Scrape by scrape, ancient Rome emerges. At the heart of the city, in pits secured by scaffolding and little wider than railway cars, the modern gives way to the Renaissance. Medieval brick falls away. Sunlight shines on imperial marble. A shovel scratches the ground. The upturned earth, undisturbed for 2,000 years, smells sharp and fresh.
In the Italian capital, where every spade hole has the potential to contain buried treasure, the ancient still governs the modern. Any underground construction project—the laying of a gas line, the expansion of a basement—requires a visit from the city’s archaeologists. So when the city planners decided in 1990 to update their subway system, attempting to plug a glaring gap in one of the least developed underground transit systems in Europe, they expected a challenge.
The new Linea C—construction on the line began in 2007 and is scheduled for completion in 2015—will be the first to service Rome’s historic center and will pass through an area of vital interest to locals, travelers, and archaeologists alike. Plotted to run from the Colosseum to the Forum, it will pitch west at Trajan’s Market and head to the Theater of Pompey, where Julius Caesar recoiled from Brutus’s knife. From there, it will slip under the Tiber River toward Hadrian’s tomb and on to the countryside beyond.
Building the line through one of the world’s most history-rich areas will require feats of technical engineering and planning unheard of in most cities. To pass under the oldest archaeological strata, the metro will have to plunge a full 90 feet below street level, three times deeper than Rome’s existing lines. In the city center, the twin tunnels will also be larger than Rome’s other metro lines, with a diameter of 29 feet instead of the standard 20. The extra width means that if an archaeological discovery—an unexpected temple, say, or an emperor’s villa—blocks a proposed subway entrance, the station (and passenger platform) can easily be shunted down the line. To further avoid damaging archaeological layers (and any resulting controversies), the contractors will have to work like laparoscopic surgeons, minimizing trauma by tunneling through existing ventilation and entrance shafts to build the stations below.
And then there are the considerations for what’s aboveground, such as that ancient symbol of the Eternal City, the Colosseum. To Francesco Rotundi, the project manager for Metro C (the contractor responsible for the new line), the amphitheater presents a technical headache. “The problem is: What happens to the Colosseum when I pass under it with the excavator?” he said, thinking of how the structure’s massive walls could shift as the ground below it settles. “And what happens after I’ve excavated and I pass through with the metro?”
Rotundi’s predecessors would have simply torn through. Rome’s first metro line, built during the 1940’s and 50’s, runs from the central train station to EUR, Benito Mussolini’s ambitious capital outside the capital. Workers dug in open pits as truckloads of history were sifted for valuables and dumped elsewhere. Subsequent expansions have been more cautious, but this new line has been the first to give preservation the same consideration as modernization: more than a year before construction could begin, every access point, ventilation shaft, and escalator tunnel for the planned line had to be examined by teams of archaeologists—a Herculean task by any measure.
“What makes Rome different from other cities is that we can’t plan,” said Luigi Napoli, technical director at Roma Metropolitane, the agency overseeing the subway’s expansion. “We have to go straight to the field and see what challenges await us.”