The Alcántara Bridge, Spain, a masterpiece of ancient bridge building

Roman bridges, built by ancient Romans, were the first large and lasting bridges built.^[1] Roman bridges were built with stone and had the arch as its basic structure. (see arch bridge). Most utilized concrete as well, which the Romans were the first to use for bridges.

Typology [edit]

Pons Fabricius in Rome, Italy

Roman pontoon bridge across the lower Danube

As with the vault and the dome the Romans were the first to fully realize the potential of arches for bridge construction.^[3]

A list of Roman bridges compiled by the engineer Colin O'Connor features 330 Roman stone bridges for traffic, 34 Roman timber bridges and 54 Roman aqueduct bridges, a substantial part still standing and even used to carry vehicles.^[4] A more complete survey by the Italian scholar Vittorio Galliazzo found 931 Roman bridges, mostly of stone, in as many as 26 different countries (including former Yugoslavia; see right table).^[5]

Roman arch bridges were usually semicircular, although a few were segmental (such as Alconétar Bridge). A segmental arch is an arch that is less than a semicircle.^[6] The advantages of the segmental arch bridge were that it allowed great amounts of flood water to pass under it, which would prevent the bridge from being swept away during floods and the bridge itself could be more lightweight. Generally, Roman bridges featured wedge-shaped primary arch stones (voussoirs) of the same in size and shape. The Romans built both single spans and lengthy multiple arch aqueducts, such as the Pont du Gard and Segovia Aqueduct. Their bridges featured from an early time onwards flood openings in the piers, e.g. in the Pons Fabricius in Rome (62 BC), one of the world's oldest major bridges still standing. Roman engineers were the first and until the industrial revolution the only ones to construct bridges with concrete, which they called Opus caementicium. The outside was usually covered with brick or ashlar, as in the Alcántara bridge.

The Romans also introduced segmental arch bridges into bridge construction. The 330 m long Limyra Bridge in southwestern Turkey features 26 segmental arches with an average span-to-rise ratio of 5.3:1,^[7] giving the bridge an unusually flat profile unsurpassed for more than a millennium. Trajan's bridge over the Danube featured open-spandrel segmental arches made of wood (standing on 40 m high concrete piers). This was to be the longest arch bridge for a thousand years both in terms of overall and individual span length, while the longest extant Roman bridge is the 790 m long Puente Romano at Mérida.

The late Roman Karamagara Bridge in Cappadocia may represent the earliest surviving bridge featuring a pointed arch.^[8]

Arch shapes [edit]

Early Roman arch bridges, influenced by the ancient notion of the ideal form of the circle, often describe a full circle, with the stone arch continuing underground. A typical example is the Pons Fabricius in Rome. Later, Roman masonry bridges rested mostly on semi-circular arches, or, to a lesser extent, on segmental arches.^[9][10] For the later design, which shows an early, local concentration in north-eastern Italy, but can be found scattered throughout the whole empire, the Limyra Bridge, the Alconétar Bridge and the Ponte San Lorenzo are prime examples. In addition, a number of other arch form make rare appearances, in some cases of which later deformations cannot be ruled out though. The late antique Karamagara Bridge represents an early example for the use of pointed arches.

Typical characteristics [edit]

• Many are more than 5 meters wide
• Most of them slope slightly
• Many have rustic work
• The stonework has alternating stretcher and header courses ; i.e. one layer of rectangular stones is laid lengthwise, and the next layer has the ends facing outwards
• Stones linked with dovetail joints or metal bars
• Indents in the stones for gripping tools to hold onto

(Source Traianus - An endeavour to identify Roman Bridges built in former Hispania)

Examples [edit]

For outstanding achievements of Roman bridge building, see List of ancient architectural records.

Pont-Saint-Martin Bridge, Italy

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 most of the time at least 2 meters above the body of water.

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

Large river bridging [edit]

Roman engineers built stone arch or stone pillar bridges over all major rivers of their Imperium, save two: the Euphrates which lay at the frontier to the rival Iranian empires, and the Nile, the longest river in the world, which was 'bridged' as late as 1902 by the British Old Aswan Dam.^[11]

The largest rivers to be spanned by solid bridges by the Romans were the Danube and the Rhine, the two largest European rivers west of the Eurasian Steppe. The lower Danube was crossed by least two (Trajan's Bridge, Constantine's Bridge) and the middle and lower Rhine by four different bridges (Roman Bridge at Mainz, Caesar's Rhine bridges, Roman Bridge at Koblenz, Roman Bridge at Cologne). For rivers with strong currents and to allow swift army movements, pontoon bridges were also routinely employed.^[12] Going from the distinct lack of records of pre-modern solid bridges spanning larger rivers,^[13] the Roman feat appears to be unsurpassed anywhere in the world until well into the 19th century.

Gallery [edit]

Footnotes [edit]

See also [edit]

• Arch bridge
• Bridges in city of Rome
• Record-holding bridges in antiquity
• Roman architecture

References [edit]

• Fuentes, Manuel Durán: La construcción de puentes romanos en Hispania, Xunta de Galicia, Santiago de Compostela 2004, ISBN 978-84-453-3937-4
• Fernández Troyano, Leonardo (2003), Bridge Engineering. A Global Perspective, London: Thomas Telford Publishing, ISBN 0-7277-3215-3 
• Galliazzo, Vittorio (1995), I ponti romani, Vol. 1, Treviso: Edizioni Canova, ISBN 88-85066-66-6 
• Galliazzo, Vittorio (1994), I ponti romani. Catalogo generale, Vol. 2, Treviso: Edizioni Canova, ISBN 88-85066-66-6 
• Gazzola, Piero (1963), Ponti romani. Contributo ad un indice sistematico con studio critico bibliografico, Florence 
• O’Connor, Colin (1993), Roman Bridges, Cambridge University Press, ISBN 0-521-39326-4 

External links [edit]

Wikimedia Commons has media related to: Roman bridges

• Traianus - Technical investigation of Roman public works
• The Waters of Rome: Tiber River Bridges and the Development of the Ancient City of Rome
• Livius.org: Pontes longi - Roman bog bridges

v t e Roman bridges England Chesters Bridge Piercebridge Roman Bridge Pons Aelius France Pont Ambroix Pont de Bornègre Pont Flavien Pont du Gard Pont Julien Pont sur la Laye Pont des Marchands Pont Serme Roman Bridge (Saint-Thibéry) Roman Bridge (Vaison-la-Romaine) Germany Caesar's Rhine bridges Römerbrücke (Trier) Iran Band-e Kaisar Italy Pons Aemilius Pons Agrippae Ponte Altinate Pons Cestius Pons Fabricius Pons Neronianus Pons Probi Pons Sublicius Pont d'Aël Pont de Pierre (Aosta) Pont-Saint-Martin Ponte d'Augusto (Rimini) Ponte Corvo Ponte del Gran Caso Ponte Milvio Ponte Molino (Padua) Ponte Nomentano Ponte Pietra (Verona) Ponte di Pioraco Ponte di Quintodecimo Ponte Salario Ponte San Lorenzo Ponte Sant'Angelo Susegana Bridge Lebanon Leontes Bridge Portugal Ponte de Rubiães Ponte Nova da Cava da Velha Roman Bridge (Chaves) Romania Constantine's Bridge (Danube) Trajan's Bridge Spain Acueducto de los Milagros Alcántara Bridge Alcántara Bridge (Toletum) Alconétar Bridge Aqüeducte de les Ferreres Puente Romano (Mérida) Segovia Aqueduct Bridge Syria Bridge at Nimreh Gemarrin Bridge Kharaba Bridge Turkey Aesepus Bridge Arapsu Bridge Bridge at Oinoanda Constantine's Bridge (Mysia) Eurymedon Bridge (Aspendos) Eurymedon Bridge (Selge) Karamagara Bridge Kemer Bridge Limyra Bridge Makestos Bridge Nysa Bridge Penkalas Bridge Pergamon Bridge Sangarius Bridge Severan Bridge Taşköprü (Adana) Valens Aqueduct Bridge White Bridge (Mysia) Full list of Roman bridges