View source for Engineering:Roman engineering

[[File:Roemerkran.jpg|thumb|right|250px|Reconstruction of a {{convert|10.4|m|ft|abbr=on}} high Roman ''[[Engineering:Treadwheel crane|Polyspastos]]'' in {{wipe|Germany}}]] 
The [[History:Ancient Rome|ancient Romans]] were famous for their advanced [[Engineering:Engineering|engineering]] accomplishments, although some of their 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 inconceivable in Greece. The architecture used in Rome was strongly influenced by Greek and  [[Place:Etruscan civilization|Etruscan]] sources.

Roads were common at that time, but the Romans improved their design and perfected the construction to the extent that many of their roads are still in use today. Their accomplishments surpassed most other civilizations of their time, and after their time, and many of their structures have withstood the test of time to inspire others, especially during the [[Philosophy:Renaissance|Renaissance]]. Moreover, their contributions were described in some detail by authors such as Vitruvius, Frontinus and Pliny the Elder, so there is a printed record of their many inventions and achievements.

==Aqueducts==
{{Main|Chemistry:Roman aqueduct}}
[[File:Segovia Aqueduct.JPG|thumb|right|250px|Aqueduct of Segovia, Spain.]]
{{convert|1000|m3|usgal}} of water were brought into Rome by 11 different aqueducts each day.  Per capita water usage in ancient Rome matched that of modern-day cities like New York City or modern Rome.  Most water was for public use, such as baths and sewers. [[Chemistry:De aquaeductu|De aquaeductu]] is the definitive two volume treatise on 1st century aqueducts of Rome, written by Frontinus.

The aqueducts could stretch from {{convert|10|-|100|km|-1|abbr=on}} long, and typically descended from an elevation of {{convert|300|m|-2|abbr=on}} above sea level at the source, to {{convert|100|m|abbr=on}} when they reached the reservoirs around the city. Roman engineers used inverted [[Physics:Siphon|siphon]]s to move water across a valley if they judged it impractical to build a raised aqueduct.  The Roman legions were largely responsible for building the aqueducts.  Maintenance was often done by slaves.<ref>Vinati, Simona and Piaggi, Marco de. “Roman Aqueducts, Aqueducts in Rome.” Rome.info. Web. 5/1/2012</ref>

The Romans were among the first civilizations to harness the power of water. They built some of the first [[Engineering:Watermill|watermill]]s outside of Greece for grinding flour and spread the technology for constructing watermills throughout the Mediterranean region. A famous example occurs at Barbegal in southern France, where no fewer than 16 overshot mills built into the side of a hill were worked by a single aqueduct, the outlet from one feeding the mill below in a cascade.

They were also skilled in mining, building aqueducts needed to supply equipment used in extracting metal ores, e.g. [[Engineering:Hydraulic mining|hydraulic mining]], and the building of reservoirs to hold the water needed at the minehead. It is known that they were also capable of building and operating mining equipment such as crushing mills and dewatering machines.  Large diameter vertical wheels of Roman vintage, for raising water, have been excavated from the Rio Tinto mines in Southwestern Spain. They were closely involved in exploiting [[Chemistry:Gold|gold]] resources such as those at Dolaucothi in south west Wales and in north-west Spain, a country where [[Earth:Gold mining|gold mining]] developed on a very large scale in the early part of the first century AD, such as at Las Medulas.

==Bridges==
[[File:Bridge Alcantara.JPG|thumb|right|250px|Alcántara Bridge, Spain]] 
Roman bridges were among the first large and lasting bridges ever built. They were built with stone, employing the [[Earth:Arch|arch]] as basic structure.  Most utilized concrete as well.
Built in 142 BC, the Pons Aemilius, later named ''Ponte Rotto'' (broken bridge) is the oldest Roman stone bridge in Rome, Italy.

The biggest Roman bridge was Trajan's bridge over the lower Danube, constructed by Apollodorus of Damascus, which remained for over a millennium; the longest bridge to have been built both in terms of overall and span length. They were normally at least 18 meters above the body of water.

An example of temporary military bridge construction is the two Caesar's Rhine bridges.

==Dams==
The Romans built many dams for water collection, such as the Subiaco dams, two of which fed Anio Novus, the largest aqueduct supplying Rome. One of the Subiaco dams was reputedly  the highest ever found or inferred. They built 72 dams in Spain, such as those at Mérida, and many more are known across the empire. At one site, Montefurado in Galicia, they appear to have built a dam across the river Sil to expose alluvial gold deposits in the bed of the river. The site is near the spectacular Roman gold mine of Las Medulas.

Several earthen dams are known from Britain, including a well-preserved example from Roman Lanchester, Longovicium, where it may have been used in industrial-scale smithing or [[Engineering:Smelting|smelting]], judging by the piles of slag found at this site in northern England. Tanks for holding water are also common along aqueduct systems, and numerous examples are known from just one site, the gold mines at Dolaucothi in west Wales. Masonry dams were common in North Africa for providing a reliable water supply from the [[Earth:Wadi|wadi]]s behind many settlements.

== Architecture ==
[[File:Colosseum in Rome, Italy - April 2007.jpg|thumb|250px|right|The Colosseum in Rome.]]
The buildings and architecture of [[History:Ancient Rome|Ancient Rome]] was impressive even by modern standards. The Circus Maximus, for example, was large enough to be used as a stadium. The [[Biology:Colosseum|Colosseum]] also provides an example of Roman architecture at its finest. One of many stadiums built by the Romans, the Colosseum exhibits the arches and curves commonly associated with Roman buildings.

The Pantheon in Rome still stands a monument and tomb, and the Baths of Diocletian and the Baths of Caracalla are remarkable for their state of preservation, the former still possessing intact [[Engineering:Dome|dome]]s. Such massive public buildings were copied in numerous provincial capitals and towns across the empire, and the general principles behind their design and construction are described by Vitruvius writing at the turn of millennium in his monumental work ''[[Engineering:De architectura|De architectura]]''.

The technology developed for the baths was especially impressive, especially the widespread use of the [[Engineering:Hypocaust|hypocaust]] for one of the first types of [[Engineering:Central heating|central heating]] developed anywhere. That invention was used not just in the large public buildings, but spread to domestic buildings such as the many villas which were built across the Empire.

== Materials ==
The most common materials used were brick, [[Chemistry:Dimension stone|stone]] or masonry, cement, [[Chemistry:Concrete|concrete]] and [[Chemistry:Marble|marble]]. Brick came in many different shapes. Curved bricks were used to build columns, and triangular bricks were used to build walls.

Marble was mainly a decorative material.  Augustus Caesar once boasted that he had turned Rome from a city of bricks to a city of marble. The Romans had originally brought marble over from Greece, but later found their own quarries in northern Italy.

Cement was made of hydrated lime (calcium oxide) mixed with sand and water. The Romans discovered that substituting or supplementing the sand with a pozzolanic additive, such as volcanic ash, would produce a very hard cement, known as hydraulic mortar or hydraulic cement. They used it widely in structures such as buildings, public baths and aqueducts, ensuring their survival into the modern era.

== Roads ==
[[File:Romeroadbuild.svg|thumb|right|Diagram of Roman road construction <ref>Duruy, Victor, and J. P. Mahaffy. [https://books.google.com/books?id=LVEZAAAAYAAJ History of Rome and the Roman People: From Its Origin to the Establishment of the Christian Empire]. London: K. Paul, Trench & Co, 1883. [https://books.google.com/books?id=LVEZAAAAYAAJ&pg=PA17 Page 17]</ref>]]
Roman roads were constructed to be immune to floods and other environmental hazards. Some roads built by the Romans are still in use today.

There were several variations on a standard Roman road. Most of the higher quality roads were composed of five layers. The bottom layer, called ''pavimentum'', was one inch thick and made of mortar. Above this were four strata of masonry. The layer directly above the pavimentum was called the ''statumen''. It was one foot thick, and was made of stones bound together by cement or clay.

Above that, there were the ''rudens'', which were made of ten inches of rammed concrete. The next layer, the ''nucleus'', was made of twelve to eighteen inches of successively laid and rolled layers of concrete. ''Summa crusta'' of silex or lava polygonal slabs, one to three feet in diameter and eight to twelve inches thick, were laid on top of the rudens. The final upper surface was made of concrete or well smoothed and fitted flint.

Generally, when a road encountered an obstacle, the Romans preferred to engineer a solution to the obstacle rather than redirecting the road around it: Bridges were constructed over all sizes of waterway; marshy ground was handled by the construction of raised causeways with firm foundations; hills and outcroppings were frequently cut or tunneled through rather than avoided (the tunnels were made with square hard rock block).

==Mining==
[[File:Archscrew2.jpg|thumb|right|Drainage wheel from Rio Tinto mines.]]
The Romans were the first to exploit mineral deposits using advanced technology, especially the use of [[Engineering:Aqueduct (water supply)|aqueducts]] to bring water from great distances to help operations at the pithead. Their technology is most visible at sites in Britain such as Dolaucothi where they exploited gold deposits with at least 5 long aqueducts tapping adjacent rivers and streams. They used the water to prospect for ore by unleashing a wave of water from a tank to scour away the soil and so reveal the bedrock with any veins exposed to sight. They used the same method (known as [[Engineering:Hushing|hushing]]) to remove waste rock, and then to quench hot rocks weakened by fire-setting.

Such methods could be very effective in opencast mining, but fire-setting was very dangerous when used in underground workings. They were made redundant with the introduction of explosives, although [[Engineering:Hydraulic mining|hydraulic mining]] is still used on alluvial [[Chemistry:Tin|tin]] ores. They were also used to produce a controlled supply to wash the crushed ore. It is highly likely that they also developed water-powered stamp mills to crush hard ore, which could be washed to collect the heavy gold dust.

At alluvial mines, they applied their [[Engineering:Hydraulic mining|hydraulic mining]] methods on a vast scale, such as Las Medulas in north-west Spain. Traces of tanks and aqueducts can be found at many other early Roman mines. The methods are described in great detail by Pliny the Elder in his Naturalis Historia.

He also described deep mining underground, and mentions the need to dewater the workings using reverse overshot water-wheels, and actual examples have been found in many Roman mines exposed during later mining attempts. The copper mines at Rio Tinto were one source of such artifacts, where a set of 16 was found in the 1920s. They also used Archimedean screws to remove water in a similar way.

==Military engineering==
{{Main|Engineering:Roman military engineering}}
Engineering was also institutionally ingrained in the Roman military, who constructed forts, camps, bridges, roads, ramps, palisades, and siege equipment amongst others. 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 by a dedicated team of engineers. Their exploits in the Dacian wars under Trajan in the early 2nd century AD are recorded on Trajan's column in Rome.

The army was also closely involved in [[Earth:Gold mining|gold mining]] and probably built the extensive complex of [[Engineering:Leat|leat]]s and [[Engineering:Cistern|cistern]]s at the Roman gold mine of Dolaucothi in Wales shortly after conquest of the region in 75 AD.

==Power technology==
[[File:Barbegal aqueduct 01.jpg|thumb|Arles Aqueduct]]
[[File:Barbegal mill 06.jpg|thumb|Mills below aqueduct]]
Water wheel technology was developed to a high level during the Roman period, a fact attested both by Vitruvius (in De Architectura) and by Pliny the Elder (in Naturalis Historia). The largest complex of water wheels existed at Barbegal near Arles, where the site was fed by a channel from the main aqueduct feeding the town. It is estimated that the site comprised 16 separate overshot water wheels arranged in two parallel lines down the hillside. The outflow from one wheel became the input to the next one down in the sequence.

Twelve kilometers north of Arles, at Barbegal, near Fontvieille, where the aqueduct arrived at a steep hill, the aqueduct fed a series of parallel [[Engineering:Water wheel|water wheel]]s to power a flourmill. There are two aqueducts which join just north of the mill complex, and a sluice which enabled the operators to control the water supply to the complex. There are substantial masonry remains of the water channels and foundations of the individual mills, together with a staircase rising up the hill upon which the mills are built. The mills apparently operated from the end of the 1st century until about the end of the 3rd century.<ref>[http://www.patrimoine.ville-arles.fr/arles/ville.cfm?action=edifice_histoire&id=95 Ville d'Histoire et de Patrimonie<!-- Bot generated title -->] {{webarchive|url=https://web.archive.org/web/20131206194648/http://www.patrimoine.ville-arles.fr/arles/ville.cfm?action=edifice_histoire&id=95 |date=2013-12-06 }}</ref> The capacity of the mills has been estimated at 4.5 tons of [[Biology:Flour|flour]] per day, sufficient to supply enough bread for the 12,500 inhabitants occupying the town of Arelate at that time.<ref>[http://www.etab.ac-caen.fr/lescourtils/provence/barbegal.htm La meunerie de Barbegal<!-- Bot generated title -->]</ref>

[[File:Römische Sägemühle.svg|thumb|250px|right|Scheme of the water-driven Roman sawmill at Hierapolis, Asia Minor.]]
The [[Engineering:Hierapolis sawmill|Hierapolis sawmill]] was a Roman water-powered stone saw mill at Hierapolis, [[Earth:Asia Minor|Asia Minor]] (modern-day [[Place:Turkey|Turkey]]). Dating to the second half of the 3rd century AD,<ref>{{harvnb|Ritti|Grewe|Kessener|2007|p=140}}</ref> the [[Engineering:Sawmill|sawmill]] is the earliest known machine to combine a [[Engineering:Crank (mechanism)|crank]] with a [[Engineering:Connecting rod|connecting rod]].<ref name="Ritti, Grewe, Kessener 2007, 161">{{harvnb|Ritti|Grewe|Kessener|2007|p=161}}</ref>

The [[Engineering:Watermill|watermill]] is shown on a raised relief on the sarcophagus of Marcus Aurelius Ammianos, a local miller. A waterwheel fed by a [[Engineering:Mill race|mill race]] is shown powering two [[Engineering:Frame saw|frame saw]]s via a [[Engineering:Gear train|gear train]] cutting rectangular blocks.<ref>{{harvnb|Ritti|Grewe|Kessener|2007|pp=139–141}}</ref>

Further crank and connecting rod mechanisms, without gear train, are archaeologically attested for the 6th century AD water-powered stone sawmills at Gerasa, Jordan, and [[History:Ephesus|Ephesus]], Turkey.<ref>{{harvnb|Ritti|Grewe|Kessener|2007|pp=149–153}}</ref> Literary references to water-powered [[Chemistry:Marble|marble]] saws in Trier, now {{wipe|Germany}}, can be found in Ausonius' late 4th century AD poem ''Mosella''. They attest a diversified use of water-power in many parts of the Roman Empire.<ref>{{harvnb|Wilson|2002|p=16}}</ref>

A complex of mills also existed on the Janiculum in [[Place:Rome|Rome]] fed by the Aqua Traiana. The Aurelian Walls were carried up the hill apparently to include the water mills used to grind grain towards providing bread [[Biology:Flour|flour]] for the city.  The mill was thus probably built at the same time as or before the walls were built by the emperor Aurelian (reigned 270–275 AD).  The mills were supplied from an aqueduct, where it plunged down a steep hill.<ref>Örjan Wikander, 'Water-mills in Ancient Rome' ''Opuscula Romana'' XII (1979), 13–36.</ref>

The site thus resembles Barbegal, although excavations in the late 1990s suggest that they may have been undershot rather than overshot in design.  The mills were in use in 537 AD when the Goths besieging the city cut off their water supply.  However they were subsequently restored and may have remained in operation until at least the time of Pope Gregory IV (827–44).<ref>Örjan Wikander, 'Water-mills in Ancient Rome' ''Opuscula Romana'' XII (1979), 13–36.</ref>

Many other sites are reported from across the Roman Empire, although many remain unexcavated.

==See also==
*[[Engineering:De architectura|De architectura]]
*[[Chemistry:De aquaeductu|De aquaeductu]]
*Frontinus
*List of Roman watermills
*Naturalis Historia
*Pliny the Elder
*Roman agriculture
*Roman aqueducts
*Roman metallurgy
*Roman mining
*[[Engineering:Roman technology|Roman technology]]
*Vitruvius

==References==
{{Reflist}}

==Bibliography==
*{{cite book|last=Davies|first=Oliver|title=Roman Mines in Europe|location=Oxford|year=1935}}
*{{cite book|last=Healy|first=A.F.|title=Pliny the Elder on Science and Technology|publisher=Clarendon |location=Oxford|year=1999}}
*{{cite book|last=Hodge |first=T.|title=Roman aqueducts and Water supply|publisher=Duckworth|edition=2nd|year=2001}}
*{{Citation
 | last = Ritti
 | first = Tullia
 | last2 = Grewe
 | first2 = Klaus
 | last3 = Kessener
 | first3 = Paul
 | title = A Relief of a Water-powered Stone Saw Mill on a Sarcophagus at Hierapolis and its Implications 
 | journal = Journal of Roman Archaeology
 | pages = 138–163
 | volume = 20
 | year = 2007
}}
*{{cite book|last=Smith|first=Norman|title=A History of Dams|publisher= Citadel Press |year=1972}}

==Further reading==
{{Library resources box |by=no |onlinebooks=yes |others=yes |about=yes |label=Roman engineering
  |viaf= |lccn= |lcheading= |wikititle= }}
*Cuomo, Serafina. 2008. "Ancient written sources for engineering and technology." In ''The Oxford handbook of engineering and technology in the classical world''. Edited by John P. Oleson, 15–34. New York: Oxford Univ. Press.
*Greene, Kevin. 2003. "Archaeology and technology." In ''A companion to archaeology''. Edited by John L. Bintliff, 155–173. Oxford: Blackwell.
*Humphrey, John W. 2006. ''Ancient technology''. Westport, CT: Greenwood.
*McNeil, Ian, ed. 1990. ''An encyclopedia of the history of technology''. London: Routledge.
*Oleson, John P., ed. 2008. ''The Oxford handbook of engineering and technology in the classical world''. New York: Oxford Univ. Press.
*Rihll, Tracey E. 2013. ''Technology and society in the ancient Greek and Roman worlds''. Washington, DC: American Historical Society.
*White, Kenneth D. 1984. ''Greek and Roman technology''. Ithaca, NY: Cornell Univ. Press.


[[Category:Ancient Roman technology]]

{{Sourceattribution|Roman engineering|1}}