With fanfare, ceremony and in honour of the 90th anniversary of the founding of the Turkish Republic, Turkey’s President and Prime Minister have opened the vast immersed rail tunnel under the Bosphorus, linking Asia and Europe in a project first proposed by an Ottoman sultan some 150 years ago. For the first time, trains will be able to run directly from London to Beijing via Istanbul.

  The Marmaray tunnel, largely financed and built by Japan, is actually two huge fire-resistant concrete tubes that lie more than 55 metres deep on the bed of the Bosphorus, jointed and covered in concrete and able to withstand even a severe earthquake in this notoriously seismic region. It has taken nine years to build, cost around US$2.5 billion and was one of the biggest engineering projects in Europe. The suburban railway inside the 13.6 km link – of which 1.4 km lie on the seabed – will be able to carry about 75,000 people a day in each direction, allowing Europe’s largest city of 14 million to grow rapidly on the Asian side.

 The project, however, will do more than just relieve Istanbul’s chronic traffic congestion. It completes the missing link in an ambitious new transcontinental railway known as the Iron Silk Road, linking China and Europe and allowing China to export millions of tons of goods by rail to its main markets in Europe.

Centuries ago the Orient supplied Europe with the luxuries it craved – spices, jade, jewels and silk – by caravans crossing the dusty plains of the old Silk Road. Today China has become the world’s workshop, and is reopening the old land routes to Europe to speed up delivery of millions of containers.

A new ‘Eurasian Land Bridge’ railway will allow freight trains to rumble thousands of miles from China through Central Asia to Istanbul and then on to destinations throughout Europe. This will dramatically speed up delivery of Chinese exports. At present a ship takes up to 45 days to reach Europe. By rail, containers could arrive in Berlin or London in about 11 or 12 days.

No country is better placed to cash in on this new transport bonanza than Kazakhstan. The vast landlocked former Soviet republic is now frantically building roads and railways to carry the torrent of trade from the Chinese frontier to the borders of Europe.

 Bolstered by its oil and minerals wealth, Kazakhstan has spent £135 billion over the past decade to open an alternative to the Trans-Siberian Railway, breaking the Russian monopoly and political control of East-West trade. In May, Nursultan Nazarbayev, the long-standing President, and President Berdymukhamedov of Turkmenistan, bolted down the last ceremonial spikes on a new stretch of track over their border. Kazakhstan has already constructed some 1,200km of rail to develop routes west from the Chinese frontier, and recently announced plans to develop industrial corridors along the route, with new towns and high-tech centres linked by internet.

‘This is a great opportunity to create Kazakhstan as a transport hub. We will become a corridor of prosperity,’ Kairat Kelimbetov, the deputy Prime Minister, told some 8,000 delegates at the sixth Astana Economic Forum in May 2013. He said the hub would bring together markets comprising two billion people, a third of the world’s population.

 But there are big challenges to overcome before the Iron Silk Road becomes a reality. There are still several months of work to do in Istanbul to link up the Bosphorus tunnel with the existing rail networks. And beyond that there is the question of the actual route. The line running through Kazakhstan, Turkmenistan and Iran to Turkey is already built, although it involves a time-consuming ferry crossing over Lake Van in eastern Turkey. But the West, influenced by America, is reluctant to use or invest in any line that passes through Iran, and political alternatives in the region mean that at any moment frontiers can be closed.

 Kazakhstan is constructing an alternative, which goes via the capital, Astana, to the shores of the Caspian Sea, where a ferry would take trains into Azerbaijan and on into Georgia, where a new link across the frontier with Turkey has almost been completed (this replaces the old route through Armenia which is now closed because of political tensions).

The second challenge is the difference in gauges. All states of the former Soviet Union use broad 1,520mm gauge track, while China, Iran, Turkey and mainland Europe use standard gauge of 1,435mm. At the various cross points between the systems, containers must be offloaded from one train and loaded onto another. (Proposals to construct a fleet of special wagons that could have their wheels changed would be ruinously expensive). Kazakhstan is therefore planning to construct a standard-gauge railway all the way from the Chinese frontier to the Caspian, but this wholly new line would have to be extended through the Caucasus into Turkey if time-consuming offloading onto other wagons is to be avoided at the frontiers.

The third and probably biggest challenge is the bureaucracy. With trains crossing six or seven different railway administrations, a simplification of the customs agreements all along the route is urgently needed. Each trainload of goods would need a single customs certificate that would be accepted at each frontier. At present corruption and bureaucracy threaten to make all border crossings expensive and unpredictable.

  China is offering loans and grants to many of its neighbours to speed up the building of the Eurasian Land Bridge. The World Bank has offered Kazakhstan a £1.4 billion loan.

Despite the backing of UN regional economic commissions and the official approval of Russia and the West, there are still political obstacles. Russia is desperate to keep traffic on the Trans-Siberian, although its route all the way to the Pacific is not convenient for exporting goods manufactured in southern China or inland. The 9,250km Trans-Siberian, completed in 1916 and electrified and doubled-tracked in communist times, is being promoted as an international East-West route, but in recent years has suffered serious degradation. It has now been upgraded and cut its charges, but, carrying 100 million tonnes of freight a year – largely from Japan – it is operating at almost full capacity.

  The new Eurasian Land Bridge comes at a time of a global renaissance in railways and a building boom in many parts of the world where railways did not penetrate in Victorian days. Pakistan is eyeing a direct link with Iran – though again this would need a change of gauge at the border – and there are advanced plans to extend the recently opened stub of railway leading south from Uzbekistan to the northern Afghan city of Mazar-e-Sharif. A railway through the high mountains of the Hindu Kush would be impossible, but Afghanistan has ambitious plans to construct a railway all around its flatter northern rim that would link up the east and west of the country. Again, China is eager to offer finance, as this would help it develop its big copper mining interests in Afghanistan.

Other regions are also proposing transnational systems. Saudi Arabia is well advanced with a north-south line up to the border with Jordan, with the eventual aim of linking up to Turkey via Syria. At the moment, politics and war make that extension impossible. The kingdom has, nevertheless, begun another cross-country scheme from the Gulf to the Red Sea, which will include a high-speed stretch to Mecca and Medina. Altogether the Saudis plan to spend $45 billion on 7,000km on new railway.

  Perhaps in the end, like the old caravan routes, there will be a multiplicity of options. What is pretty certain is that passengers will not be able to journey across continents on these new lines. No one is likely to take a journey of some 11 days when you can fly from East to West in 11 hours. But freight is too heavy to fly. And for the workshops of the East, the new Iron Silk Road will become a lifeline to get their products more quickly to eager customers in the West.