As Old as Warfare Itself

Soldiers have always built fortifications. For as long as there have been wars, soldiers have sought “cover.” Everything from the humble foxhole to pillboxes, bunkers, and castles. Obstacles range from barbed wire to antitank ditches and dragon’s teeth.

As long as there have been fortifications, armies have sought ways to overcome them. The easiest way is envelopment. Von Schlieffen devised the Germans’ celebrated “right hook” to outflank the Maginot Line. “Let the last man on the right brush the Channel with his sleeve.” Paratroopers and Air Cavalry were developed to execute the modern “vertical envelopment.” Dropping airborne armies behind enemy lines by parachute or glider. Flying troops into a combat zone by helicopter instead of fighting through on the ground.

At the Battle of Messines, during World War I, the British enveloped German trenches from below. Sappers tunneled beneath the German trenches and packed the mines with explosives. Before the infantry attack, they detonated the mines. The explosion annihilated the trenches and killed up to 10,000 German soldiers. The explosion was comparable to a 1-kiloton nuclear blast. The earth heaved for miles around. Some said the explosion was heard across the English Channel.

When all else fails, fortifications have to be destroyed by simple battering. That means artillery and bombing. In an earlier post, we discussed glide bombs, which are much more effective than artillery in destroying fixed fortifications. Simply put, a 1,500 or 3,000-kilogram bomb carries more explosives than a 152mm or 203mm artillery shell.

Artillery is Still There When Planes Can’t Fly

But planes cannot always fly. Enemy air defense can hold aircraft at bay beyond the range of glide bombs. The greater the size of a glide bomb, the shorter its range. That means the delivery platform is at greater risk from enemy air defense.

The largest siege cannons were built by the Germans during World Wars 1 and 2. To overcome the Belgian forts at Liege, the Germans rolled up 420mm siege mortars, fondly named “Big Berthas.” This heavy artillery fired heavy shells in high-arching trajectories that broke up the Belgian forts.

Figure 1 gives an idea of the sheer size of the mortar. Figure 2 shows the effect of shelling on the forts. The 420mm shells cracked the thick concrete like hammers, crushing eggshells.

Fig.1 Big Bertha, a German 4.2cm Siege Mortar used at Liege.