A wheellock, wheel-lock, or wheel lock is a friction-wheel mechanism which creates a spark that causes a
firearm
A firearm is any type of gun that uses an explosive charge and is designed to be readily carried and operated by an individual. The term is legally defined further in different countries (see legal definitions).
The first firearms originate ...
to fire. It was the next major development in firearms technology after the matchlock, and the first self-igniting firearm. Its name is from its rotating steel wheel to provide ignition. Developed in Europe around 1500, it was used alongside the
matchlock
A matchlock or firelock is a historical type of firearm wherein the gunpowder is ignited by a burning piece of flammable cord or twine that is in contact with the gunpowder through a mechanism that the musketeer activates by pulling a lever or Tri ...
(), the
snaplock (), the
snaphance (), and the
flintlock
Flintlock is a general term for any firearm that uses a flint-striking lock (firearm), ignition mechanism, the first of which appeared in Western Europe in the early 16th century. The term may also apply to a particular form of the mechanism its ...
().
Design
The wheellock works by spinning a spring-loaded steel wheel against a piece of
pyrite
The mineral pyrite ( ), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral.
Pyrite's metallic luster and pale brass-yellow hue ...
to generate intense sparks, which ignite
gunpowder
Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, charcoal (which is mostly carbon), and potassium nitrate, potassium ni ...
in a pan, which flashes through a small touchhole to ignite the main charge in the firearm's barrel. The pyrite is clamped in
vise
A vise or vice (British English) is a mechanical apparatus used to secure an object to allow work to be performed on it. Vises have two parallel jaws, one fixed and the other movable, threaded in and out by a screw and lever. The jaws are ofte ...
jaws on a spring-loaded arm (or 'dog'), which rests on the pan cover. When the trigger is pulled, the pan cover is opened, and the wheel is rotated, with the pyrite pressed into contact.
A close modern analogy of the wheellock mechanism is the operation of a
lighter
A lighter is a portable device which uses mechanical or electrical means to create a controlled flame, and can be used to ignite a variety of flammable items, such as cigarettes, butane gas, fireworks, candles, or campfires. A lighter typic ...
, where a toothed steel wheel is spun in contact with a piece of sparking material to ignite the liquid or gaseous fuel.
A wheellock firearm had the advantage that it could be instantly readied and fired even with one hand, in contrast to common matchlock firearms, which required a burning cord of
slow match
Slow match, also called match cord, is the slow-burning cord or twine fuse used by early gunpowder musketeers, artillerymen, and soldiers to ignite matchlock muskets, cannons, shells, and petards. Slow matches were most suitable for use ar ...
ready if the gun might be needed and demanded the operator's full attention and two hands to operate. On the other hand, wheellock mechanisms were complex to make, making them relatively costly.
The "dog"
The ''
dog
The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the gray wolf. Also called the domestic dog, it was selectively bred from a population of wolves during the Late Pleistocene by hunter-gatherers. ...
'' is a spring-loaded arm pivoted on the outside of the lock plate. A sparking material, usually a small piece of iron
pyrite
The mineral pyrite ( ), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral.
Pyrite's metallic luster and pale brass-yellow hue ...
, is clamped and held by vise-like jaws at the swinging end of the arm. The dog has two possible positions to which it can be pivoted by hand: a "safe" position, in which the dog is pushed towards the
muzzle of the firearm, and an "operating" position, where the dog is pulled towards the operator so that the pyrite in its jaws can engage either the top of the
pan cover (see below), or (in the absence of the pan cover) the edge of a steel wheel bearing longitudinal grooves around its circumference.
Flint
Flint, occasionally flintstone, is a sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Historically, flint was widely used to make stone tools and start ...
is not suitable as a sparking material in the wheellock because it is too hard and would quickly wear away the wheel grooves.
The wheel
The upper segment of the grooved wheel, made of hardened
steel
Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...
, projects through a slot cut to its precise dimensions in the base of the
priming pan. The wheel is grooved on its outside circumference with three or more V-shaped grooves with transverse cuts at intervals to provide a friction surface for the iron pyrite. The wheel is fixed to a shaft, one end of which projects outside the lockplate. The outside projection is of square section to permit a spanner (wrench) to be engaged for subsequent tensioning of the lock. The other end of the shaft fits through a hole in the lockplate, and on this end is forged a
cam
Cam or CAM may refer to:
Science and technology
* Cam (mechanism), a mechanical linkage which translates motion
* Camshaft, a shaft with a cam
* Camera or webcam, a device that records images or video
In computing
* Computer-aided manufacturin ...
, or
eccentric. One end of a short, robust chain (made of three or four flat, parallel links like a short piece of
bicycle chain
A bicycle chain is a roller chain that transfers power (physics), power from the Bicycle pedal, pedals to the Drive wheel, drive-Bicycle wheel, wheel of a bicycle, thus propelling it. Most bicycle chains are made from carbon steel, plain carbo ...
) is fixed to the cam, while the other end of the chain is held in a groove at the end of the longer branch of a large heavy V-spring, which is generally retained by a screw and a headed bracket through upstands inside the lockplate.
The pan
As in all muzzle-loading firearms (prior to the introduction of the
percussion cap
The percussion cap, percussion primer, or caplock, introduced in the early 1820s, is a type of single-use percussion ignition device for muzzle loader firearm locks enabling them to fire reliably in any weather condition. Its invention gave ...
), the
pan transmits the fire to the main charge of gunpowder inside the breech of the barrel, via a small hole (or "
vent
Vent or vents may refer to:
Science and technology Biology
*Vent, the cloaca region of an animal
*Vent DNA polymerase, a thermostable DNA polymerase
Geology
*Hydrothermal vent, a fissure in a planet's surface from which geothermally heated water ...
") in the side of the breech, that gives on to the pan. The priming pan of all wheellocks is provided with a sliding cover that has two purposes, the first of which is to contain the priming powder and afford it some protection from the elements (the second is examined below, under '
Operation'). The pan cover may be slid open and closed by hand, but it is also attached to an arm inside the lock plate, which is acted upon by the eccentric on the shaft of the wheel.
The sear or trigger mechanism
The
trigger engages one arm of a "z"-shaped
sear pivoting in its centre between two upstanding brackets riveted or brazed to the inside of the lockplate. The other arm of the sear passes through a hole in the lockplate, and engages in a blind hole on the inner side of the wheel, thus effectively locking it and preventing any rotation but only because of a secondary sear or wedge that is pressed under the rear arm of the sear—that is between the lockplate and the sear—when the forward part of it engages into the recess in the wheel. When the trigger is pulled, the secondary lever is withdrawn from its position and the strong pull of the mainspring pushes the unsupported main sear back into the lock and the wheel is free to rotate. The mechanism may seem overconstructed, but it prevents the trigger mechanism from working against the very powerful mainspring as it is the case with all vertical acting sears in flint and percussion locks or even modern firearms that still have cocks (revolvers).
Preparing to fire
First, the dog is rotated forward to the "safe" position, and the priming pan is pushed open (if it is not already so). After loading a powder charge and ball through the muzzle in the usual way, the operator takes his "
spanner", slips it onto the square section of the wheel shaft, and turns it until a click is heard (about one-half to three-quarters of a revolution), and the wheel is felt to lock in place, whereupon the spanner is withdrawn. What occurs is that when the wheel is turned, the mainspring is tensioned via the chain, which is wound partially around the shaft. The click is the sound of one end of the sear engaging in the blind hole on the inside of the wheel, thus immobilising it.
The pan is then primed with powder, and the pan cover pulled shut. Finally the dog is pulled back so that the pyrite in its jaws is resting on the top of the pan cover, under some pressure from the spring at the toe of its arm.
Operation
On pulling the trigger of a wheellock firearm, the sear effects a slight rotation as described above. The end of the sear arm (that has hitherto locked the wheel and prevented it from turning) is disengaged, leaving the wheel free to turn under the tension of the mainspring. There is a subtlety here that is of vital importance: the "hole" in the side of the wheel into which the sear engages, is not a parallel-sided shaft. If it were, then under the tremendous tension of the mainspring, it would require a huge force on the trigger to disengage the sear. Nor is the tip of the sear arm cylindrical, which would have a similar effect. Rather, the "hole" is a depression in the wheel (like a small crater), and the sear has a rounded end: the wheel is locked by reason of lateral force on the shaft of the wheel rather than vertical force on the sear.
As soon as the wheel is released by the sear, the longer arm of the mainspring pulls the chain engaged in it. The other end of the chain being fixed to the cam on the wheel shaft, the latter rotates at high speed, whilst the rotating cam pushes forward the arm to which the pan cover is attached, thus causing the pan cover to slide forward towards the muzzle of the piece, and the pyrites to fall (under tension of the dog spring) on to the now rotating wheel. That is the second purpose of a sliding pan cover: were the pyrites to engage a stationary wheel, it would almost certainly jam the mechanism: but the built-in delay allows the pyrites to slip off the sliding pan-cover on to an already rotating wheel. A more modern development has been the use of a ball bearing between the wheel and the sear. This design allows a smoother and lighter trigger pull, requiring less force to operate.
The fast rotation of the wheel against the pyrites produces white-hot sparks that ignite the powder in the pan, which is transferred to the main charge in the breech of the barrel via the vent, and the gun discharges.
The wheellock took around a minute to load, prepare and fire. Many contemporary illustrations of a wheellock pistol in action show the gun held slightly rotated (about 45 degree angle from the horizontal) rather than vertically as with a
hand cannon
The hand cannon ( or ), also known as the gonne or handgonne, is the first true firearm and the successor of the fire lance. It is the oldest type of small arms, as well as the most mechanically simple form of metal barrel firearms. Unlike match ...
, to ensure that the priming powder in the pan lay against the vent in the barrel, and avoid a 'flash in the pan' or misfire. This was not the case for the
flintlock
Flintlock is a general term for any firearm that uses a flint-striking lock (firearm), ignition mechanism, the first of which appeared in Western Europe in the early 16th century. The term may also apply to a particular form of the mechanism its ...
, where the sparks had to fall vertically a certain distance on to the pan.
History
Though not a firearm, a wheellock mechanism for a
land mine
A land mine, or landmine, is an explosive weapon often concealed under or camouflaged on the ground, and designed to destroy or disable enemy targets as they pass over or near it. Land mines are divided into two types: anti-tank mines, wh ...
is described in the ''
Huolongjing'', a 14th century Chinese military manual.
When stepped on, a pin is dislodged, causing a weight to fall, which spun a drum attached to two steel wheels. The wheels struck sparks against a
flint
Flint, occasionally flintstone, is a sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Historically, flint was widely used to make stone tools and start ...
, igniting the fuse.
The invention of the wheellock in Europe can be placed at about 1500. There is a vocal group of scholars who believe
Leonardo da Vinci
Leonardo di ser Piero da Vinci (15 April 1452 - 2 May 1519) was an Italian polymath of the High Renaissance who was active as a painter, draughtsman, engineer, scientist, theorist, sculptor, and architect. While his fame initially rested o ...
was the inventor. Drawings made by Leonardo of a wheellock mechanism date (depending on the authority) from either the mid-1490s or the first decade of the 16th century. However, a drawing from a book of German inventions (dated 1505) and a 1507 reference to the purchase of a wheellock in Austria may indicate the inventor was an unknown German mechanic instead.
In 1517 and 1518, the first
gun control
Gun control, or firearms regulation, is the set of laws or policies that regulate the manufacture, sale, transfer, possession, modification, or use of firearms and ammunition by civilians.
Most countries allow civilians to own firearms, bu ...
laws banning the wheellock were proclaimed by the Emperor
Maximilian I, initially in Austria and later throughout the
Holy Roman Empire
The Holy Roman Empire, also known as the Holy Roman Empire of the German Nation after 1512, was a polity in Central and Western Europe, usually headed by the Holy Roman Emperor. It developed in the Early Middle Ages, and lasted for a millennium ...
. Several Italian states followed suit in the 1520s and 1530s, another argument used by the pro-German camp.
As Lisa Jardine relates in her account of the assassination of
William the Silent
William the Silent or William the Taciturn (; 24 April 153310 July 1584), more commonly known in the Netherlands as William of Orange (), was the leader of the Dutch revolt against the Spanish Habsburg Netherlands, Habsburgs that set off the ...
of the Netherlands, in 1584, the small size, ease of concealment and user-friendly loading aspect of the wheellock, compared to larger and more cumbersome hand-held weapons, meant that it was used for the killing of public figures, such as
Francis, Duke of Guise and William himself. Jardine also argues that a stray wheellock pistol shot may have been responsible for the
St. Bartholomew's Day massacre of French
Huguenots
The Huguenots ( , ; ) are a Religious denomination, religious group of French people, French Protestants who held to the Reformed (Calvinist) tradition of Protestantism. The term, which may be derived from the name of a Swiss political leader, ...
in 1572.
Wheellock pistols were in common use during the Thirty Years' War (1618–1648) on both sides for cavalry and officers. Around 1650 the flintlock began to replace the wheellock as it was cheaper and easier to use than the wheellock.
Wheel-lock firearms were never mass-produced for military purposes, but the best preserved armoury collection at the
Landeszeughaus in
Graz
Graz () is the capital of the Austrian Federal states of Austria, federal state of Styria and the List of cities and towns in Austria, second-largest city in Austria, after Vienna. On 1 January 2025, Graz had a population of 306,068 (343,461 inc ...
, Austria, contains over 3,000 examples, many of which were produced in small batches for military units.
Features
Among the advantages of the wheellock was a better resistance to rain or damp conditions than the matchlock and the absence of a telltale glow, or smell from the burning
slow match
Slow match, also called match cord, is the slow-burning cord or twine fuse used by early gunpowder musketeers, artillerymen, and soldiers to ignite matchlock muskets, cannons, shells, and petards. Slow matches were most suitable for use ar ...
, itself a hazard in proximity to
gunpowder
Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, charcoal (which is mostly carbon), and potassium nitrate, potassium ni ...
. A
slow match
Slow match, also called match cord, is the slow-burning cord or twine fuse used by early gunpowder musketeers, artillerymen, and soldiers to ignite matchlock muskets, cannons, shells, and petards. Slow matches were most suitable for use ar ...
could be next to impossible to light in rain, but the wheellock allowed sparks to be generated in any weather, and the priming pan was fitted with a cover that was not opened until the instant the gun was fired. That made it feasible for the first time to conceal a firearm under clothing. The high production cost and complexity of the mechanism, however, hindered the wheellock's widespread adoption. A highly skilled gunsmith was required to build the mechanism, and the variety of parts and complex design made it liable to
malfunction
A malfunction is a state in which something functions incorrectly or is obstructed from functioning at all.
Some types of malfunctions are:
*Malfunction (parachuting)
A malfunction is a partial or total failure of a Parachute, parachuting de ...
if it was not carefully maintained. Early models also had trouble with unreliable
springs, but the problem was quickly solved.
[David J. Blackmore, ''Arms and Armour of the English Civil Wars'', Trustees of the Royal Armouries, 2003: ]
The wheellock was used along with the matchlock until both were replaced by the simpler and less-costly
flintlock
Flintlock is a general term for any firearm that uses a flint-striking lock (firearm), ignition mechanism, the first of which appeared in Western Europe in the early 16th century. The term may also apply to a particular form of the mechanism its ...
, by the late 17th century. The wheellock mechanism however gave faster ignition than the flintlock, because the sparks were produced directly in the pan rather than having to fall a certain distance from the
frizzen
The frizzen, historically called the "hammer" or the steel,This may appear anomalous since, in later firearm designs (e.g. percussion locks), the component operating in the same manner as the ''cock'' is called the hammer. is an L-shaped piece of ...
.
See also
*
Miquelet
Miquelet lock is a modern term used by collectors and curators for a type of firing mechanism used in muskets and pistols. It is a distinctive form of snaplock, originally as a flint-against-steel ignition form, once prevalent in the Spanish ...
*
Percussion cap
The percussion cap, percussion primer, or caplock, introduced in the early 1820s, is a type of single-use percussion ignition device for muzzle loader firearm locks enabling them to fire reliably in any weather condition. Its invention gave ...
References
External links
Miniature Wheellock pistol, possibly by Michel Mann, Nuremberg, late 16th century fro
with an animated demonstration of the mechanism.
Firearms from the collections of the Prince of Liechtenstein an exhibition catalog from The Metropolitan Museum of Art (fully available online as PDF), which contains material on wheellocks
16th Century German Wheellock Pistol with Extensive Scrimshaw Inlays, Dated 1596 Images and more description. It has the marks of Baltwarar Dressler.
{{Early firearms
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Early firearms
Weapons of Germany
Weapons of Scotland