Exploring Da Vinci's Military Weaponry

Separating Leonardo the peacenik from Leonardo the warmonger is difficult, but there you have it: Many of Leonardo da Vinci's machines were, in fact, intended to defend his patron and duke of Milan Ludovico Sforza's honor (not to mention Milan itself). He designed both offensive equipment and, in case the enemy hatched the same idea, fortifications and defense machines.

By Leonardo's time, military engineering was the highest of arts. Thus, many of his offensive weapons weren't original per se, but were improvements designed to increase the firepower and speed of some of these more deadly weapons.

Moving across enemy lines: Armored tanks

In his 1482 job letter, Leonardo wrote the following to Ludovico Sforza, the duke of Milan:

I can make armoured cars, safe and unassailable, which will enter the serried ranks of the enemy with their artillery, and there is no company of men at arms so great that they will break it. And behind these the infantry will be able to follow quite unharmed and without any opposition.

This boast wasn't exactly an idle one: Leonardo's armored tank (shown in Figure 1) was, indeed, formidable. Had it not been too heavy to move, it surely would've wiped out enemy troops. Incidentally, Leonardo imagined this tank as a replacement for the elephant!

Leonardo wasn't the first to work on the idea of a tank; some inventors before him had designed several sail-powered tanks, none of which ever saw the light of day. But around 1487, Leonardo invented a new kind of tank. His model showed a four-wheeled vehicle powered by animals or humans (it required eight men!) turning cranks attached to different kinds of wheels. The tank had holes at the base for firing cannons and a turret at the top for observation and more shooting. The body itself was turtle-shaped, reinforced with metal plates and armed with guns. But the design had a fatal flaw. The front and rear wheels were geared to turn in opposite directions.

Despite its flaws, Leonardo's design (which no one built during his lifetime) served as a model 400 years later for tanks that saw action during World War I.

Storming walls

During the Middle Ages, people had built fortified castles to protect villagers. At the first sign of danger, folks would hightail it up the hill to the castle and hide out in its confines. Then, after first trampling or burning the village below, the enemy would arrive at the fortress, ask for surrender, and if the answer was no, storm its walls with a battering ram, light it on fire, shoot at it, or tunnel underneath it — and either make it in, or not.

By the time of the Renaissance, much of Europe — and almost all of Italy, with its belligerent city-states — was at war. Compared with armies from the Middle Ages, Renaissance-era armies were more orderly , tactical entities that, in turn, required more effective weapons. Besides the obvious (such as simple rope ladders for attacking walls), Leonardo developed some innovations for storming walls:

• A battering ram: A wheel-mounted frame fitted with a bridge that could span a moat and lean up against enemy walls.

• Scaling ladders: By Leonardo's time, scaling ladders (kind of like today's hook-and-ladder, which allows people to climb over high walls or knock down an enemy's ladders while firing missiles at them!) were in full use. Some were mounted on mobile platforms, making them more difficult to knock over. Others used baskets to lift men over the walls. Leonardo added a few new elements to these models. He designed rigid ladders, some with grappling hooks to attach to the wall, and others with spikes to hook into the ground. He based many of these designs on the scaling ladders presented in Roberto Valturio's treatise On Things Military (1472).

But what if the enemy used the same type of equipment? Leonardo took a few precautions and designed some countermeasures, including a large cog that unbalanced attackers from the wall and toppled them over the side.

Diving 20,000 leagues under the sea: The submarine

Around 1515, Leonardo drew a submarine. He described it as a "ship to sink another ship." Leo's sub was a shell with room for one person inside, but it couldn't — like modern submarines — submerge completely. Had he built it, it may have worked with the proper power source. It sank (or, may have sunk) other ships by ramming into them.

Leonardo's model of a submarine differed just a tad from the submarine that Jules Verne depicted in 20,000 Leagues Under the Sea. No gigantic sea monsters threatened it, either. But it was still more or less a submarine — one that predated the real submarine by more than 100 years. (That honor went to a Dutch inventor, Cornelius van Drebbel, in 1624. However, no one used a sub in combat until 1776, three years after an American, David Bushnell, invented his wood-and-propeller sub.)

Although Leonardo's submarine never made it off paper, Leo was commemorated during World War II, when Italy named one of its hero subs (it sunk 17 Allied ships) the Leonardo da Vinci.

Improving cannons and prefiguring the machine gun

Cannons weren't all that practical on the battlefield in Leonardo's day, mostly because of their weight and lengthy loading time. They were cast iron or bronze, with a short barrel and a short range. So Leonardo experimented with already existing models to find ways to improve upon them. Thus he designed a breech-loading cannon and a three-barreled cannon, measured the power of a missile, and even reportedly launched a rocket-powered cannonball 10,000 feet into the air! He even may have tested one of his more innovative designs — a steam-powered cannon. Ever thoughtful, Leonardo also invented a hoist for lifting cannons and a model to improve the ignition of firearms. Historians generally agree that Leonardo's ideas (never tested, of course) were as sophisticated as those of an artillerist in the mid-1800s!

In his letter to the duke of Milan, Ludovico Sforza, Leonardo boasted of his skills in making fast, light, and accurate firearms — should the use of cannons become impractical in emergency situations. A few of his designs prefigured the modern machine guns:

• A front-loading firearm that had an adjustable gear with a peg-blocking system, intended to be used by soldiers

• An adjustable and relatively light eight-barreled gun made up of small muzzles mounted on a two-wheeled carriage

• A 33-barreled machine gun, mounted on a revolving framework, that could fire 11 shots simultaneously

• A split-trail gun carriage, with a mechanism that allowed for greater angles of rotation and elevation

As far as gunpowder goes, Leonardo designed shells that exploded immediately and others that coughed out large balls that then coughed out smaller explosives. Leonardo also invented the wheel-lock, a better system than the flintlock, for igniting the gunpowder.