Why didn't the Romans or Egyptians or other great civilisations invent railways?

The impressive achievements of the ancients have sometimes prompted historians to ponder whether they might eventually have industrialised at some point, if not for the disruptive impact of the so-called 'Dark Ages' which took hold in the early Medieval period.

Ancient Greece is the ultimate test case for this argument. Some historians have noted that classical Greek society produced many innovations in science, philosophy, politics and the arts, as well as in other fields such as mathematics and geometry. Why then, did they not industrialise? Could it be that they were, as some authors have argued, on the cusp of an industrial revolution, when their civilisation was overcome by events?

Actually, as far back as the 6th century BC a paved trackway near Corinth existed which is considered an early form of railway.

The Diolkos was a trackway paved with hard limestone with parallel grooves running about 1.60 metres apart. The wheels of carts and other vehicles using the trackway would go into the grooves, so that they cannot leave the track.

It is believed the Ancient Greeks used the trackway to transport ships over the Isthmus of Corinth overland, thus saving a long journey round the tip of the Peloponnese by sea.

The ancient Greeks also invented steam power - the aeliopile described by the Greek scientist Hero of Alexandria in the first century AD. His machine was a simple bladeless radial steam turbine which spins when the central water container is heated.

These facts provide a tantalising hint towards the potential of Greek ingenuity in antiquity. They came so close to unlocking the power of steam, yet the two concepts were never combined in ancient Greece or Rome, largely because those societies had no incentive to develop this kind of technology. The Roman Empire relied on slave labour, and human workers were cheap to use.

The industrial revolution which gave us railways in the 19th century was the product of the evolution of banking, merchant trade, capitalism, international competition and globally connected markets, as well as several centuries of technological advances, metallurgy, scientific advances and a sufficiently stable political environment, as well as increased population, wealth and demand for goods.

None of these factors existed in the ancient Roman Empire, or any other ancient civilisation. Perhaps the ancient Greeks came the closest, with their multiple competing states, technological advances and innovations in the sciences. But the conquest of the whole area by Rome from the second century BC onwards undoubtedly muted much of the competitive drive that might have pushed innovation forward. Relatively little advance was made during the Roman period beyond the achievements of the Greeks, in part because the Roman economy was based on slavery, so there was little incentive to invest in new technologies that might reduce labour costs.

Once Christianity emerged as the state religion in the 4th century AD, some scholars have argued that society became even less receptive to new ideas. The Platonic Academy in Athens, for instance, was shut down in the 6th century after the Roman Emperor Justinian forbade 'pagan' (i.e. non-Christian) teachers from teaching.

The famous Platonic Academy in Athens, founded 387 BC, as depicted by the Italian Renaissance artist Raphael in this painting from 1510

In the event, the world had to wait another 1,800 years before the technology discovered by Hero of Alexandria could be put to practical use. Wooden railed wagonways emerged in Germany in the 16th century, and eventually the rails became steel instead of wood. This created the track that recognisably modern railways have, but transport power was still provided by horses.

A steam turbine was described in Ottoman Egypt as early as 1551, and by the 17th century the first commercial steam water pumps were being sold - but these were generally used in underground mining. The technology was gradually improved over the 1700s and by the late 1700s the first road vehicles moving under steam power existed. Notably in France, the French military experimented with an artillery carriage propelled by steam, although the idea did not catch on at that time.

In 1804, the first steam train hauled a train along a tramway at Pen Y Darren in Wales. The age of steam had finally arrived. But it is tantalising to speculate as to what might have been, had the ancients investigated just a little further into the aeliopile. As we have seen, there were solid practical reasons why they did not. It was arguably one of the greatest missed opportunities in history.