You can say that the cannon is a kind of giant revolver: inside it, a metallic piece (the hammer) hits an ammunition full of gunpowder, causing an explosion that spits a projectile towards the target. The operating principle of this indispensable weapon in armies’ arsenals has remained more or less the same since its emergence in the 13th century, when Europeans discovered gunpowder. Since then, cannons have already decided several wars – and continue to decide, as more modern models are used by all armed forces in the world. In a cannon, the shot cannot undergo changes in trajectory and range after firing. This makes it different from a rocket launcher, which fires autonomously propelled objects, and from a missile launcher, whose projectile changes course during flight by remote control or internal devices. In the cannon family there are also howitzers, which shoot a little differently. While the cannons shoot straight and short, up to 3 km, the howitzers fire in a parabola, up to 11 km away. Apart from this difference, both cannons and howitzers work in a very similar way. The weapon that we represented in the infographic is an M101 howitzer, built for the Second World War and used by the Americans against Japan and by Brazil in Italy. The weapon fires 10.5 cm diameter, 33 kg grenades at a range of 11 km. Its destruction reaches 100% within a radius of 30 meters and its effects are felt up to 100 meters from the point of impact.
Cannon family projectiles fly 11 km and cause destruction within 100 meters1. The first step in firing a cannon shot is to secure the gun. When they arrive at the battle site, the soldiers open the cannon arrows, two rods driven underground in cut logs to prevent the cannon from moving with the shots2. After fixation, it’s time to adjust the sights. The tube position is adjusted by two cranks, one for lateral movement and one for elevation. This position is calculated according to the distance to the target, the gun used, the ammunition and the wind speed.
3. Unlike pirate guns, modern models are rear loaded. At the back of the tube is the breech, a door through which the ammunition enters and which is hermetically closed at the time of the shot, to prevent the shot from coming out in the opposite direction.
4. Prepared at the time of use by soldiers, ammunition has three parts: the case, a metallic support that holds the gunpowder that propels the shot; the grenade, the explosive part of the projectile; and the fuze, the tip of the projectile that defines the time of explosion
5. It’s shooting time! When the commander shouts “fire!”, one of the soldiers pulls a string. It releases a compressed spring which, in turn, pushes a kind of hammer against the base of the case.
6. The impact of the hammer against the base of the case causes a spark that burns the gunpowder in the ammunition. This burning quickly releases a large volume of gas, which pushes the grenade through the mouth of the tube at a speed of up to 1,700 km/h.
7. The difference between cannons and howitzers appears in the tube. In cannons, it is smooth, making the shot come out straight. On howitzers, it has scratches on the inner wall, making the trajectory of the shot a spiral parabola, which increases the range and accuracy of the shot.
8. With the projectile in the air, who decides the time of the grenade explosion is the fuze. It has explosives that, depending on the type, detonate the grenade explosion at the time of impact with the target, a fraction of a second later or even at a previously programmed time.
9. After firing, the gases that propel the grenade forward also push the tube backwards – this is the “recoil” of the shot. To alleviate it, there is a structure called a cradle, through which the tube slides at the time of shooting and returns to the initial position.