2. ARTILLERY

Artillery (used by land forces) is usually divided into guns, howitzers, and mortars.

Guns are, at least in principle, used in direct fire; that is, the gunner sees and aims at the target. For longer ranges, the gunner points the barrel higher and/or uses a heavier power charge. Artillery bores usually range from about 3 inches (76 mm) to 8 inches (200 mm). Naval guns go up to 16 inches (400 mm) and there have been a few at 18 inches.

Mortars fire at very high angles, typically 60°-70° above the horizontal. In that situation, aiming higher gives shorter range. Although huge mortars have been made (e. g., a 10 foot barrel with 36 inch bore), mortars in current use are relatively light so that they can be moved easily by troops near the enemy. They typically have bores of 3 to 4 inches (81 106 mm). Those are usually not even called artillery. The projectiles are often stabilized by fins rather than by rifling.

Howitzers have an intermediate position: they fire at a lower angle than mortars, but higher than guns, though they may be used for direct fire in an emergency. (Early howitzers were distinguished from guns in having a smaller 'chamber' to hold the gunpowder.) Mortar and howitzer gunners usually do not see their targets, and rely on forward observers for guidance (indirect fire). That is also the case for guns used at long range.

All artillery and firearms were originally loaded with a loose charge of gunpowder, then a 'wad' to hold the powder in place and reduce leakage of propellant gas past the ball, and then with a ball (stone, cast iron, or lead).

Artillery: Pounds and inches

In the early days, there were various ways of naming artillery pieces. One was by weight or the projectile. At that time, the projectile in question was a spherical iron ball. Here are some listings relating caliber to shot weight. Note that these relations do not apply at all to modern elongated projectiles, are approximate at best, and should be used with caution.

Naval Warfare in the Age of Sail
Bernard Ireland, W. W. Norton & Co., New York/London, 2000

Weights of guns in hundredweight (112 lb/cwt) or 50.9 kg/cwt 

Carronades:  (short-barreled naval cannon firing a heavy charge for a short range):

Nominal weight of shot (lb):   68        42         32          24         18          12

Length (ft)                             5.17     4.29      4.02       3.63      3.25       2.17

Gun weight                             36      22.25    17.13      13         9           5.96

(cwt)

Artillery Through the Ages
Albert Manucy
US Gov't. Printing Office, Washington DC 1949

p. 35 Principal English guns of the sixteenth century

Smaller artillery pieces and modern firearms now use fixed ammunition, with powder charge and projectile combined in a metal case so that only one piece need be handled. The larger artillery is often separate-loading, so that larger or smaller powder charges can be used as needed to adjust range. Gun and howitzer gunners add bags of powder; while mortar gunners typically remove sheets of propellant ('increments') fastened to the base of the shell. (Note that there are "modern" muzzle-loading firearms.)

The first cannon fired solid shot, originally stones and later cast iron. Still later, other projectiles were made:

Fuzes for shells now include time fuzes for air bursts, or VT (variable time) fuzes which are small radar sets to burst the shell as it approaches an aircraft or at a fixed distance from the ground; delay fuzes, which fire only after penetration (of armor, for instance), and super-quick fuzes which fire on first contact. (A fuse, with an 's', is different; see the glossary below.)

Tank and antitank guns have become a very special field. At present, they are typically 120 mm (5 inch) and are equipped with thermal sights and laser rangefinders. A typical antitank projectile is a solid rod of a dense metal (tungsten or uranium) fired at extremely high velocity. To get the velocity, the projectile is commonly smaller in diameter than the gun bore, and is carried by a 'sabot' which fills the bore and drops off when the projectile leaves the barrel. The velocity is so high that rifling no longer works, and the projectile is fin-stabilized (APFSDS: armor-piercing fin-stabilized discarding sabot) (Flügelstabilsiertes Treibkäfiggeschoss). On impact, the projectile punches a hole through the tank armor, releasing hot fragments that bounce around inside. Other anti-tank projectiles include HEAT (high-explosive anti-tank) with a shaped charge that produces a penetrating jet, and HESH (high-explosive squash-head) which is not intended to penetrate, but to make a piece of armor flake off at high speed inside the tank.

Back to top

Copyright © 2010 Denzel Dyer, all rights reserved.