets, bombs, and land mines, before
inventing guns as a projectile weapon.[23] Archaeological
evidence of a hand cannon has been excavated in Manchuria dated from the late
1200s[24] and
the shells of explosive bombs have been discovered in a shipwreck off the shore
of Japan dated from 1281, during the Mongol invasions of Japan.[25]
The Chinese "Wu
Ching Tsung Yao" (Complete Essentials from the Military Classics),
written by Tseng Kung-Liang between 1040–1044, provides encyclopedia references
to a variety of mixtures which included petrochemicals, as well as garlic and
honey. A slow match for flame throwing mechanisms using the siphon principle
and for fireworks and rockets are mentioned. The mixture formulas in this book
do not contain enough saltpeter to create an explosive however; being limited
to at most 50% saltpeter, they produce an incendiary.[26] The Essentials was
however written by a Song Dynasty court bureaucrat, and there's little
evidence that it had any immediate impact on warfare; there is no mention of
gunpowder use in the chronicles of the wars against the Tanguts in
the eleventh century, and China was otherwise mostly at peace during this
century. The first chronicled use of "fire spears" (or "fire
lances") is at the siege of De'an in 1132.[27]
Formula for gunpowder in 1044 Wujing zongyaopart I
vol 12
Instruction for fire bomb in Wujing zongyao
Fire bomb
Fire grenade
Land mine from the Ming Dynasty textHuolongjing
Error creating thumbnail: File seems to be missing:
Fire arrow rocket launcher from theWujing zongyao
MIDDLE EAST
The Muslims acquired knowledge of gunpowder some time between
1240 and 1280, by which time the Syrian Hasan al-Rammah had written, in Arabic,
recipes for gunpowder, instructions for the purification of saltpeter, and
descriptions of gunpowder incendiaries. Gunpowder arrived in the Middle East,
possibly through India, from China. This is implied by al-Rammah's usage of
"terms that suggested he derived his knowledge from Chinese sources"
and his references to saltpeter as "Chinese snow", fireworks as
"Chinese flowers" and rockets as "Chinese arrows".[28] However,
because al-Rammah attributes his material to "his father and
forefathers", al-Hassan argues that gunpowder became
prevalent in Syria and Egypt by "the end of the twelfth century or the
beginning of the thirteenth".[29]
Al-Hassan claims that in the Battle of Ain Jalut of 1260, the Mamluks used against the Mongols in
"the first cannon in history" gunpowder formula with near-identical
ideal composition ratios for explosive gunpowder.[29] Other
historians urge caution regarding claims of Islamic firearms use in the
1204-1324 period as late medieval Arabic texts used the same word for
gunpowder, naft, that they used for an earlier incendiary naptha.[10][14] Khan
claims that it was invading Mongols who introduced gunpowder to the Islamic world[30] and
cites Mamluk antagonism
towards early musketeers in their infantry as an example of how gunpowder
weapons were not always met with open acceptance in the Middle East.[31] Similarly,
the refusal of their Qizilbash forces to use firearms contributed to the Safavid rout
at Chaldiran in 1514.[31]
The earliest surviving documentary evidence for the use
of the hand cannon, considered the oldest type of portable
firearm and a forerunner of the handgun, are from
several Arabic manuscripts dated to the 14th century.[32] Al-Hassan
argues that these are based on earlier originals and that they report hand-held
cannons being used by the Mamluks at the Battle of Ain Jalut in 1260.[29]
Hasan al-Rammah included 107 gunpowder recipes in his
text al-Furusiyyah wa al-Manasib al-Harbiyya (The Book of Military
Horsemanship and Ingenious War Devices), 22 of which are for rockets. If one
takes the median of 17 of these 22 compositions for rockets (75% nitrates,
9.06% sulfur, and 15.94% carbon), it is nearly identical to the modern reported
ideal gunpowder recipe of 75% potassium nitrate, 10% sulfur, and 15% carbon.[29]
The state-controlled manufacture of gunpowder by the Ottoman
Empire through early supply
chains to obtain salpeter, sulfur and high-quality charcoal from
oaks in Anatolia contributed
significantly to its expansion the 15th and 18th century. It was not until
later in the 19th century when the syndicalist production of Turkish gun powder
was greatly reduced, which coincided with the decline of its military might.[33]
MAINLAND EUROPE
Several sources mention Chinese firearms and gunpowder
weapons being deployed by the Mongols against European forces at theBattle
of Mohi in 1241.[34][35][36] Professor
Kenneth Warren Chase credits the Mongols for introducing into Europe gunpowder
and its associated weaponry.[37]
C. F. Temler interprets Peter, Bishop of Leon, as
reporting the use of cannon in Seville in
1248.[38]
In Europe, one of the first mentions of gunpowder use appears
in a passage found in Roger Bacon's Opus Maius and Opus
Tertium in what has been interpreted as being firecrackers.
The most telling passage reads: "We have an example of these things (that
act on the senses) in [the sound and fire of] that children's toy which is made
in many [diverse] parts of the world; i.e. a device no bigger than one's thumb.
From the violence of that salt called saltpetre [together with sulphur and
willow charcoal, combined into a powder] so horrible a sound is made by the
bursting of a thing so small, no more than a bit of parchment [containing it],
that we find [the ear assaulted by a noise] exceeding the roar of strong
thunder, and a flash brighter than the most brilliant lightning."[7] In
early 20th century, British artillery officer Henry William Lovett Hime
proposed that another work tentatively attributed to Bacon, Epistola
de Secretis Operibus Artis et Naturae, et de Nullitate Magiae contained an
encrypted formula for gunpowder. This claim has been disputed by historians of
science including Lynn Thorndike, John Maxson Stillman and George
Sarton and by Bacon's editor Robert Steele, both in terms of
authenticity of the work, and with respect to the decryption method.[7] In
any case, the formula claimed to have been decrypted (7:5:5
saltpeter:charcoal:sulfur) is not useful for firearms use or even firecrackers,
burning slowly and producing mostly smoke.[39][40]
The Liber Ignium, or Book of Fires, attributed to Marcus Graecus, is
a collection of incendiary recipes, including some gunpowder recipes.
Partington dates the gunpowder recipes to approximately 1300.[41] One
recipe for "flying fire" (ingis volatilis) involves saltpetre,
sulfur, and colophonium, which, when inserted into a reed or hollow
wood, "flies away suddenly and burns up everything." Another recipe,
for artificial "thunder", specifies a mixture of one pound native
sulfur, two pounds linden or willow charcoal, and six pounds of saltpeter.[42] Another
specifies a 1:3:9 ratio.[42]
Some of the gunpowder recipes of De Mirabilibus Mundi of Albertus
Magnus are identical to the recipes of the Liber Ignium, and
according to Partington, "may have been taken from that work, rather than
conversely."[43] Partington
suggests that some of the book may have been compiled by Albert's students,
"but since it is found in thirteenth century manuscripts, it may well be
by Albert."[43]Albertus
Magnus died in 1280.
A common German folk-tale is
of the German priest/monk named Berthold
Schwarz who independently invented gunpowder, thus earning it the
German name Schwarzpulver or in English Schwarz's powder.
Schwarz is also German for black so this folk-tale,
while likely containing elements of truth, is considered problematic.
A major advance in manufacturing began in Europe in the
late 14th century when the safety and thoroughness of incorporation was
improved by wet grinding; liquid, such as distilled spirits or perhaps the
urine of wine-drinking bishops[44] was
added during the grinding-together of the ingredients and the moist paste dried
afterwards. (The principle of wet mixing to prevent the separation of dry
ingredients, invented for gunpowder, is used today in the pharmaceutical
industry.[45])
It was also discovered that if the paste was rolled into balls before drying
the resulting gunpowder absorbed less water from the air during storage and
traveled better. The balls were then crushed in a mortar by the gunner
immediately before use, with the old problem of uneven particle size and
packing causing unpredictable results.
If the right size particles were chosen, however, the
result was a great improvement in power. Forming the damp paste into corn-sized
clumps by hand or with the use of a sieve instead of larger balls produced a
product after drying that loaded much better, as each tiny piece provided its
own surrounding air space that allowed much more rapid combustion than a fine
powder. This "corned" gunpowder was from 30% to 300% more powerful.
An example is cited where 34 pounds of serpentine was needed to shoot a 47
pound ball, but only 18 pounds of corned powder.[44] The
optimum size of the grain depended on its use; larger for large cannon, finer
for small arms. Larger cast cannon were easily muzzle-loaded with corned powder
using a long-handled ladle. Corned powder also retained the advantage of low
moisture absorption, as even tiny grains still had much less surface area to
attract water than a floury powder.
During this time, European manufacturers also began
regularly purifying saltpeter, using wood ashes containing potassium carbonateto precipitate calcium from
their dung liquor, and using ox blood, alum, and slices of turnip to
clarify the solution.[44]
The art of gunpowder-making and metal-smelting and
casting for shot and cannon was closely held by skilled military tradesmen, who
formed guilds which collected dues, tested apprentices, and gave pensions.
"Fire workers" were also required to craft fireworks for celebrations
of victory or peace. During the Renaissance, two European schools of
pyrotechnic thought emerged, one in Italy and the other at Nuremberg, Germany.
The Italian school of pyrotechnics emphasized elaborate fireworks, and the German
school stressed scientific advancement. Vannoccio Biringuccio, born in 1480, was a
member of the guild Fraternita di Santa Barbara but broke with the
tradition of secrecy by setting down everything he knew in a book titled De
la pirotechnia, written in vernacular. The first printed book on either
gunpowder or metalworking, it was published posthumously in 1540, with 9
editions over 138 years, and also reprinted byMIT Press in
1966.[44] By
the mid-17th century fireworks were used for entertainment on an unprecedented
scale in Europe, being popular even at resorts and public gardens.[46]
In 1774 Louis XVI ascended
to the throne of France at age 20. After he discovered that France was not
self-sufficient in gunpowder, a Gunpowder Administration was established; to
head it, the lawyer Antoine
Lavoisier was appointed. Although from a bourgeois family, after his
degree in law Lavoisier became wealthy from a company set up to collect taxes
for the Crown; this allowed him to pursue experimental natural science as a
hobby.[47]
Without access to cheap Indian saltpeter
(controlled by the British), for hundreds of years France had relied on
saltpetermen with royal warrants, the droit de fouille or "right
to dig", to seize nitrous-containing soil and demolished walls of
barnyards, without compensation to the owners.[48] This
caused farmers, the wealthy, or entire villages to bribe the petermen and the
associated bureaucracy to leave their buildings alone and the saltpeter
uncollected. Lavoisier instituted a crash program to increase saltpeter
production, revised (and later eliminated) the droit de fouille,
researched best refining and powder manufacturing methods, instituted
management and record-keeping, and established pricing that encouraged private
investment in works. Although saltpeter from new Prussian-style putrefaction
works had not been produced yet (the process taking about 18 months), in only a
year France had gunpowder to export. A chief beneficiary of this surplus was
the American Revolution. By careful testing and
adjusting the proportions and grinding time, powder from mills such as at Essonne outside
Paris became the best in the world by 1788, and inexpensive.[48] [49]
BRITAIN AND IRELAND
Gunpowder production in Britain appears to have started
in the mid 14th century AD with the aim of supplying The English Crown.[50]Records
show that gunpowder was being made, in England, in 1346, at the Tower
of London; a powder house existed at the Tower in 1461; and in 1515 three
King's gunpowder makers worked there.[50] Gunpowder
was also being made or stored at other Royal castles, such as Portchester. By the early 14th century,
according to N.J.G. Pounds's study The Medieval Castle in England and
Wales, many English castles had been deserted and others were
crumbling. Their military significance faded except on the borders. Gunpowder
had made smaller castles useless.[51]
Henry VIII of England was short of
gunpowder when he invaded France in 1544 AD and England needed to import
gunpowder via the port of Antwerp.[50]
The English
Civil War, 1642–1645, led to an expansion of the gunpowder industry, with
the repeal of the Royal Patent in August 1641.[50]
The introduction of smokeless
powder in the late 19th century led to a contraction of the gunpowder
industry. After the end of World War I,
the majority of the United Kingdom gunpowder manufacturers merged into a single
company, "Explosives Trades limited"; and number of sites were closed
down, including those in Ireland. This company became Nobel Industries Limited;
and in 1926 became a founding member of Imperial Chemical Industries. The Home Office removed
gunpowder from its list of Permitted Explosives; and shortly afterwards,
on 31 December 1931, the former Curtis & Harvey's Glynneath gunpowder
factory at Pontneddfechan, in Wales, closed down,
and it was demolished by fire in 1932.[53]
This left the sole United Kingdom gunpowder factory at
ICI Nobel's Ardeer site in Scotland; it
too closed in October 1976.[54] Since
then gunpowder has been imported into the United Kingdom. In the late 1970s /
early 1980s gunpowder was bought from eastern Europe, particularly from what
was then the East Germany and former Yugoslavia.
INDIA
Ever since the founding of the Sultanate of Mysore by Hyder Ali, French military
officers were employed to train the Mysore Army. Hyder Ali and his son Tipu
Sultan were the first to introduce modern Cannons and Muskets, their army
was also the first in India to have official uniforms. During the Second Anglo-Mysore War Hyder Ali and
his son Tipu Sultan unleashed the Mysorean rockets at
their British opponents effectively defeating them on various occasions. The Mysorean
rockets inspired the development of theCongreve
rocket, which the British widely utilized during the Napoleonic
Wars and the War of 1812.[63]
INDONESIA
The Javanese Majapahit Empire
was arguably able to encompass much of modern day Indonesia due
to its unique mastery of bronze smithing and use of a central arsenal fed
by a large number of cottage industries within the immediate region.
Documentary and archeological evidence indicate that Arab or Indian traders
introduced gunpowder, gonnes, muskets, blunderbusses,
and cannon to the Javanese, Acehnese,
and Batak via long established commercial trade
routes around the early to mid 14th century CE.[64]Portuguese
and Spanish invaders were unpleasantly surprised and occasionally even
outgunned on occasion.[65] The
resurgentSinghasari Empire
overtook Sriwijaya and
later emerged as the Majapahit whose warfare featured the use of fire-arms
and cannonade.[66] Circa
1540 CE the Javanese, always alert for new weapons found the
newly arrived Portuguese weaponry superior to that of the locally made
variants. Javanese bronze breech-loaded swivel-guns, known as meriam, or
erroneously as lantaka, was used widely by the Majapahit navy as well as by
pirates and rival lords. The demise of the Majapahit empire
and the dispersal of disaffected skilled bronze cannon-smiths to Brunei, modern Sumatra, Malaysia and
the Philippines lead
to widespread use, especially in theMakassar
Strait.
A Chinese pirate or commercial shipwreck site[where?] yielded
a paired swivel gun, for rapid firing: one barrel would fire
whiles its opposite was being reloaded, though this remains a rare find. Other
archaeological finds have unearthed triple-barrel and double-barrel
swivel-guns, though they were not widely duplicated.
Saltpetre harvesting was recorded by Dutch and German
travelers as being common in even the smallest villages and was collected from
the decomposition process of large dung hills specifically piled for the
purpose. The Dutch punishment for possession of unpermitted gunpowder appears
to have been amputation.[67][unreliable
source?] Ownership and manufacture of gunpowder was later prohibited
by the colonial Dutch occupiers.[64] According
to a colonel McKenzie quoted in Sir Thomas Stamford Raffles, The History
of Java (1817), the purest sulphur was supplied from a crater from a mountain near
the straits of Bali.[66]
MANUFACTURING TECHNOLOGY
For the most powerful black powder meal, a wood charcoal is
used. The best wood for the purpose is Pacific willow,[68] but
others such as alder or buckthorn can
be used. In Great Britain between the 15th to 19th centuries charcoal from alder
buckthorn was greatly prized for gunpowder manufacture; cottonwood was used by the American Confederate States.[69] The
ingredients are reduced in particle size and mixed as intimately as possible.
Originally this was with a mortar-and-pestle or a similarly operating
stamping-mill, using copper, bronze or other non-sparking materials, until
supplanted by the rotating ball mill principle with non-sparking bronze orlead. Historically, a marble or limestone edge
runner mill, running on a limestone bed was used in Great Britain; however, by
the mid 19th century AD this had changed to either an iron shod stone wheel or
a cast
iron wheel running on an iron bed.[70] The
mix was dampened with alcohol or water during grinding to prevent accidental
ignition. This also helps the extremely soluble saltpeter mix into the
microscopic nooks and crannies of the very high surface-area charcoal.
Around the late 14th century AD, European powdermakers
first began adding liquid during grinding to improve mixing, reduce dust, and
with it the risk of explosion.[71] The
powdermakers would then shape the resulting paste of dampened gunpowder, known
as mill cake, into corns, or grains, to dry. Not only did corned powder keep
better because of its reduced surface area, gunners also found that it was more
powerful and easier to load into guns. Before long, powdermakers standardized
the process by forcing mill cake through sieves instead of corning powder by
hand.
The improvement was based on having a reduced surface
area of a higher density composition. At the beginning of the 19th century,
density was increased further by static pressing. Shoveling the damp mill cake
into a two-foot square box, this was placed beneath a screw press and reduced
to 1/2 its volume. "Presscake" had the hardness of slate; the dried
slabs were then broken with hammers or with rollers, and the granules sorted with
sieves into different grades. In the United States, Irenee
du Pont, who had learned the trade from Lavoisier, tumbled the dried grains
in rotating barrels to round the edges and increase its durability during
shipping and handling. Sharp grains would round off in transport, producing
fine "meal dust" which changes the burning properties.
Another advance was the manufacture of kiln charcoal by
distilling wood in heated iron retorts instead of burning it in earthern pits;
controlling the temperature influenced the power and consistency of the
finished gunpowder. In 1863, in response to high prices for Indian saltpeter, DuPont chemists
developed a process using potash or mined potassium chloride to convert plentiful Chilean sodium
nitrate to potassium nitrate.[72]
During the 18th century gunpowder factories became
increasingly dependent on mechanical energy.[73] Despite
mechanization, production difficulties related to humidity control, especially
during the pressing, were still present in the late 19th century. A paper from
1885 laments that "Gunpowder is such a nervous and sensitive spirit, that
in almost every process of manufacture it changes under our hands as the
weather changes." Pressing times to the desired density could vary by
factor of three depending on the atmospheric humidity.[74]
COMPOSITION AND CHARACTERISTICS
The term black powder was coined in the late
19th century, primarily in the United
States, to distinguish prior gunpowder formulations from the new smokeless
powders and semi-smokeless powders, in cases where these are not
referred to as cordite. Semi-smokeless powders featured bulk volume
properties that approximated black powder, but had significantly reduced
amounts of smoke and combustion products. Smokeless powder has different
burning properties (pressure vs. time) and can generate higher pressures and
work per gram. This can rupture older weapons designed for black powder.
Smokeless powders ranged in colour from brownish tan to yellow to white. Most
of the bulk semi-smokeless powders ceased to be manufactured in the 1920s.[75][76][77]
Black powder is a granular mixture of
charcoal, which provides carbon and other fuel for the
reaction, simplified as carbon (C);
sulfur (S), which, while also serving as a fuel, lowers
the temperature required to ignite the mixture, thereby increasing the rate of combustion.
Potassium nitrate is the most important ingredient in
terms of both bulk and function because the combustion process releases oxygen
from the potassium nitrate, promoting the rapid burning of the other
ingredients.[78] To
reduce the likelihood of accidental ignition by static electricity, the granules of modern black
powder are typically coated with graphite, which
prevents the build-up of electrostatic charge.
Charcoal does not consist of pure carbon; rather, it
consists of partially pyrolyzed cellulose, in which the wood is not completely
decomposed. Carbon differs
from charcoal.
Whereas charcoal's autoignition temperature is relatively low, carbon's is much
greater. Thus, a black powder composition containing pure carbon would burn
similarly to a match head, at best.[79]
The current standard composition for the black powders
that are manufactured by pyrotechnicians was
adopted as long ago as 1780. Proportions by weight are 75% potassium
nitrate (known as saltpeter or saltpetre), 15% softwood charcoal, and
10% sulfur.[70] These
ratios have varied over the centuries and by country, and can be altered
somewhat depending on the purpose of the powder. For instance, power grades of
black powder, unsuitable for use in firearms but adequate for blasting rock in
quarrying operations, is called blasting powder rather than gunpowder with
standard proportions of 70% nitrate, 14% charcoal, and 16% sulfur; blasting
powder may be made with the cheaper sodium
nitrate substituted for potassium nitrate and proportions may be as
low as 40% nitrate, 30% charcoal, and 30% sulfur.[80] In
1857 Lamont DuPont solved the main problem when using cheaper sodium nitrate
formulations when he patented DuPont "B" Blasting powder; after
manufacturing grains from press-cake in the usual way, the powder was tumbled
with graphite dust for 12 hours, forming a coating on each grain which in this
case reduced its ability to pick up moisture.[81]
French war powder in 1879 used the ratio 75% saltpeter,
12.5% charcoal, 12.5% sulfur. English war powder in 1879 used the ratio 75%
saltpeter, 15% charcoal, 10% sulfur.[82] The
British Congreve rockets used 62.4% saltpeter, 23.2% charcoal and 14.4% sulfur,
but the British Mark VII gunpowder was changed to 65% saltpeter, 20% charcoal
and 15% sulfur. The explanation for the wide variety in formulation
relates to usage. Powder used for rocketry can use a slower burn rate since it
will accelerate the projectile for a much longer period of time, whereas
powders for use in weapons such as flintlocks, caplocks or matchlocks need a
higher burn rate since they must accelerate the projectile in a much shorter
distance. Cannons usually used lower burn rate powders because most would burst
if higher burn rate powders are used.
SERPENTINE
The original dry-compounded powder used in
fifteenth-century Europe was known as "Serpentine", either a
reference to Satan[83] or
to a common artillery piece that used it.[84] The
ingredients were ground together with a mortar and pestle, perhaps for 24
hours,[84]resulting
in a fine flour. Vibration during transportation could cause the components to
separate again, requiring remixing in the field. Also if the quality of the
saltpeter was low (for instance if it was contaminated with highly hygroscopic calcium
nitrate), or if the powder was simply old (due to the mildly hygroscopic
nature of potassium nitrate), in humid weather it would need to be redried. The
dust from "repairing" powder in the field was a major hazard.
Loading cannon or bombards before
the powdermaking advances of the Renaissance was a skilled art. Fine powder
loaded haphazardly or too tightly would burn incompletely or too slowly.
Typically, the breech-loading powder chamber in the rear of the piece was
filled only about half full, the serpentine powder neither too compressed nor
too loose, a wooden bung pounded in to seal the chamber from the barrel when
assembled, and the projectile placed on that. A carefully determined empty
space was necessary for the charge to burn effectively. When the cannon was
fired through the touchhole, turbulence from the initial surface combustion
caused the rest of the powder to be rapidly exposed to the flame.[84]
The advent of much more powerful and easy to use corned powder
changed this procedure, but serpentine was used with older guns into the
seventeenth century.[85]
CORNING
In order for gunpowder to explode effectively, the
combustible mixture needs to be reduced to the smallest possible particle sizes
and as intimately mixed with one another as possible. But once mixed, for
better results in a gun it was discovered that the final product should be in
the form of individual, dense, grains which allow the fire to spread quickly
from grain to grain, much as straw or twigscatch fire more quickly than a pile of sawdust.
Primarily for safety reasons, size reduction and mixing
is done while the ingredients are damp, usually with water. After 1800, instead
of forming grains by hand or with sieves, the damp millcake was
pressed in molds to increase its density and extract the liquid, formingpresscake.
The pressing took varying amounts of time, depending on conditions such as
atmospheric humidity. The hard, dense product was then broken again into tiny
pieces which were separated with sieves to have a uniform product for each
purpose; coarse powders were used for cannons, finer
grained powders for muskets, and the finest for small hand guns and priming.[85]Inappropriately
fine-grained powder often caused cannons to burst before the projectile could
move down the barrel, due to the high initial spike in pressure.[86] Mammoth powder
with large grains made for Rodman's
15-inch cannon reduced the pressure to only 20 percent as high as ordinary
cannon powder would have produced.[87]
In the mid-nineteenth century, measurements were made
determining that the burning rate within a grain of black powder (or a tightly
packed mass) is about 0.20 fps, while the rate of ignition propagation from
grain to grain is around 30 fps, over two orders of magnitude faster.[85]
MODERN TYPES
Modern corning first compresses the fine black powder
meal into blocks with a fixed density (1.7 g/cm³). In the United
States, gunpowder grains were designated F (for fine) or C (for coarse).
Grain diameter decreased with a larger number of Fs and increased with a larger
number of Cs, ranging from about 2 mm for 7F to 15 mm for 7C. Even
larger grains were produced for artillery bore diameters greater than about 17 cm
(6.7 in). The standard DuPont Mammoth powder developed by Thomas
Rodman and Lammot du Pont for use during the American Civil War had grains averaging
0.6 inches diameter, with edges rounded in a glazing barrel.[87] Other
versions had grains the size of golf and tennis balls for use in 20-inch
(50-cm) Rodman guns.[88] In
1875 DuPont introducedHexagonal powder for large artillery, which was
pressed using shaped plates with a small center core; about 1.5 inches
diameter, like a wagon wheel nut, the center hole widened as the grain burned.[89] By
1882 German makers also produced hexagonal grained powders of a similar size
for artillery.[89]
By the late 19th century manufacturing focused on
standard grades of black powder from Fg used in large bore rifles and shotguns,
through FFg (medium and smallbore arms such as muskets and fusils), FFFg
(smallbore rifles and pistols), and FFFFg (extreme small bore, short pistols
and most commonly for priming flintlocks).[90] A
coarser grade for use in military artillery blanks was
designated A-1. These grades were sorted on a system of screens with oversize
retained on a mesh of 6 wires per inch, A-1 retained on 10 wires per inch, Fg
retained on 14, FFg on 24, FFFg on 46, and FFFFg on 60. Fines designated FFFFFg
were usually reprocessed to minimize explosive dust hazards.[91] In
the United Kingdom, the main service gunpowders were
classified RFG (rifle grained fine) with diameter of one or two millimeters and
RLG (rifle grained large) for grain diameters between two and six millimeters.[88] Gunpowder
grains may alternatively be categorised by mesh size: the BSS sieve
mesh size, being the smallest mesh size on which no grains were retained.
Recognised grain sizes are Gunpowder G 7, G 20, G 40, and G 90.
Owing to the large market of antique and replica
black-powder firearms in the US, modern gunpowder substitutes like Pyrodex, Triple
Seven and Black Mag3[92] pellets
have been developed since the 1970s. These products, which should not be
confused with smokeless powders, aim to produce less fouling (solid residue),
while maintaining the traditional volumetric measurement system for charges.
Claims of less corrosiveness of these products have been controversial however.
New cleaning products for black-powder guns have also been developed for this
market.[90]
OTHER TYPES OF GUNPOWDER
Besides black powder, there are other historically
important types of gunpowder. "Brown gunpowder" is cited as composed
of 79% nitre, 3% sulphur, and 18% charcoal per 100 of dry powder, with about 2%
moisture.[93] Prismatic
Brown Powder is a large-grained product the Rottweil Company
introduced in 1884 in Germany, which was adopted by the British Royal Navy
shortly thereafter. The French navy adopted a fine, 3.1 millimeter, not
prismatic grained product called Slow Burning Cocoa (SBC) or
"cocoa powder". These brown powders reduced burning rate even further
by using as little as 2 percent sulfur and using charcoal made from rye straw that had
not been completely charred, hence the brown color.[89]
Lesmok powder was a product developed by DuPont in
1911[94] one
of several semismokeless products in the industry containing a mixture of black
and nitrocellulose powder. It was sold to Winchester and others
primarily for .22 and .32 small calibres. Its advantage was that it was less
corrosive than smokeless powders then in use as the bulkier load carried away
more of the primer residue, and somewhat less fouling than straight black
powder in that the bore did not require cleaning after every shot.[95] It
was last sold by Winchester in 1947.
SULFUR-FREE GUNPOWDER
The development of smokeless
powders, such as cordite, in the late 19th century created the need for a
spark-sensitive priming charge, such as gunpowder. However, the sulfur
content of traditional gunpowders caused corrosion problems
with Cordite Mk I and this led to the introduction of a range of sulfur-free
gunpowders, of varying grain sizes.[54] They
typically contain 70.5 parts of saltpetre and 29.5 parts of charcoal.[54] Like
black powder, they were produced in different grain sizes. In the United
Kingdom, the finest grain was known as sulfur-free mealed powder (SMP).
Coarser grains were numbered as sulfur-free gunpowder (SFG n): 'SFG 12', 'SFG
20', 'SFG 40' and 'SFG 90', for example; where the number represents the
smallest BSS sieve mesh size on which no grains were retained.
The main purpose of sulfur in gunpowder is to decrease
the ignition temperature. A sample reaction for sulfur-free gunpowder would be
6 KNO3 + C7H4O → 3 K2CO3 + 4 CO2 + 2 H2O + 3 N2
COMBUSTION CHARACTERISTICS
A balanced, but still simplified, equation is[96]
10 KNO3 + 3 S + 8 C → 2 K2CO3 + 3 K2SO4 +
6 CO2 + 5 N2.
Although charcoal's
chemical formula varies, it can be best summed up by its empirical formula: C7H4O.
Therefore, an even more accurate equation of the decomposition of regular black
powder with the use of sulfur can be described as:
6 KNO3 + C7H4O + 2 S → K2CO3 + K2SO4 +
K2S + 4 CO2 + 2 CO + 2 H2O + 3 N2
Black powder without the use of sulfur:
6 KNO3 + C7H4O → 3 K2CO3 +
CO2 + 6 CO + 2 H2O + 2 N2
The burning of gunpowder does not take place as a single
reaction, however, and the byproducts are not easily predicted. One study's
results showed that it produced (in order of descending quantities) 55.91%
solid products: potassium carbonate, potassium
sulfate, potassium sulfide, sulfur, potassium
nitrate, potassium thiocyanate, carbon, ammonium carbonate and 42.98% gaseous
products: carbon dioxide, nitrogen, carbon
monoxide, hydrogen sulfide, hydrogen, methane, 1.11%
water.
Black powder made with less-expensive and more plentiful sodium
nitrate (in appropriate proportions) works just as well but is morehygroscopic than
powders made from Potassium nitrate—popularly known as saltpeter.
Because corned black powder grains made with saltpeter are less
affected by moisture in the air, they can be stored unsealed without
degradation by humidity. Muzzleloadershave
been known to fire after hanging on a wall for decades in a loaded state,
provided they remained dry. By contrast, black powder made with sodium nitrate
must be kept sealed to remain stable.
Gunpowder contains 3 megajoules per kilogram, and
contains its own oxidant. For comparison, the energy density of TNT is
4.7 megajoules per kilogram, and the energy density of gasoline is
47.2 megajoules per kilogram. Gunpowder is a low explosive and as such it does not detonate;
rather it deflagrates.[97] Since
it contains its own oxidizer and additionally burns faster under pressure, its
combustion is capable of rupturing containers such as shell, grenade, or
improvised "pipe bomb" or "pressure cooker" casings,
forming shrapnel.
ADVANTAGES
In quarrying, high explosives are generally preferred for
shattering rock. However, because of its low brisance, black
powder causes fewer fractures and results in more usable stone compared to
other explosives, making black powder useful for blasting monumental stone such
as granite and marble. Black
powder is well suited for blank
rounds, signal flares, burst
charges, and rescue-line launches. Black powder is also used in fireworks for
lifting shells, in rockets as fuel, and in certain special
effects.
DISADVANTAGES
Black powder has a low energy
density compared to modern "smokeless" powders, and thus to
achieve high energy loadings, large amounts of black powder are needed with
heavy projectiles. In military applications black powder also produces thick
smoke as a byproduct, which may give a soldier's location away to an enemy
observer. The smoke may also impair aiming for additional shots.
Combustion converts less than half the mass of black
powder to gas. The rest ends up as a thick layer of soot inside the
barrel. In addition to being a nuisance, the residue from burnt black powder is hygroscopic and
with the addition of moisture absorbed from the air, this residue forms a caustic substance. The soot contains potassium
oxide or sodium oxide that turns into potassium hydroxide, orsodium
hydroxide, which will corrode wrought
iron or steel gun
barrels. Black powder arms must be well cleaned both inside and out to remove
the residue. The matchlock musket or pistol (an early gun ignition
system), as well as the flintlock would often be unusable in wet weather, due
to powder in the pan being exposed and dampened. Because of this unreliability,
soldiers carrying muskets, known as musketeers,
were armed with additional weapons such as swords or pikes. The bayonet was
developed to allow the musket to be used as a pike, thus eliminating the need
for the soldier to carry a secondary weapon.
TRANSPORTATION
The United
Nations Model Regulations on the Transportation of Dangerous
Goods and national transportation authorities, such asUnited States Department of
Transportation, have classified gunpowder (black powder) as a Group A:
Primary explosive substance for shipment because it ignites so easily. Complete
manufactured devices containing black powder are usually classified as Group
D: Secondary detonating substance, or black powder, or article containing
secondary detonating substance, such as firework, class Dmodel
rocket engine, etc., for shipment because they are harder to ignite
than loose powder. As explosives, they all fall into the category of Class 1.
OTHER USES
Besides its use as an explosive, gunpowder has been
occasionally employed for other purposes; after the Battle of Aspern-Essling(1809), the
surgeon of the Napoleonic Army Larrey combated the lack of food for the
wounded under his care by preparing a bouillonof horse meat seasoned
with gunpowder for lack of salt.[98][99] It
was also used for sterilizing on ships when there was no alcohol.
Jack Tars (British sailors) used gunpowder to create tattoos when
ink wasn't available, by pricking the skin and rubbing the powder into the
wound in a method known as traumatic tatooing.[100]
Fireworks use gunpowder as lifting and burst charges,
although sometimes other more powerful compositions are added to the burst
charge to improve performance in small shells or provide a louder report. Most
modern firecrackers no longer contain black powder.
Beginning in the 1930s, gunpowder or smokeless powder was
used in rivet guns, stun guns for animals, cable splicers and other industrial
construction tools.[101] The
"stud gun" drove nails or screws into solid concrete, a function not
possible with hydraulic tools. See Powder-actuated tool. Shotguns have been used
to eliminate persistent material rings in operating rotary kilns (such as those
for cement, lime, phosphate, etc.) and clinker in operating furnaces, and
commercial tools make the method more reliable.[102]
Near London in 1853, Captain Shrapnel (presumably a grandson
of the inventor of the Shrapnel
shell) demonstrated a method for crushing gold-bearing ores by firing them
from a cannon into an iron chamber, and "much satisfaction was expressed
by all present". He hoped it would be useful on the goldfields of California and Australia.
Nothing came of the invention, as continuously-operating crushing machines
which achieved more reliable comminution were
already coming into use.[103]
SEE ALSO
Bulk loaded liquid propellants
Technology of the Song Dynasty
NOTES
REFERENCES
.
Cressy, David. Saltpeter: The Mother of Gunpowder (Oxford
University Press, 2013) 237 pp online review by Robert Tiegs
.
Khan, Iqtidar Alam (1996a). "The Role of the Mongols
in the Introduction of Gunpowder and Firearms in South Asia". Chapter 3,
In Buchanan, Brenda J. (1996). Gunpowder: The History of an International
Technology. Bath: Bath University Press. (. 2006 re-issue).
.
EXTERNAL LINKS
Gun and Gunpowder
The Origins of Gunpowder
Cannons and Gunpowder
Oare Gunpowder Works, Kent, UK
Royal Gunpowder Mills
The DuPont Company on the Brandywine A digital exhibit
produced by the Hagley Library that covers the founding and early history of
the DuPont Company powder yards in Delaware
the Medieval Siege Society's Guns, Including showing
ignition of gunpowder
Black Powder Recipes
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