Roman military engineering
Encyclopedia
The military engineering of Ancient Rome
's armed forces were of a scale and frequency far beyond that of any of its contemporaries'. Indeed, military engineering was in many ways institutionally endemic in Roman military culture, as demonstrated by the fact that each Roman legionary had as part of his equipment a shovel, alongside his gladius
(sword) and pila
(spears).
Fabri were workers, craftsmen or atisans in Roman society and descriptions of early Roman army structure (Legion assumed) attributed to king Servius Tullius describe there being two centuriae of fabri under an officer, the praefectus fabrum.
Roman military engineering took both routine and extraordinary forms, the former a proactive part of standard military procedure, and the latter of an extraordinary or reactionary nature.
had a military legionary fort as its permanent base. However, when on the march, particularly in enemy territory, the legion would, after a day's marching, construct a fortified camp or castra
, requiring as raw materials only earth, turf and timber. Camp construction were the responsibility of special engineering units to which specialists of many types belonged, officered by architecti (engineers), from a class of troops known as immunes
since they were excused from or, literally, immune from, regular duties. These engineers would requisition manual labor from the soldiers at large as required. A legion could throw up a camp under enemy attack in as little as a few hours. Judging from the names, they probably used a repertory of camp plans from a set textbook, selecting the one appropriate to the length of time a legion would spend in it: tertia castra
, quarta castra
: "a camp of three days", "four days", etc.
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The engineers also built bridges from both timber and stone depending on required permanence, time available etc. Some Roman stone bridges survive to this day. Stone bridges were made possible by the innovative use of the keystone
to allow an arch construction. One of the most notable examples of military bridge-building in the Roman Empire was Julius Caesar's Bridge over the Rhine River
. This bridge was completed in only ten days and is conservatively estimated to be more than 100 m (300 feet) long. The construction was deliberately over-engineered for Caesar's stated purpose of impressing the Germanic tribes, who had little experience of engineering, and to emphasise that Rome could travel wherever she wished. Caesar was able to cross over the completed bridge and explore the area uncontested, before crossing back over and dismantling the bridge. Caesar relates in his War in Gaul that he "sent messengers to the Sugambri to demand the surrender of those who had made war on me and on Gaul, they replied that the Rhine was the limit of Roman power". The bridge was intended to show otherwise.
were adaptations from earlier Greek designs, the Romans were adept at engineering them swiftly and efficiently, as well as innovating variations such as the repeating ballista
. The 1st century BC army engineer Vitruvius
describes in detail many of the Roman siege machines in his manuscript De Architectura
.
credits the Roman building of the Via Appia with winning them the Second Samnite War.
The Roman army also took part in building projects for civilian use. There were sound reasons for the use of the army in building projects: primarily, that if they weren't directly engaged in military campaigns, the legions were largely unproductive, costing the Roman state large sums of money. But the involvement of the soldiers in building works, kept them not only well accustomed to hard physical labour, but also kept them busy, since it was the widely held belief that busy armies weren't plotting to mutiny, whereas idle armies were.
Of both military and civilian use was the construction of roads within the boundaries of the Empire, in which the army was heavily involved. But so too were soldiers put to use in the construction of town walls, the digging of shipping canals, the drainage of land, aqueducts, harbours, even in the cultivation of vineyards. In some rare cases soldiers were even used in mining work.
, and the building of reservoirs to hold the water at the minehead. It is likely that they were also capable of building and operating mine equipment such as water mills, stamp mill
s and dewatering machines. It is likely that they were closely involved in exploiting gold
resources such as those at Dolaucothi in south west Wales
. It was developed soon after conquest of the region under Frontinus, and the local auxiliary troop came from north-west Spain, a country where gold mining developed on a very large scale in the early part of the first century AD.
One of the most famous of such extraordinary constructions was the circumvallation of the entire city of Alesia
and its Celtic leader Vercingetorix
, within a massive length of double-wall - one inward-facing to prevent escape or offensive sallies from the city, and one outward-facing to prevent attack by Celtic reinforcements. This wall is estimated to be over 20 km (12.4 mi) long
A second example would be the massive ramp built using thousands of tons of stones and beaten earth up to the invested city of Masada
in the Jewish Revolt. The siege works and the ramp remain in a remarkable state of preservation today.
Ancient Rome
Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....
's armed forces were of a scale and frequency far beyond that of any of its contemporaries'. Indeed, military engineering was in many ways institutionally endemic in Roman military culture, as demonstrated by the fact that each Roman legionary had as part of his equipment a shovel, alongside his gladius
Gladius
Gladius was the Latin word for sword, and is used to represent the primary sword of Ancient Roman soldiers. Early ancient Roman swords were similar to those used by the Greeks. From the 3rd century BC, the Romans adopted swords similar to those used by the Celtiberians and others during the early...
(sword) and pila
Pilum
The pilum was a javelin commonly used by the Roman army in ancient times. It was generally about two metres long overall, consisting of an iron shank about 7 mm in diameter and 60 cm long with pyramidal head...
(spears).
Fabri were workers, craftsmen or atisans in Roman society and descriptions of early Roman army structure (Legion assumed) attributed to king Servius Tullius describe there being two centuriae of fabri under an officer, the praefectus fabrum.
Roman military engineering took both routine and extraordinary forms, the former a proactive part of standard military procedure, and the latter of an extraordinary or reactionary nature.
The Roman legionary fortified camp
Each Roman legionRoman legion
A Roman legion normally indicates the basic ancient Roman army unit recruited specifically from Roman citizens. The organization of legions varied greatly over time but they were typically composed of perhaps 5,000 soldiers, divided into maniples and later into "cohorts"...
had a military legionary fort as its permanent base. However, when on the march, particularly in enemy territory, the legion would, after a day's marching, construct a fortified camp or castra
Castra
The Latin word castra, with its singular castrum, was used by the ancient Romans to mean buildings or plots of land reserved to or constructed for use as a military defensive position. The word appears in both Oscan and Umbrian as well as in Latin. It may have descended from Indo-European to Italic...
, requiring as raw materials only earth, turf and timber. Camp construction were the responsibility of special engineering units to which specialists of many types belonged, officered by architecti (engineers), from a class of troops known as immunes
Immunes
Ancient Rome's military was highly advanced for its time, divided into multiple units to maximize efficiency and power. One such unit was the immune class. By definition, the immunes were legionary soldiers who possessed specialized skills, qualifying them to perform duties atypical of a Roman...
since they were excused from or, literally, immune from, regular duties. These engineers would requisition manual labor from the soldiers at large as required. A legion could throw up a camp under enemy attack in as little as a few hours. Judging from the names, they probably used a repertory of camp plans from a set textbook, selecting the one appropriate to the length of time a legion would spend in it: tertia castra
Castra
The Latin word castra, with its singular castrum, was used by the ancient Romans to mean buildings or plots of land reserved to or constructed for use as a military defensive position. The word appears in both Oscan and Umbrian as well as in Latin. It may have descended from Indo-European to Italic...
, quarta castra
Castra
The Latin word castra, with its singular castrum, was used by the ancient Romans to mean buildings or plots of land reserved to or constructed for use as a military defensive position. The word appears in both Oscan and Umbrian as well as in Latin. It may have descended from Indo-European to Italic...
: "a camp of three days", "four days", etc.
Bridge building
Keystone (architecture)
A keystone is the wedge-shaped stone piece at the apex of a masonry vault or arch, which is the final piece placed during construction and locks all the stones into position, allowing the arch to bear weight. This makes a keystone very important structurally...
to allow an arch construction. One of the most notable examples of military bridge-building in the Roman Empire was Julius Caesar's Bridge over the Rhine River
Caesar's Rhine bridges
Caesar's Bridge across the Rhine, the first two bridges to cross the Rhine River, were built by Julius Caesar and his legionaries during the Gallic War in 55 BC and 53 BC, respectively...
. This bridge was completed in only ten days and is conservatively estimated to be more than 100 m (300 feet) long. The construction was deliberately over-engineered for Caesar's stated purpose of impressing the Germanic tribes, who had little experience of engineering, and to emphasise that Rome could travel wherever she wished. Caesar was able to cross over the completed bridge and explore the area uncontested, before crossing back over and dismantling the bridge. Caesar relates in his War in Gaul that he "sent messengers to the Sugambri to demand the surrender of those who had made war on me and on Gaul, they replied that the Rhine was the limit of Roman power". The bridge was intended to show otherwise.
Engineering siege machines
Although most Roman siege enginesRoman siege engines
Roman siege engines were, for the most part, adapted from Hellenistic siege technology. Relatively small efforts were made to develop the technology; however, the Romans brought an unrelentingly aggressive style to siege warfare that brought them repeated success...
were adaptations from earlier Greek designs, the Romans were adept at engineering them swiftly and efficiently, as well as innovating variations such as the repeating ballista
Polybolos
Polybolos was an ancient Greek repeating ballista reputedly invented by Dionysius of Alexandria, a 3rd century BC Greek engineer at the Rhodes arsenal and used in antiquity. Philo of Byzantium encountered and described the polybolos, a catapult that like a modern machine gun could fire again and...
. The 1st century BC army engineer Vitruvius
Vitruvius
Marcus Vitruvius Pollio was a Roman writer, architect and engineer, active in the 1st century BC. He is best known as the author of the multi-volume work De Architectura ....
describes in detail many of the Roman siege machines in his manuscript De Architectura
De architectura
' is a treatise on architecture written by the Roman architect Vitruvius and dedicated to his patron, the emperor Caesar Augustus, as a guide for building projects...
.
Road making
When invading enemy territories, the Roman army would often construct roads as they went, to allow swift reinforcement and resupply, as well as a path for easy retreat if necessary. Roman road-making skills are such that some Roman roads survive to this day. Michael GrantMichael Grant (author)
Michael Grant was an English classicist, numismatist, and author of numerous popular books on ancient history. His 1956 translation of Tacitus’s Annals of Imperial Rome remains a standard of the work. Having studied and held a number of academic posts in the United Kingdom and the Middle East, he...
credits the Roman building of the Via Appia with winning them the Second Samnite War.
Civilian engineering by military troops
Of both military and civilian use was the construction of roads within the boundaries of the Empire, in which the army was heavily involved. But so too were soldiers put to use in the construction of town walls, the digging of shipping canals, the drainage of land, aqueducts, harbours, even in the cultivation of vineyards. In some rare cases soldiers were even used in mining work.
Mining operations
They were also skilled in conducting mining operations such as building the many aqueducts needed for prospecting for metal veins, in methods like hydraulic miningHydraulic mining
Hydraulic mining, or hydraulicking, is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment. In the placer mining of gold or tin, the resulting water-sediment slurry is directed through sluice boxes to remove the gold.-Precursor - ground...
, and the building of reservoirs to hold the water at the minehead. It is likely that they were also capable of building and operating mine equipment such as water mills, stamp mill
Stamp mill
A stamp mill is a type of mill machine that crushes material by pounding rather than grinding, either for further processing or for extraction of metallic ores. Breaking material down is a type of unit operation....
s and dewatering machines. It is likely that they were closely involved in exploiting gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
resources such as those at Dolaucothi in south west Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
. It was developed soon after conquest of the region under Frontinus, and the local auxiliary troop came from north-west Spain, a country where gold mining developed on a very large scale in the early part of the first century AD.
Reactive and extraordinary engineering
The knowledge and experience learned through such routine engineering lent itself readily to any extraordinary engineering projects required by the army, and it is here that the scale of Roman military engineering exceeded that of any of its contemporaries in both imagination and scope.One of the most famous of such extraordinary constructions was the circumvallation of the entire city of Alesia
Battle of Alesia
The Battle of Alesia or Siege of Alesia took place in September, 52 BC around the Gallic oppidum of Alesia, a major town centre and hill fort of the Mandubii tribe...
and its Celtic leader Vercingetorix
Vercingetorix
Vercingetorix was the chieftain of the Arverni tribe, who united the Gauls in an ultimately unsuccessful revolt against Roman forces during the last phase of Julius Caesar's Gallic Wars....
, within a massive length of double-wall - one inward-facing to prevent escape or offensive sallies from the city, and one outward-facing to prevent attack by Celtic reinforcements. This wall is estimated to be over 20 km (12.4 mi) long
A second example would be the massive ramp built using thousands of tons of stones and beaten earth up to the invested city of Masada
Masada
Masada is the name for a site of ancient palaces and fortifications in the South District of Israel, on top of an isolated rock plateau, or horst, on the eastern edge of the Judean Desert, overlooking the Dead Sea. Masada is best known for the violence that occurred there in the first century CE...
in the Jewish Revolt. The siege works and the ramp remain in a remarkable state of preservation today.
See also
- Technological history of the Roman militaryTechnological history of the Roman militaryThe technology history of the Roman military covers the development of and application of technologies for use in the armies and navies of Rome from the Roman Republic to the fall of the Western Roman Empire. The rise of Hellenism and the Roman Republic are generally seen as signalling the end of...
- List of Roman Pontoon bridges
- Roman architectureRoman architectureAncient Roman architecture adopted certain aspects of Ancient Greek architecture, creating a new architectural style. The Romans were indebted to their Etruscan neighbors and forefathers who supplied them with a wealth of knowledge essential for future architectural solutions, such as hydraulics...
- Roman aqueducts
- Roman engineeringRoman engineeringRomans are famous for their advanced engineering accomplishments, although some of their own inventions were improvements on older ideas, concepts and inventions. Technology for bringing running water into cities was developed in the east, but transformed by the Romans into a technology...
- Trajan's columnTrajan's ColumnTrajan's Column is a Roman triumphal column in Rome, Italy, which commemorates Roman emperor Trajan's victory in the Dacian Wars. It was probably constructed under the supervision of the architect Apollodorus of Damascus at the order of the Roman Senate. It is located in Trajan's Forum, built near...
External links
- Traianus - Technical investigation of Roman public works