Riddle of Colossal flooding solved
How Rome relived sea battles
Thursday June 19, 2003
The mystery of the flooded amphitheatre has puzzled historians and scientists for almost 2000 years. But now an Edinburgh engineer has come up with a theory for how Emperor Titus flooded the Colosseum in Rome at its opening in 80AD.
A crowd of 87,000 cheering citizens and slaves had watched gladiators battle to the death in the arena that stood at the heart of the Roman empire. More than 5000 animals had been killed for sport.
But the highlight of the 100-day inauguration was a series of naval battles re-enacted in the Colosseum, according to Cassius Dio, chronicler of ancient Rome, who said: "Titus suddenly filled this same theatre with water and brought in horses and bulls and other domesticated animals that had been taught to behave in the liquid element just as on land. He also brought in people on ships, who engaged in a sea-fight there, impersonating the Corcyreans and Corinthians."
His account left historians with a colossal question, only now answered by Martin Crapper, lecturer in civil and environmental engineering at Edinburgh University : Was the giant arena flooded to stage the mock sea battles - known as naumachiae -or were the naval re-enactments actually staged elsewhere in Rome?
Academics have long argued that holding sea battles at the Colosseum was impossible due to the underground tunnels used to spirit wild animals, slaves and gladiators to different parts of the arena.
Tales of thousands of slaves and convicts drowning in the sea battles with ships built to scale were told by Latin poets such as Martial, but were dismissed as sycophantic works of fantasy written to enhance the reputation of the emperor.
However, Dr Crapper believes he has solved the puzzle of the flooded Colosseum.
His theories have been tested by a team of experts assembled by the American ABC Discovery Channel.
Programme makers and archaeologists from the University of California spent a year creating a virtual reality simulation Colosseum to assess the logistical problems involved.
Dr Crapper said the first challenge was to determine if it was possible to blast the millions of gallons of water needed for the sea battles into the Colosseum.
"It's purely speculation but I believe a timber structure could have been used to transport water from the main aqueduct. However, the real constraints were not moving the water but ensuring it could flow through a series of inlet wells and concentric pipes beneath the seating area to actually reach the arena," he said.
After detailed research, Dr Crapper was able to prove it was possible for the sluice gates to be closed off and for water pressure to reach the correct level for the arena to be flooded by four million gallons of water to a depth of five feet within seven hours.
Other members of the research team used X-ray imaging to prove waterproof material had been used in some parts of the underground structure. Further work uncovered 18 sunken blocks used to hold wooden props which held up the arena's floor and which could be removed to allow the area to be used for both gladiatorial battles and naumachiae.