How The Ancient Greeks Transported 20 Ton War Ships Over Dry Land
The Diolkos of Corinth: the ancient Panama Canal without the water
I remember having a conversation with a friend once about the ruins of a massive stone structure. He visited them on a trip to South America. The size of the stones and method of their assembly had him nearly convinced aliens built the ruins. After all, how could primitive people build something like this?
Well, we need to adjust our impression of “primitive people.” All human beings are inventive, finding solutions to problems over time.
For instance, the ancient Greeks had a method of transporting war ships weighing anywhere from twenty to twenty-five tons up-hill, over a landmass about four miles wide. According to Mark Cartwright at the World History Encyclopedia, these “triremes” could hold about two-hundred sailors.
It makes you wonder how these “primitive people” pulled off something so difficult? Well, they used a diolkos. The root “dia” means “across” and “holkos” translates to “portage machine.” It was a paved road to the sea where heavy cargo and ships could be guided across land.
The city-state of Corinth happened to have a famous one of these, (created around the sixth or seventh century BC) which was mentioned by many Greek writers. In fact, its remains are in the process of excavation.
That’s all well and good, but I know what you’re thinking. Why would you want to pull heavy warships over land? Well, for very logical reasons. You just have to put yourselves in the shoes of an inventive Greek in ancient times.
Sea Travel In Ancient Greece
Historian Victor Davis Hanson mentions sailing in ancient Greek times was very different than what we’re used to today. For instance, we call many vessels “ocean liners” in present times. It reflects our idea of sea travel. Ships travel directly from one destination to another over a body of water.
According to Hanson, in A War Like No Other the Greeks didn’t do this. They preferred to hug shorelines for various reasons. First, it was safer. Navigational abilities weren’t as developed as our methods today. Second, ships only carried limited supplies — particularly military ships.
So, ships rarely took a direct approach to distance shores, preferring to make many stops along a route. Hanson also notes many military vessels would be periodically pulled on shore during trips. They were also vulnerable to rough waters and storms.
In other words, sailing could be a dangerous and timely process.
Now, with all that calculated into the equation, what if you were offered a way to avoid a notoriously dangerous coast and save lots of time in the process? Sounds tempting, doesn’t it? Suddenly dragging heavy ships across a narrow landmass doesn’t sound too crazy.
The Diolkos Of Corinth
The City State of Corinth sat at the top of the Peloponnese peninsula, which was home to Sparta. It had a very strategic location, being a choke point to the overall landmass. Corinth also sat between the Gulf of Corinth (left) and the Saronic Gulf (right), leading to the Aegean Sea.
The small neck of land it occupied was called the Isthmus of Corinth and it offered a unique opportunity.
According to Patricia Claus at The Greek Reporter, if ships or their cargo could traverse this small land bridge, it could save a trip of nearly two-hundred miles by sea. Remember, this was ancient sea travel. Claus notes the journey was treacherous, with gale force winds and dangerous shorelines rounding the Peloponnese.
While timelines of its creation are debated, Claus quotes Archaeologist Georgios Spyropoulos as estimating it to be around the sixth or seventh century BC.
Professor David K. Pettegrew notes the diolkos resembles a road made of limestone cobblestones, which bisects the modern-day Canal of Corinth. His article in the American Journal of Archeology explains excavations began in the 1950s.
So far, the diolkos consists of a quay or loading platform from the sea. The first excavator Nikolaos Verdelis also found evidence of iron and bronze nails, along with decayed organic matter, and notches within the stones around this area. He imagined a crane or a lifting device in the spot.
Sections of the path also had deep ruts dug within them. Verdelis believed they were deeper than the marks wagon wheels would leave. They were likely tracks. There were also low-lying walls which resembled ramps along the path.
According to Pettegrew, the isthmus may look small on a map, but it was an accomplishment to cross. The path stretches about four miles. It also raises from sea level up to nearly 262 feet at points, although Pettegrew says the diolkos doesn’t exceed an incline of more than one and a half percent.
While the evidence of the Diolkos Of Corinth is inarguable, archeologist don’t know what exactly to make of it. Ancient writers say Corinth used the path to excise tolls and grow rich on trade. Pettegrew sees it differently.
A Pathway For Special Cargo
For Corinth to grow rich on tolls for the diolkos, one would expect regular trade crossed the land route. However, according to Pettegrew, there isn’t much evidence of pottery shards along the path. You’d expect to see this at a great East to West trade hub, especially since olive oil was carried in these containers.
Pettegrew also uses the regular trade good of olive oil to show the diolkos would be a poor method to transport it. He states:
“The protracted process of unloading and restacking cargoes…would have required a minimum of a full day, and probably a couple for even small merchant ships, such as the third-century BCE Iembos carrying 360 amphoras containing 25 tons of olive oil. Larger coastal traders with cargoes of 2,000 amphoras — or crates and bags — would easily have requested many days of unloading, transferring, and careful restacking. Servicing more than a few ships per day would indeed have generated “intolerable congestion” unless a myriad of personnel were employed to keep up with the arrivals and departures.”
Pettegrew also says the physical transfer along the causeway would also be a headache. Let’s be generous and say two oxen can pull one ton. Then, you’d need a team of fifty to drag the small cargo of twenty-five tons across the causeway.
However, he does note many sources refer to ships being taken over the diolkos. Thucydides reports over twenty ships were transferred in 412BC. In 220 and 217 BC, Polybius reports two separate occasions of ships being drug across the isthmus.
The Professor believes with the infrastructure of the diolkos, occasional heavy cargo like ships and construction material made more sense. Think about it: the tracks dug in the road, the ramps, and the possible crane or cranes.
It’s more logically fit for random crossings of ships and large stone pillars for temples, instead of regular everyday trade goods, which might swamp and backlog the path.
Pettegrew also says excavations have found limited infrastructure on the Western end of the diolkos. No loading facilities, locations for warehouses, or lodgings for crews have been discovered. Well, at least yet.
Ancient Technology For Crossing The Ocean
“According to the first excavator of the monument, the ships arrived at the northwestern end of Diolkos, at the current location of Poseidonia, Corinth, where there was a paved platform for their towing on land. They were then placed — with the help of cranes — on wheeled structures…Thus the ship was transported from one end of the Corinthian Gulf to the Saronic or vice versa…”
— Georgios Spyropoulos, as quoted by Patricia Claus at The Greek Reporter
The Diolkos of Corinth isn’t much to look at today — just faded cobblestone jutting out of the ground, heading to the sea. But I want you to transport yourself backwards a few thousand years for a minute.
In a time without internal combustion engines, ancient Greeks lifted twenty- ton ships out of the water, put them on carts, drug them across a limestone road which was graded to incline at a gentle level, then dropped them back in the ocean.
Hardly the work of a primitive people. With technology and ingenuity, the Corinthians figured out a way to deal with a relentlessly ruthless section of the sea. Just avoid it altogether.
Think of an ancient Panama Canal — just without the canal.
It’s something you might ponder in the future as one of your friends wonders out loud if aliens built an ancient structure. You may just want to put your money on our ancestors. In many ways they’re less primitive than you think.
-Originally posted on Medium 6/9/22