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User:KDS4444/Expansion of article on cannon

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Cannon in general have the form of a truncated cone with an internal cylindrical bore for holding an explosive charge and a projectile. The thickest, strongest, and closed part of the cone is located near the explosive charge. As any explosive charge will dissipate in all directions equally, the thickest portion of the cannon is useful for containing and directing this dissipation. The extent to which a cannon experiences backward motion as its projectile leaves the bore is termed its recoil and the effectiveness of the cannon can be measured in terms of how much this response can be diminished, though obviously diminishing recoil through increasing the overall mass of the cannon means decreased field mobility.

Cannon were initially made most often of bronze, though later forms were constructed of cast iron and eventually steel. [1]: 61  Bronze has several characteristics that made it preferable as a construction material: although it is relatively expensive, does not always alloy well, and can result in a final product that is "spongy about the bore", [1]: 61  bronze is more flexible than iron and therefore less prone to bursting when exposed to high pressure; cast iron cannon are less expensive and more durable generally than bronze and withstand being fired more times without deteriorating. However, cast iron cannon have a tendency to burst without having shown any previous weakness or wear, and this makes them more dangerous to operate.

The older and more-stable forms of cannon were muzzle-loading as opposed to breech-loading— in order to be used they had to have their ordnance packed down the bore through the muzzle rather than inserted through the breech.

The following terms are used to refer to the components or aspects of a classical western cannon (circa 1850 CE): the bore; the bottom of the bore; the muzzle; the face; the muzzle mouldings consisting of the lip and the fillet; the swell of the muzzle; the neck; the various astragals and fillets; the chase; the chase girdle; the reinforce and reinforce rings or reinforce bands; the breech; the base ring; the cascable which consists of the base of the breech, the fillet, the neck, and the knob; the trunnions; the rimbases; the handles or dolphins(for bronze 12-pound cannon only); the vent piece (bronze cannon only); the vent field, and the vent.[1]: 66  In what follows, the words near, close, and behind will refer to those parts towards the thick, closed end of the piece, and far, front, in front of, and before to the thinner, open end.

Negative spaces[edit]

  • Bore: The hollow cylinder bored down the center of the cannon, including the base of the bore or bottom of the bore, the nearest end of the bore into which the ordnance (wadding, shot, etc.) gets packed. The diameter of the bore represents the cannon's caliber.
  • Chamber: The cylindrical, conical, or spherical recess at the nearest end of the bottom of the bore into which the gunpowder is packed.
  • Vent: A thin tube on the near end of the cannon connecting the explosive charge inside with an ignition source outside and often filled with a length of fuse; always located near the breech. Sometimes called the fuse hole or the touch hole. On the top of the vent on the outside of the cannon is a flat circular space called the vent field where the charge is lit. If the cannon is bronze, it will often have a vent piece made of copper screwed into the length of the vent.

Solid spaces[edit]

The main body of a cannon consists of three basic extensions— the foremost and the longest is called the chase, the middle portion is the reinforce, and the closest and briefest portion is the cascabel or cascable.

  • The chase: Simply the entire conical part of the cannon in front of the reinforce. It is the longest portion of the cannon, and includes the following elements:
    • The neck: the narrowest part of the chase, always located near the foremost end of the piece.
    • The muzzle: the portion of the chase forward of the neck. It includes the following:
      • The swell of the muzzle refers to the slight swell in the diameter of the piece at the very end of the chase. It is often chamferred on the inside to make loading the cannon easier. In some guns, this element is replaced with a wide ring and is called a muzzle band.
      • The face is the flat vertical plane at the foremost edge of the muzzle (and of the entire piece).
      • The muzzle mouldings are the tiered rings which connect the face with the rest of the muzzle, the first of which is called the lip and the second the fillet
      • The muzzle astragal and fillets are a series of three narrow rings running around the outside of the chase just behind the neck. Sometimes also collectively called the chase ring.
    • The chase astragal and fillets: these are a second series of such rings located at the near end of the chase.
    • The chase girdle: this is the brief length of the chase between the chase astragal and fillets and the reinforce.
  • The reinforce: This portion of the piece is frequently divided into a first reinforce and a second reinforce, but in any case is marked as separate from the chase by the presence of a narrow circular reinforce ring or band at its foremost end. The span of the reinforce also includes the following:
    • The trunnions are located at the foremost end of the reinforce just behind the reinforce ring. They consist of two cylinders perpendicular to the bore and below it which are used to mount the cannon on its carriage.
    • The rimbases are short broad rings located at the union of the trunnions and the cannon which provide support to the carriage attachment.
    • The reinforce band is only present if the cannon has two reinforces, and it divides the first reinforce from the second.
    • The breech refers to the mass of solid metal behind the bottom of the bore extending to the base of the breech and including the base ring; it also generally refers to the end of the cannon opposite the muzzle, i.e., the location where the explosion of the gunpowder begins as opposed to the opening through which the pressurized gas escapes.
    • The base ring forms a ring at the widest part of the entire cannon at the nearest end of the reinforce just before the cascable.
  • The cascable: This is that portion of the cannon behind the reinforce(s) and behind the base ring. It includes the following:
    • The knob which is the small spherical terminus of the piece;
    • The neck, a short, narrow piece of metal holding out the knob; and
    • The fillet, the tiered disk connecting the neck of the cascable to the base of the breech.
    • The base of the breech is the metal disk that forms the most forward part of the cascable and rests against the breech itself, right next to the base ring.

To pack a muzzle-loading cannon, first gunpowder is poured down the bore. This is followed by a layer of wadding (often nothing more than paper), and then the cannon ball itself. A certain amount of windage allows the ball to fit down the bore, though the greater the windage the less efficient the propulsion of the ball when the gunpowder is ignited. To fire the cannon, the fuse located in the vent is lit, quickly burning down to the gunpowder, which then explodes violently, propelling wadding and ball down the bore and out of the muzzle. A small portion of exploding gas also escapes through the vent, but this does not dramatically affect the total force exerted on the ball.



  1. ^ a b c Kingsbury, Charles P. (1849). An elementary treatise on artillery and infantry. New York: GP Putnam. OCLC 761213440. {{cite book}}: Cite has empty unknown parameters: |editorn-first= and |editorn-last= (help)
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