BRIDGES


Roads require bridges to cross waterways and leap across gorges. Undoubtedly, many timber bridges must have perished without leaving any archaeological trace. We also know that capable military engineers crossed wide rivers on wooden, collapsible, or pontoon bridges. One such master who left ample literary and visual record was Apollodorus of Damascus, Trajan's architect, whose long bridge across the Danube was immortalized by its various sculptural illustrations on Trajan's Column in Rome (A25).

The Pons Subiacus, the rope-and-timber suspension bridge over the Tiber, crossing the river at Insula Tiberina, was an important landmark from the earliest days of the republic. But, for the purposes of this review, we shall only consider a small selection of masonry bridges. The single or multi-span arches (really, vaults) of Roman bridges are often built in concrete but faced in blocks of ashlar, or in smaller examples, in irregular blocks or rubble. The study of Roman bridge construction and design is important because some of the earliest and boldest uses of concrete technology was invested in bridges and aqueducts; therefore, they represent pioneering developments influencing vaulted architecture itself. Or, to put it more dramatically, without the ability to master the 32-meter span of distant Ponte d'Augusto (see below), there could have been no Pantheon in Rome.

(A24, A23) The first stone bridge of Rome is Pons Aemilius, downstream from Insula Tiberina, originally built in 179 B.C. by the censors M. Fulvius Nobilor and M. Aemilius Lepidus. Though rebuilt and much restored in later times, one remaining span (locally known as Ponte Rotto), displays a sturdy vault of travertine faced concrete. Ponte d'Augusto, the bridge that carries Via Flamminia over the Nera River at Narni (central Italy), built c. 27 B.C., is also preserved in one majestic arch which spans 19.2 meters at a height of 30 meters above water (A22, A21, A60).


[A24]

[A23]

[A22]

[A21]

[A60]

Originally, this impressive bridge had four arches (and three piers), the main arch reaching a span of 32.1 meters. The north abutment of the third pier displays an interesting ribbed-vault construction (A61). The travertine ribs are designed to increase the stiffness of the structure and provide greater lateral stability so that the 160-meter long, 8-meter wide "plane" of the bridge does not buckle, although the core construction of the piers is entirely in concrete (A58).


[A61]

[A58]

(A57, A56, A55) The Severan Bridge near ancient Arsameia in southeastern Turkey, is situated at the mouth of a deep gorge where Cendere Cayi torrent eases out into the Kahta plain. The simple, unadorned, single, majestic arch (at 34.2 meters, the second largest arch ever achieved by the Romans), leaps across the turbulent waters with the grace of a ballet dancer. It helps to place things in perspective to remember that this piece of competent local engineering in the remote frontiers of the empire achieved a span not significantly short of the span of the greatest vaults of the capital's imperial baths.


[A57]

[A56]

[A55]

(A54) However, most Roman bridges, especially those crossing wide, peaceful waters and numerous, smaller arches. Aezane, in northwest Turkey, was bisected by the Rhyndacus river. Of the four bridges which connected the two banks of the city, two are still in use. The northern bridge has five arches; some of the original marble parapets, still preserved on site, are decorated with reliefs of marine scenes and simplified representations of what appear to be river boats (A53).


[A54]

[A53]

Two single-span bridges, also in Turkey, span turbulent mountain streams across formidable looking gorges (A52, A51). The first, near the source of River Aksu (ancient Eurymedon), displays a handsome bearded male head on its keystone, probably personification of the local river god. This location may indeed been the site of a sanctuary sacred to Eurymedon and other chthonic deities; a deep cave (Zindan magarasi) is located across from the Aksu bridge and contains traces of ancient occupation. Some 50-miles downstream on the Eurymedon is the second bridge crossing a deep gorge (A50). This impressive bridge, carrying the road connecting the wealthy coastal cities of Pamphylia with the mountain-top city of Selge and the inner Pisidian highlands, still provides the only vehicular access to a whole region lost in the pathless wilds of the Taurus mountains (A49, A48). Built of local stone, the narrow, sturdy arch leaps over the swift Eurymedon at a dizzying height. It is a testimony to the spirit of service of local Roman administrators and the technical competence of its nameless engineers.


[A52]

[A51]

[A50]

[A49]

[A48]

[Back to Home Page]
[Move on to Water Supply Systems: Cisterns, Reservoirs, Aqueducts]