Étiquette : Korea

 

Thanks to WEST’s new record, world’s nuclear fusion community moving forward

nuclear fusion ahead
Alain Bécoulet, in charge of ITER’s engineering department.


Karel Vereycken: Mr. Bécoulet, good morning, it’s great to have you on the phone.

Alain Bécoulet: Hello Mr. Vereycken, if I’ve understood correctly, you’re interested in what happened at WEST, in connection with the press releases that went out just about everywhere around May 15. (more below)

That’s right; I’ll give you my impressions and you can correct me. I understand that the Tore SUPRA Tokamak (in southern France)1, who with six minutes held a world record in duration till 2021, was a bit like your baby.

To tell the truth, I was director of the IRFM2, in charge of Tore SUPRA. If it can be considered “my baby”, it’s because under my governance it was radically modified and upgraded, and renamed “WEST”. Before me, it was Robert Aymar‘s baby3.

Tore SUPRA tokamak under construction.

Right! But in WEST, it’s the W that does it all. And it’s a W for tungsten, a very heat resisting material that absorbs less than graphite and makes the machine more efficient?

Yes, it does. The major change we made with WEST, is that we went from a circular-limiter machine 4 to a “divertor” machine.5

On Tore SUPRA, the vertical plasma action was a circle resting on a graphite limiter and the plasma simply touched it.

For some years now, we’ve discovered that making a plasma in the shape of a D, or in the shape of a fish with an X point — called a “divertor” — produces much better results in terms of confining heat and impurities, particles, etc. So it was time for Tore SUPRA to go there.

At the same time, Tore SUPRA itself made it clear for us, that for ITER, it was not possible to continue with carbon – which was ITER’s original intention – and so ITER switched and was reconfigured to tungsten.

Picture inside the WEST vacuum vessel showing the various tungsten armoured plasma-facing components (April 2018).

That’s when we took the opportunity to install a cooled tungsten divertor in Tore SUPRA. What’s more, Tore SUPRA’s mission has always been, even before ITER – we’ve been talking about it for a very long time now – the development and integration of technological solutions, and not so much performance-fusion.

If you put tritium in Tore SUPRA, you’re not going to get much in the way of power: it’s too small and not powerful enough in any ways to make fusion reactions of any note; but on the other hand, it’s perfectly relevant for all technological developments – it was on Tore SUPRA, it has to be recalled, that the first successful full-scale test of the superconducting coils now used in ITER took place!

I’m fully aware of that.

It was also Tore SUPRA that supplied all the rules for actively cooling all the components in front of the plasma, including diagnostics [i.e. measuring instruments], etc.; not forgetting solutions for continuous additional heating, in short a huge amount of technology.

So the idea, in the transition from Tore SUPRA to WEST, was to continue along the path of the “actively cooled tungsten divertor”.

Comparaison between Tore SUPRA and WEST.


I think the Koreans, too, with KSTAR, had already.…

There are several superconducting machines that have made equivalent advances –more successive than simultaneous– and that have inspired others; in this case, before talking about KSTAR, the machine that is closest to WEST, its little sister – you’re going to smile, but I didn’t call it WEST for nothing — is a machine that started up when Tore SUPRA was already operating, in Hefei, China, called EAST — with which we have cooperated enormously, both on coils and on plasma components, etc.

Chinese tokamak EAST.

So the two laboratories have cooperated enormously; I chose the name WEST because we wanted to change the name of Tore SUPRA, to rejuvenate it and mark the fact that we were making this technology; so we called it WEST, a sort of sister machine to EAST, and the two machines really work together (EAST has now installed a tungsten divertor, etc.). ); even some of the modifications we made to WEST were made in cooperation, in partnership with the EAST machine, with the Chinese Academy of Sciences, which supplied us with components, in particular the power supplies for the divertor coils, the new ICRH antennas, etc.; we had all this done by the Chinese.6

It’s extraordinary that this kind of cooperation can still take place in this world of conflict…

It really is! As for KSTAR, it’s quite a similar machine too, but I’d call it less pioneering. It’s only now arriving in this kind of world; it’s a long way behind –not that I’m blaming them, because since the teams are smaller, it’s more difficult– but that doesn’t stop us from cooperating a lot with KSTAR.

The only real difference with WEST lies in the coils, which are all inside a single cryostat (refrigeration system) – as with ITER, whereas in Tore SUPRA, when we built it, the coils were each in a separate cryostat.

To sum up: today, the large superconducting machines accompanying the ITER project are WEST, EAST, KSTAR and now the new JT60SA tokamak which has just gone into operation in Japan. It’s the size of the JET (at Culham in the UK) in superconductor, but doesn’t yet have a tungsten environment, and won’t for several years yet; so it’s not yet fully in a world as relevant, but it’s coming! And because it’s larger, it’ll probably outperform those EAST, WEST, etc. machines.

The press, and the official press release, reports a 15% gain in energy produced – which is still less than the energy spent on the reaction – and at the same time, they talk of a doubling of plasma density.

Please note: machines like WEST, EAST and KSTAR will never produce power fusion, for at least two good reasons:

  • they’re too small;
  • they’re not designed to hold tritium.

So there’s no fusion in these machines. Also, beware of energy gains and the like: these are gains in energy stored inside the machine, but not at all in energy supplied, in energy produced by fusion energy.

It’s not yet “break-even” (when the energy produced exceeds that of the reaction).

In fact, we improve confinement and increase confinement time. This improves the possibility of fusion, but we don’t enjoy fusion in these machines, which are too small and not powerful enough for that, particularly in terms of core plasma.

On the other hand, they are used because their edge plasma, i.e. the plasma inside the plasma interacting with structures such as tungsten, etc., is very similar to ITER’s. That’s why they’re so interesting, and as they can produce very long-lasting plasmas, the tests carried out in these machines are perfectly relevant to ITER.

So I’d like to come back to one of your questions, namely how this advances the promises of ITER. ITER is being built, and things are being manufactured, but ITER is a kind of big eater, constantly asking: “Can you continue the research?”

Inspection of tungstene components facing plasma in WEST Tokamak.

Obviously, we’re into things we’ve never tested, so anything we can test, anything that can debug things for us, is very welcome. So these machines, in particular WEST, EAST, etc., are helping us to consolidate our position, both in terms of design and in terms of manufacturing solutions –a divertor like the tungsten divertor currently cooled, it works!

And what WEST has just demonstrated– compared with the last time, when it achieved very high performance, particularly in terms of duration, with the Tore SUPRA configuration, on a carbon limiter, etc. — it did so in even more relevant conditions, thanks to a tungsten divertor.

The result of WEST was 364 seconds, or 6 minutes and 4 seconds, with an injected energy of 1.15 GJ, a stationary temperature of 50 million°C (4 keV) and an electron density twice that of the discharges obtained in the previous tokamak configuration, that of Tore SUPRA.

However, what’s really new and very important for ITER is that when these machines do this, it’s with components facing the plasma that are the same as ITER’s. We’ve taken great care to ensure that the WEST divertor has exactly the same technology as the ITER divertor. That’s how we test this technology, over timescales and with power flows arriving on these components that are highly relevant, as they are representative of the conditions in which they will live in ITER.


So ITER has become a globalized scientific experiment, decentralized and centralized at the same time.

ITER is the place where all the world’s fusion knowledge is being synthesized; but this process didn’t stop the day we signed the treaty, it’s being synthesized every day!

We continue to feed ITER with scientific and technical results. For example, if a machine says to us “wait a minute, you’ve done that, but we’ve found results that are different now that we’ve done more work”, we look at that very carefully, to find out whether or not there are any impacts. We’re in constant contact with all these people, to find out what’s coming out of the labs, experiments and simulations, and to find out whether or not there’s an impact on ITER, in which case we’re able to rectify the situation according to the scale of things

This sharing of cooperative data takes place in conditions of great trust?

It’s a scientific community that works like a scientific community, with no preconceptions, no ulterior motives, nothing at all.

A bit like the astronauts on the international space station?

Absolutely. We used to say “in the old days, it was taken for granted”, but now it’s true that it’s become almost surprising. If there’s a result in a Russian or Chinese machine, we have access to it and then we understand, we work, we discuss with them, it’s really very open.

That’s very promising.

We have to fight against the journalists who love to wonder whether there’s competition, whether someone has won or whatever…. That’s not what we’re about at all; we’re about cooperative scientific development. Everyone works in their own corner, of course, but for everyone! There’s no such thing as “I know, I know”, no, none of that exists in the world of fusion.

In the article I’m preparing, I’ll conclude by saying that the big problem with ITER is that there’s only one problem!

In a way, it’s almost true, it’s not the “big problem”, but it’s something that doesn’t encourage acceleration; competition encourages acceleration, we agree on that.

After all, the Chinese have 6 fusion reactors…

Be careful, they’re not “reactors”, beware of the vocabulary. They’re experiments, Tokamaks, plasma experiments, all much smaller. The biggest one I mentioned, in Japan, is ten times smaller than ITER!

Now there are start-ups and others, which we’re hosting here (at the CEA center in Cadarache, France) for three days; 50 start-ups are here, downstairs in the amphitheater, chatting with us; they’re all convinced they’re making reactors, but no! They’re just doing experiments, manips, experimental prototypes. Yes, even ITER isn’t a reactor. Mind you, the meaning of the word “reactor” is to produce electricity or energy, and we’re not there yet!

If someone tells you he is selling you a reactor, you can laugh in his face, because it’s not true, and it will remain so for a long time, unfortunately or fortunately, I don’t know. As far as the reactor phase is concerned, we’ve only just begun, with ITER, the transition to industry. That’s what we’re also doing these days, looking at how to transfer knowledge from laboratories – and ITER is THE world laboratory, in the true sense of the word, in the sense of a public research laboratory. How do we begin to transfer this to the industrialists who will have to build the reactors? But the time scale here isn’t next week!

Wouldn’t your real competitor be the National Ignition Facility (NIF)?7

Not even close! Because with the Americans, it’s in a way even worse, because they’re even less developed in their public research, it’s a long way from maturity. They once did a demonstration in a machine that wasn’t designed for it, and so on.

So if we wanted to go from the NIF to the reactor, we’d already have to make up all the ground we’ve accumulated since the state of magnetic fusion with the big JET experiments in 1997. So we’re almost 30 years away from reaching the levels of technological maturity, integration and overall maturity needed to move towards a reactor. And we, too, are still a long way from moving towards the reactor.

As far as competitors are concerned, to be honest, no one feels like a competitor today, and this is no joke: may the best man win! The problem is so complicated, and the stakes so high, that whoever comes up with the solution will have us all on our feet! There’s no such thing as competition.

We’re starting to see, with these new start-ups, people saying “yes, but we’re moving towards industrial solutions, etc., so we may develop patents that we obviously don’t want to reveal or sell”. Fair enough!

But hey, if they know how to make one of the “technological bricks” and it has a patent, good for them. But that’s not even going to stop us talking. A patent, once you’ve registered it, isn’t a secret, it’s simply something that belongs to you and that you can put on the public square; whoever uses it is just going to have to pay for it, that’s all. So it’s not a war or anything.

The problem is really extremely complicated, and we’re now entering the pre-industrial world of the thing, which is very exciting, isn’t it! I started my career as a theoretician 35 years ago, and I can tell you that we were really on the calculator and not even on the computer yet. Now we’re in: 1/ a complete demonstration of the feasibility of the whole system with ITER, which is in a way the end (the objective) of fundamental public research; 2/ the moment when we’ll say “here’s the great recipe, now it’s up to you to industrialize it, improve it, make it economically viable, etc.”. But ITER still has to show that we can do it, and I believe we can, even though we’re still building the machine and haven’t yet made plasma! But then again, on paper it’s always beautiful…

What do you see as the final hurdles? What more can the public authorities in the various countries do?

I’d encourage you to keep an eye on things until October-November, when the International Atomic Energy Agency (IAEA) will issue a strategic document, prepared by all of us –and I’m one of its key authors. It’s a global strategy document on the development of fusion energy, i.e. the production of energy through fusion.

It’s a very interesting document which, in around twenty pages, covers all the regulatory, technological, scientific and industrial aspects – everything you could possibly dream of: it’s got it all!

And it gives a great deal of information on the challenges facing this community – which is in the process of moving from a purely public research community to a mixed public-private community, moving towards industry, etc. – and on what remains to be done by this community, in terms of nuclear regulations, industrialization, work on the overall efficiency of all sub-systems, and availability (a reactor can’t just run for three minutes every day, it has to work 24 hours a day for 40 years).

This strategic document, which will be issued by the International Agency, should enable all players – I’d almost say “outsiders”: investors, the press, politicians, etc. – to understand where the merger stands and what remains to be done. So it’s a fairly ambitious document, with such a lofty goal, but one that has been made simple and readable for once; we’ve put a lot of effort into it, and I think we’ve succeeded.

It’s really condensed: each paragraph covers 40 or 50 years of research (!), but I think it’s understandable; at the moment it’s being edited by the IAEA, and will be published in early autumn.

Ok, we’ll watch that.

And finally, here are my thoughts on what remains to be done for fusion:

  • New technological building blocks. There are things that even ITER won’t be able to do, such as fully demonstrating the closure of the tritium cycle – how to make tritium, and how to really burn it in situ; we’re going to do a few demonstrations, but we don’t yet have the complete cycle, and we won’t have it just with ITER.
  • Materials. Since magnetic fusion generates very energetic neutrons, and lots of them – a machine like ITER is designed to live for a certain time with a certain plasma rhythm, so it has no problem surviving these neutrons. But if we built the same ITER and ran it for 40 years, 24 hours a day, it wouldn’t last; its materials wouldn’t stand up to the shock. So we need other materials, and materials research and development.
  • This brings us to maintenance: how can we learn to intervene in these kinds of objects without disturbing them too much, working with robotics and appropriate intelligence to understand these extremely complex systems? So we also need to model them; some elements are very difficult to manufacture, so we need to think about how to work on the design so that manufacturers have less difficulty in doing what they’re asked to do, etc.
  • There are also nuclear regulations.

Is this new measuring device just demonstrated on WEST really a breakthrough?

The first to communicate this WEST result were the Americans, which surprised me, but hey, why not?

Yes, it surprised me too.

Because of an unfortunate sentence at the beginning of their article, we got the impression that WEST was a machine from the Princeton laboratory!

Yes, that’s right!

International Cooperation

I spoke to you about the collaboration with China; when I created WEST, we set up a collaborative, partnership-based process that is almost even more ambitious than ITER. We partnered some thirty laboratories around the world to help us build WEST. It thus became a kind of international machine, operated by the CEA without any problems, but an international machine, and we played the same role as ITER: we tried to do what we call supply in kind –I mentioned the Chinese, who gave us power supplies, heating antennas, etc., but there are many countries like that: the Indians have manufactured and supplied us with things, and in this case the Princeton laboratory has designed, manufactured and installed a diagnostic: what you call a measuring instrument is in fact an advance that we test on the machine, and the Americans, or the Princeton people now, can now say “there, we know how to do that, and the proof: we tested it there and there, etc.”. You can think of these major research instruments (like WEST, EAST, etc.), particularly in the field of fusion, as test benches for all kinds of things.

Do we have a machine that actually makes plasma? It’s a bit like CERN (Geneva based particle accellerator), where you’ve got a device that accelerates particles, and then you’ve got lots of people who come to watch, put particles together, make them collide like this, put them in this detector, make them do something, and exploit the science that goes with it.

A Tokamak is also a test bench somewhere, for testing components with plasma, diagnostics, heating systems and so on. So it lends itself well to partnership, because you’ve got a central unit, a central operator who’s going to do the bulk of the machine, who’s going to rectify the coils or the enclosures, etc.; and then afterwards, you can have a huge number of people who are going to come and contribute to a brick that we’re going to put into this machine.

And WEST works with China, with Korea, with many French laboratories –CNRS laboratories and universities that simply bring us diagnostics or simulations – with the United States, with India and with many other countries. And we have a steering committee; for this machine, it’s not just the CEA that decides on its experimental plan: once a year, people from all these labs get together to examine what we’ve done and what we want to do with this machine. Remember that these are always integrated contributions, mixing technology and physics.

It’s wonderful! Thank you for your answers, which have shown us the global, shared process towards a more peaceful world.

We’re trying… We believe in scientific diplomacy here. It’s not easy, it’s no easier than normal diplomacy, but scientific diplomacy does exist, it’s an aspect we believe in and demonstrate every day, we show that it exists and that it also contributes, effectively, to the planet’s progress, even if sometimes it’s more difficult… I’m used to comparing it to sports or artistic diplomacy; the Olympic Games shouldn’t turn as sour as it’s turning, it doesn’t make sense.

Thank you, congratulations, we’re proud of you and your teams, keep up the good work!

Thank you very much. See you soon.

  1. With a major radius of 2.25m (machine centre to plasma centre) and a minor radius of 0,70m,  Tore Supra (before it was reconfigured as WEST) was one of the largest tokamaks in the world. Its main feature was the superconducting toroidal magnets which enabled generation of a permanent toroidal magnetic field. Tore Supra was also the only tokamak with plasma facing components actively cooled. Theses two features allow the study of plasma with long pulse duration. ↩︎
  2. Institut de recherche sur la fusion par confinement magnétique (Institute for Research on Fusion by Magnetic Confinement. ↩︎
  3. Robert Aymar was the Director General of CERN (2004–2008), serving a five-year term in that role. In 1977, Robert Aymar was appointed Head of the Tore Supra Project, to be constructed at Cadarache (France). In 1990, he was appointed Director of the Direction des Sciences de la Matière of the CEA, where he directed a wide range of basic research programmes, both experimental and theoretical. ↩︎
  4. The “Limiter” of the Tore SUPRA tokamak (made of graphite), was the element that extracted most of the energy contained in the plasma (in the shape of a flat circular ring located in the lower part of the donut shaped machine).
    ↩︎
  5. In WEST, the actively cooled 456-component divertor at the bottom of the vacuum vessel extracts the heat and ash produced by the fusion reaction, minimizes plasma contamination and protects the surrounding walls from thermal and neutron loads. ↩︎
  6. Most of this industrial production (i.e. 16,000 blocks of tungsten), was carried out by AT&M (China), with the support of the Chinese laboratory ASIPP as part of the joint CEA-China collaboration (SIFFER, SIno French Fusion Energy centeR). Already, in 2016, the Institute of Plasma Physics (ASIPP) of the Chinese Academy of Sciences (CAS), had supplied ICRH (Ion Cyclotron Resonant Heating) antennas for Tore SUPRA. ↩︎
  7. In December 2022, an NIF experiment used 2.05 megajoules of laser energy to produce 3.15 megajoules of fusion energy.
    ↩︎
Merci de partager !

The Maritime Silk Road, a history of 1001 Cooperations

Identical reconstruction of one of the ships featured on the bas-reliefs of the 8th-century Buddhist temple of Bonobudur in Indonesia.

Today, it’s fashionable to present maritime issues in the context of a moribund British geopolitical ideology that pits countries and peoples against each other. However, as this brief history of the Maritime Silk Road, drawn mainly from a document by the International Tourism Organization, demonstrates, the ocean has above all been a fantastic place for fertile encounters, cultural cross-fertilization and mutually beneficial cooperation.

The ancient Chinese invented many of the things we use today, including paper, matches, wheelbarrows, gunpowder, the noria (water elevator), sluice locks, the sundial, astronomy, porcelain, lacquer paint, the potter’s wheel, fireworks, paper money, the compass, the stern rudder, the tangram, the seismograph, dominoes, skipping rope, kites, the tea ceremony, the folding umbrella, ink, calligraphy, animal harnesses, card games, printing, the abacus, wallpaper, the crossbow, ice cream, and especially silk, which we’ll be talking about here.

Chinese silk.

The Origins of Silk

Before we talk about silk « routes », a few words about the origins of sericulture, i.e. the rearing of silkworms.

As recent archaeological discoveries confirm, silk production is an age-old skill. The presence of the mulberry tree for silkworm rearing was noted in China around the Yellow River by the Yangshao culture during the Middle Neolithic period in China, from 4500 to 3000 BC.

In general, we prefer to retain the legend that silk was discovered around 2500 BC, by the Chinese princess Si Ling-chi, when a cocoon accidentally fell into her tea bowl. When she tried to remove it, she discovered that the cocoon, softened by the hot water, had a delicate, soft and strong thread that could be unwound and assembled. Thus was born the idea of making cloth. The princess then decided to plant a number of white mulberry trees in her garden to raise silkworms.

The silkworm’s reproductive cycle.

The silkworms (or bombyx) and mulberry trees were divinely cared for by the princess (silkworms feed solely on the leaves of white mulberry trees).

Silk production is a time-consuming process that requires careful monitoring. Silk moths lay around 500 eggs during their lives, which last from 4 to 6 days. After the eggs hatch, the baby worms feed on mulberry leaves in a controlled environment. They have a ferocious appetite and their weight can increase considerably. Once they’ve stored up enough energy, the worms secrete a white jelly from their silk glands and use it to build a cocoon around themselves. After eight or nine days, the worms are killed and the cocoons are immersed in boiling water to soften the protective filaments, which are wound onto a spool. These filaments can be 600 to 900 meters long. Several filaments are assembled to form a thread. The silk threads are then woven into a fabric or used for fine embroidery or brocade, a rich silk fabric embellished with brocaded designs in gold and silver thread.

Chinese treatise on agiculture and silk production (1313).

The Early Silk Trade

Under threat of capital punishment, sericulture remained a well-kept secret, and China retained its monopoly on manufacturing for millennia.

It wasn’t until the Zhou dynasty (1112 BC) that a maritime Silk Road was established from China to Japan and Korea, as the government decided to send Chinese from the port in Bohai Bay (on the Shandong Peninsula) to train local inhabitants in sericulture and agriculture. The techniques of silkworm rearing, reeling and weaving were gradually introduced to Korea via the Yellow Sea.

When Emperor Qin Shi Huang unified China (221 BC), many people from the states of Qi, Yan and Zhao fled to Korea, taking with them silkworms and their rearing techniques. This accelerated the development of silk spinning in Korea.

Korea played a central role in China’s international relations, particularly as an intellectual bridge between China and Japan. Its trade with China also enabled the spread of Buddhism and porcelain-making methods. Although initially reserved for the imperial court, silk spread throughout Asian culture, both geographically and socially. Silk quickly became the luxury fabric par excellence that the whole world craved.

During the Han dynasties (206 BC to 220), a dense network of trade routes exploded cultural and commercial exchanges across Central Asia, profoundly impacting civilizational dynamics. The Han dynasty continued to build the Great Wall, notably creating the commandery of Dunhuang (Gansu), a key post on the Silk Road. Over two centuries B.C., its trade extended to Greece and Rome, where silk was reserved for the elite.

In the IIIrd century, India, Japan and Persia (Iran) unlocked the secret of silk manufacture and became major producers.

Silk Reaches Europe

The Nestorian monks sent by Justinian give the silkworms to the emperor.

According to a story by Procopius, it was not until 552 AD that the Byzantine emperor Justinian obtained the first silkworm eggs. He had sent two Nestorian monks to Central Asia, and they were able to smuggle silkworm eggs to him hidden in rods of bamboo. While under the monks’ care, the eggs hatched, though they did not cocoon before arrival.

A church manufacture in the Byzantine Empire was thus able to make fabrics for the emperor. Later emerged the intention of developing a large silk industry in the Eastern Roman Empire, using techniques copied from the Persian Sassanids.

Another version claims that it was the Han emperor Wu (IInd century) who sent ambassadors, bearing gifts such as silk, to the West.

In the VIIth century, sericulture spread to Africa and Sicily, from where, under the impetus of Roger I of Sicily (c. 1034-1101) and his son Roger II (1093-1154), the silkworm and mulberry were introduced to the ancient Peloponnese.

In the Xth century, Andalusia became the epicenter of silk manufacturing with Granada, Toledo and Seville. With the Arab conquest, sericulture spread to the rest of Spain, Italy (Venice, Florence and Milan) and France. The earliest French traces of sericulture date back to the 13th century, notably in the Gard (1234) and Paris (1290).

In the XVth century, faced with the ruinous import of Italian silk (raw or manufactured), Louis XI tried to set up silk factories, first in Tours on the Loire, then in Lyon, a city at the crossroads of north-south routes where Italian emigrants were already trading in silks.

In the XIXth century, silk production was industrialized in Japan, but in the XXth century, China regained its place as the world’s largest producer. Today, India, Japan, the Republic of Korea, Thailand, Vietnam, Uzbekistan and Brazil all have large production capacities.

Cultural Melting Pot

Kingdom of Funan

As much as silk itself, the transportation of silk by sea dates back to time immemorial.

For the Chinese, there are two main routes: the East China Silk Road (to Korea and Japan) and the South China Silk Road (via the Strait of Malacca to India, the Persian Gulf, Africa and Europe).

In Vietnam, the Hanoi Museum holds a coin dating back to the year 152, bearing the effigy of the Roman emperor Antoninus the Pious. The coin was discovered in the remains of Oc Eo, a Vietnamese town south of the Mekong Delta, thought to have been the main port of the Funan Kingdom (Ist to IXth centuries).

This kingdom, which covered the territory of present-day Cambodia and the Mekong Delta administrative region of Vietnam, flourished from the 1st to the 9th century. The first mention of the Fou-nan kingdom appears in the report of a Chinese mission that visited the area in the 3rd century.

The Founamians were at the height of their power when Hinduism and Buddhism were introduced to Southeast Asia.

Then, from Egypt, Greek merchants reached the Bay of Bengal. Considerable quantities of pepper then reached Ostia, Rome’s port of entry. All the historical evidence shows that East-West trade was flourishing as early as the first millennium.

Persians and Arabs in India, China and Asia

Island of Failaka (Persian Gulf in front of Kuweit), a meeting place where Greek, Roman and Chinese traders exchanged good.

On the western side, at the entrance to Kuwait Bay, 20 kilometers off the coast of Kuwait City, not far from the mouth of the shared estuary of the Tigris and Euphrates rivers in the Persian Gulf, the island of Failaka was one of the meeting places where Greece, Rome and China exchanged goods.

Sassanid Empire.

Under the Sassanid dynasty (226-651), the Persians developed their trade routes all the way to Southeast Asia, via India and Sri Lanka.

This trading infrastructure was later taken over by the Arabs when, in 762, they moved to Baghdad.

Chinese and Indian presidents, Xi Jinping and Narendra Modi, exploring the workings of the weaving wheel, the fruit of exchanges between Arabs, Indians and Chinese.
Arab dhow.

From the IXth century onwards, the city of Quilon (Kollam), the capital of Kerala in India, was home to colonies of Arab, Christian, Jewish and Chinese merchants.

On the western side, Persian and then Arab navigators played a central role in the birth of the maritime Silk Road. Following the Sassanid routes, the Arabs pushed their dhows, or traditional Arab sailing ships, from the Red Sea to the Chinese coast and as far as Malaysia and Indonesia.

These sailors brought with them a new religion, Islam, which spread throughout Southeast Asia. While the traditional pilgrimage (the hajj) to Mecca was initially only an aspiration for many Muslims, it became increasingly possible for them to make it.

During the monsoon season, when winds were favorable for sailing to India in the Indian Ocean, the twice-yearly trade missions were transformed into veritable international fairs, offering an opportunity to transport large quantities of goods by sea in conditions (apart from pirates and unpredictable weather) relatively less exposed to the dangers of overland transport.

The Maritime Silk Road under the Sui, Tang and Song Dynasties

Luoyang Bridge, a masterpiece of ancient architecture in Quanzhou.

It was under the Sui dynasty (581-618) that the Maritime Silk Road set out from Quanzhou, a coastal city in Fujian province in south-east China, on its first trade routes.

With its wealth of scenic spots and historic sites, Quanzhou has been proclaimed « the starting point of the Maritime Silk Road » by UNESCO.

It was at this time that the first printing methods appeared in China. Wooden blocks were used to print on textiles. In 593, the Sui emperor Wen-ti ordered the printing of Buddhist images and writings. One of the earliest printed texts is a Buddhist script dating from 868, found in a cave near Dunhuang, a stopover town on the Silk Road.

Under the Tang dynasty (618-907), the Kingdom’s military expansion brought security, trade and new ideas. The fact that the stability of Tang China coincided with that of Sassanid Persia enabled the land and sea Silk Roads to flourish. The great transformation of the maritime Silk Road began in the 7th century, when China opened up to international trade. The first Arab ambassador took up his post in 651.

Mural fresco executed in 706, of the Tang Emperor’s tomb, with diplomatic emissaries to the Imperial Court. The two figures on the right, carefully dressed, represent Korea, while the one in the middle (a monk?), without a headdress and with a « big nose », represents the West.

The Tang Dynasty chose Chang’an (now Xi’an) as its capital. It adopted an open attitude towards different beliefs. Buddhist, Taoist and Confucian temples coexisted peacefully with mosques, synagogues and Nestorian Christian churches. As the terminus of the Silk Road, Chang’an’s western market is becoming the center of world trade. According to the Tang Authority Six register, over 300 nations and regions had trade relations with Chang’an.

Almost 10,000 foreign families from the west lived in the city, especially in the area around the western market. There were many foreign inns staffed by foreign maids chosen for their beauty. The most famous poet in Chinese history, Li Bai, often strolled among them. Foreign food, costumes and music were the fashion of Chang’an.

After the fall of the Tang dynasty, the Five Dynasties and the Ten Kingdoms (907-960), the arrival of the Song dynasty (960-1279) ushered in a new period of prosperity, characterized by increased centralization and economic and cultural renewal. The maritime silk route regained its momentum. In 1168, a synagogue was built in Kaifeng, capital of the Southern Song dynasty, to serve merchants on the Silk Road.

During the same period, as Islam expanded, trading posts sprang up all around the Indian Ocean and the rest of Southeast Asia.

China encouraged its merchants to seize the opportunities offered by maritime traffic, in particular the sale of camphor, a highly sought-after medicinal plant. A veritable trade network developed in the East Indies under the auspices of the Kingdom of Sriwijaya, a city-state in southern Sumatra, Indonesia (see below), which for nearly six centuries served as a link between Chinese merchants on the one hand, and Indians and Malays on the other. A trade route truly emerged, deserving the name of the maritime « Silk Road ».

Increasing quantities of spices passed through India, the Red Sea and Alexandria in Egypt, before reaching the merchants of Genoa, Venice and other Western ports. From there, they moved on to the northern European markets of Lübeck (Germany), Riga (Lithuania) and Tallinn (Estonia), which from the 12th century onwards became important cities in the Hanseatic League.

After seven years of excavation, over 60,000 porcelain objects dating from the Song Dynasty (960-1279) were discovered on the Nanhai ship (South China Sea), which had been underwater for over 800 years.
A XVth-century junk from the Ming dynasty.

In China, during the reign of the Song emperor Renzong (1022-1063), a great deal of money and energy was spent on bringing together knowledge and know-how. The economy was the first to benefit.

Drawing on the know-how of Arab and Indian sailors, Chinese ships became the most advanced in the world.

The Chinese, who had invented the compass (at least by 1119), quickly surpassed their competitors in cartography and the art of navigation, as the Chinese junk became the bulk carrier par excellence.

In his geographical treatise, Zhou Qufei, in 1178, reports:

« The big ships that cruise the South Sea are like houses. When they unfold their sails, they look like huge clouds. Their rudders are dozens of feet long. A single ship can house several hundred men. On board, there’s enough food to last a year.« 


Archaeological digs confirm this reality, such as the wreck of a XIVth-century junk found off the coast of Korea, in which over 10,000 pieces of ceramic were discovered.

During this period, coastal trade gradually shifted from the hands of Arab traders to those of Chinese merchants. Trade expanded, notably with the inclusion of Korea and the integration of Japan, the Malabar coast of India, the Persian Gulf and the Red Sea into existing trade networks.

China exported tea, silk, cotton, porcelain, lacquers, copper, dyes, books and paper. In return, it imported luxury goods and raw materials, including rare woods, precious metals, precious and semi-precious stones, spices and ivory.

Copper coins from the Song period have been discovered in Sri Lanka, and porcelain from this period has been found in East Africa, Egypt, Turkey, some Gulf states and Iran, as well as in India and Southeast Asia.

The Importance of Korea and the Kingdom of Silla


During the first millennium, culture and philosophy flourished on the Korean peninsula. A well-organized and well-protected trading network with China and Japan operated there.

On the Japanese island of Okino-shima, numerous historical traces bear witness to the intense exchanges between the Japanese archipelago, Korea and the Asian continent.

Excavations carried out in ancient tombs in Gyeongju, today a South Korean city of 264,000 inhabitants and capital of the ancient Kingdom of Silla (from 57 BC to 935), which controlled most of the peninsula from the VIIth to the IXth century, demonstrate the intensity of this kingdom’s exchanges with the rest of the world, via the Silk Road.

Indonesia, a Major Maritime Power at the Heart of the Maritime Silk Road



In Indonesia, Malaysia and southern Thailand, the Kingdom of Sriwijaya (VIIth to XIIIth centuries) played a major role as a maritime trading post, storing high-value goods from the region and beyond for later sale by sea. In particular, Sriwijaya controlled the Strait of Malacca, the essential sea passage between India and China.

At the height of its power in the XIth century, Sriwijaya’s network of ports and trading posts traded a vast array of products and commodities: rice, cotton, indigo and silver from Java, aloe (a succulent plant of African origin), vegetable resins, camphor, ivory and rhinoceros horns, tin and gold from Sumatra, rattan, redwoods and other rare woods, gems from Borneo, rare birds and exotic animals, iron, sandalwood and spices from East Indonesia, India and Southeast Asia, and porcelain, lacquer, brocade, textiles and silk from China.

With its capital at Palembang (population 1.7 million) on the Musi River in what is now the southern province of Sumatra, this Hindu-Buddhist-inspired kingdom, which flourished from the VIIIth to the XIIIth century, was the first major Indonesian kingdom and the country’s first maritime power.

By the VIIth century, it ruled a large part of Sumatra, the western part of Java and a significant part of the Malay Peninsula. It extended as far north as Thailand, where archaeological remains of Sriwijaya cities still exist.

Buddhism on the Maritime Silk Road

The museum in Palembang (today Indonesia) – a town where Chinese, Indian, Arab and Yemeni communities, each with their own particular institutions, have co-prospered for generations – tells a wonderful story of how the Maritime Silk Road generated exemplary mutual cultural enrichment.

Buddhism was closely tied to international or cross-boundary trade. Early inscriptions indicate it was common for seafarers to pray to the Buddha for a safe voyage.

The maritime routes were very challenging as they were often beset with cyclones and typhoons, and piracy was an ever-present danger.

As a consequence, merchant support for Buddhism along these travel routes helped to establish monastic life far beyond India. Monks and nuns also took passage on these trading ships, and the merchants sought good karma by helping them travel to spread the teachings of the Buddha.

Madagascar, Sanskrit and the Cinnamon Road


Map of the expansion of Austronesian languages.


Today, Madagascar is inhabited by Blacks and Asians. DNA tests have confirmed what has long been known: many of the island’s inhabitants are descended from Malay and Indonesian sailors who set foot on the island around the year 830, when the Sriwijaya Empire extended its maritime influence towards Africa.

Further evidence of this presence is the fact that the language spoken on the island borrows Sanskrit and Indonesian words.

Bas-relief from the Buddhist temple of Borobudur (8th century, Indonesia)

To demonstrate the feasibility of such sea voyages, in 2003 a team of researchers sailed from Indonesia to Ghana via Madagascar aboard the Borobudur, a reconstruction of one of the sailing ships featured in many of the 1,300 bas-reliefs decorating the 8th-century Buddhist temple of Borobudur on the island of Java in Indonesia.

Many believe that this vessel is a representation of those once used by Indonesian merchants to cross the ocean to Africa. Indonesian navigators usually used relatively small boats. To ensure balance, they fitted them with outriggers, both double (ngalawa) and single.

Their boats, whose hulls were carved from a single tree trunk, were called sanggara. Merchants from the Indonesian archipelago could reach as far east as Hawaii and New Zealand, a distance of over 7,000 km.

On the Cinnamon Route, the ship made its way from Indonesia to Accra, Ghana, via Madagascar.

In any case, the researchers’ boat, equipped with an 18-meter-high mast, managed to cover the Jakarta – Maldives – Cape of Good Hope – Ghana route, a distance of 27,750 kilometers, or more than half the circumference of the Earth!

The expedition aimed to retrace a very specific route: the cinnamon route, which took Indonesian merchants all the way to Africa to sell spices, including cinnamon, a highly sought-after commodity at the time. Cinnamon was already highly prized in the Mediterranean basin long before the Christian era.

On the walls of the Egyptian temple at Deir el-Bahari (Luksor), a painting depicts a major naval expedition.

On the walls of the Egyptian temple at Deir el-Bahari (Luksor), a painting depicts a major naval expedition said to have been ordered by Queen Hatshepsut, who reigned from 1503 to 1482 BC. Around the painting, hieroglyphs explain that these ships carried various species of plants and fragrant essences destined for the cult. One of these was cinnamon. Rich in aroma, it was an important component of ritual ceremonies in the kingdoms of Egypt.

Cinnamon originally grew in Central Asia, the eastern Himalayas and northern Vietnam. The southern Chinese transplanted it from these regions to their own country and cultivated it under the name gui zhi.

Unsurprisingly, the map of Austronesian language expansion is almost identical to that of the « Cinnamon Road. »


From China, gui zhi spread throughout the Indonesian archipelago, finding a very fertile home there, particularly in the Moluccas. In fact, the international cinnamon trade was a monopoly held by Indonesian merchants. Indonesian cinnamon was prized for its excellent quality and highly competitive price.

The Indonesians sailed great distances, up to 8,000 km, across the Indian Ocean to Madagascar and northeast Africa. From Madagascar, products were transported to Rhapta, in a coastal region that later became known as Somalia. From there, Arab merchants shipped them north to the Red Sea.

The Strait of Malacca

For China, the Strait of Malacca has always represented a major strategic interest. When the great Chinese admiral Zheng He led the first of his expeditions to India, the Near East and East Africa between 1405 and 1433, a Chinese pirate by the name of Chen Zuyi took control of Palembang.

Zheng He defeated Chen’s fleet and captured the survivors. As a result, the strait once again became a safe shipping route.

According to tradition, a prince of Sriwijaya, Parameswara, took refuge on the island of Temasek (present-day Singapore), but eventually settled on the west coast of the Malay Peninsula around 1400 and founded the city of Malacca, which would become the largest port in Southeast Asia, both successor to Sriwijaya and precursor to Singapore.

Following the decline of Sriwijaya, the Kingdom of Majapahit (1292-1527), founded at the end of the XIIIth century on the island of Java, came to dominate most of present-day Indonesia.

This was the period when Arab sailors began to settle in the region.

The Majapahit kingdom established relations with the Kingdom of Champa (192-1145; 1147-1190; 1220-1832) (South Vietnam), Cambodia, Siam (Thailand) and southern Myanmar.

The Majapahit kingdom also sent missions to China. As its rulers extended their power to other islands and sacked neighboring kingdoms, they sought above all to increase their share and control of the trade in goods passing through the archipelago.

The island of Singapore and the southernmost part of the Malay Peninsula was a key crossroads on the ancient maritime Silk Road.

Archaeological excavations in the Kallang estuary and along the Singapore River have uncovered thousands of shards of glass, natural and gold beads, ceramics and Chinese coins from the Northern Song period (960-1127).

The rise of the Mongol Empire in the middle of the XIIIth century led to an increase in seaborne trade and contributed to the vitality of the Maritime Silk Road.

Marco Polo, after a 17-year overland journey to China, returned by ship. After witnessing a shipwreck, he sailed from China to Sumatra in Indonesia, before setting foot on land again at Hormuz in Persia (Iran).

Under the Yuan and Ming Dynasties

Under the Song dynasty, large quantities of silk goods were exported to Japan. Under the Yuan dynasty (1271-1368), the government set up the Shi Bo Si, a trade office, in a number of ports, including Ningbo, Canton, Shanghai, Ganpu, Wenzhou and Hangzhou, enabling silk exports to Japan.

During the Tang, Song and Yuan dynasties, and at the beginning of the Ming dynasty, each port set up an oceanic trading department to manage all foreign maritime trade.

Maritime travel was dependent on the seasonal winds: the summer monsoons blow from the south-west (May to September) and reverse direction in the winter (October to April). As a result, seafaring merchants developed sailing circuits that allowed them to use the monsoon winds to travel long distances, then return home when the wind patterns shifted.

Trade with southern India and the Persian Gulf flourished. Trade with East Africa also developed with the monsoon season, bringing ivory, gold and slaves. In India, guilds began to control Chinese trade on the Malabar coast and in Sri Lanka.

Trade relations became more formalized, while remaining highly competitive. Cochin and Kozhikode (Calicut), two major cities in the Indian state of Kerala, competed to dominate this trade.

Admiral Zheng He’s Maritime Explorations

Map of Admiral Zheng He’s maritime expeditions.

Chinese maritime exploration reached its apogee in the early XVth century under the Ming dynasty (1368-1644), which chose a Muslim court eunuch, Admiral Zheng He, to lead seven diplomatic naval expeditions.

Financed by Emperor Ming Yongle, these peaceful missions to Southeast Asia, East Africa, the Indian Ocean, the Persian Gulf and the Red Sea were intended above all to demonstrate the prestige and grandeur of China and its Emperor. The aim was also to recognize some thirty states and establish political and commercial relations with them.

In 1409, prior to one of these expeditions, the Chinese admiral Zheng He asked craftsmen to make a carved stone stele in Nanjing, the present-day capital of Jiangsu province (eastern China). The stele traveled with the flotilla and was left in Sri Lanka as a gift to a local Buddhist temple. Prayers to the deities in three languages – Chinese, Persian and Tamil – were engraved on the stele. It was found in 1911 in the town of Galle, in south-west Sri Lanka, and a replica is now in China.

Zheng’s armada was made up of armed bulk carriers, the most modest being larger than Columbus’ caravels. The largest were 100 meters long and 50 meters wide. According to Ming chronicles of the time, an expedition could comprise 62 ships, each carrying 500 people. Some carried military cavalry, others tanks of drinking water. Chinese shipbuilding was ahead of its time. The technique of hermetic bulkheads, imitating the internal structure of bamboo, offered incomparable safety. It became the standard for the Chinese fleet before being copied by the Europeans 250 years later. Compasses and celestial maps painted on silk were also used.

The synergy that may have existed between Arab, Indian and Chinese sailors, all men of the sea who fraternized in the face of ocean adversity, was impressive. For example, some historians believe that the name « Sindbad the Sailor », which appears in the Persian tale of a sailor’s adventures from the time of the Abbasid dynasty (VIIIth century) and was included in the Tales of the One Thousand and One Nights, derives from the word Sanbao, the honorary nickname given by the Chinese Emperor to Admiral Zheng He, literally meaning « The Three Jewels », i.e. the three indissociable capital virtues: essence, breath, and spirit.

Statue of Admiral Zheng Ho in front of a mosque built in his honor in Indonesia.

Maritime museums in China (Hong Kong, Macau, Fuzhou, Tianjin and Nanjing), Singapore, Malaysia and Indonesia showcase Admiral Zheng’s expeditions.

However, at least twelve other admirals carried out similar expeditions to Southeast Asia and the Indian Ocean.

In 1403, Admiral Ma Pi led an expedition to Indonesia and India. Wu Bin, Zhang Koqing and Hou Xian made others. After lightning caused a fire in the Forbidden City, a dispute broke out between the eunuch class, supporters of the expeditions, and the learned mandarins, who obtained the cessation of expeditions deemed too costly. The last voyage took place between 1430 and 1433, 64 years before the Portuguese explorer Vasco da Gama arrived in 1497.

Japan, for its part, similarly restricted its contacts with the outside world during the Tokugawa period (1600-1868), although its trade with China was never suspended. It was only after the Meiji Restoration in 1868 that a Japan open to the world re-emerged.

Withdrawing into themselves, trade with both China and Japan fell into the hands of maritime trading posts such as Malacca in Malaysia or Hi An in Vietnam, two cities now recognized by Unesco as world heritage sites. H?i An was a major stopover port on the sea route linking Europe and Japan via India and China. In the shipwrecks found at Hi An, researchers have discovered ceramics awaiting their departure for Sinai in Egypt.

History of Chinese Ports

Over the years, the main ports on the Maritime Silk Road have changed. From the 330s onwards, Canton and Hepu were the two most important ports. However, Quanzhou replaced Canton from the end of the Song to the end of the Yuan dynasty. At that time, Quanzhou in Fujian province and Alexandria in Egypt were considered the world’s largest ports. Due to the policy of closure to the outside world imposed from 1435 and the influence of war, Quanzhou was gradually replaced by the ports of Yuegang, Zhangzhou and Fujian.

From the beginning of the IVth century, Canton was an important port on the Silk Road. Gradually, under the Tang and Song dynasties, it became not only the largest, but also the most renowned port of the Orient worldwide. During this period, the sea route linking Canton to the Persian Gulf via the South China Sea and the Indian Ocean was the longest in the world.

Although later supplanted by Quanzhou under the Yuan dynasty, Canton remained China’s second-largest commercial port. Compared with the others, it is considered to have been a consistently prosperous port over the 2,000-year history of the Maritime Silk Road.

The Tributary System of 1368

China’s last imperial dynasty, the Qing, reigned from 1644 to 1912.

Since the arrival of the Ming dynasty, maritime trade with China proceded in two different ways:

  • The Chinese « tributary system » ;
  • The Canton system (1757-1842).

Born under the Ming in 1368, the « tributary system » reached its apogee under the Qing. It took the refined form of a mutually beneficial, inclusive hierarchy.

States adhering to it showed respect and gratitude by regularly presenting the Emperor with tribute made up of local products and performing certain ritual ceremonies, notably the « kowtow » (three genuflections and nine prostrations). They also demanded the Emperor’s investiture of their leaders and adopted the Chinese calendar. In addition to China, they included Japan, Korea, Vietnam, Thailand, Indonesia, the Ryükyü Islands, Laos, Myanmar and Malaysia.

Paradoxically, while occupying a central cultural status, the tributary system offered its vassals the status of sovereign entities, enabling them to exercise authority over a given geographical area.

The Emperor won their submission by showing virtuous concern for their welfare and promoting a doctrine of non-intervention and non-exploitation. Indeed, according to historians, in financial terms, China was never directly enriched by the tributary system. In general, all travel and subsistence expenses for tributary missions were covered by the Chinese government. In addition to the costs of running the system, the gifts offered by the Emperor were generally far more valuable than the tributes he received. Each tributary mission was entitled to be accompanied by a large number of merchants, and once the tribute had been presented to the Emperor, trade could begin.

It should be noted that when a country lost its status as a tributary state as a result of a disagreement, it would try at all costs, and sometimes violently, to be allowed to pay tribute again.

The Canton System of 1757

Port of Canton in 1850 with American, French and British trade missions.

The second system concerned foreign, mainly European, powers wishing to trade with China. This involved the port of Guangzhou (then called Canton), the only port accessible to Westerners.

This meant that merchants, notably those of the British East India Company, could dock not in the port but off the coast of Canton, from October to March, during the trading season. It was in Macao, then a Portuguese possession, that the Chinese provided them with permission to do so. The Emperor’s representatives would then authorize Chinese merchants (hongs) to go on board to trade with foreign ships, while instructing them to collect customs duties before they left.

This way of trading expanded at the end of the XVIIIth century, particularly with the strong English demand for tea.

In fact, it was Chinese tea from Fujian that American « insurgents » threw into the sea during the famous « Boston Tea Party » in December 1773, one of the first events against the British Empire that sparked off the American Revolution.

Products from India, particularly cotton and opium, were exchanged by the East India Company for tea, porcelain and silk.

The customs duties collected by the Canton system were a major source of revenue for the Qing dynasty, even though it banned the purchase of opium from India. This restriction imposed by the Chinese Emperor in 1796 led to the outbreak of the Opium Wars, the first as early as 1839.

At the same time, rebellions broke out in the 1850-60s against the weakened Qing reign, coupled with further wars against hostile European powers.

Sacking of the Summer Palace by the British and French in 1860.

In 1860, the former Summer Palace (Yuanming Park), with its collection of pavilions, temples, pagodas and libraries – the residence of the Qing dynasty emperors 15 kilometers northwest of Beijing’s Forbidden City – was ravaged by British and French troops during the Second Opium War.

This assault goes down in history as one of the worst acts of cultural vandalism of the XIXth century. The Palace was sacked a second time in 1900 by an eight-nation alliance against China.

Today, a statue of Victor Hugo and a text he wrote against Napoleon III and the destruction of French imperialism can be admired there, as a reminder that this was not the work of a nation, but of a government.

By the end of the First World War, China had 48 open ports where foreigners could trade according to their own jurisdictions.

The 20th century was an era of revolution and social change. The founding of the People’s Republic of China in 1949 led to inward-looking attitudes.

It wasn’t until 1978 that Deng Xiaoping announced a policy of opening up to the outside world in order to modernize the country.

China’s New Silk Roads initiative.

In the XXIst century, thanks to the One Belt (economic) One Road (maritime) Initiative launched by President Xi Jingping, China is re-emerging as a major world power offering mutually beneficial cooperation in the service of a better shared future for mankind.

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