Loading...

December 11, 2007

Diolkos

The Diolkos — from the Greek dia (across) and holkos (portage) – was an artificial trackway, resembling a modern portage railway, constructed in ancient times to enable boats to be moved overland across the Isthmus of Corinth, a neck of land 4 miles (6.4 km) wide at its narrowest, which separated the Gulf of Corinth from the Saronic Gulf.

The Diolkos allowed ships sailing from the Ionian Sea to the Aegean Sea to avoid sailing around the Peloponnese peninsula, whose rocky, exposed coastline was extremely hazardous: many a merchant ship was wrecked on the three headlands of the peninsula, especially Cape Matapan and Cape Malea. By contrast, both the Gulf of Corinth and the Saronic Gulf were relatively sheltered waters. In addition, the overland passage of the Isthmus offered a much shorter route to Athens for ships sailing to/from the Ionian coast of Greece.

The Diolkos was first constructed in the 7th century BC and remained in use for well over a thousand years, into the early Middle Ages.

Strategic position of Isthmus of Corinth between two seas
Strategic position of Isthmus of Corinth between two seas
Satellite picture of the Isthmus of Corinth. Track of the present-day Corinth Canal can be clearly seen. The diolkos ran close alongside, first on the S side, then on the N
Satellite picture of the Isthmus of Corinth. Track of the present-day Corinth Canal can be clearly seen. The diolkos ran close alongside, first on the S side, then on the N

Construction

It is likely that the Diolkos was built by the second tyrant (ruler) of Corinth, Periander (628-588 B.C.).

If so, this means of portage was apparently Periander's second choice, as he originally envisaged a canal through the Isthmus[1].He was dissuaded apparently by some Egyptian mathematicians, who warned him that directly linking the two seas risked submerging the entire Peloponnese.

Periander replaced the previous method of transporting boats – on large wooden rollers – with a 4-mile (6 km) long trackway from Schinous on the Saronic Gulf to Poseidonia on the Gulf of Corinth.

The trackway, varying between 3m to 6m in width, was paved with limestone blocks. These were set in a deep layer of sand and gravel. Two parallel grooves were cut into the trackway, 1.5m apart (surprisingly close to the 1.435m standard gauge of modern railways). Along these ran the wheels of the olkos (Ancient Greek ὁλκός), a vehicle analogous to a modern rail flatcar, on which boats were pulled by teams of slaves or animals.[2] The transported boats' cargoes would be unloaded to reduce weight and carried separately across the isthmus and then reloaded at the other end [3]

The limits to the lifting capacity of ancient cranes, and to the carrying capacity of the olkos, must have restricted use of the diolkos to the smaller range of boats, keeping alive the issue of cutting a canal through the isthmus.

Roman era

The Diolkos remained in use throughout the period of Roman Greece (c. 146 BC- 330 A.D.) and well into the era of the Byzantine Empire to as late as the 9th century.

However, Periander's idea of a canal continued to fascinate Roman rulers. The historian Suetonius tells us that Julius Caesar, Roman dictator from 48 to 44 BC, planned a canal through the Isthmus[4], among other grandiose engineering schemes: however, he was assassinated before he could bring the scheme to fruition. The Roman Emperor Nero (reigned 54- 68 A.D.) actually launched an excavation, personally breaking the ground with a golden pickaxe and removing the first basket-load of soil, [5] but the project was abandoned when he died shortly afterwards.

The Diolkos and the Corinth canal

Image of a ship on Attic black-figure pottery. c.520 B.C. This is the sort of boat that the diolkos may have transported in Periander's time
Image of a ship on Attic black-figure pottery. c.520 B.C. This is the sort of boat that the diolkos may have transported in Periander's time

Almost 2,000 years were to pass from these abortive attempts before ships were able to sail directly through the Isthmus. In 1893 the Corinth Canal was finally opened, transforming the Peloponnese into an island. The canal closely follows the route of the Diolkos, as that remained overall the shortest and lowest section of the Isthmus' topography.

Much of the Diolkos was consequently destroyed in the construction of the canal, but about 500m of its course were excavated in the period 1956-62. Sections of the trackway are still visible at the southern side of the west entrance of the canal: 37°56'59.95" N, 22°57'40.61"E.

No comments: