03.05.32 22-10 B.C. Construction of the Artificial Seaport Harbor at Caesarea
Herod had a passion to make his domain the “Rome of the East.” But this would not occur without a major improvement of trade and commerce. While the Hasmoneans of the previous century had a strong navy, they did not have a good harbor for their ships. To accomplish his dream, Herod decided to build a city and the world’s first artificial harbor – one that was 40 acres in size that could accommodate an estimated 300 ships. He chose the former Phoenician port known as Strabo’s Tower as his location; a new seaport that would not only accommodate the ships of the Roman navy, but also ships of trade that would build the wealth he desired.
Back in Rome, a newly developed material called “hydraulic concrete,” was developed. It was a mixture of local lime and volcanic sand, called “pozzolana,” shipped in from the Bay of Naples. Architectural archaeologists believe there were two possible ways that Herod built the world’s first artificial harbor.
- He may have placed the concrete powder material in forty-five foot long chests or barges and floated them to the desired position. Carpenters then drilled holes in the sides of the barges, carefully sinking each vessel beside another one to create a breakwater. When the water mixed with the pozzolana, the wet powder hardened to become concrete. In essence, Herod created a “train” of sunken barges that that extended out into the Mediterranean Sea almost a half mile, and the breakers were wide enough to accommodate a modern two lane highway.
- Some scholars believe that Herod may have constructed forty-five foot long caissons which were then filled with the concrete powder that hardened when in contact with water.
Regardless of how the breaker was constructed, he was certainly an engineering genius of his time. After twelve years of hard work, the harbor could accommodate a sizeable navy. He was one of the most prolific builders of antiquity and his projects dotted the entire eastern Mediterranean area as evidenced by numerous archaeological sites.
However, visitors today do not see much of Herod’s famed harbor. Only divers who explore the depths of the sea can admire the work of this incredible architectural mastermind. Historians have always assumed that the harbor was buried as the result of the many earthquakes that have rocked the region. However, in recent years archaeological divers, using sophisticated equipment, have come to a different conclusion. When the barges sank, they rested on sand. Over time, they simply continued to sink deeper into the sand until they were no longer visible from the shore or useful for ships. Jesus said that he who builds his house on the sand is not wise, and Herod’s harbor, after a few centuries, met the same fate – it sank into the archives of history and disappeared.
The harbor was a huge success and immediately became a center bustling with commercial and military activity. Nearly all ships crossing the eastern Mediterranean stopped there. And when the harbor and city of Caesarea were finished, he constructed a three-story ship so he and his friends could sail in comfort and style to Rome. Little wonder then, that the Greeks and Romans gave him the sur-title “the Great.”
. However, some scholars believe hydraulic plaster may have originated in the Aegean Sea area in the late second millennium B.C. by the Philistines.
. In 2005, Professor Robert Hohlfelder of the University of Colorado and his team uncovered the ancient concrete recipe written by Roman engineer Pollio Vitruvius. With it, they recreated the Roman process of pouring underwater concrete. “Caesarea’s Underwater Concrete Recreated.” Artifax Spring, 2005.20:2,7; www.azom.com Retrieved April 7, 2005.
. Crossan and Reed, Excavating Jesus. 58.
. For further study on this possible technique, see Palley, Concrete: A Seven-Thousand Year History. 30-38.
. Josephus, Antiquities 14.14.3 (378).