Roman bridge over the Moselle at Trier · Wikimedia Commons (CC BY-SA)

Roman Bridge of Trier

Pons Mosellae

BridgeGallia Belgica · Trier, GermanyBuilt 144 CE

Not standing in 117 CE

About

Seven basalt piers still carry road traffic across the Moselle, quarried from Eifel volcano rock and pointed upstream to split ice floes. Masons raised them between about 144 and 152 CE, the third bridge on the spot and the only one that lasted. It postdates the 117 CE snapshot: under Trajan the crossing was the timber bridge of 71 CE. The piers have stood for more than 1,800 years, the oldest bridge structure in Germany.

What happened here

Piers are set on cofferdams — a ring of driven piles, pumped dry, filled with concrete that sets under water. They are built with a cutwater pointing upstream to split the current and the ice. The span above may be stone arches or timber on stone, and timber is not a poor relation: it is cheaper, faster, and replaceable. Roads approach on an embankment so the crossing stays level. Tolls are common, shrines at either end are usual, and the inscription names whoever paid. Floods are the enemy; a bridge is inspected after every big one, and the scour around the piers is packed with rubble. A bridge fixes a town's position for a thousand years, which is why so many are still standing.

In ancient writing

Ernst Hollstein, Mitteleuropäische Eichenchronologie: Trierer dendrochronologische Forschungen zur Archäologie und Kunstgeschichte (Trierer Grabungen und Forschungen, Band XI) Mainz: Philipp von Zabern, 1980
Foundational tree-ring chronology study for the Rhineland, built from oak piles recovered at the Trier bridge site; it establishes the dated sequence of bridge phases at 17 BCE, 71 CE, and the surviving stone-pier phase of 144-152 CE, fixing the piers as later than the 117 CE snapshot.