Leonardo and the Military Engineering

Discovering studies of fortified architecture, from Milan to Romagna

ROCCA DI MONTAGNANational Museum of Science and Technology Leonardo Da Vinci

Scythed chariots, giant crossbows, ships with moving spurs, assault ladders: Leonardo designed machines of the most diverse types. Let's discover this fascinating history through models in Milan's Museum of Science.

Rivellino triangolare, particolare frontaleNational Museum of Science and Technology Leonardo Da Vinci

Impressing the Duke

Leonardo’s interest in undertaking charges of military engineering for the Sforza court dates back as far as 1482-83, when he wrote a letter of presentation to Ludovico il Moro. Although his preparation up until that time related primarily to the tradition of workshop artisanship, Leonardo enumerates his capabilities with emphasis on his preparation in relation to military engineering, listing his activities as painter only at the end. Leonardo’s intention was to impress the duke.

Fortezza di montagna, particolareNational Museum of Science and Technology Leonardo Da Vinci

The art of fortification

His first drawings relating to military architecture, to be found in Paris Manuscript B, date between 1485 and 1490. During these Milanese years, Leonardo attempted to update his knowledge regarding the art of fortification, which up until that time was limited to what he could get from the mechanical tradition of Tuscany stemming from Brunelleschi and Taccola.

Castello Sforzesco di MilanoNational Museum of Science and Technology Leonardo Da Vinci

The Castle of Milan
Leonardo measured, observed, and described attentively the Castle of Milan and with distinct, scrutinized strokes, admirable for their efficiency. Leonardo also studied the castle ravelins, that is, the fortified access towers, which later evolved into the more modern form of the actual bastion.

Difesa angolare con fiancheggiamentoNational Museum of Science and Technology Leonardo Da Vinci

While his early studies of fortified architecture were in line with the works of his contemporaries, Leonardo provided significant innovations in his graphic representations, using not only axonometric and prospect views, but also plan views, cutaway views, and horizontal sections.

Balestra gigante, particolareNational Museum of Science and Technology Leonardo Da Vinci

Astonish, astonish and astonish again
Initially, Leonardo drew machines of the most various types, from scythed chariots to gigantic crossbows, from bombards to ships with movable bow rams, from assault ladders to mortars, illustrating through his drawings what he had previously declared in his letter to Ludovico il Moro.

Machina secondo li populi de ArabiaNational Museum of Science and Technology Leonardo Da Vinci

De Re Militari

During these Milanese years, Leonardo attempted to update his knowledge regarding the art of fortification, which up until that time was limited to what he could get from the mechanical tradition of Tuscany. He came into possession of certain classical and modern texts on the military arts that were in circulation in the Sforza court. Leonardo knew of classical authors through second-hand sources and he paralleled study of these with his examination of the fundamental contemporary text De re militari (On military matters), by Roberto Valturio. Valturio’s drawings of war apparatus, reflect the state of military engineering during the second half of the fifteenth century, in which the mêlée weapons of medieval tradition coexisted with the new firearms, and all were depicted in a fantastical, nearly theatrical, key.

Carri falcatiNational Museum of Science and Technology Leonardo Da Vinci

The scythed chariot

Fascinated by Valturio’s fantastical machines, Leonardo studied and assimilated their nomenclature. A war engine such as the scythed chariot demonstrates the line of continuity leading from classical sources, Vegetius in this case, through Valturio’s work and on to Leonardo’s drawings.

Balista per lancio di proiettili by Argan GiovenaleNational Museum of Science and Technology Leonardo Da Vinci

Power to the imagination

These drawings are characterized not only by their unbridled fantasy, but also by their detachment from any practical implication. Leonardo was fascinated by the extraordinary and dramatic aspects of war-faring engines. Leonardo combined elements from tradition with automations and complex mechanical elements. In his drawings of war machines, engineering interweaves with artistic representation in a manner conferring tones of excitement and drama upon many drawings.

PROIETTILI OGIVALINational Museum of Science and Technology Leonardo Da Vinci

From fantasies to physics

In 1490, Leonardo met the Sienese engineer Francesco di Giorgio Martini, who had been called to Milan by the cathedral fabric management for consultation relating to statics problems in the construction of the lantern for the Duomo. After 1490, Leonardo’s researches in the field of fortified architecture and firearms underwent an evolution, with further theoretical investigation in the fields of ballistics and physics.

Ponte di circostanza su doppia fila di cavallettiNational Museum of Science and Technology Leonardo Da Vinci

Solving practical problems in Romagna
The drawings from the Romagnese period were not abstract exercises, but rather studies aimed at resolving urgently practical problems.

CORTINA CON SALIENTI SEMICIRCOLARINational Museum of Science and Technology Leonardo Da Vinci

Leonardo and Cesare Borgia

In 1502, Leonardo had his first contacts with the leader Cesare Borgia, son of pope Alexander VI. He was at the head of a state in Romagna created for him by his father. Thus Leonardo’s charge was that of military consultant with the objective of visiting all the fortifications in Romagna for works of repairs and reconstructions.

Cortina fortificata con salienti semicircolari, particolareNational Museum of Science and Technology Leonardo Da Vinci

Back to regularity

After 1503-04, Leonardo would appear to have abandoned the revolutionary forms of the Borgia period, approaching closer to the more conservative lines of Francesco di Giorgio Martini, for whom he showed complete adherence by his transcriptions of many passages from his treatise.

Fossato con difesa sommersaNational Museum of Science and Technology Leonardo Da Vinci

Isolating Pisa from the sea
In Florence, as consultant for the Republic, Leonardo was involved in the project of rerouting the course of the Arno, with the purpose of isolating Pisa from the sea.

ROCCA DI MONTAGNANational Museum of Science and Technology Leonardo Da Vinci

Leonardo is back in Milan

In 1506 Leonardo was back in Milan, in service to the governor Charles d’Amboise, who praised him for his works of military architecture. During these years, Leonardo drew the Castle of Milan many more times.

DOUBLE SILING, detailNational Museum of Science and Technology Leonardo Da Vinci

Leaving for Rome

Leonardo left Milan for the last time on 25 September 1513, called to Rome in service of Giuliano de’ Medici, with responsibilities of military consultation. These were among Leonardo’s last studies in the field of fortified architecture.

Angolo di rocca con triplice difesa radenteNational Museum of Science and Technology Leonardo Da Vinci

Corner of a stronghold with threefold defense by grazing fire

The model represents the corner of a stronghold with two square fortifications at the corner: the first is included within the perimeter of the main stronghold wall, while the second protrudes out from the corner with the majority of its volume. The moat is fashioned not by means of excavation but by a retaining wall and large quantities of earth. A particularly interesting feature is the innovative position for the defense of the flanker, which is realized by arranging for a line of firearms on the protruding part of the fortification, so that the defenders could strike any assailants who might reach the top of the moat. The objective of this structure is to be able to organize through successive phases a series of grazing shots to strike assailants at the points where it is most difficult to advance: the bank, the moat, the curtain wall, and the upper patrol walk.

Torre angolare con beccatelli modelloNational Museum of Science and Technology Leonardo Da Vinci

Corner tower with corbels

The model represents the corner of a stronghold, with a circular tower at the corner, with pronounced escarpment. The tower is covered with a double conical crown, equipped with traditional machicolations and loopholes for artillery. This tower shows a blend of elements typical of medieval military engineering together with innovations coming from Renaissance fortified architecture. An example of traditional architecture is the presence of the embattlements supported by a series of corbels, which help conceal the drop holes through which boiling oil could be thrown down upon the enemy. An innovation, by contrast, would be the massive escarpment for the tower: on the basis of its inclination, it is clearly designed to withstand the incoming strikes of firearms. In the moat, a wall with loopholes is designed for positioning of artillery.

Rivellino triangolare, dettaglioNational Museum of Science and Technology Leonardo Da Vinci

Ravelin or triangular bastion

The model represents a ravelin, or a defensive outpost, on triangular plan. Leonardo drew this, with the page turned upside down, in plan and prospect views, giving details about the crown on a separate folio. Its walls are steeply sloping and are divided into two sectors by a ribbing. The much shorter upper sector shows corbels between small arches and loopholes, for positioning of artillery, alternating with embattlements. The corners of the ravelin are blunted, and on the terrace roof there is a covered patrol walk and three small service buildings. Rather than a ravelin, this could be a bulwark of bastions that Leonardo may have seen, possibly referring to the stronghold at Ostia or at Civita Castellana, in Lazio, both of which were on plans of Giuliano da Sangallo.

Fossato con difesa sommersaNational Museum of Science and Technology Leonardo Da Vinci

Moat with underwater defense

This large drawing in ink and watercolor dates from the Romagna period. Leonardo depicted a broad cross sectional view of a polygonal stronghold defended by two rows of walls and two moats. Separately he drew details of the embrasures, of the protection of the external walls using hay, and a variant for the coverings. Lastly he drew a detail of the moat. The model represents this section of fortification. At the center of the moat is a submerged ravelin, that is, a low tower, of great diameter and with a conical superstructure: its profile barely surfaces through the water. It has an underground access and a line of fire over the water’s surface. The external walls are covered with hay to deaden blows of artillery. The tower is equipped with a cavity to be utilized as a vent for fumes and noises produced by cannon fire. It is also equipped with a platform for elevating the level of soldiers’ feet, thus making their fire from the loopholes as grazing as possible.

PONTE MOBILE D’ASSEDIONational Museum of Science and Technology Leonardo Da Vinci

Mobile assault bridge

The model represents a section of fortification and moat, over which two war-faring machines are being used for assault against the walls: a carriage with mobile bridge covered by a roof and an adjustable ladder. These allowed soldiers to position themselves behind enemy walls and to pass over the moats to climb the walls. The bridge could be moved on its rollers and wheels, and it had a covered structure for protecting the soldiers as they crossed. The inclination of the covered bridge could be adjusted using the cables attached to a transmission shaft.

Organo a trentatre canne by Argan GiovenaleNational Museum of Science and Technology Leonardo Da Vinci

Multiple barrel guns

These artillery pieces with multiple barrels were destined for accompanying infantry in action, with the purpose of increasing the rhythm of firing. Leonardo drew them on one folio, defining them as organ-style mortar on account of their resemblance to organ pipes. The first is constituted of a battery of 33 small firearm barrels ordered in three rows of 11 each on a single rotating frame. The fusils are frontmounting and fixed on the frame with a hinge for rotating upward for loading. An endless screw is inserted in the gun mount. Once the first row was discharged, the artillery piece would have been able successively to move the second and third rows into firing position. Once loaded, the barrels were maintained in position by a metal staff fixed to the sides by means of pegs. The endless screw was used for adjusting the height of aim.

CARRO COPERTO DA GUERRANational Museum of Science and Technology Leonardo Da Vinci

Covered war carriage

With this carriage, Leonardo rediscovered with admiration, studied, and innovated with the models from the war-faring tradition of the Middle Ages. Of the form of a tortoise, the carriage is reinforced with metal tiles and is shown in an open view to the side to display the interior. It is surmounted by a tower allowing sighting from the inside and armed with cannons. Movement for the carriage was provided from the inside by eight men who actuated a system of gears connected to the four wheels. The direction of fire could be decided by the men positioned at the upper part of the carriage, from where they could view the battlefield through narrow openings.

CARRO COPERTO DA GUERRANational Museum of Science and Technology Leonardo Da Vinci

Balista per lancio di proiettili by Argan GiovenaleNational Museum of Science and Technology Leonardo Da Vinci

Ballista

This ballista, an actual exercise on one of the traditional assault machines from classical and medieval times, was conceived for launching stones with a parabolic trajectory and for a long distance, to open a breach in the enemy walls. It is constituted of a wooden spring that is drawn by a bolt positioned at the base of the trestle structure: the energy for the launch is provided by the extreme torsion of the cords. This instrument of war was conceived for obtaining a great power within modest dimensions, by contrast with the trebuchet, an assault weapon working on the counterweight principle, which often reached over 10 m in height.

DOUBLE SILINGNational Museum of Science and Technology Leonardo Da Vinci

Double ballista

The model represents a double ballista. Two crossbow-style springs of wooden strips are mounted on a wooden structure. At the extremities of the springs there are two toothed wheels connected by a cord. Two staves are inserted onto the two wheels: one terminates with a sling (fromba), the other with a shallow spoon-shaped recipient. The two toothed wheels also engage two endless screws positioned at the end of a transmission shaft divided into two half-axles, connected in turn with a crank by means of a coupled toothed wheel and endless screw. The shaft is also connected to a lever that can engage the two loaded toothed wheels connected to the springs. The crank causes the two half-axles of the shaft to rotate, which twists the cords and compresses the two crossbow-type springs.

Balestra giganteNational Museum of Science and Technology Leonardo Da Vinci

Giant crossbow

This crossbow, a veritable “technological dream”, was to be used, in Leonardo’s intentions, for casting great balls of stone, creating panic and fright among the enemy. The proportions were colossal and Leonardo represented their impact by drawing a soldier operating the weapon, intent on utilizing the trigger system: the arms had a total open span of 42 braccia, about 24 m, mounted on a stock 23 m long and 1.2 m thick. The machine moved on six wheels.

Sfonda-carene comandato by Tursini LuigiNational Museum of Science and Technology Leonardo Da Vinci

Keel-breaching device

The model represent one of the weapons designed for sinking enemy ships by breaking a wooden plank of the hull with a violent jerk. Leonardo resumed the proposals from medieval tradition, just as Taccola did, but while the Sienese engineer drew the keel-breaching devices for positioning beneath the water’s surface at the entrance to port, Leonardo associated them with underwater attacks. In this keel-breaching device, a U-shaped clamp is combined with a large central screw. The two branches of the U are attached to two non-contiguous boards of the ship’s hull. The screw is then screwed into the central board. Once this has been firmly screwed in and fixed, the second crank is actuated: by exerting pressure on the two arms of the device, the hull is breached, provoking the sinking of the ship.

Scafandro per palombaro by Tursini LuigiNational Museum of Science and Technology Leonardo Da Vinci

Underwater diving suit

Leonardo describes this diving suit in detail: “Jacket and trousers, and a small skin for urinating, a skirt of tasses, and a skin for holding the air, with half-circles of iron to keep it apart from your chest. If you have a whole skin, with balls for valves, when you deflate it you will go to the bottom with it, drawn by the sacks of coarse sand. When you inflate it, you will return upward, onto the water. A mask with the eyes covered with glass. But have the weight be what you can lift in your swimming. Take a knife that cuts well, so a net will not end up catching you. Take with you 2 or 3 small skins, deflated, which you can inflate like balls if you need” . The leather diving suit, thus, was composed of jacket, trousers, and mask with glass viewing pieces. The inflating of the jacket was sustained by a structure of iron circles, and a skin was provided for containing a reserve of air.

FAST RAMMING BOATNational Museum of Science and Technology Leonardo Da Vinci

Rapid ship for ramming

This craft was conceived for ramming enemy ships. The elongated hull allowed the craft to reach a very high speed and thus also a notable force of impact. A metal ram concealed under the surface of the water allowed the craft to breach the enemy’s hull by repeated blows. At a short distance from the enemy ship, the craft would begin making use of the prow’s weaponry, which included an adjustable cannon, which would thus have shot at close range, to the enemy’s surprise.

Circumfolgore by Tursini LuigiNational Museum of Science and Technology Leonardo Da Vinci

Multiple bombard

“Circumfulgore is a naval machine. It was the invention of the people of Majolica, and it is made of a circle of bombards, of whatever number you please – as long as it is not an uneven number, since, in order for the blow to be effective, and for the craft not to recoil, it is necessary for one bombard to be at the back of and to block another. And to do this, it is necessary to give fire at the same time to two contrary bombards, so that if one causes recoil toward one direction, the other will contradict it”. The model represents a study of a multiple bombard conceived for positioning on the bridge of a ship. Leonardo called it circumtronito or circumfolgore (roughly surround with thunder or surround with lightning). It is constituted of a section of the hull of a watercraft, on which an artillery turret is installed, composed of a turning platform on which 12 firearm barrels are arranged. The bombards, probably breech-loading, are arranged radially so as to allow them to shoot simultaneously in opposite directions, thus balancing the recoils after shots so that the ship would not be subject to dangerous yawing or rolling.

Affusto di cannone a code divaricabili by Argan GiovenaleNational Museum of Science and Technology Leonardo Da Vinci

Cannon mount with spread tail stocks

The mount is the structure on which a piece of artillery rests. The example drawn by Leonardo shows end stocks that are spread out, permitting sweeping coverage of notable sectors by rotating the firearm while maintaining stability of fire. The firearm could shift rapidly in the horizontal direction by means of a guiding system, as well as in the vertical, by means of a system of rungs.

Argano per sollevare le artiglierie by Argan GiovenaleNational Museum of Science and Technology Leonardo Da Vinci

Winch for raising artillery

This winch described and observed by Leonardo was used for raising pieces of artillery, such as bombards, or columns. The winch is of the classical trestle form. At the upper part, a balance-type arm rocks on a pivot: one extremity is connected with an endless screw, while the other bears a bombard tied with cords. The raising and lowering is effected by means of an endless screw and a helicoid wheel acting as screw bolt. The movement causes the central axis on which the cannon is hanging to oscillate slowly, thus raising it.

Acciarino automatico a pietra focaia Acciarino automatico a pietra focaia by Somenzi VittorioNational Museum of Science and Technology Leonardo Da Vinci

Automatic striker

The striker is a flint stone instrument used for repeatedly triggering a firearm. The device is constituted of a helicoid spring connected, by means of a jointed chain with three links, to an upper wheel lodged in a ring and sustained at the center of a bridge with four arms screwed onto the ring itself.

The wheel rubs against a piece of flint on the left. To the right is the trigger. With a turn of the wheel, the jointed chain stretches the large spring, loading the weapon. When the trigger is pressed, the stop tooth frees the wheel, which turns, striking the flint and igniting the gunpowder.

Cupolino per respirazione by Tursini LuigiNational Museum of Science and Technology Leonardo Da Vinci

Diving bell for breathing underwater

“New method for a bellows that works very well”. On a folio in the Codex Arundel, compiled in 1508, Leonardo dwells on a breathing system for use in working underwater. Twenty years after his sketches for an underwater diving suit, on a folio of the Codex Atlanticus rich with many military indications for underwater attacks against enemy ships, Leonardo approached this theme again from a new perspective, indicating the utility of the system for the purpose of caulking, meaning the leak-proofing of the ship’s planking by filling in the cracks with oakum.

With this breathing system, a man could work under water without needing to dry-dock the ship. The span of 20 years between these and the earlier drawings of the diver is obvious.

Ponte di circostanza su doppia fila di cavallettiNational Museum of Science and Technology Leonardo Da Vinci

Circumstantial bridges on trestles

This model represent circumstantial bridge, or bridge of happenstance, designed for military purposes. Its advantage was in being able to be easily constructed or dismantled and in using easily available materials. Leonardo studied and drew a provisional bridge constituted of a system of bridge beams supported by a row of trestles or armoring. The bridge beams partially cover it, leaving uncovered one section of it to show the succession of the constructional phases. The construction was realized summarily using a structure of thin boards of light wood (spears). Successively, the provisional bearing structure was substituted by a definitive structure, realized using large logs in the form of a trestle.

PONTE GIREVOLE A PROFILO PARABOLICONational Museum of Science and Technology Leonardo Da Vinci

Parabolic swing bridge

The model represents a swing bridge with parabolic profile constructed over a watercourse. To the left is the end portion of a road constructed on an embankment. The bridge is constituted of an arched span with parabolic profile. The free end, which is thin and light, rests when the bridge is closed upon a support of trunks on the other bank of the river, where the road begins again. The pivot is connected to two winches positioned at the two sides of the embankment and is also provided with a counterweight container for balancing and facilitating the maneuvers when the bridge remains suspended in air, before coming to rest on the other shore. Movement of the bridge is effected by means of cords and winches and with the aid of metal wheels or rollers.

Ponte di Galata by De Rizzardi AlcideNational Museum of Science and Technology Leonardo Da Vinci

Bridge over the golden horn

The model represents a single span bridge that ought to have measured 240 m long, 23 m wide, and 40 m over the water level at its peak. The two ends of the bridge each have a double, swallow’s tail type support, providing better resistance to transverse thrust. The model was realized on the basis of indications from a small drawing by Leonardo in Manuscript L, conceived for crossing the strait of the Bosporus at the Golden Horn. The hypothesis about this project of Leonardo would appear also to be confirmed by a letter written in Turkish, now in the archives at Topkapi Palace in Istanbul, apparently the translation of the actual letter in which Leonardo offered his services to the Ottoman sultan.

Credits: Story

Exhibition by
Museo Nazionale della Scienza e della Tecnologia
Leonardo da Vinci

Via San Vittore 21
Milano

www.museoscienza.org

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