Diolkos

• The Diolkos was an ancient stone road with cart ruts where sea vessels could be mounted on a trolley and pushed from the Gulf of Corinth, across the 4 mile (6km) Isthmus of Corinth, into the Aegean Sea.
• This saved them having to undertake the dangerous sea passage around the Peloponnesian Peninsular. Diolkos is from the Greek ‘Dia meaning Across’ and ‘Holkos meaning Portage’.

History

• Built by the Greeks around 600 BCE, across the Isthmus of Corinth, the Diolkos continued in use during the Roman and Byzantine Period.
• The Diolkos saved several days sailing around the notorious coasts of the Peloponnese, in particular, Cape Matapan and Cape Malea.

The World’s first Railway?

• It consisted of a 4 to 5 mile long (6-8km) limestone paved track with two parallel grooves for a wheeled trolley or trolleys, which carried small vessels.
• The trackway entered the water at both ends, and was submerged to allow vessels to float onto the trolley and float off at each end.
• It roughly followed the course of today’s Corinth Canal, whose construction in the 19th century destroyed various sections of the Diolkos.
• It is the only surviving example in the world of such a device.
• The Romans planned, on two occasions, to build a Corinth Canal, but never completed the project.

The Gauge

• The gauge between the grooves is 1.6 metres (5 feet 3 inches, which is currently in use on Brazilian Railways.)
• This is a little wider than the 4 feet 8 inches of the Roman Cart Gauge, which is still in use on the railways as the Standard Gauge of 4 feet 8 and a half inches.

Timeline of the Diolkos

• Peacetime:
  • It was used continually by cargo ships, according to Pliny the Elder and Strabo.
• Wartime:
  • It was used by naval vessels as large as a Trireme. It has been calculated that this would have required up to 180 men (it had a crew of 200) three hours to pull a Trireme across the Isthmus.
  • 428 BCE The Spartans proposed to threaten Athens by moving their warships over the Diolkos.
  • 411 BCE During the Peloponnesian War, a squadron of Spartan warships was transported over the Diolkos en route to Chios.
  • 220 BCE Demetrios of Pharos sent 50 vessels over it into the Gulf of Corinth.
  • 217 BCE Philip V of Macedon sent 38 vessels over it.
  • 31 BCE After the Battle of Actium, Octavian sent part of his fleet of Liburnians across it, to pursue Mark Anthony and Queen Cleopatra VII to Egypt.
  • 868 CE The Byzantine Admiral, Nikitas Oryphas, moved 100 Dromons across the Isthmus (whether it was the same route as the Diolkos is not clear)

Ancient Authors who cite the Diolkos

• The following authors all mention ships crossing the isthmus by this road:
• Thucydides, Aristophanes, Polybius, Strabo, Pliny the Elder and Cassius Dio.

Other Diolkos Structures in Literature

• Two similar Diolkos are described as existing in Egypt:
  • Oribasius (320-400 CE)
    • He quotes Xenocrates (first century CE) who described a Diolkos located in the harbour of Alexandria.
  • Ptolemy (c.150 CE)
    • He mentions a Diolkos in his Geographia (Book IV.5.10), located between a silted up branch of the Nile and the Mediterranean.

The Site of the Diolkos